本文将讨论本机内存跟踪 (NMT)，我们可以使用它来隔离在 VM 级别增长的任何异常内存。

1.什么是本机内存？

本机内存是指计算机系统上运行的应用程序或程序可直接访问的内存空间。它是程序在执行期间存储和操作数据的内存区域。本机内存不同于托管内存，后者是由运行时环境或虚拟机管理的内存。

1.1.组成部分

本机内存的主要组件可能因所使用的操作系统和编程语言而异。一般而言，本机内存通常由以下组件组成：

1. 堆栈
   堆栈是程序执行期间用于存储局部变量、函数调用和其他相关数据的内存区域。每个线程通常都有自己的堆栈。
2. 堆
   堆是用于动态内存分配的内存区域。它是程序执行期间分配和释放对象和数据结构的地方。在 C 和 C++ 等语言中，堆通常由程序员管理，而在 Java 等语言中，堆由运行时环境通过垃圾收集器管理。
3. 代码内存
   代码内存，也称为可执行内存或文本段，是存储程序编译代码的内存区域。它包含组成程序可执行代码的指令。
4. 静态变量和全局变量
   静态变量和全局变量的内存空间在程序启动时分配，并在整个程序执行过程中保持不变。这些变量可以在不同范围内访问，并且可以在多个函数或模块之间共享。
5. 库和DDL
   本机内存还包括共享库或动态链接库 (DLL) 占用的内存。这些库包含可供多个程序使用的预编译代码和资源。
6. 操作系统数据结构
   操作系统使用内存来存储其数据结构，例如进程控制块、文件表、网络缓冲区和其他与系统相关的数据。
7. 内存映射文件
   内存映射文件允许将文件视为计算机内存的一部分进行访问。文件的某些部分可以加载到内存中并直接访问，这对于高效的 I/O 操作非常有用。

2.什么是本机内存跟踪 (NMT)？

本机内存跟踪 (NMT) 是 Java 虚拟机 (JVM) 提供的一项功能，允许开发人员监视和分析 Java 应用程序中本机内存的分配和使用情况。它有助于识别和诊断本机内存泄漏和过度内存消耗。

3.如何进行本机内存跟踪 (NMT)？

3.1.确认您当前所使用的JDK版本

不同的JDK版本所使用的工具，以及具体工具的参数可能存在差异，在使用时需要注意，比如我在下面的示例中使用的是JDK17，如下：

3.2.示例程序

我在此处使用的程序是一个简易的内存占用逐渐增加的JAVA程序，源码如下：

import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.concurrent.Callable;

public class MemoryLeakExample {
    public static class DataProcessor  {
        private List<byte[]> data = new ArrayList<>();
 
        public void processData() {
            byte[] buffer = new byte[10240];
            new Random().nextBytes(buffer);
            data.add(buffer);
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

    }

    public static void main(String[] args) {
        DataProcessor processor = new DataProcessor();
        while (true) {
            processor.processData();
        }
    }
}

3.3.编译示例程序

javac MemoryLeakExample.java

3.3.启动示例程序（添加支持NMT功能的参数）

java -XX:NativeMemoryTracking=detail MemoryLeakExample

3.4.定义 NMT 的基线

jcmd {pid} VM.native_memory baseline scale=MB

3.5.捕获内存细节

jcmd {pid} VM.native_memory detail scale=MB > native_memory_detail

上述命令所捕获到的内存细节会保存到native_memory_detail文件中，其内容如下：

3195:

Native Memory Tracking:

(Omitting categories weighting less than 1MB)

Total: reserved=3534MB, committed=219MB
-                 Java Heap (reserved=2048MB, committed=130MB)
                            (mmap: reserved=2048MB, committed=130MB) 
 
-                     Class (reserved=1024MB, committed=0MB)
                            (classes #497)
                            (  instance classes #412, array classes #85)
                            (mmap: reserved=1024MB, committed=0MB) 
                            (  Metadata:   )
                            (    reserved=64MB, committed=0MB)
                            (    used=0MB)
                            (    waste=0MB =56.19%)
                            (  Class space:)
                            (    reserved=1024MB, committed=0MB)
                            (    used=0MB)
                            (    waste=0MB =96.15%)
 
-                    Thread (reserved=21MB, committed=21MB)
                            (thread #21)
                            (stack: reserved=21MB, committed=21MB)
 
-                      Code (reserved=242MB, committed=7MB)
                            (mmap: reserved=242MB, committed=7MB) 
 
-                        GC (reserved=117MB, committed=46MB)
                            (malloc=9MB #803) 
                            (mmap: reserved=108MB, committed=37MB) 
 
-                    Symbol (reserved=1MB, committed=1MB)
                            (malloc=1MB #67) 
 
-        Shared class space (reserved=16MB, committed=12MB)
                            (mmap: reserved=16MB, committed=12MB) 
 
-                 Metaspace (reserved=64MB, committed=0MB)
                            (mmap: reserved=64MB, committed=0MB) 
 
Virtual memory map:
 
[0x0000000105274000 - 0x0000000105374000] reserved and committed 1MB for Thread Stack from
    [0x0000000104779757] JNI_CreateJavaVM+0x57
    [0x0000000103910822] JavaMain+0x122
    [0x00000001039137e9] ThreadJavaMain+0x9
    [0x00007fff5e514661] _pthread_body+0x154

	[0x0000000105274000 - 0x0000000105374000] committed 1MB 
 
[0x000000010cb16000 - 0x000000010cc01000] reserved 1MB for Code from
    [0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
    [0x00000001046b3400] CodeHeap::reserve(ReservedSpace, unsigned long, unsigned long)+0x140
    [0x00000001044fb3b5] CodeCache::add_heap(ReservedSpace, char const*, int)+0x115
    [0x00000001044fb071] CodeCache::initialize_heaps()+0x481
 
[0x000000010cc01000 - 0x000000010ccec000] reserved 1MB for Code from
    [0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
    [0x00000001046b3400] CodeHeap::reserve(ReservedSpace, unsigned long, unsigned long)+0x140
    [0x00000001044fb3b5] CodeCache::add_heap(ReservedSpace, char const*, int)+0x115
    [0x00000001044fb0be] CodeCache::initialize_heaps()+0x4ce
 
[0x000000010d0f0000 - 0x000000010d4f0000] reserved 4MB for GC from
    [0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
    [0x000000010460884d] G1CollectedHeap::initialize()+0x2ed
    [0x0000000104c2ce69] universe_init()+0xb9
    [0x00000001046e2ae3] init_globals()+0x33
 
[0x000000010d4f0000 - 0x000000010d8f0000] reserved 4MB for GC from
    [0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
    [0x000000010460890c] G1CollectedHeap::initialize()+0x3ac
    [0x0000000104c2ce69] universe_init()+0xb9
    [0x00000001046e2ae3] init_globals()+0x33
 
[0x000000010da4f000 - 0x000000010de4f000] reserved 4MB for GC from
    [0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
    [0x00000001046089cd] G1CollectedHeap::initialize()+0x46d
    [0x0000000104c2ce69] universe_init()+0xb9
    [0x00000001046e2ae3] init_globals()+0x33
 
[0x000000010de4f000 - 0x000000010fe4f000] reserved 32MB for GC from
    [0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
    [0x0000000104608a7f] G1CollectedHeap::initialize()+0x51f
    [0x0000000104c2ce69] universe_init()+0xb9
    [0x00000001046e2ae3] init_globals()+0x33

	[0x000000010de4f000 - 0x000000010e04f000] committed 2MB from
            [0x0000000104647366] G1PageBasedVirtualSpace::commit_internal(unsigned long, unsigned long)+0x126
            [0x0000000104647566] G1PageBasedVirtualSpace::commit(unsigned long, unsigned long)+0x116
            [0x0000000104651cf4] G1RegionsLargerThanCommitSizeMapper::commit_regions(unsigned int, unsigned long, WorkGang*)+0x104
            [0x00000001046c88fb] HeapRegionManager::commit_regions(unsigned int, unsigned long, WorkGang*)+0xab
 
[0x000000010fe4f000 - 0x0000000111e4f000] reserved 32MB for GC from
    [0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
    [0x0000000104608b22] G1CollectedHeap::initialize()+0x5c2
    [0x0000000104c2ce69] universe_init()+0xb9
    [0x00000001046e2ae3] init_globals()+0x33

	[0x000000010fe4f000 - 0x000000011004f000] committed 2MB from
            [0x0000000104647366] G1PageBasedVirtualSpace::commit_internal(unsigned long, unsigned long)+0x126
            [0x0000000104647566] G1PageBasedVirtualSpace::commit(unsigned long, unsigned long)+0x116
            [0x0000000104651cf4] G1RegionsLargerThanCommitSizeMapper::commit_regions(unsigned int, unsigned long, WorkGang*)+0x104
            [0x00000001046c8911] HeapRegionManager::commit_regions(unsigned int, unsigned long, WorkGang*)+0xc1
 
[0x0000000111e4f000 - 0x0000000113e4f000] reserved and committed 32MB for GC from
    [0x00000001046142fe] G1CMMarkStack::resize(unsigned long)+0x3e
    [0x000000010461539b] G1ConcurrentMark::G1ConcurrentMark(G1CollectedHeap*, G1RegionToSpaceMapper*, G1RegionToSpaceMapper*)+0x68b
    [0x0000000104608f4e] G1CollectedHeap::initialize()+0x9ee
    [0x0000000104c2ce69] universe_init()+0xb9

	[0x0000000111e4f000 - 0x0000000113e4f000] committed 32MB from
            [0x0000000104614317] G1CMMarkStack::resize(unsigned long)+0x57
            [0x000000010461539b] G1ConcurrentMark::G1ConcurrentMark(G1CollectedHeap*, G1RegionToSpaceMapper*, G1RegionToSpaceMapper*)+0x68b
            [0x0000000104608f4e] G1CollectedHeap::initialize()+0x9ee
            [0x0000000104c2ce69] universe_init()+0xb9
 
[0x0000000115000000 - 0x0000000116000000] reserved 16MB for Shared class space from
    [0x0000000104a90a43] os::reserve_memory_aligned(unsigned long, unsigned long, bool)+0x23
    [0x0000000104c6c9f5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x345
    [0x0000000104c6c2c3] ReservedSpace::initialize(unsigned long, unsigned long, unsigned long, char*, bool)+0x83
    [0x0000000104a25be8] Metaspace::reserve_address_space_for_compressed_classes(unsigned long)+0x28

	[0x0000000115000000 - 0x0000000115be4000] committed 12MB from
            [0x00000001045eb6ae] FileMapInfo::map_region(int, long, char*, ReservedSpace)+0xae
            [0x00000001045eb528] FileMapInfo::map_regions(int*, int, char*, ReservedSpace)+0xa8
            [0x0000000104a2d139] MetaspaceShared::map_archive(FileMapInfo*, char*, ReservedSpace)+0x79
            [0x0000000104a2c9db] MetaspaceShared::map_archives(FileMapInfo*, FileMapInfo*, bool)+0x16b
 
[0x0000000116000000 - 0x0000000156000000] reserved 1024MB for Class from
    [0x0000000104a90a43] os::reserve_memory_aligned(unsigned long, unsigned long, bool)+0x23
    [0x0000000104c6c9f5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x345
    [0x0000000104c6c2c3] ReservedSpace::initialize(unsigned long, unsigned long, unsigned long, char*, bool)+0x83
    [0x0000000104a25be8] Metaspace::reserve_address_space_for_compressed_classes(unsigned long)+0x28
 
[0x0000000156000000 - 0x000000015a000000] reserved 64MB for Metaspace from
    [0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
    [0x0000000104c6c2c3] ReservedSpace::initialize(unsigned long, unsigned long, unsigned long, char*, bool)+0x83
    [0x0000000104c6b5ff] metaspace::VirtualSpaceNode::create_node(unsigned long, metaspace::CommitLimiter*, metaspace::AbstractCounter<unsigned long>*, metaspace::AbstractCounter<unsigned long>*)+0x4f
    [0x0000000104c6ac5e] metaspace::VirtualSpaceList::allocate_root_chunk()+0x3e
 
[0x0000000780000000 - 0x0000000800000000] reserved 2048MB for Java Heap from
    [0x0000000104c6c98e] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2de
    [0x0000000104c6cd23] ReservedHeapSpace::try_reserve_heap(unsigned long, unsigned long, unsigned long, char*)+0xb3
    [0x0000000104c6d325] ReservedHeapSpace::initialize_compressed_heap(unsigned long, unsigned long, unsigned long)+0x3f5
    [0x0000000104c6d694] ReservedHeapSpace::ReservedHeapSpace(unsigned long, unsigned long, unsigned long, char const*)+0x154

	[0x0000000780000000 - 0x0000000788000000] committed 128MB from
            [0x0000000104647366] G1PageBasedVirtualSpace::commit_internal(unsigned long, unsigned long)+0x126
            [0x0000000104647566] G1PageBasedVirtualSpace::commit(unsigned long, unsigned long)+0x116
            [0x0000000104651cf4] G1RegionsLargerThanCommitSizeMapper::commit_regions(unsigned int, unsigned long, WorkGang*)+0x104
            [0x00000001046c88e5] HeapRegionManager::commit_regions(unsigned int, unsigned long, WorkGang*)+0x95

	[0x00000007ffe76000 - 0x00000007fff00000] committed 1MB from
            [0x0000000104647366] G1PageBasedVirtualSpace::commit_internal(unsigned long, unsigned long)+0x126
            [0x0000000104647566] G1PageBasedVirtualSpace::commit(unsigned long, unsigned long)+0x116
            [0x0000000104651cf4] G1RegionsLargerThanCommitSizeMapper::commit_regions(unsigned int, unsigned long, WorkGang*)+0x104
            [0x00000001046c88e5] HeapRegionManager::commit_regions(unsigned int, unsigned long, WorkGang*)+0x95

	[0x00000007fff00000 - 0x00000007fff80000] committed 1MB from
            [0x00000001045ec75a] FileMapInfo::map_heap_data(MemRegion**, int, int, int*, bool)+0x1ca
            [0x00000001045ec3be] FileMapInfo::map_heap_regions_impl()+0x39e
            [0x00000001045ec8a7] FileMapInfo::map_heap_regions()+0x17
            [0x0000000104a2cbb5] MetaspaceShared::map_archives(FileMapInfo*, FileMapInfo*, bool)+0x345

	[0x00000007fff80000 - 0x0000000800000000] committed 1MB from
            [0x0000000104647366] G1PageBasedVirtualSpace::commit_internal(unsigned long, unsigned long)+0x126
            [0x0000000104647566] G1PageBasedVirtualSpace::commit(unsigned long, unsigned long)+0x116
            [0x0000000104651cf4] G1RegionsLargerThanCommitSizeMapper::commit_regions(unsigned int, unsigned long, WorkGang*)+0x104
            [0x00000001046c88e5] HeapRegionManager::commit_regions(unsigned int, unsigned long, WorkGang*)+0x95
 
[0x000001fcf9f2b000 - 0x000001fd08f2b000] reserved 240MB for Code from
    [0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
    [0x0000000104c6d89c] ReservedCodeSpace::ReservedCodeSpace(unsigned long, unsigned long, unsigned long)+0xac
    [0x00000001044fb22e] CodeCache::reserve_heap_memory(unsigned long)+0x8e
    [0x00000001044faf6a] CodeCache::initialize_heaps()+0x37a

	[0x000001fcf9f2b000 - 0x000001fcfa19b000] committed 2MB from
            [0x0000000104c6dcf6] VirtualSpace::expand_by(unsigned long, bool)+0x126
            [0x0000000104c6daf4] VirtualSpace::initialize(ReservedSpace, unsigned long)+0xb4
            [0x00000001046b3359] CodeHeap::reserve(ReservedSpace, unsigned long, unsigned long)+0x99
            [0x00000001044fb3b5] CodeCache::add_heap(ReservedSpace, char const*, int)+0x115

	[0x000001fd01462000 - 0x000001fd016d2000] committed 2MB from
            [0x0000000104c6dcf6] VirtualSpace::expand_by(unsigned long, bool)+0x126
            [0x0000000104c6daf4] VirtualSpace::initialize(ReservedSpace, unsigned long)+0xb4
            [0x00000001046b3359] CodeHeap::reserve(ReservedSpace, unsigned long, unsigned long)+0x99
            [0x00000001044fb3b5] CodeCache::add_heap(ReservedSpace, char const*, int)+0x115

	[0x000001fd019f3000 - 0x000001fd01c63000] committed 2MB from
            [0x0000000104c6dcf6] VirtualSpace::expand_by(unsigned long, bool)+0x126
            [0x0000000104c6daf4] VirtualSpace::initialize(ReservedSpace, unsigned long)+0xb4
            [0x00000001046b3359] CodeHeap::reserve(ReservedSpace, unsigned long, unsigned long)+0x99
            [0x00000001044fb3b5] CodeCache::add_heap(ReservedSpace, char const*, int)+0x115
 
[0x0000700008dea000 - 0x0000700008eea000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x0000700008dea000 - 0x0000700008eea000] committed 1MB 
 
[0x0000700008eed000 - 0x0000700008fed000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x0000700008eed000 - 0x0000700008fed000] committed 1MB 
 
[0x0000700008ff0000 - 0x00007000090f0000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x0000700008ff0000 - 0x00007000090f0000] committed 1MB 
 
[0x00007000090f3000 - 0x00007000091f3000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x00007000090f3000 - 0x00007000091f3000] committed 1MB 
 
[0x00007000091f6000 - 0x00007000092f6000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x00007000091f6000 - 0x00007000092f6000] committed 1MB 
 
[0x00007000092f9000 - 0x00007000093f9000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x00007000092f9000 - 0x00007000093f9000] committed 1MB 
 
[0x00007000093fc000 - 0x00007000094fc000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x00007000093fc000 - 0x00007000094fc000] committed 1MB 
 
[0x00007000094ff000 - 0x00007000095ff000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x00007000094ff000 - 0x00007000095ff000] committed 1MB 
 
[0x0000700009602000 - 0x0000700009702000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x0000700009602000 - 0x0000700009702000] committed 1MB 
 
[0x0000700009705000 - 0x0000700009805000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x0000700009705000 - 0x0000700009805000] committed 1MB 
 
[0x0000700009808000 - 0x0000700009908000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x0000700009808000 - 0x0000700009908000] committed 1MB 
 
[0x000070000990b000 - 0x0000700009a0b000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x000070000990b000 - 0x0000700009a0b000] committed 1MB 
 
[0x0000700009a0e000 - 0x0000700009b0e000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x0000700009a0e000 - 0x0000700009b0e000] committed 1MB 
 
[0x0000700009b11000 - 0x0000700009c11000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x0000700009b11000 - 0x0000700009c11000] committed 1MB 
 
[0x0000700009c14000 - 0x0000700009d14000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x0000700009c14000 - 0x0000700009d14000] committed 1MB 
 
[0x0000700009d17000 - 0x0000700009e17000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x0000700009d17000 - 0x0000700009e17000] committed 1MB 
 
[0x0000700009e1a000 - 0x0000700009f1a000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x0000700009e1a000 - 0x0000700009f1a000] committed 1MB 
 
[0x0000700009f1d000 - 0x000070000a01d000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x0000700009f1d000 - 0x000070000a01d000] committed 1MB 
 
[0x000070000a020000 - 0x000070000a120000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x000070000a020000 - 0x000070000a120000] committed 1MB 
 
[0x000070000a123000 - 0x000070000a223000] reserved and committed 1MB for Thread Stack from
    [0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
    [0x00007fff5e514661] _pthread_body+0x154
    [0x00007fff5e51450d] _pthread_body+0x0
    [0x00007fff5e513bf9] thread_start+0xd

	[0x000070000a123000 - 0x000070000a223000] committed 1MB 
Details:

[0x00000001046081e1] G1CollectedHeap::G1CollectedHeap()+0x7d1
[0x00000001045f89db] G1Arguments::create_heap()+0x2b
[0x0000000104c2ce31] universe_init()+0x81
[0x00000001046e2ae3] init_globals()+0x33
                             (malloc=4MB type=GC #4)

[0x00000001046154b8] G1ConcurrentMark::G1ConcurrentMark(G1CollectedHeap*, G1RegionToSpaceMapper*, G1RegionToSpaceMapper*)+0x7a8
[0x0000000104608f4e] G1CollectedHeap::initialize()+0x9ee
[0x0000000104c2ce69] universe_init()+0xb9
[0x00000001046e2ae3] init_globals()+0x33
                             (malloc=4MB type=GC #4)

[0x0000000104b5a65f] ConcurrentHashTable<StringTableConfig, (MEMFLAGS)10>::ConcurrentHashTable(unsigned long, unsigned long, unsigned long, void*)+0x12f
[0x0000000104b57be8] StringTable::create_table()+0x88
[0x0000000104c2cfd1] universe_init()+0x221
[0x00000001046e2ae3] init_globals()+0x33
                             (malloc=1MB type=Symbol #1)

[0x0000000104c6c98e] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2de
[0x0000000104c6cd23] ReservedHeapSpace::try_reserve_heap(unsigned long, unsigned long, unsigned long, char*)+0xb3
[0x0000000104c6d325] ReservedHeapSpace::initialize_compressed_heap(unsigned long, unsigned long, unsigned long)+0x3f5
[0x0000000104c6d694] ReservedHeapSpace::ReservedHeapSpace(unsigned long, unsigned long, unsigned long, char const*)+0x154
                             (reserved=2048MB, committed=130MB Type=Java Heap)

[0x0000000104a90a43] os::reserve_memory_aligned(unsigned long, unsigned long, bool)+0x23
[0x0000000104c6c9f5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x345
[0x0000000104c6c2c3] ReservedSpace::initialize(unsigned long, unsigned long, unsigned long, char*, bool)+0x83
[0x0000000104a25be8] Metaspace::reserve_address_space_for_compressed_classes(unsigned long)+0x28
                             (reserved=1040MB, committed=12MB Type=Shared class space)

[0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
[0x0000000104c6d89c] ReservedCodeSpace::ReservedCodeSpace(unsigned long, unsigned long, unsigned long)+0xac
[0x00000001044fb22e] CodeCache::reserve_heap_memory(unsigned long)+0x8e
[0x00000001044faf6a] CodeCache::initialize_heaps()+0x37a
                             (reserved=240MB, committed=7MB Type=Code)

[0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
[0x0000000104c6c2c3] ReservedSpace::initialize(unsigned long, unsigned long, unsigned long, char*, bool)+0x83
[0x0000000104c6b5ff] metaspace::VirtualSpaceNode::create_node(unsigned long, metaspace::CommitLimiter*, metaspace::AbstractCounter<unsigned long>*, metaspace::AbstractCounter<unsigned long>*)+0x4f
[0x0000000104c6ac5e] metaspace::VirtualSpaceList::allocate_root_chunk()+0x3e
                             (reserved=64MB, committed=0MB Type=Metaspace)

[0x00000001046142fe] G1CMMarkStack::resize(unsigned long)+0x3e
[0x000000010461539b] G1ConcurrentMark::G1ConcurrentMark(G1CollectedHeap*, G1RegionToSpaceMapper*, G1RegionToSpaceMapper*)+0x68b
[0x0000000104608f4e] G1CollectedHeap::initialize()+0x9ee
[0x0000000104c2ce69] universe_init()+0xb9
                             (reserved=32MB, committed=32MB Type=GC)

[0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
[0x0000000104608a7f] G1CollectedHeap::initialize()+0x51f
[0x0000000104c2ce69] universe_init()+0xb9
[0x00000001046e2ae3] init_globals()+0x33
                             (reserved=32MB, committed=2MB Type=GC)

[0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
[0x0000000104608b22] G1CollectedHeap::initialize()+0x5c2
[0x0000000104c2ce69] universe_init()+0xb9
[0x00000001046e2ae3] init_globals()+0x33
                             (reserved=32MB, committed=2MB Type=GC)

[0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
[0x00007fff5e514661] _pthread_body+0x154
[0x00007fff5e51450d] _pthread_body+0x0
[0x00007fff5e513bf9] thread_start+0xd
                             (reserved=20MB, committed=20MB Type=Thread Stack)

[0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
[0x00000001046089cd] G1CollectedHeap::initialize()+0x46d
[0x0000000104c2ce69] universe_init()+0xb9
[0x00000001046e2ae3] init_globals()+0x33
                             (reserved=4MB, committed=0MB Type=GC)

[0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
[0x000000010460884d] G1CollectedHeap::initialize()+0x2ed
[0x0000000104c2ce69] universe_init()+0xb9
[0x00000001046e2ae3] init_globals()+0x33
                             (reserved=4MB, committed=0MB Type=GC)

[0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
[0x000000010460890c] G1CollectedHeap::initialize()+0x3ac
[0x0000000104c2ce69] universe_init()+0xb9
[0x00000001046e2ae3] init_globals()+0x33
                             (reserved=4MB, committed=0MB Type=GC)

[0x0000000104779757] JNI_CreateJavaVM+0x57
[0x0000000103910822] JavaMain+0x122
[0x00000001039137e9] ThreadJavaMain+0x9
[0x00007fff5e514661] _pthread_body+0x154
                             (reserved=1MB, committed=1MB Type=Thread Stack)

[0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
[0x00000001046b3400] CodeHeap::reserve(ReservedSpace, unsigned long, unsigned long)+0x140
[0x00000001044fb3b5] CodeCache::add_heap(ReservedSpace, char const*, int)+0x115
[0x00000001044fb0be] CodeCache::initialize_heaps()+0x4ce
                             (reserved=1MB, committed=0MB Type=Code)

[0x0000000104c6c9a5] ReservedSpace::reserve(unsigned long, unsigned long, unsigned long, char*, bool)+0x2f5
[0x00000001046b3400] CodeHeap::reserve(ReservedSpace, unsigned long, unsigned long)+0x140
[0x00000001044fb3b5] CodeCache::add_heap(ReservedSpace, char const*, int)+0x115
[0x00000001044fb071] CodeCache::initialize_heaps()+0x481
                             (reserved=1MB, committed=0MB Type=Code)

(2313 call sites weighting less than 1MB each omitted.)

3.6.捕获差异

jcmd {pid} VM.native_memory detail.diff scale=MB > native_memory_diff

3195:

Native Memory Tracking:

(Omitting categories weighting less than 1MB)

Total: reserved=3534MB +2MB, committed=219MB +2MB

-                 Java Heap (reserved=2048MB, committed=130MB)
                            (mmap: reserved=2048MB, committed=130MB)
 
-                     Class (reserved=1024MB, committed=0MB)
                            (classes #497)
                            (  instance classes #412, array classes #85)
                            (mmap: reserved=1024MB, committed=0MB)
                           : (  Metadata)
                            (    reserved=64MB, committed=0MB)
                            (    used=0MB)
                            (    waste=0MB =56.19%)
                           : (  Class space)
                            (    reserved=1024MB, committed=0MB)
                            (    used=0MB)
                            (    waste=0MB =96.15%)
 
-                    Thread (reserved=21MB +2MB, committed=21MB +2MB)
                            (thread #0)
                            (stack: reserved=21MB +2MB, committed=21MB +2MB)
 
-                      Code (reserved=242MB, committed=7MB)
                            (mmap: reserved=242MB, committed=7MB)
 
-                        GC (reserved=117MB, committed=46MB)
                            (malloc=9MB #804 +226)
                            (mmap: reserved=108MB, committed=37MB)
 
-                    Symbol (reserved=1MB, committed=1MB)
                            (malloc=1MB #67)
 
-        Shared class space (reserved=16MB, committed=12MB)
                            (mmap: reserved=16MB, committed=12MB)
 
-                 Metaspace (reserved=64MB, committed=0MB)
                            (mmap: reserved=64MB, committed=0MB)
 
[0x0000000104a8b5e8] thread_native_entry(Thread*)+0x148
[0x00007fff5e514661] _pthread_body+0x154
[0x00007fff5e51450d] _pthread_body+0x0
[0x00007fff5e513bf9] thread_start+0xd
                             (mmap: reserved=20MB +2MB, committed=20MB +2MB Type=Thread Stack)

3.7.借助JCMD工具进行定位分析

jcmd {pid} help

JFR.dump
JFR.start
JFR.stop
JVMTI.agent_load
JVMTI.data_dump
ManagementAgent.start
ManagementAgent.start_local
ManagementAgent.status
ManagementAgent.stop
Thread.print
VM.cds
VM.class_hierarchy
VM.classloader_stats
VM.classloaders
VM.command_line
VM.dynlibs
VM.events
VM.flags
VM.info
VM.log
VM.metaspace
VM.native_memory
VM.print_touched_methods
VM.set_flag
VM.stringtable
VM.symboltable
VM.system_properties
VM.systemdictionary
VM.uptime
VM.version
help

For more information about a specific command use 'help <command>'.

3.7.1.VM.classloader_stats

jcmd {pid} VM.classloader_stats

3195:
ClassLoader         Parent              CLD*               Classes   ChunkSz   BlockSz  Type
0x00000001150840a0  0x0000000115086378  0x00007fb585f0f940       2       768       508  jdk.internal.loader.ClassLoaders$AppClassLoader
0x0000000115086378  0x0000000000000000  0x00007fb585f0d6d0       0         0         0  jdk.internal.loader.ClassLoaders$PlatformClassLoader
0x0000000000000000  0x0000000000000000  0x00007fb585c6a650     495    557056     10889  <boot class loader>
Total = 3                                                      497    557824     11397  
ChunkSz: Total size of all allocated metaspace chunks
BlockSz: Total size of all allocated metaspace blocks (each chunk has several blocks)

3.7.2.VM.class_hierarchy

jcmd {pid} VM.class_hierarchy

3195:
java.lang.Object/null
|--java.security.SecureClassLoader$DebugHolder/null
|--jdk.internal.loader.URLClassPath/null
|--java.net.URLStreamHandlerFactory/null (intf)
|--sun.invoke.util.VerifyAccess/null
|--java.lang.ThreadGroup/null
|--java.lang.reflect.Modifier/null
|--java.util.Map/null (intf)
|--java.lang.invoke.MemberName/null
|--jdk.internal.access.JavaLangModuleAccess/null (intf)
|--jdk.internal.reflect.ReflectionFactory$GetReflectionFactoryAction/null
|--java.lang.module.ModuleDescriptor$1/null
|--java.util.Arrays/null
|--jdk.internal.reflect.MethodAccessor/null (intf)
|--java.lang.reflect.ReflectAccess/null
|--jdk.internal.access.JavaLangReflectAccess/null (intf)
|--jdk.internal.access.SharedSecrets/null
|--java.lang.Math/null
|--java.lang.StackFrameInfo/null
|  |--java.lang.LiveStackFrameInfo/null
|--java.lang.PublicMethods$Key/null
|--java.io.File/null
|--java.io.Writer/null
|  |--java.io.OutputStreamWriter/null
|  |--java.io.BufferedWriter/null
|  |--sun.nio.cs.StreamEncoder/null
|--java.lang.reflect.Array/null
|--java.lang.module.ModuleDescriptor$Provides/null
|--sun.nio.ByteBuffered/null (intf)
|--java.lang.StackWalker$StackFrame/null (intf)
|--java.lang.module.ModuleDescriptor$Version/null
|--java.lang.LiveStackFrame/null (intf)
|--java.lang.PublicMethods$MethodList/null
|--java.lang.Class$Atomic/null
|--java.lang.invoke.MethodHandles/null
|--java.nio.charset.Charset/null
|  |--sun.nio.cs.Unicode/null
|  |  |--sun.nio.cs.UTF_8/null
|--java.lang.invoke.MethodHandle/null
|  |--java.lang.invoke.DirectMethodHandle/null
|--sun.security.action.GetPropertyAction/null
|--jdk.internal.loader.URLClassPath$3/null
|--java.lang.Module$ArchivedData/null
|--sun.nio.cs.HistoricallyNamedCharset/null (intf)
|--jdk.internal.loader.URLClassPath$Loader/null
|  |--jdk.internal.loader.URLClassPath$FileLoader/null
|--java.lang.Void/null
|--java.util.jar.Manifest/null
|--jdk.internal.loader.ClassLoaderHelper/null
|--java.net.URLStreamHandler/null
|  |--sun.net.www.protocol.file.Handler/null
|--java.io.ObjectStreamField/null
|--java.lang.reflect.Parameter/null
|--java.io.DefaultFileSystem/null
|--java.security.SecureClassLoader$CodeSourceKey/null
|--java.security.SecureClassLoader$1/null
|--java.util.KeyValueHolder/null
|--java.util.concurrent.locks.AbstractOwnableSynchronizer/null
|--jdk.internal.misc.Unsafe/null
|--java.lang.Boolean/null
|--jdk.internal.loader.ClassLoaders/null
|--jdk.internal.misc.VM/null
|--jdk.internal.reflect.Reflection/null
|--jdk.internal.vm.PostVMInitHook$1/null
|--java.security.PermissionCollection/null
|  |--sun.security.util.LazyCodeSourcePermissionCollection/null
|  |--java.security.BasicPermissionCollection/null
|  |--java.security.Permissions/null
|--java.security.cert.Certificate/null
|--jdk.internal.module.ModuleHashes$HashSupplier/null (intf)
|--java.net.URI$1/null
|--java.lang.ref.Cleaner/null
|--java.util.HashMap$Node/null
|  |--java.util.LinkedHashMap$Entry/null
|  |  |--java.util.HashMap$TreeNode/null
|--sun.launcher.LauncherHelper/null
|--jdk.internal.module.SystemModuleFinders$3/null
|--java.util.concurrent.ThreadFactory/null (intf)
|--sun.net.util.URLUtil/null
|--java.lang.Runtime/null
|--java.lang.module.ModuleFinder/null (intf)
|--java.util.AbstractCollection/null
|  |--java.util.AbstractSet/null
|  |  |--java.util.ImmutableCollections$MapN$1/null
|  |  |--java.util.HashMap$EntrySet/null
|  |  |--java.util.Collections$SetFromMap/null
|  |  |--java.util.Collections$EmptySet/null
|  |  |--java.util.HashSet/null
|  |  |--java.util.WeakHashMap$KeySet/null
|  |--java.util.ArrayDeque/null
|  |--java.util.AbstractList/null
|  |  |--java.util.Collections$EmptyList/null
|  |  |--java.util.ArrayList/null
|  |--java.util.ImmutableCollections$AbstractImmutableCollection/null
|  |  |--java.util.ImmutableCollections$AbstractImmutableSet/null
|  |  |  |--java.util.ImmutableCollections$SetN/null
|  |  |  |--java.util.ImmutableCollections$Set12/null
|  |  |--java.util.ImmutableCollections$AbstractImmutableList/null
|  |  |  |--java.util.ImmutableCollections$ListN/null
|  |  |  |--java.util.ImmutableCollections$List12/null
|--java.security.PrivilegedExceptionAction/null (intf)
|--jdk.internal.ref.CleanerFactory$1/null
|--java.lang.ClassLoader$ParallelLoaders/null
|--jdk.internal.module.Modules/null
|--jdk.internal.module.SystemModuleFinders$SystemModuleFinder/null
|--java.lang.StackTraceElement/null
|--java.net.URL/null
|--jdk.internal.loader.NativeLibraries/null
|--java.lang.Thread$UncaughtExceptionHandler/null (intf)
|--java.util.Optional/null
|--java.util.random.RandomGenerator/null (intf)
|--jdk.internal.misc.OSEnvironment/null
|--java.security.CodeSource/null
|--java.io.FileSystem/null
|  |--java.io.UnixFileSystem/null
|--java.lang.invoke.MemberName$Factory/null
|--java.util.Collections/null
|--jdk.internal.reflect.ConstantPool/null
|--java.security.ProtectionDomain/null
|--jdk.internal.util.ArraysSupport/null
|--java.security.Guard/null (intf)
|--java.util.Comparator/null (intf)
|--jdk.internal.reflect.FieldAccessor/null (intf)
|--java.lang.String/null
|--java.security.Permission/null
|  |--java.security.BasicPermission/null
|  |  |--java.lang.RuntimePermission/null
|  |  |--java.lang.reflect.ReflectPermission/null
|  |--java.security.AllPermission/null
|  |--java.security.UnresolvedPermission/null
|--java.lang.String$CaseInsensitiveComparator/null
|--java.lang.annotation.Annotation/null (intf)
|--java.nio.charset.spi.CharsetProvider/null
|  |--sun.nio.cs.StandardCharsets/null
|--java.lang.StringLatin1/null
|--java.util.Random/null
|--jdk.internal.reflect.CallerSensitive/null (intf)
|--java.util.Queue/null (intf)
|--java.security.Principal/null (intf)
|--java.util.HexFormat/null
|--java.util.RandomAccess/null (intf)
|--java.security.AccessControlContext/null
|--jdk.internal.access.JavaSecurityAccess/null (intf)
|--java.util.Hashtable$Entry/null
|--java.security.ProtectionDomain$JavaSecurityAccessImpl/null
|--jdk.internal.math.FDBigInteger/null
|--java.security.ProtectionDomain$Key/null
|--java.util.Deque/null (intf)
|--java.lang.StringCoding/null
|--MemoryLeakExample$DataProcessor/0x00007fb585f0f940
|--MemoryLeakExample/0x00007fb585f0f940
|--java.net.URL$DefaultFactory/null
|--java.lang.StackStreamFactory$AbstractStackWalker/null
|--java.lang.invoke.VarHandle/null
|--jdk.internal.access.JavaNetURLAccess/null (intf)
|--jdk.internal.loader.Resource/null
|  |--jdk.internal.loader.URLClassPath$FileLoader$1/null
|--java.io.FileInputStream$1/null
|--java.net.URL$3/null
|--java.lang.Module/null
|--java.lang.NamedPackage/null
|--java.lang.constant.ConstantDesc/null (intf)
|--sun.net.www.ParseUtil/null
|--java.lang.SecurityManager/null
|--java.lang.invoke.TypeDescriptor$OfMethod/null (intf)
|--java.util.Collections$UnmodifiableMap/null
|--java.lang.Class$ReflectionData/null
|--jdk.internal.ref.CleanerFactory/null
|--jdk.internal.reflect.ConstructorAccessor/null (intf)
|--java.lang.StackWalker/null
|--java.lang.ref.Cleaner$1/null
|--java.lang.module.ModuleDescriptor$Requires/null
|--java.lang.Throwable/null
|  |--java.lang.Error/null
|  |  |--java.lang.ThreadDeath/null
|  |  |--java.lang.LinkageError/null
|  |  |  |--java.lang.NoClassDefFoundError/null
|  |  |  |--java.lang.BootstrapMethodError/null
|  |  |--java.lang.VirtualMachineError/null
|  |  |  |--java.lang.InternalError/null
|  |  |  |--java.lang.OutOfMemoryError/null
|  |  |  |--java.lang.StackOverflowError/null
|  |--java.lang.Exception/null
|  |  |--java.lang.InterruptedException/null
|  |  |--java.lang.RuntimeException/null
|  |  |  |--java.lang.ClassCastException/null
|  |  |  |--java.lang.NullPointerException/null
|  |  |  |--java.lang.ArithmeticException/null
|  |  |  |--java.lang.ArrayStoreException/null
|  |  |  |--java.lang.IllegalArgumentException/null
|  |  |  |--java.lang.IllegalMonitorStateException/null
|  |  |--java.lang.ReflectiveOperationException/null
|  |  |  |--java.lang.ClassNotFoundException/null
|--jdk.internal.reflect.MagicAccessorImpl/null
|  |--jdk.internal.reflect.FieldAccessorImpl/null
|  |  |--jdk.internal.reflect.UnsafeFieldAccessorImpl/null
|  |  |  |--jdk.internal.reflect.UnsafeStaticFieldAccessorImpl/null
|  |--jdk.internal.reflect.MethodAccessorImpl/null
|  |--jdk.internal.reflect.ConstructorAccessorImpl/null
|  |  |--jdk.internal.reflect.NativeConstructorAccessorImpl/null
|--jdk.internal.ref.CleanerImpl/null
|--java.lang.module.ModuleDescriptor$Exports/null
|--java.lang.invoke.MethodType/null
|--java.lang.module.ModuleDescriptor$Opens/null
|--java.util.function.Function/null (intf)
|--java.lang.invoke.CallSite/null
|  |--java.lang.invoke.ConstantCallSite/null
|  |--java.lang.invoke.MutableCallSite/null
|  |--java.lang.invoke.VolatileCallSite/null
|--java.lang.reflect.Member/null (intf)
|--jdk.internal.invoke.NativeEntryPoint/null
|--java.lang.invoke.MethodHandleNatives$CallSiteContext/null
|--java.lang.invoke.StringConcatFactory/null
|--java.lang.AssertionStatusDirectives/null
|--java.security.PrivilegedAction/null (intf)
|--sun.util.locale.BaseLocale$Key/null
|--jdk.internal.module.ModuleTarget/null
|--java.lang.reflect.AccessibleObject/null
|  |--java.lang.reflect.Field/null
|  |--java.lang.reflect.Executable/null
|  |  |--java.lang.reflect.Method/null
|  |  |--java.lang.reflect.Constructor/null
|--java.lang.invoke.MethodHandleStatics/null
|--java.security.AccessController/null
|--jdk.internal.module.ModuleBootstrap/null
|--jdk.internal.module.ServicesCatalog/null
|--jdk.internal.access.JavaLangRefAccess/null (intf)
|--java.lang.ref.Reference$1/null
|--sun.util.locale.LocaleUtils/null
|--jdk.internal.misc.Signal$Handler/null (intf)
|--java.lang.Runnable/null (intf)
|--jdk.internal.loader.BootLoader/null
|--java.lang.Terminator$1/null
|--java.lang.ClassLoader/null
|  |--java.security.SecureClassLoader/null
|  |  |--jdk.internal.loader.BuiltinClassLoader/null
|  |  |  |--jdk.internal.loader.ClassLoaders$PlatformClassLoader/null
|  |  |  |--jdk.internal.loader.ClassLoaders$AppClassLoader/null
|  |  |  |--jdk.internal.loader.ClassLoaders$BootClassLoader/null
|  |--jdk.internal.reflect.DelegatingClassLoader/null
|--jdk.internal.reflect.ReflectionFactory/null
|--jdk.internal.misc.Signal/null
|--java.lang.System/null
|--java.lang.Comparable/null (intf)
|--java.lang.Thread/null
|  |--java.lang.ref.Reference$ReferenceHandler/null
|  |--jdk.internal.misc.InnocuousThread/null
|  |--java.lang.ref.Finalizer$FinalizerThread/null
|--java.lang.ref.ReferenceQueue/null
|  |--java.lang.ref.ReferenceQueue$Null/null
|--java.util.concurrent.ConcurrentMap/null (intf)
|--java.nio.ByteOrder/null
|--sun.net.util.IPAddressUtil/null
|--java.lang.Terminator/null
|--sun.util.locale.BaseLocale/null
|--jdk.internal.util.Preconditions/null
|--jdk.internal.module.ModuleLoaderMap$Mapper/null
|--java.lang.module.ModuleReference/null
|  |--jdk.internal.module.ModuleReferenceImpl/null
|--java.lang.ModuleLayer/null
|--java.lang.invoke.StringConcatFactory$3/null
|--java.util.function.Supplier/null (intf)
|--java.lang.CharacterData/null
|  |--java.lang.CharacterDataLatin1/null
|--java.lang.invoke.StringConcatFactory$2/null
|--java.lang.Enum/null
|  |--java.lang.module.ModuleDescriptor$Requires$Modifier/null
|  |--java.io.File$PathStatus/null
|--jdk.internal.access.JavaIOFileDescriptorAccess/null (intf)
|--java.lang.module.ModuleDescriptor/null
|--java.lang.invoke.StringConcatFactory$1/null
|--java.io.FileDescriptor/null
|--java.util.concurrent.locks.LockSupport/null
|--java.io.FileDescriptor$1/null
|--jdk.internal.vm.PostVMInitHook/null
|--java.lang.Long$LongCache/null
|--java.nio.charset.CharsetEncoder/null
|  |--sun.nio.cs.UTF_8$Encoder/null
|--jdk.internal.module.ModulePatcher/null
|--java.lang.Byte$ByteCache/null
|--java.lang.invoke.LambdaForm/null
|--java.io.InputStream/null
|  |--java.io.FilterInputStream/null
|  |  |--java.io.BufferedInputStream/null
|  |--java.io.ByteArrayInputStream/null
|  |--java.io.FileInputStream/null
|--java.lang.Short$ShortCache/null
|--java.util.AbstractMap/null
|  |--java.util.ImmutableCollections$AbstractImmutableMap/null
|  |  |--java.util.ImmutableCollections$MapN/null
|  |--java.util.concurrent.ConcurrentHashMap/null
|  |--java.util.HashMap/null
|  |--java.util.Collections$EmptyMap/null
|  |--java.util.WeakHashMap/null
|--jdk.internal.access.JavaNioAccess/null (intf)
|--jdk.internal.module.SystemModuleFinders$2/null
|--java.lang.Character$CharacterCache/null
|--java.lang.AbstractStringBuilder/null
|  |--java.lang.StringBuilder/null
|  |--java.lang.StringBuffer/null
|--java.util.List/null (intf)
|--jdk.internal.access.JavaNetUriAccess/null (intf)
|--java.nio.Buffer$1/null
|--jdk.internal.module.ModuleHashes/null
|--java.util.HashMap$HashIterator/null
|  |--java.util.HashMap$EntryIterator/null
|--jdk.internal.util.StaticProperty/null
|--sun.util.locale.LocaleObjectCache/null
|  |--sun.util.locale.BaseLocale$Cache/null
|  |--java.util.Locale$Cache/null
|--java.lang.CharSequence/null (intf)
|--jdk.internal.misc.Signal$NativeHandler/null
|--java.util.ImmutableCollections$MapN$MapNIterator/null
|--java.util.Map$Entry/null (intf)
|--java.util.ImmutableCollections/null
|--jdk.internal.access.JavaLangAccess/null (intf)
|--jdk.internal.misc.CDS/null
|--java.util.Set/null (intf)
|--java.lang.invoke.MethodHandles$Lookup/null
|--java.lang.Record/null
|--java.util.concurrent.locks.Lock/null (intf)
|--jdk.internal.module.ModuleBootstrap$Counters/null
|--java.util.concurrent.locks.ReentrantLock/null
|  |--java.util.concurrent.ConcurrentHashMap$Segment/null
|--jdk.internal.module.ArchivedBootLayer/null
|--java.util.concurrent.ConcurrentHashMap$CounterCell/null
|--jdk.internal.module.ArchivedModuleGraph/null
|--java.util.concurrent.ConcurrentHashMap$Node/null
|  |--java.util.concurrent.ConcurrentHashMap$ReservationNode/null
|--java.util.Iterator/null (intf)
|--java.lang.reflect.RecordComponent/null
|--java.net.URI/null
|--java.util.Collection/null (intf)
|--jdk.internal.vm.vector.VectorSupport/null
|--java.lang.Iterable/null (intf)
|--jdk.internal.module.ServicesCatalog$ServiceProvider/null
|--java.lang.invoke.MethodHandleNatives/null
|--java.util.Objects/null
|--jdk.internal.loader.ArchivedClassLoaders/null
|--java.lang.invoke.ResolvedMethodName/null
|--java.lang.module.ResolvedModule/null
|--jdk.internal.vm.vector.VectorSupport$VectorPayload/null
|  |--jdk.internal.vm.vector.VectorSupport$Vector/null
|  |--jdk.internal.vm.vector.VectorSupport$VectorMask/null
|  |--jdk.internal.vm.vector.VectorSupport$VectorShuffle/null
|--java.util.concurrent.CopyOnWriteArrayList/null
|--sun.security.util.Debug/null
|--java.util.Dictionary/null
|  |--java.util.Hashtable/null
|  |  |--java.util.Properties/null
|--java.util.Locale/null
|--java.lang.ThreadLocal/null
|--java.lang.Number/null
|  |--java.lang.Long/null
|  |--java.lang.Integer/null
|  |--java.lang.Double/null
|  |--java.lang.Float/null
|  |--java.lang.Short/null
|  |--java.lang.Byte/null
|  |--java.util.concurrent.atomic.AtomicInteger/null
|  |--java.util.concurrent.atomic.AtomicLong/null
|--java.io.Serializable/null (intf)
|--java.lang.Integer$IntegerCache/null
|--java.lang.StringConcatHelper/null
|--java.lang.VersionProps/null
|--java.lang.constant.Constable/null (intf)
|--jdk.internal.util.SystemProps$Raw/null
|--java.util.jar.Attributes$Name/null
|--java.lang.reflect.Type/null (intf)
|--java.lang.System$2/null
|--java.lang.ref.Cleaner$Cleanable/null (intf)
|--java.lang.reflect.GenericDeclaration/null (intf)
|--jdk.internal.util.SystemProps/null
|--java.lang.invoke.TypeDescriptor/null (intf)
|--java.lang.Appendable/null (intf)
|--java.lang.ref.ReferenceQueue$Lock/null
|--java.io.Flushable/null (intf)
|--java.lang.reflect.AnnotatedElement/null (intf)
|--java.lang.ref.Reference/null
|  |--java.lang.ref.SoftReference/null
|  |  |--sun.util.locale.LocaleObjectCache$CacheEntry/null
|  |--java.lang.ref.WeakReference/null
|  |  |--java.util.WeakHashMap$Entry/null
|  |--java.lang.ref.FinalReference/null
|  |  |--java.lang.ref.Finalizer/null
|  |--java.lang.ref.PhantomReference/null
|  |  |--jdk.internal.ref.Cleaner/null
|  |  |--jdk.internal.ref.PhantomCleanable/null
|  |  |  |--jdk.internal.ref.CleanerImpl$PhantomCleanableRef/null
|  |  |  |--jdk.internal.ref.CleanerImpl$CleanerCleanable/null
|  |  |  |--java.io.FileCleanable/null
|--java.io.Closeable/null (intf)
|--java.nio.charset.CodingErrorAction/null
|--java.lang.AutoCloseable/null (intf)
|--java.lang.invoke.TypeDescriptor$OfField/null (intf)
|--java.lang.Character/null
|--java.lang.Class/null
|--jdk.internal.loader.AbstractClassLoaderValue/null
|  |--jdk.internal.loader.ClassLoaderValue/null
|--jdk.internal.loader.BuiltinClassLoader$LoadedModule/null
|--jdk.internal.misc.ScopedMemoryAccess/null
|--java.lang.module.Configuration/null
|--jdk.internal.misc.UnsafeConstants/null
|--java.lang.Cloneable/null (intf)
|--java.io.OutputStream/null
|  |--java.io.FileOutputStream/null
|  |--java.io.FilterOutputStream/null
|  |  |--java.io.PrintStream/null
|  |  |--java.io.BufferedOutputStream/null
|--java.nio.Buffer/null
|  |--java.nio.ByteBuffer/null
|  |  |--java.nio.HeapByteBuffer/null

3.7.3.GC.class_histogram

3.7.3.1.第一次

jcmd {pid} GC.class_histogram

3195:
 num     #instances         #bytes  class name (module)
-------------------------------------------------------
   1:         12293       46516400  [B (java.base@17.0.8)
   2:          7710         185040  java.lang.String (java.base@17.0.8)
   3:          1428         177896  java.lang.Class (java.base@17.0.8)
   4:           879         117344  [Ljava.lang.Object; (java.base@17.0.8)
   5:             6          33016  [C (java.base@17.0.8)
   6:           998          31936  java.util.HashMap$Node (java.base@17.0.8)
   7:           467          30904  [I (java.base@17.0.8)
   8:           905          28960  java.util.concurrent.ConcurrentHashMap$Node (java.base@17.0.8)
   9:           257          23696  [Ljava.util.HashMap$Node; (java.base@17.0.8)
  10:            19          19312  [Ljava.util.concurrent.ConcurrentHashMap$Node; (java.base@17.0.8)
  11:           259          12432  java.util.HashMap (java.base@17.0.8)
  12:           341          10912  jdk.internal.math.FDBigInteger (java.base@17.0.8)
  13:           362           8688  java.lang.module.ModuleDescriptor$Exports (java.base@17.0.8)
  14:           256           6144  java.lang.Long (java.base@17.0.8)
  15:           248           5952  java.util.ImmutableCollections$Set12 (java.base@17.0.8)
  16:            62           4960  java.net.URI (java.base@17.0.8)
  17:           132           4224  java.lang.module.ModuleDescriptor$Requires (java.base@17.0.8)
  18:           256           4096  java.lang.Byte (java.base@17.0.8)
  19:           256           4096  java.lang.Integer (java.base@17.0.8)
  20:           256           4096  java.lang.Short (java.base@17.0.8)
  21:            62           3968  java.lang.module.ModuleDescriptor (java.base@17.0.8)
  22:            68           3808  java.lang.Module (java.base@17.0.8)
  23:            10           3680  java.lang.Thread (java.base@17.0.8)
  24:            62           3472  jdk.internal.module.ModuleReferenceImpl (java.base@17.0.8)
  25:           137           3288  java.util.ImmutableCollections$SetN (java.base@17.0.8)
  26:           196           3136  java.util.HashSet (java.base@17.0.8)
  27:            39           2496  java.util.concurrent.ConcurrentHashMap (java.base@17.0.8)
  28:           128           2048  java.lang.Character (java.base@17.0.8)
  29:            61           1952  jdk.internal.loader.BuiltinClassLoader$LoadedModule (java.base@17.0.8)
  30:             7           1864  [J (java.base@17.0.8)
  31:            62           1488  java.lang.module.ResolvedModule (java.base@17.0.8)
  32:            62           1488  jdk.internal.module.ServicesCatalog$ServiceProvider (java.base@17.0.8)
  33:            62           1488  jdk.internal.module.SystemModuleFinders$2 (java.base@17.0.8)
  34:            60           1440  java.lang.module.ModuleDescriptor$Provides (java.base@17.0.8)
  35:             1           1376  [Ljdk.internal.math.FDBigInteger; (java.base@17.0.8)
  36:            50           1200  java.util.ImmutableCollections$List12 (java.base@17.0.8)
  37:            72           1152  java.lang.Object (java.base@17.0.8)
  38:             1           1040  [Ljava.lang.Byte; (java.base@17.0.8)
  39:             1           1040  [Ljava.lang.Integer; (java.base@17.0.8)
  40:             1           1040  [Ljava.lang.Long; (java.base@17.0.8)
  41:             1           1040  [Ljava.lang.Short; (java.base@17.0.8)
  42:            24            960  java.io.ObjectStreamField (java.base@17.0.8)
  43:            60            960  jdk.internal.module.SystemModuleFinders$3 (java.base@17.0.8)
  44:            12            864  java.lang.reflect.Field (java.base@17.0.8)
  45:            30            720  java.util.concurrent.CopyOnWriteArrayList (java.base@17.0.8)
  46:            20            640  java.util.Locale (java.base@17.0.8)
  47:            20            640  sun.util.locale.BaseLocale (java.base@17.0.8)
  48:            26            624  java.util.jar.Attributes$Name (java.base@17.0.8)
  49:             1            528  [Ljava.lang.Character; (java.base@17.0.8)
  50:            13            520  java.security.AccessControlContext (java.base@17.0.8)
  51:             6            480  [S (java.base@17.0.8)
  52:            12            480  java.lang.OutOfMemoryError (java.base@17.0.8)
  53:             1            376  java.lang.ref.Finalizer$FinalizerThread (java.base@17.0.8)
  54:             1            376  jdk.internal.misc.InnocuousThread (java.base@17.0.8)
  55:             1            368  java.lang.ref.Reference$ReferenceHandler (java.base@17.0.8)
  56:            14            336  java.util.ImmutableCollections$ListN (java.base@17.0.8)
  57:             8            240  [Ljava.io.ObjectStreamField; (java.base@17.0.8)
  58:             7            224  java.util.Hashtable$Entry (java.base@17.0.8)
  59:             9            216  java.util.ArrayList (java.base@17.0.8)
  60:             5            200  java.security.ProtectionDomain (java.base@17.0.8)
  61:             5            200  java.util.WeakHashMap$Entry (java.base@17.0.8)
  62:             6            192  java.lang.ref.ReferenceQueue (java.base@17.0.8)
  63:             4            160  java.security.CodeSource (java.base@17.0.8)
  64:             5            160  java.util.ImmutableCollections$MapN (java.base@17.0.8)
  65:             5            144  [Ljava.lang.String; (java.base@17.0.8)
  66:             3            144  java.lang.ThreadGroup (java.base@17.0.8)
  67:             6            144  java.lang.module.ModuleDescriptor$Requires$Modifier (java.base@17.0.8)
  68:             3            144  java.util.Hashtable (java.base@17.0.8)
  69:             3            128  [Ljava.util.Hashtable$Entry; (java.base@17.0.8)
  70:             2            128  java.lang.Class$ReflectionData (java.base@17.0.8)
  71:             8            128  java.lang.ref.ReferenceQueue$Lock (java.base@17.0.8)
  72:             4            128  jdk.internal.loader.NativeLibraries (java.base@17.0.8)
  73:             3            120  java.io.FileDescriptor (java.base@17.0.8)
  74:             3            120  java.lang.ref.SoftReference (java.base@17.0.8)
  75:             3            112  [Ljava.lang.Thread; (java.base@17.0.8)
  76:             2            112  [Ljava.lang.invoke.MethodHandle; (java.base@17.0.8)
  77:             2            112  java.nio.HeapByteBuffer (java.base@17.0.8)
  78:             1            104  jdk.internal.loader.ClassLoaders$AppClassLoader (java.base@17.0.8)
  79:             1            104  jdk.internal.loader.ClassLoaders$BootClassLoader (java.base@17.0.8)
  80:             1            104  jdk.internal.loader.ClassLoaders$PlatformClassLoader (java.base@17.0.8)
  81:             1             96  [Lsun.util.locale.BaseLocale; (java.base@17.0.8)
  82:             3             96  java.lang.invoke.MethodHandles$Lookup (java.base@17.0.8)
  83:             4             96  java.lang.module.ModuleDescriptor$Opens (java.base@17.0.8)
  84:             2             96  sun.nio.cs.StreamEncoder (java.base@17.0.8)
  85:             2             96  sun.nio.cs.UTF_8$Encoder (java.base@17.0.8)
  86:             1             88  java.lang.reflect.Method (java.base@17.0.8)
  87:             2             80  [Ljava.lang.OutOfMemoryError; (java.base@17.0.8)
  88:             5             80  [Ljava.security.Principal; (java.base@17.0.8)
  89:             1             80  [Ljava.util.WeakHashMap$Entry; (java.base@17.0.8)
  90:             2             80  java.io.BufferedWriter (java.base@17.0.8)
  91:             2             80  java.io.PrintStream (java.base@17.0.8)
  92:             2             80  java.lang.IllegalArgumentException (java.base@17.0.8)
  93:             2             80  java.lang.ModuleLayer (java.base@17.0.8)
  94:             2             80  java.lang.module.Configuration (java.base@17.0.8)
  95:             5             80  java.security.ProtectionDomain$Key (java.base@17.0.8)
  96:             2             80  sun.util.locale.LocaleObjectCache$CacheEntry (java.base@17.0.8)
  97:             3             72  jdk.internal.misc.Signal (java.base@17.0.8)
  98:             1             64  [Ljava.lang.reflect.Field; (java.base@17.0.8)
  99:             2             64  java.io.BufferedOutputStream (java.base@17.0.8)
 100:             2             64  java.io.FileOutputStream (java.base@17.0.8)
 101:             2             64  java.lang.ref.ReferenceQueue$Null (java.base@17.0.8)
 102:             1             64  java.net.URL (java.base@17.0.8)
 103:             2             64  java.util.HexFormat (java.base@17.0.8)
 104:             3             56  [Ljava.lang.Class; (java.base@17.0.8)
 105:             1             56  java.util.Properties (java.base@17.0.8)
 106:             2             48  [Ljava.security.ProtectionDomain; (java.base@17.0.8)
 107:             2             48  java.io.File$PathStatus (java.base@17.0.8)
 108:             2             48  java.io.OutputStreamWriter (java.base@17.0.8)
 109:             1             48  java.lang.NullPointerException (java.base@17.0.8)
 110:             3             48  java.nio.charset.CodingErrorAction (java.base@17.0.8)
 111:             2             48  java.util.ArrayDeque (java.base@17.0.8)
 112:             1             48  java.util.WeakHashMap (java.base@17.0.8)
 113:             3             48  jdk.internal.loader.ClassLoaderValue (java.base@17.0.8)
 114:             2             48  jdk.internal.misc.Signal$NativeHandler (java.base@17.0.8)
 115:             3             48  jdk.internal.module.ServicesCatalog (java.base@17.0.8)
 116:             1             48  jdk.internal.ref.CleanerImpl$PhantomCleanableRef (java.base@17.0.8)
 117:             1             40  java.io.BufferedInputStream (java.base@17.0.8)
 118:             1             40  java.lang.ArithmeticException (java.base@17.0.8)
 119:             1             40  java.lang.VirtualMachineError (java.base@17.0.8)
 120:             1             40  jdk.internal.loader.URLClassPath (java.base@17.0.8)
 121:             1             40  jdk.internal.ref.CleanerImpl$CleanerCleanable (java.base@17.0.8)
 122:             2             32  [Ljava.lang.StackTraceElement; (java.base@17.0.8)
 123:             1             32  [Ljava.lang.ThreadGroup; (java.base@17.0.8)
 124:             1             32  [Ljava.lang.module.ModuleDescriptor$Requires$Modifier; (java.base@17.0.8)
 125:             1             32  [Ljdk.internal.module.ServicesCatalog; (java.base@17.0.8)
 126:             1             32  java.io.File (java.base@17.0.8)
 127:             1             32  java.io.FileInputStream (java.base@17.0.8)
 128:             1             32  java.io.UnixFileSystem (java.base@17.0.8)
 129:             2             32  java.lang.Boolean (java.base@17.0.8)
 130:             1             32  java.lang.Module$ArchivedData (java.base@17.0.8)
 131:             2             32  java.lang.ThreadLocal (java.base@17.0.8)
 132:             1             32  java.lang.module.ModuleDescriptor$Version (java.base@17.0.8)
 133:             2             32  java.nio.ByteOrder (java.base@17.0.8)
 134:             1             32  java.util.Collections$UnmodifiableMap (java.base@17.0.8)
 135:             2             32  java.util.concurrent.atomic.AtomicInteger (java.base@17.0.8)
 136:             1             32  jdk.internal.loader.ArchivedClassLoaders (java.base@17.0.8)
 137:             1             32  jdk.internal.module.ArchivedModuleGraph (java.base@17.0.8)
 138:             1             32  sun.util.locale.BaseLocale$Key (java.base@17.0.8)
 139:             1             24  [Ljava.io.File$PathStatus; (java.base@17.0.8)
 140:             1             24  [Ljava.lang.reflect.Method; (java.base@17.0.8)
 141:             1             24  [Ljava.net.URL; (java.base@17.0.8)
 142:             1             24  [Ljava.util.jar.Manifest; (java.base@17.0.8)
 143:             1             24  java.lang.NamedPackage (java.base@17.0.8)
 144:             1             24  java.lang.RuntimePermission (java.base@17.0.8)
 145:             1             24  java.lang.StringBuilder (java.base@17.0.8)
 146:             1             24  java.lang.reflect.ReflectPermission (java.base@17.0.8)
 147:             1             24  java.security.BasicPermissionCollection (java.base@17.0.8)
 148:             1             24  java.security.Permissions (java.base@17.0.8)
 149:             1             24  java.util.Collections$EmptyMap (java.base@17.0.8)
 150:             1             24  java.util.Collections$SetFromMap (java.base@17.0.8)
 151:             1             24  java.util.Locale$Cache (java.base@17.0.8)
 152:             1             24  java.util.concurrent.atomic.AtomicLong (java.base@17.0.8)
 153:             1             24  jdk.internal.loader.URLClassPath$FileLoader (java.base@17.0.8)
 154:             1             24  jdk.internal.module.ModuleHashes (java.base@17.0.8)
 155:             1             24  jdk.internal.module.SystemModuleFinders$SystemModuleFinder (java.base@17.0.8)
 156:             1             24  jdk.internal.ref.CleanerImpl (java.base@17.0.8)
 157:             1             24  sun.nio.cs.StandardCharsets (java.base@17.0.8)
 158:             1             24  sun.nio.cs.UTF_8 (java.base@17.0.8)
 159:             1             24  sun.security.util.LazyCodeSourcePermissionCollection (java.base@17.0.8)
 160:             1             24  sun.util.locale.BaseLocale$Cache (java.base@17.0.8)
 161:             1             16  [Ljava.lang.Throwable; (java.base@17.0.8)
 162:             1             16  [Ljava.security.cert.Certificate; (java.base@17.0.8)
 163:             1             16  MemoryLeakExample$DataProcessor
 164:             1             16  java.io.FileDescriptor$1 (java.base@17.0.8)
 165:             1             16  java.lang.CharacterDataLatin1 (java.base@17.0.8)
 166:             1             16  java.lang.Runtime (java.base@17.0.8)
 167:             1             16  java.lang.String$CaseInsensitiveComparator (java.base@17.0.8)
 168:             1             16  java.lang.System$2 (java.base@17.0.8)
 169:             1             16  java.lang.Terminator$1 (java.base@17.0.8)
 170:             1             16  java.lang.invoke.MemberName$Factory (java.base@17.0.8)
 171:             1             16  java.lang.invoke.StringConcatFactory$1 (java.base@17.0.8)
 172:             1             16  java.lang.invoke.StringConcatFactory$2 (java.base@17.0.8)
 173:             1             16  java.lang.invoke.StringConcatFactory$3 (java.base@17.0.8)
 174:             1             16  java.lang.module.ModuleDescriptor$1 (java.base@17.0.8)
 175:             1             16  java.lang.ref.Cleaner (java.base@17.0.8)
 176:             1             16  java.lang.ref.Cleaner$1 (java.base@17.0.8)
 177:             1             16  java.lang.ref.Reference$1 (java.base@17.0.8)
 178:             1             16  java.lang.reflect.ReflectAccess (java.base@17.0.8)
 179:             1             16  java.net.URI$1 (java.base@17.0.8)
 180:             1             16  java.net.URL$3 (java.base@17.0.8)
 181:             1             16  java.net.URL$DefaultFactory (java.base@17.0.8)
 182:             1             16  java.nio.Buffer$1 (java.base@17.0.8)
 183:             1             16  java.security.ProtectionDomain$JavaSecurityAccessImpl (java.base@17.0.8)
 184:             1             16  java.security.SecureClassLoader$CodeSourceKey (java.base@17.0.8)
 185:             1             16  java.util.Collections$EmptyList (java.base@17.0.8)
 186:             1             16  java.util.Collections$EmptySet (java.base@17.0.8)
 187:             1             16  java.util.HashMap$EntrySet (java.base@17.0.8)
 188:             1             16  java.util.Optional (java.base@17.0.8)
 189:             1             16  java.util.WeakHashMap$KeySet (java.base@17.0.8)
 190:             1             16  jdk.internal.misc.ScopedMemoryAccess (java.base@17.0.8)
 191:             1             16  jdk.internal.misc.Unsafe (java.base@17.0.8)
 192:             1             16  jdk.internal.module.ArchivedBootLayer (java.base@17.0.8)
 193:             1             16  jdk.internal.module.ModuleLoaderMap$Mapper (java.base@17.0.8)
 194:             1             16  jdk.internal.module.ModulePatcher (java.base@17.0.8)
 195:             1             16  jdk.internal.module.ModuleTarget (java.base@17.0.8)
 196:             1             16  jdk.internal.reflect.ReflectionFactory (java.base@17.0.8)
 197:             1             16  sun.net.www.protocol.file.Handler (java.base@17.0.8)
Total         29036       47290376

3.7.3.2.第二次

jcmd {pid} GC.class_histogram

3195:
 num     #instances         #bytes  class name (module)
-------------------------------------------------------
   1:         15811       82597008  [B (java.base@17.0.8)
   2:          7710         185040  java.lang.String (java.base@17.0.8)
   3:          1428         177896  java.lang.Class (java.base@17.0.8)
   4:           879         129840  [Ljava.lang.Object; (java.base@17.0.8)
   5:             6          33016  [C (java.base@17.0.8)
   6:           998          31936  java.util.HashMap$Node (java.base@17.0.8)
   7:           467          30904  [I (java.base@17.0.8)
   8:           905          28960  java.util.concurrent.ConcurrentHashMap$Node (java.base@17.0.8)
   9:           257          23696  [Ljava.util.HashMap$Node; (java.base@17.0.8)
  10:            19          19312  [Ljava.util.concurrent.ConcurrentHashMap$Node; (java.base@17.0.8)
  11:           259          12432  java.util.HashMap (java.base@17.0.8)
  12:           341          10912  jdk.internal.math.FDBigInteger (java.base@17.0.8)
  13:           362           8688  java.lang.module.ModuleDescriptor$Exports (java.base@17.0.8)
  14:           256           6144  java.lang.Long (java.base@17.0.8)
  15:           248           5952  java.util.ImmutableCollections$Set12 (java.base@17.0.8)
  16:            62           4960  java.net.URI (java.base@17.0.8)
  17:           132           4224  java.lang.module.ModuleDescriptor$Requires (java.base@17.0.8)
  18:           256           4096  java.lang.Byte (java.base@17.0.8)
  19:           256           4096  java.lang.Integer (java.base@17.0.8)
  20:           256           4096  java.lang.Short (java.base@17.0.8)
  21:            62           3968  java.lang.module.ModuleDescriptor (java.base@17.0.8)
  22:            68           3808  java.lang.Module (java.base@17.0.8)
  23:            10           3680  java.lang.Thread (java.base@17.0.8)
  24:            62           3472  jdk.internal.module.ModuleReferenceImpl (java.base@17.0.8)
  25:           137           3288  java.util.ImmutableCollections$SetN (java.base@17.0.8)
  26:           196           3136  java.util.HashSet (java.base@17.0.8)
  27:            39           2496  java.util.concurrent.ConcurrentHashMap (java.base@17.0.8)
  28:           128           2048  java.lang.Character (java.base@17.0.8)
  29:            61           1952  jdk.internal.loader.BuiltinClassLoader$LoadedModule (java.base@17.0.8)
  30:             7           1864  [J (java.base@17.0.8)
  31:            62           1488  java.lang.module.ResolvedModule (java.base@17.0.8)
  32:            62           1488  jdk.internal.module.ServicesCatalog$ServiceProvider (java.base@17.0.8)
  33:            62           1488  jdk.internal.module.SystemModuleFinders$2 (java.base@17.0.8)
  34:            60           1440  java.lang.module.ModuleDescriptor$Provides (java.base@17.0.8)
  35:             1           1376  [Ljdk.internal.math.FDBigInteger; (java.base@17.0.8)
  36:            50           1200  java.util.ImmutableCollections$List12 (java.base@17.0.8)
  37:            72           1152  java.lang.Object (java.base@17.0.8)
  38:             1           1040  [Ljava.lang.Byte; (java.base@17.0.8)
  39:             1           1040  [Ljava.lang.Integer; (java.base@17.0.8)
  40:             1           1040  [Ljava.lang.Long; (java.base@17.0.8)
  41:             1           1040  [Ljava.lang.Short; (java.base@17.0.8)
  42:            24            960  java.io.ObjectStreamField (java.base@17.0.8)
  43:            60            960  jdk.internal.module.SystemModuleFinders$3 (java.base@17.0.8)
  44:            12            864  java.lang.reflect.Field (java.base@17.0.8)
  45:            30            720  java.util.concurrent.CopyOnWriteArrayList (java.base@17.0.8)
  46:            20            640  java.util.Locale (java.base@17.0.8)
  47:            20            640  sun.util.locale.BaseLocale (java.base@17.0.8)
  48:            26            624  java.util.jar.Attributes$Name (java.base@17.0.8)
  49:             1            528  [Ljava.lang.Character; (java.base@17.0.8)
  50:            13            520  java.security.AccessControlContext (java.base@17.0.8)
  51:             6            480  [S (java.base@17.0.8)
  52:            12            480  java.lang.OutOfMemoryError (java.base@17.0.8)
  53:             1            376  java.lang.ref.Finalizer$FinalizerThread (java.base@17.0.8)
  54:             1            376  jdk.internal.misc.InnocuousThread (java.base@17.0.8)
  55:             1            368  java.lang.ref.Reference$ReferenceHandler (java.base@17.0.8)
  56:            14            336  java.util.ImmutableCollections$ListN (java.base@17.0.8)
  57:             8            240  [Ljava.io.ObjectStreamField; (java.base@17.0.8)
  58:             7            224  java.util.Hashtable$Entry (java.base@17.0.8)
  59:             9            216  java.util.ArrayList (java.base@17.0.8)
  60:             5            200  java.security.ProtectionDomain (java.base@17.0.8)
  61:             5            200  java.util.WeakHashMap$Entry (java.base@17.0.8)
  62:             6            192  java.lang.ref.ReferenceQueue (java.base@17.0.8)
  63:             4            160  java.security.CodeSource (java.base@17.0.8)
  64:             5            160  java.util.ImmutableCollections$MapN (java.base@17.0.8)
  65:             5            144  [Ljava.lang.String; (java.base@17.0.8)
  66:             3            144  java.lang.ThreadGroup (java.base@17.0.8)
  67:             6            144  java.lang.module.ModuleDescriptor$Requires$Modifier (java.base@17.0.8)
  68:             3            144  java.util.Hashtable (java.base@17.0.8)
  69:             3            128  [Ljava.util.Hashtable$Entry; (java.base@17.0.8)
  70:             2            128  java.lang.Class$ReflectionData (java.base@17.0.8)
  71:             8            128  java.lang.ref.ReferenceQueue$Lock (java.base@17.0.8)
  72:             4            128  jdk.internal.loader.NativeLibraries (java.base@17.0.8)
  73:             3            120  java.io.FileDescriptor (java.base@17.0.8)
  74:             3            120  java.lang.ref.SoftReference (java.base@17.0.8)
  75:             3            112  [Ljava.lang.Thread; (java.base@17.0.8)
  76:             2            112  [Ljava.lang.invoke.MethodHandle; (java.base@17.0.8)
  77:             2            112  java.nio.HeapByteBuffer (java.base@17.0.8)
  78:             1            104  jdk.internal.loader.ClassLoaders$AppClassLoader (java.base@17.0.8)
  79:             1            104  jdk.internal.loader.ClassLoaders$BootClassLoader (java.base@17.0.8)
  80:             1            104  jdk.internal.loader.ClassLoaders$PlatformClassLoader (java.base@17.0.8)
  81:             1             96  [Lsun.util.locale.BaseLocale; (java.base@17.0.8)
  82:             3             96  java.lang.invoke.MethodHandles$Lookup (java.base@17.0.8)
  83:             4             96  java.lang.module.ModuleDescriptor$Opens (java.base@17.0.8)
  84:             2             96  sun.nio.cs.StreamEncoder (java.base@17.0.8)
  85:             2             96  sun.nio.cs.UTF_8$Encoder (java.base@17.0.8)
  86:             1             88  java.lang.reflect.Method (java.base@17.0.8)
  87:             2             80  [Ljava.lang.OutOfMemoryError; (java.base@17.0.8)
  88:             5             80  [Ljava.security.Principal; (java.base@17.0.8)
  89:             1             80  [Ljava.util.WeakHashMap$Entry; (java.base@17.0.8)
  90:             2             80  java.io.BufferedWriter (java.base@17.0.8)
  91:             2             80  java.io.PrintStream (java.base@17.0.8)
  92:             2             80  java.lang.IllegalArgumentException (java.base@17.0.8)
  93:             2             80  java.lang.ModuleLayer (java.base@17.0.8)
  94:             2             80  java.lang.module.Configuration (java.base@17.0.8)
  95:             5             80  java.security.ProtectionDomain$Key (java.base@17.0.8)
  96:             2             80  sun.util.locale.LocaleObjectCache$CacheEntry (java.base@17.0.8)
  97:             3             72  jdk.internal.misc.Signal (java.base@17.0.8)
  98:             1             64  [Ljava.lang.reflect.Field; (java.base@17.0.8)
  99:             2             64  java.io.BufferedOutputStream (java.base@17.0.8)
 100:             2             64  java.io.FileOutputStream (java.base@17.0.8)
 101:             2             64  java.lang.ref.ReferenceQueue$Null (java.base@17.0.8)
 102:             1             64  java.net.URL (java.base@17.0.8)
 103:             2             64  java.util.HexFormat (java.base@17.0.8)
 104:             3             56  [Ljava.lang.Class; (java.base@17.0.8)
 105:             1             56  java.util.Properties (java.base@17.0.8)
 106:             2             48  [Ljava.security.ProtectionDomain; (java.base@17.0.8)
 107:             2             48  java.io.File$PathStatus (java.base@17.0.8)
 108:             2             48  java.io.OutputStreamWriter (java.base@17.0.8)
 109:             1             48  java.lang.NullPointerException (java.base@17.0.8)
 110:             3             48  java.nio.charset.CodingErrorAction (java.base@17.0.8)
 111:             2             48  java.util.ArrayDeque (java.base@17.0.8)
 112:             1             48  java.util.WeakHashMap (java.base@17.0.8)
 113:             3             48  jdk.internal.loader.ClassLoaderValue (java.base@17.0.8)
 114:             2             48  jdk.internal.misc.Signal$NativeHandler (java.base@17.0.8)
 115:             3             48  jdk.internal.module.ServicesCatalog (java.base@17.0.8)
 116:             1             48  jdk.internal.ref.CleanerImpl$PhantomCleanableRef (java.base@17.0.8)
 117:             1             40  java.io.BufferedInputStream (java.base@17.0.8)
 118:             1             40  java.lang.ArithmeticException (java.base@17.0.8)
 119:             1             40  java.lang.VirtualMachineError (java.base@17.0.8)
 120:             1             40  jdk.internal.loader.URLClassPath (java.base@17.0.8)
 121:             1             40  jdk.internal.ref.CleanerImpl$CleanerCleanable (java.base@17.0.8)
 122:             2             32  [Ljava.lang.StackTraceElement; (java.base@17.0.8)
 123:             1             32  [Ljava.lang.ThreadGroup; (java.base@17.0.8)
 124:             1             32  [Ljava.lang.module.ModuleDescriptor$Requires$Modifier; (java.base@17.0.8)
 125:             1             32  [Ljdk.internal.module.ServicesCatalog; (java.base@17.0.8)
 126:             1             32  java.io.File (java.base@17.0.8)
 127:             1             32  java.io.FileInputStream (java.base@17.0.8)
 128:             1             32  java.io.UnixFileSystem (java.base@17.0.8)
 129:             2             32  java.lang.Boolean (java.base@17.0.8)
 130:             1             32  java.lang.Module$ArchivedData (java.base@17.0.8)
 131:             2             32  java.lang.ThreadLocal (java.base@17.0.8)
 132:             1             32  java.lang.module.ModuleDescriptor$Version (java.base@17.0.8)
 133:             2             32  java.nio.ByteOrder (java.base@17.0.8)
 134:             1             32  java.util.Collections$UnmodifiableMap (java.base@17.0.8)
 135:             2             32  java.util.concurrent.atomic.AtomicInteger (java.base@17.0.8)
 136:             1             32  jdk.internal.loader.ArchivedClassLoaders (java.base@17.0.8)
 137:             1             32  jdk.internal.module.ArchivedModuleGraph (java.base@17.0.8)
 138:             1             32  sun.util.locale.BaseLocale$Key (java.base@17.0.8)
 139:             1             24  [Ljava.io.File$PathStatus; (java.base@17.0.8)
 140:             1             24  [Ljava.lang.reflect.Method; (java.base@17.0.8)
 141:             1             24  [Ljava.net.URL; (java.base@17.0.8)
 142:             1             24  [Ljava.util.jar.Manifest; (java.base@17.0.8)
 143:             1             24  java.lang.NamedPackage (java.base@17.0.8)
 144:             1             24  java.lang.RuntimePermission (java.base@17.0.8)
 145:             1             24  java.lang.StringBuilder (java.base@17.0.8)
 146:             1             24  java.lang.reflect.ReflectPermission (java.base@17.0.8)
 147:             1             24  java.security.BasicPermissionCollection (java.base@17.0.8)
 148:             1             24  java.security.Permissions (java.base@17.0.8)
 149:             1             24  java.util.Collections$EmptyMap (java.base@17.0.8)
 150:             1             24  java.util.Collections$SetFromMap (java.base@17.0.8)
 151:             1             24  java.util.Locale$Cache (java.base@17.0.8)
 152:             1             24  java.util.concurrent.atomic.AtomicLong (java.base@17.0.8)
 153:             1             24  jdk.internal.loader.URLClassPath$FileLoader (java.base@17.0.8)
 154:             1             24  jdk.internal.module.ModuleHashes (java.base@17.0.8)
 155:             1             24  jdk.internal.module.SystemModuleFinders$SystemModuleFinder (java.base@17.0.8)
 156:             1             24  jdk.internal.ref.CleanerImpl (java.base@17.0.8)
 157:             1             24  sun.nio.cs.StandardCharsets (java.base@17.0.8)
 158:             1             24  sun.nio.cs.UTF_8 (java.base@17.0.8)
 159:             1             24  sun.security.util.LazyCodeSourcePermissionCollection (java.base@17.0.8)
 160:             1             24  sun.util.locale.BaseLocale$Cache (java.base@17.0.8)
 161:             1             16  [Ljava.lang.Throwable; (java.base@17.0.8)
 162:             1             16  [Ljava.security.cert.Certificate; (java.base@17.0.8)
 163:             1             16  MemoryLeakExample$DataProcessor
 164:             1             16  java.io.FileDescriptor$1 (java.base@17.0.8)
 165:             1             16  java.lang.CharacterDataLatin1 (java.base@17.0.8)
 166:             1             16  java.lang.Runtime (java.base@17.0.8)
 167:             1             16  java.lang.String$CaseInsensitiveComparator (java.base@17.0.8)
 168:             1             16  java.lang.System$2 (java.base@17.0.8)
 169:             1             16  java.lang.Terminator$1 (java.base@17.0.8)
 170:             1             16  java.lang.invoke.MemberName$Factory (java.base@17.0.8)
 171:             1             16  java.lang.invoke.StringConcatFactory$1 (java.base@17.0.8)
 172:             1             16  java.lang.invoke.StringConcatFactory$2 (java.base@17.0.8)
 173:             1             16  java.lang.invoke.StringConcatFactory$3 (java.base@17.0.8)
 174:             1             16  java.lang.module.ModuleDescriptor$1 (java.base@17.0.8)
 175:             1             16  java.lang.ref.Cleaner (java.base@17.0.8)
 176:             1             16  java.lang.ref.Cleaner$1 (java.base@17.0.8)
 177:             1             16  java.lang.ref.Reference$1 (java.base@17.0.8)
 178:             1             16  java.lang.reflect.ReflectAccess (java.base@17.0.8)
 179:             1             16  java.net.URI$1 (java.base@17.0.8)
 180:             1             16  java.net.URL$3 (java.base@17.0.8)
 181:             1             16  java.net.URL$DefaultFactory (java.base@17.0.8)
 182:             1             16  java.nio.Buffer$1 (java.base@17.0.8)
 183:             1             16  java.security.ProtectionDomain$JavaSecurityAccessImpl (java.base@17.0.8)
 184:             1             16  java.security.SecureClassLoader$CodeSourceKey (java.base@17.0.8)
 185:             1             16  java.util.Collections$EmptyList (java.base@17.0.8)
 186:             1             16  java.util.Collections$EmptySet (java.base@17.0.8)
 187:             1             16  java.util.HashMap$EntrySet (java.base@17.0.8)
 188:             1             16  java.util.Optional (java.base@17.0.8)
 189:             1             16  java.util.WeakHashMap$KeySet (java.base@17.0.8)
 190:             1             16  jdk.internal.misc.ScopedMemoryAccess (java.base@17.0.8)
 191:             1             16  jdk.internal.misc.Unsafe (java.base@17.0.8)
 192:             1             16  jdk.internal.module.ArchivedBootLayer (java.base@17.0.8)
 193:             1             16  jdk.internal.module.ModuleLoaderMap$Mapper (java.base@17.0.8)
 194:             1             16  jdk.internal.module.ModulePatcher (java.base@17.0.8)
 195:             1             16  jdk.internal.module.ModuleTarget (java.base@17.0.8)
 196:             1             16  jdk.internal.reflect.ReflectionFactory (java.base@17.0.8)
 197:             1             16  sun.net.www.protocol.file.Handler (java.base@17.0.8)
Total         32554       83383480