终结器线程 ID

Finalizer Thread Id

我们发现我们的一个 WCF 应用程序存在内存泄漏,我想知道是否有人可以为我澄清一些事情。使用 windbg I 运行 !finalizequeue,它显示每个堆中的数千个对象设置为 "Ready for finalization"。

Heap 0
generation 0 has 464 finalizable objects (0000000033877190->0000000033878010)
generation 1 has 52 finalizable objects (0000000033876ff0->0000000033877190)
generation 2 has 19958 finalizable objects (0000000033850040->0000000033876ff0)
Ready for finalization 228791 objects (0000000033878010->0000000033a36dc8)
------------------------------
Heap 1
generation 0 has 1508 finalizable objects (000000002ee2e168->000000002ee31088)
generation 1 has 91 finalizable objects (000000002ee2de90->000000002ee2e168)
generation 2 has 23498 finalizable objects (000000002ee00040->000000002ee2de90)
Ready for finalization 249421 objects (000000002ee31088->000000002f0182f0)
------------------------------
Heap 2
generation 0 has 66 finalizable objects (00000000292660d0->00000000292662e0)
generation 1 has 63 finalizable objects (0000000029265ed8->00000000292660d0)
generation 2 has 19411 finalizable objects (0000000029240040->0000000029265ed8)
Ready for finalization 238531 objects (00000000292662e0->00000000294380f8)
------------------------------
Heap 3
generation 0 has 510 finalizable objects (0000000034e470d8->0000000034e480c8)
generation 1 has 77 finalizable objects (0000000034e46e70->0000000034e470d8)
generation 2 has 19910 finalizable objects (0000000034e20040->0000000034e46e70)
Ready for finalization 226933 objects (0000000034e480c8->0000000035003470)
Statistics for all finalizable objects (including all objects ready for finalization):

这告诉我终结器线程卡住了。所以我 运行 windbg 中的 !Threads 命令获取终结器线程 ID,这就是它显示的内容....

ThreadCount:      2969
UnstartedThread:  0
BackgroundThread: 187
PendingThread:    0
DeadThread:       2782
Hosted Runtime:   no
                                                                                                        Lock  
       ID OSID ThreadOBJ           State GC Mode     GC Alloc Context                  Domain           Count Apt Exception
XXXX    2 19e8 0000000001f64b10 80039220 Preemptive  0000000000000000:0000000000000000 000000000d4aacb0 0     Ukn (Finalizer) 
  18    3  cb4 000000000d9bf7a0  102a220 Preemptive  0000000000000000:0000000000000000 000000000150e940 0     MTA (Threadpool Worker) 
  19    4 1a24 000000000f762720    21220 Preemptive  0000000000000000:0000000000000000 000000000150e940 0     Ukn 
  20    6  e1c 0000000010f4eae0  3029220 Preemptive  0000000000000000:0000000000000000 000000000d4aacb0 0     MTA (Threadpool Worker) 
  22   48 1548 000000001feb1880    21220 Preemptive  0000000000000000:0000000000000000 000000000150e940 0     Ukn 
  23   49 11a4 000000001feb2050    21220 Preemptive  0000000000000000:0000000000000000 000000000150e940 0     Ukn 
  24   50  a64 000000001feb2820    21220 Preemptive  0000000000000000:0000000000000000 000000000150e940 0     Ukn 

列表中的第一个线程是终结器线程,线程 ID 是 XXXX。那是什么意思?我猜这意味着线程不再存在,或者不是 运行。有人可以确认或纠正我的理解吗?

更新

我 运行 ~2s;kb 命令,如评论中建议的 Kjell Gunnar,这是输出。

0:028> ~2s;kb
ntdll!ZwRemoveIoCompletion+0xa:
00000000`77c1bdca c3              ret
RetAddr           : Args to Child                                                           : Call Site
000007fe`fe0e16ad : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : ntdll!ZwRemoveIoCompletion+0xa
00000000`776f9991 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : KERNELBASE!GetQueuedCompletionStatus+0x39
000007fe`fb7f6bb1 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : kernel32!GetQueuedCompletionStatusStub+0x11
00000000`777059cd : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : nativerd!NOTIFICATION_THREAD::ThreadProc+0x71
00000000`77bfa561 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : kernel32!BaseThreadInitThunk+0xd
00000000`00000000 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : ntdll!RtlUserThreadStart+0x1d 

ZwRemoveIoCompletion 是什么意思?

您看到的前三列是

  • WinDbg 线程 ID。你可以例如在 ~xs 命令中使用它,其中 x 是线程的 ID。
  • CLR 线程 ID,它与 .NET 堆上的 Thread 个对象相关(尝试 !dumpheap -type Thread,然后在线程对象上 !do,查看 m_ManagedThreadId ).我从未找到真正的用例。
  • 内核线程 ID,也由许多其他工具显示,例如任务管理器或进程资源管理器

有一些特殊情况,您似乎 运行 属于其中之一。如果第一列显示 XXXX,.NET 没有分配固定物理 OS 线程。对于由 .NET 运行时管理的线程,例如来自线程池的线程。在某个时间点,它可能会再次获得物理线程。

此外,似乎有些情况下 .NET 仍然记得 OS 线程(以下示例的第一行,OS ID f28),而当它不记得时(第二、三行,其中OS ID为0):

XXXX    3  f28 00000087c5f974c0 80030228 Preemptive  00000087C6033180:00000087C6033FD0 00000087c4213450 0     Ukn 
XXXX    4    0 00000087c5fa24b0    39820 Preemptive  0000000000000000:0000000000000000 00000087c4213450 0     MTA 
XXXX    5    0 00000087c5fd0eb0    39820 Preemptive  0000000000000000:0000000000000000 00000087c4213450 0     MTA 

通常 OS 线程 ID 很有用,因为它与 ~ 的输出相关(1098 是进程 ID)。但是,在我的转储文件中,没有 ID 为 f28:

的本机线程
0:009> ~
   0  Id: 1098.564 Suspend: 0 Teb: 000007f5`ffd3d000 Unfrozen
   1  Id: 1098.1e98 Suspend: 0 Teb: 000007f5`ffd3b000 Unfrozen
   2  Id: 1098.1d6c Suspend: 0 Teb: 000007f5`ffd39000 Unfrozen
   3  Id: 1098.458 Suspend: 0 Teb: 000007f5`ffd35000 Unfrozen
   4  Id: 1098.13d4 Suspend: 0 Teb: 000007f5`ffd33000 Unfrozen
   5  Id: 1098.1b20 Suspend: 0 Teb: 000007f5`ffb5e000 Unfrozen
   6  Id: 1098.80c Suspend: 0 Teb: 000007f5`ffb52000 Unfrozen
   7  Id: 1098.944 Suspend: 0 Teb: 000007f5`ffb5c000 Unfrozen
   8  Id: 1098.90 Suspend: 0 Teb: 000007f5`ffb5a000 Unfrozen
.  9  Id: 1098.1738 Suspend: 0 Teb: 000007f5`ffb58000 Unfrozen

您可以检查的一件事是线程状态,在您的情况下报告为 80039220。这给了我们:

0:009> !ThreadState 80039220
    Legal to Join
    Background
    CLR Owns
    In Multi Threaded Apartment
    Reported Dead
    Fully initialized
    Detached

Reported dead似乎印证了你的悲伤