requesttimedout_ping_sinfor dlan连接失败(3)

000000da6bf0da48 000000da0aac3ea0 System.Threading.ThreadAbortException

000000da6bf0db30 000000da0aac3ea0 System.Threading.ThreadAbortException

000000da6bf0dc98 000000da0aa93c90 System.Web.HttpContext

000000da6bf0dca0 000000da0aac3498 System.ComponentModel.EventHandlerList

000000da6bf0dd70 000000da0aac3498 System.ComponentModel.EventHandlerList

000000da6bf0dd90 000000da0aa93c90 System.Web.HttpContext

从这个调用栈上我们可以看出来这个异常来自于Thread::UserSleep -> Thread::HandleThreadInterrupt ->Thread::HandleThreadAbort

由于这个调用栈是CLR非托管代码，我们需要一份.NETFrameworkCLR的源代码作为参考，可以到微软下载一份Share Source CLI。找到\sscli20_20060311\sscli20\clr\src\vm\threads.cpp这个源文件，这个类封装的一系列CLR线程相关的属性和方法。

因为我们调用了Sleep方法，首先看一下Sleep函数的实现。原来线程调用Sleep方法之后进入系统内核，内核将其置于等待状态，一旦CLRSleepEx返回WAIT_IO_COMPLETION并且通过m_State & TS_Interrupted两个标志位来判断是interrupt的话，系统将开始执行HandleThreadInterrupt方法，进而在HandleThreadInterrupt方法中抛出ThreadAbortException。

// Implementation of Thread.Sleep().
void Thread::UserSleep(INT32 time)
{
    CONTRACTL {
        THROWS;
        GC_TRIGGERS;
    }
    CONTRACTL_END;

    INCONTRACT(_ASSERTE(!GetThread()->GCNoTrigger()));

    DWORD   res;

    GCX_PREEMP();

    // A word about ordering for Interrupt.  If someone tries to interrupt a thread
    // that's in the interruptible state, we queue an APC.  But if they try to interrupt
    // a thread that's not in the interruptible state, we just record that fact.  So
    // we have to set TS_Interruptible before we test to see whether someone wants to
    // interrupt us or else we have a race condition that causes us to skip the APC.
    FastInterlockOr((ULONG *) &m_State, TS_Interruptible);

    // If someone has interrupted us, we should not enter the wait.
    if (IsUserInterrupted())
    {
        HandleThreadInterrupt(FALSE);
    }

    ThreadStateHolder tsh(TRUE, TS_Interruptible | TS_Interrupted);

    FastInterlockAnd((ULONG *) &m_State, ~TS_Interrupted);

retry:

    res = ClrSleepEx (time, TRUE);

    if (res == WAIT_IO_COMPLETION)
    {
        // We could be woken by some spurious APC or an EE APC queued to
        // interrupt us. In the latter case the TS_Interrupted bit will be set
        // in the thread state bits. Otherwise we just go back to sleep again.
        if ((m_State & TS_Interrupted))
        {
            HandleThreadInterrupt(FALSE);
        }

        // Don't bother with accurate accounting here.  Just ensure we make progress.
        // Note that this is not us doing the APC.
        if (time == 0)
        {
            res = WAIT_TIMEOUT;
        }
        else
        {
            if (time != (INT32) INFINITE)
            {
                time--;
            }

            goto retry;
        }
    }
    _ASSERTE(res == WAIT_TIMEOUT || res == WAIT_OECT_0);
}

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