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-rw-r--r--win/tclWinPipe.c621
1 files changed, 457 insertions, 164 deletions
diff --git a/win/tclWinPipe.c b/win/tclWinPipe.c
index 4775418..4a1e75a 100644
--- a/win/tclWinPipe.c
+++ b/win/tclWinPipe.c
@@ -109,24 +109,17 @@ typedef struct PipeInfo {
Tcl_ThreadId threadId; /* Thread to which events should be reported.
* This value is used by the reader/writer
* threads. */
+ TclPipeThreadInfo *writeTI; /* Thread info of writer and reader, this */
+ TclPipeThreadInfo *readTI; /* structure owned by corresponding thread. */
HANDLE writeThread; /* Handle to writer thread. */
HANDLE readThread; /* Handle to reader thread. */
+
HANDLE writable; /* Manual-reset event to signal when the
* writer thread has finished waiting for the
* current buffer to be written. */
HANDLE readable; /* Manual-reset event to signal when the
* reader thread has finished waiting for
* input. */
- HANDLE startWriter; /* Auto-reset event used by the main thread to
- * signal when the writer thread should
- * attempt to write to the pipe. */
- HANDLE stopWriter; /* Manual-reset event used to alert the reader
- * thread to fall-out and exit */
- HANDLE startReader; /* Auto-reset event used by the main thread to
- * signal when the reader thread should
- * attempt to read from the pipe. */
- HANDLE stopReader; /* Manual-reset event used to alert the reader
- * thread to fall-out and exit */
DWORD writeError; /* An error caused by the last background
* write. Set to 0 if no error has been
* detected. This word is shared with the
@@ -1571,7 +1564,6 @@ TclpCreateCommandChannel(
Tcl_Pid *pidPtr) /* An array of process identifiers. */
{
char channelName[16 + TCL_INTEGER_SPACE];
- DWORD id;
PipeInfo *infoPtr = ckalloc(sizeof(PipeInfo));
PipeInit();
@@ -1599,13 +1591,13 @@ TclpCreateCommandChannel(
*/
infoPtr->readable = CreateEvent(NULL, TRUE, TRUE, NULL);
- infoPtr->startReader = CreateEvent(NULL, FALSE, FALSE, NULL);
- infoPtr->stopReader = CreateEvent(NULL, TRUE, FALSE, NULL);
infoPtr->readThread = CreateThread(NULL, 256, PipeReaderThread,
- infoPtr, 0, &id);
+ TclPipeThreadCreateTI(&infoPtr->readTI, infoPtr, infoPtr->readable),
+ 0, NULL);
SetThreadPriority(infoPtr->readThread, THREAD_PRIORITY_HIGHEST);
infoPtr->validMask |= TCL_READABLE;
} else {
+ infoPtr->readTI = NULL;
infoPtr->readThread = 0;
}
if (writeFile != NULL) {
@@ -1614,12 +1606,14 @@ TclpCreateCommandChannel(
*/
infoPtr->writable = CreateEvent(NULL, TRUE, TRUE, NULL);
- infoPtr->startWriter = CreateEvent(NULL, FALSE, FALSE, NULL);
- infoPtr->stopWriter = CreateEvent(NULL, TRUE, FALSE, NULL);
infoPtr->writeThread = CreateThread(NULL, 256, PipeWriterThread,
- infoPtr, 0, &id);
+ TclPipeThreadCreateTI(&infoPtr->writeTI, infoPtr, infoPtr->writable),
+ 0, NULL);
SetThreadPriority(infoPtr->writeThread, THREAD_PRIORITY_HIGHEST);
infoPtr->validMask |= TCL_WRITABLE;
+ } else {
+ infoPtr->writeTI = NULL;
+ infoPtr->writeThread = 0;
}
/*
@@ -1805,12 +1799,12 @@ PipeClose2Proc(
int errorCode, result;
PipeInfo *infoPtr, **nextPtrPtr;
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
- DWORD exitCode;
+ int inExit = (TclInExit() || TclInThreadExit());
errorCode = 0;
result = 0;
- if ((!flags || flags == TCL_CLOSE_READ) && (pipePtr->readFile != NULL)) {
+ if ((!flags || flags & TCL_CLOSE_READ) && (pipePtr->readFile != NULL)) {
/*
* Clean up the background thread if necessary. Note that this must be
* done before we can close the file, since the thread may be blocking
@@ -1818,55 +1812,10 @@ PipeClose2Proc(
*/
if (pipePtr->readThread) {
- /*
- * The thread may already have closed on its own. Check its exit
- * code.
- */
-
- GetExitCodeThread(pipePtr->readThread, &exitCode);
-
- if (exitCode == STILL_ACTIVE) {
- /*
- * Set the stop event so that if the reader thread is blocked
- * in PipeReaderThread on WaitForMultipleEvents, it will exit
- * cleanly.
- */
-
- SetEvent(pipePtr->stopReader);
-
- /*
- * Wait at most 20 milliseconds for the reader thread to
- * close.
- */
-
- if (WaitForSingleObject(pipePtr->readThread,
- 20) == WAIT_TIMEOUT) {
- /*
- * The thread must be blocked waiting for the pipe to
- * become readable in ReadFile(). There isn't a clean way
- * to exit the thread from this condition. We should
- * terminate the child process instead to get the reader
- * thread to fall out of ReadFile with a FALSE. (below) is
- * not the correct way to do this, but will stay here
- * until a better solution is found.
- *
- * Note that we need to guard against terminating the
- * thread while it is in the middle of Tcl_ThreadAlert
- * because it won't be able to release the notifier lock.
- */
-
- Tcl_MutexLock(&pipeMutex);
-
- /* BUG: this leaks memory */
- TerminateThread(pipePtr->readThread, 0);
- Tcl_MutexUnlock(&pipeMutex);
- }
- }
+ TclPipeThreadStop(&pipePtr->readTI, pipePtr->readThread);
CloseHandle(pipePtr->readThread);
CloseHandle(pipePtr->readable);
- CloseHandle(pipePtr->startReader);
- CloseHandle(pipePtr->stopReader);
pipePtr->readThread = NULL;
}
if (TclpCloseFile(pipePtr->readFile) != 0) {
@@ -1875,80 +1824,34 @@ PipeClose2Proc(
pipePtr->validMask &= ~TCL_READABLE;
pipePtr->readFile = NULL;
}
- if ((!flags || flags & TCL_CLOSE_WRITE)
- && (pipePtr->writeFile != NULL)) {
+ if ((!flags || flags & TCL_CLOSE_WRITE) && (pipePtr->writeFile != NULL)) {
if (pipePtr->writeThread) {
+
/*
* Wait for the writer thread to finish the current buffer, then
* terminate the thread and close the handles. If the channel is
- * nonblocking but blocked during exit, bail out since the worker
+ * nonblocking or may block during exit, bail out since the worker
* thread is not interruptible and we want TIP#398-fast-exit.
*/
- if (TclInExit()
- && (pipePtr->flags & PIPE_ASYNC)) {
+ if ((pipePtr->flags & PIPE_ASYNC) && inExit) {
/* give it a chance to leave honorably */
- SetEvent(pipePtr->stopWriter);
+ TclPipeThreadStopSignal(&pipePtr->writeTI, pipePtr->writable);
- if (WaitForSingleObject(pipePtr->writable, 0) == WAIT_TIMEOUT) {
+ if (WaitForSingleObject(pipePtr->writable, 20) == WAIT_TIMEOUT) {
return EWOULDBLOCK;
}
} else {
- WaitForSingleObject(pipePtr->writable, INFINITE);
+ WaitForSingleObject(pipePtr->writable, inExit ? 5000 : INFINITE);
}
- /*
- * The thread may already have closed on it's own. Check its exit
- * code.
- */
-
- GetExitCodeThread(pipePtr->writeThread, &exitCode);
+ TclPipeThreadStop(&pipePtr->writeTI, pipePtr->writeThread);
- if (exitCode == STILL_ACTIVE) {
- /*
- * Set the stop event so that if the reader thread is blocked
- * in PipeReaderThread on WaitForMultipleEvents, it will exit
- * cleanly.
- */
-
- SetEvent(pipePtr->stopWriter);
-
- /*
- * Wait at most 20 milliseconds for the reader thread to
- * close.
- */
-
- if (WaitForSingleObject(pipePtr->writeThread,
- 20) == WAIT_TIMEOUT) {
- /*
- * The thread must be blocked waiting for the pipe to
- * consume input in WriteFile(). There isn't a clean way
- * to exit the thread from this condition. We should
- * terminate the child process instead to get the writer
- * thread to fall out of WriteFile with a FALSE. (below)
- * is not the correct way to do this, but will stay here
- * until a better solution is found.
- *
- * Note that we need to guard against terminating the
- * thread while it is in the middle of Tcl_ThreadAlert
- * because it won't be able to release the notifier lock.
- */
-
- Tcl_MutexLock(&pipeMutex);
-
- /* BUG: this leaks memory */
- TerminateThread(pipePtr->writeThread, 0);
- Tcl_MutexUnlock(&pipeMutex);
- }
- }
-
- CloseHandle(pipePtr->writeThread);
CloseHandle(pipePtr->writable);
- CloseHandle(pipePtr->startWriter);
- CloseHandle(pipePtr->stopWriter);
+ CloseHandle(pipePtr->writeThread);
pipePtr->writeThread = NULL;
}
if (TclpCloseFile(pipePtr->writeFile) != 0) {
@@ -1983,7 +1886,7 @@ PipeClose2Proc(
}
}
- if ((pipePtr->flags & PIPE_ASYNC) || TclInExit()) {
+ if ((pipePtr->flags & PIPE_ASYNC) || inExit) {
/*
* If the channel is non-blocking or Tcl is being cleaned up, just
* detach the children PIDs, reap them (important if we are in a
@@ -2161,7 +2064,10 @@ PipeOutputProc(
DWORD bytesWritten, timeout;
*errorCode = 0;
- timeout = (infoPtr->flags & PIPE_ASYNC) ? 0 : INFINITE;
+
+ /* avoid blocking if pipe-thread exited */
+ timeout = ((infoPtr->flags & PIPE_ASYNC) || !TclPipeThreadIsAlive(&infoPtr->writeTI)
+ || TclInExit() || TclInThreadExit()) ? 0 : INFINITE;
if (WaitForSingleObject(infoPtr->writable, timeout) == WAIT_TIMEOUT) {
/*
* The writer thread is blocked waiting for a write to complete and
@@ -2202,7 +2108,7 @@ PipeOutputProc(
memcpy(infoPtr->writeBuf, buf, (size_t) toWrite);
infoPtr->toWrite = toWrite;
ResetEvent(infoPtr->writable);
- SetEvent(infoPtr->startWriter);
+ TclPipeThreadSignal(&infoPtr->writeTI);
bytesWritten = toWrite;
} else {
/*
@@ -2712,7 +2618,9 @@ WaitForRead(
* Synchronize with the reader thread.
*/
- timeout = blocking ? INFINITE : 0;
+ /* avoid blocking if pipe-thread exited */
+ timeout = (!blocking || !TclPipeThreadIsAlive(&infoPtr->readTI)
+ || TclInExit() || TclInThreadExit()) ? 0 : INFINITE;
if (WaitForSingleObject(infoPtr->readable, timeout) == WAIT_TIMEOUT) {
/*
* The reader thread is blocked waiting for data and the channel
@@ -2786,7 +2694,7 @@ WaitForRead(
*/
ResetEvent(infoPtr->readable);
- SetEvent(infoPtr->startReader);
+ TclPipeThreadSignal(&infoPtr->readTI);
}
}
@@ -2814,33 +2722,27 @@ static DWORD WINAPI
PipeReaderThread(
LPVOID arg)
{
- PipeInfo *infoPtr = (PipeInfo *)arg;
- HANDLE *handle = ((WinFile *) infoPtr->readFile)->handle;
+ TclPipeThreadInfo *pipeTI = (TclPipeThreadInfo *)arg;
+ PipeInfo *infoPtr = NULL; /* access info only after success init/wait */
+ HANDLE handle = NULL;
DWORD count, err;
int done = 0;
- HANDLE wEvents[2];
- DWORD waitResult;
-
- wEvents[0] = infoPtr->stopReader;
- wEvents[1] = infoPtr->startReader;
while (!done) {
/*
* Wait for the main thread to signal before attempting to wait on the
* pipe becoming readable.
*/
-
- waitResult = WaitForMultipleObjects(2, wEvents, FALSE, INFINITE);
-
- if (waitResult != (WAIT_OBJECT_0 + 1)) {
- /*
- * The start event was not signaled. It might be the stop event or
- * an error, so exit.
- */
-
+ if (!TclPipeThreadWaitForSignal(&pipeTI)) {
+ /* exit */
break;
}
+ if (!infoPtr) {
+ infoPtr = (PipeInfo *)pipeTI->clientData;
+ handle = ((WinFile *) infoPtr->readFile)->handle;
+ }
+
/*
* Try waiting for 0 bytes. This will block until some data is
* available on NT, but will return immediately on Win 95. So, if no
@@ -2860,7 +2762,7 @@ PipeReaderThread(
infoPtr->readFlags |= PIPE_EOF;
done = 1;
} else if (err == ERROR_INVALID_HANDLE) {
- break;
+ done = 1;
}
} else if (count == 0) {
if (ReadFile(handle, &(infoPtr->extraByte), 1, &count, NULL)
@@ -2882,12 +2784,11 @@ PipeReaderThread(
infoPtr->readFlags |= PIPE_EOF;
done = 1;
} else if (err == ERROR_INVALID_HANDLE) {
- break;
+ done = 1;
}
}
}
-
/*
* Signal the main thread by signalling the readable event and then
* waking up the notifier thread.
@@ -2913,6 +2814,12 @@ PipeReaderThread(
Tcl_MutexUnlock(&pipeMutex);
}
+ /*
+ * If state of thread was set to stop, we can sane free info structure,
+ * otherwise it is shared with main thread, so main thread will own it
+ */
+ TclPipeThreadExit(&pipeTI);
+
return 0;
}
@@ -2937,37 +2844,27 @@ static DWORD WINAPI
PipeWriterThread(
LPVOID arg)
{
- PipeInfo *infoPtr = (PipeInfo *)arg;
- HANDLE *handle = ((WinFile *) infoPtr->writeFile)->handle;
+ TclPipeThreadInfo *pipeTI = (TclPipeThreadInfo *)arg;
+ PipeInfo *infoPtr = NULL; /* access info only after success init/wait */
+ HANDLE handle = NULL;
DWORD count, toWrite;
char *buf;
int done = 0;
- HANDLE wEvents[2];
- DWORD waitResult;
-
- wEvents[0] = infoPtr->stopWriter;
- wEvents[1] = infoPtr->startWriter;
while (!done) {
/*
* Wait for the main thread to signal before attempting to write.
*/
-
- waitResult = WaitForMultipleObjects(2, wEvents, FALSE, INFINITE);
-
- if (waitResult != (WAIT_OBJECT_0 + 1)) {
- /*
- * The start event was not signaled. It might be the stop event or
- * an error, so exit.
- */
-
- if (waitResult == WAIT_OBJECT_0) {
- SetEvent(infoPtr->writable);
- }
-
+ if (!TclPipeThreadWaitForSignal(&pipeTI)) {
+ /* exit */
break;
}
+ if (!infoPtr) {
+ infoPtr = (PipeInfo *)pipeTI->clientData;
+ handle = ((WinFile *) infoPtr->writeFile)->handle;
+ }
+
buf = infoPtr->writeBuf;
toWrite = infoPtr->toWrite;
@@ -3011,6 +2908,12 @@ PipeWriterThread(
Tcl_MutexUnlock(&pipeMutex);
}
+ /*
+ * If state of thread was set to stop, we can sane free info structure,
+ * otherwise it is shared with main thread, so main thread will own it.
+ */
+ TclPipeThreadExit(&pipeTI);
+
return 0;
}
@@ -3159,6 +3062,396 @@ TclpOpenTemporaryFile(
}
/*
+ *----------------------------------------------------------------------
+ *
+ * TclPipeThreadCreateTI --
+ *
+ * Creates a thread info structure, can be owned by worker.
+ *
+ * Results:
+ * Pointer to created TI structure.
+ *
+ *----------------------------------------------------------------------
+ */
+
+TclPipeThreadInfo *
+TclPipeThreadCreateTI(
+ TclPipeThreadInfo **pipeTIPtr,
+ ClientData clientData,
+ HANDLE wakeEvent)
+{
+ TclPipeThreadInfo *pipeTI;
+#ifndef _PTI_USE_CKALLOC
+ pipeTI = malloc(sizeof(TclPipeThreadInfo));
+#else
+ pipeTI = ckalloc(sizeof(TclPipeThreadInfo));
+#endif
+ pipeTI->evControl = CreateEvent(NULL, FALSE, FALSE, NULL);
+ pipeTI->state = PTI_STATE_IDLE;
+ pipeTI->clientData = clientData;
+ pipeTI->evWakeUp = wakeEvent;
+ return (*pipeTIPtr = pipeTI);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclPipeThreadWaitForSignal --
+ *
+ * Wait for work/stop signals inside pipe worker.
+ *
+ * Results:
+ * 1 if signaled to work, 0 if signaled to stop.
+ *
+ * Side effects:
+ * If this function returns 0, TI-structure pointer given via pipeTIPtr
+ * may be NULL, so not accessible (can be owned by main thread).
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclPipeThreadWaitForSignal(
+ TclPipeThreadInfo **pipeTIPtr)
+{
+ TclPipeThreadInfo *pipeTI = *pipeTIPtr;
+ LONG state;
+ DWORD waitResult;
+ HANDLE wakeEvent;
+
+ if (!pipeTI) {
+ return 0;
+ }
+
+ wakeEvent = pipeTI->evWakeUp;
+ /*
+ * Wait for the main thread to signal before attempting to do the work.
+ */
+
+ /* reset work state of thread (idle/waiting) */
+ if ((state = InterlockedCompareExchange(&pipeTI->state,
+ PTI_STATE_IDLE, PTI_STATE_WORK)) & (PTI_STATE_STOP|PTI_STATE_END)) {
+ /* end of work, check the owner of structure */
+ goto end;
+ }
+ /* entering wait */
+ waitResult = WaitForSingleObject(pipeTI->evControl, INFINITE);
+
+ if (waitResult != WAIT_OBJECT_0) {
+
+ /*
+ * The control event was not signaled, so end of work (unexpected
+ * behaviour, main thread can be dead?).
+ */
+ goto end;
+ }
+
+ /* try to set work state of thread */
+ if ((state = InterlockedCompareExchange(&pipeTI->state,
+ PTI_STATE_WORK, PTI_STATE_IDLE)) & (PTI_STATE_STOP|PTI_STATE_END)) {
+ /* end of work */
+ goto end;
+ }
+
+ /* signaled to work */
+ return 1;
+
+end:
+ /* end of work, check the owner of the TI structure */
+ if (state != PTI_STATE_STOP) {
+ *pipeTIPtr = NULL;
+ } else {
+ pipeTI->evWakeUp = NULL;
+ }
+ if (wakeEvent) {
+ SetEvent(wakeEvent);
+ }
+ return 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclPipeThreadStopSignal --
+ *
+ * Send stop signal to the pipe worker (without waiting).
+ *
+ * After calling of this function, TI-structure pointer given via pipeTIPtr
+ * may be NULL.
+ *
+ * Results:
+ * 1 if signaled (or pipe-thread is down), 0 if pipe thread still working.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+TclPipeThreadStopSignal(
+ TclPipeThreadInfo **pipeTIPtr, HANDLE wakeEvent)
+{
+ TclPipeThreadInfo *pipeTI = *pipeTIPtr;
+ HANDLE evControl;
+ int state;
+
+ if (!pipeTI) {
+ return 1;
+ }
+ evControl = pipeTI->evControl;
+ pipeTI->evWakeUp = wakeEvent;
+ switch (
+ (state = InterlockedCompareExchange(&pipeTI->state,
+ PTI_STATE_STOP, PTI_STATE_IDLE))
+ ) {
+
+ case PTI_STATE_IDLE:
+
+ /* Thread was idle/waiting, notify it goes teardown */
+ SetEvent(evControl);
+
+ *pipeTIPtr = NULL;
+
+ case PTI_STATE_DOWN:
+
+ return 1;
+
+ default:
+ /*
+ * Thread works currently, we should try to end it, own the TI structure
+ * (because of possible sharing the joint structures with thread)
+ */
+ InterlockedExchange(&pipeTI->state, PTI_STATE_END);
+ break;
+ }
+
+ return 0;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclPipeThreadStop --
+ *
+ * Send stop signal to the pipe worker and wait for thread completion.
+ *
+ * May be combined with TclPipeThreadStopSignal.
+ *
+ * After calling of this function, TI-structure pointer given via pipeTIPtr
+ * is not accessible (owned by pipe worker or released here).
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * Can terminate pipe worker (and / or stop its synchronous operations).
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TclPipeThreadStop(
+ TclPipeThreadInfo **pipeTIPtr,
+ HANDLE hThread)
+{
+ TclPipeThreadInfo *pipeTI = *pipeTIPtr;
+ HANDLE evControl, wakeEvent;
+ int state;
+
+ if (!pipeTI) {
+ return;
+ }
+ pipeTI = *pipeTIPtr;
+ evControl = pipeTI->evControl;
+ wakeEvent = pipeTI->evWakeUp;
+ pipeTI->evWakeUp = NULL;
+ /*
+ * Try to sane stop the pipe worker, corresponding its current state
+ */
+ switch (
+ (state = InterlockedCompareExchange(&pipeTI->state,
+ PTI_STATE_STOP, PTI_STATE_IDLE))
+ ) {
+
+ case PTI_STATE_IDLE:
+
+ /* Thread was idle/waiting, notify it goes teardown */
+ SetEvent(evControl);
+
+ /* we don't need to wait for it at all, thread frees himself (owns the TI structure) */
+ pipeTI = NULL;
+ break;
+
+ case PTI_STATE_STOP:
+ /* already stopped, thread frees himself (owns the TI structure) */
+ pipeTI = NULL;
+ break;
+ case PTI_STATE_DOWN:
+ /* Thread already down (?), do nothing */
+
+ /* we don't need to wait for it, but we should free pipeTI */
+ hThread = NULL;
+ break;
+
+ /* case PTI_STATE_WORK: */
+ default:
+ /*
+ * Thread works currently, we should try to end it, own the TI structure
+ * (because of possible sharing the joint structures with thread)
+ */
+ if ((state = InterlockedCompareExchange(&pipeTI->state,
+ PTI_STATE_END, PTI_STATE_WORK)) == PTI_STATE_DOWN
+ ) {
+ /* we don't need to wait for it, but we should free pipeTI */
+ hThread = NULL;
+ };
+ break;
+ }
+
+ if (pipeTI && hThread) {
+ DWORD exitCode;
+
+ /*
+ * The thread may already have closed on its own. Check its exit
+ * code.
+ */
+
+ GetExitCodeThread(hThread, &exitCode);
+
+ if (exitCode == STILL_ACTIVE) {
+
+ int inExit = (TclInExit() || TclInThreadExit());
+ /*
+ * Set the stop event so that if the pipe thread is blocked
+ * somewhere, it may hereafter sane exit cleanly.
+ */
+
+ SetEvent(evControl);
+
+ /*
+ * Cancel all sync-IO of this thread (may be blocked there).
+ */
+ if (tclWinProcs->cancelSynchronousIo) {
+ tclWinProcs->cancelSynchronousIo(hThread);
+ }
+
+ /*
+ * Wait at most 20 milliseconds for the reader thread to
+ * close (regarding TIP#398-fast-exit).
+ */
+
+ /* if we want TIP#398-fast-exit. */
+ if (WaitForSingleObject(hThread, inExit ? 0 : 20) == WAIT_TIMEOUT) {
+
+ /*
+ * The thread must be blocked waiting for the pipe to
+ * become readable in ReadFile(). There isn't a clean way
+ * to exit the thread from this condition. We should
+ * terminate the child process instead to get the reader
+ * thread to fall out of ReadFile with a FALSE. (below) is
+ * not the correct way to do this, but will stay here
+ * until a better solution is found.
+ *
+ * Note that we need to guard against terminating the
+ * thread while it is in the middle of Tcl_ThreadAlert
+ * because it won't be able to release the notifier lock.
+ *
+ * Also note that terminating threads during their initialization or teardown phase
+ * may result in ntdll.dll's LoaderLock to remain locked indefinitely.
+ * This causes ntdll.dll's LdrpInitializeThread() to deadlock trying to acquire LoaderLock.
+ * LdrpInitializeThread() is executed within new threads to perform
+ * initialization and to execute DllMain() of all loaded dlls.
+ * As a result, all new threads are deadlocked in their initialization phase and never execute,
+ * even though CreateThread() reports successful thread creation.
+ * This results in a very weird process-wide behavior, which is extremely hard to debug.
+ *
+ * THREADS SHOULD NEVER BE TERMINATED. Period.
+ *
+ * But for now, check if thread is exiting, and if so, let it die peacefully.
+ *
+ * Also don't terminate if in exit (otherwise deadlocked in ntdll.dll's).
+ */
+
+ if ( pipeTI->state != PTI_STATE_DOWN
+ && WaitForSingleObject(hThread,
+ inExit ? 50 : 5000) != WAIT_OBJECT_0
+ ) {
+ /* BUG: this leaks memory */
+ if (inExit || !TerminateThread(hThread, 0)) {
+ /* in exit or terminate fails, just give thread a chance to exit */
+ if (InterlockedExchange(&pipeTI->state,
+ PTI_STATE_STOP) != PTI_STATE_DOWN) {
+ pipeTI = NULL;
+ }
+ };
+ }
+ }
+ }
+ }
+
+ *pipeTIPtr = NULL;
+ if (pipeTI) {
+ if (pipeTI->evWakeUp) {
+ SetEvent(pipeTI->evWakeUp);
+ }
+ CloseHandle(pipeTI->evControl);
+ #ifndef _PTI_USE_CKALLOC
+ free(pipeTI);
+ #else
+ ckfree(pipeTI);
+ #endif
+ }
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * TclPipeThreadExit --
+ *
+ * Clean-up for the pipe thread (removes owned TI-structure in worker).
+ *
+ * Should be executed on worker exit, to inform the main thread or
+ * free TI-structure (if owned).
+ *
+ * After calling of this function, TI-structure pointer given via pipeTIPtr
+ * is not accessible (owned by main thread or released here).
+ *
+ * Results:
+ * None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+TclPipeThreadExit(
+ TclPipeThreadInfo **pipeTIPtr)
+{
+ LONG state;
+ TclPipeThreadInfo *pipeTI = *pipeTIPtr;
+ /*
+ * If state of thread was set to stop (exactly), we can sane free its info
+ * structure, otherwise it is shared with main thread, so main thread will
+ * own it.
+ */
+ if (!pipeTI) {
+ return;
+ }
+ *pipeTIPtr = NULL;
+ if ((state = InterlockedExchange(&pipeTI->state,
+ PTI_STATE_DOWN)) == PTI_STATE_STOP) {
+ CloseHandle(pipeTI->evControl);
+ if (pipeTI->evWakeUp) {
+ SetEvent(pipeTI->evWakeUp);
+ }
+ #ifndef _PTI_USE_CKALLOC
+ free(pipeTI);
+ #else
+ ckfree(pipeTI);
+ /* be sure all subsystems used are finalized */
+ Tcl_FinalizeThread();
+ #endif
+ }
+}
+
+/*
* Local Variables:
* mode: c
* c-basic-offset: 4
generated by cgit v0.12 at 2024-07-01 02:26:28 (GMT)