From 3ae2132f422286c745ba221dc1076475957fc2f8 Mon Sep 17 00:00:00 2001 From: sebres Date: Tue, 11 Apr 2017 18:09:38 +0000 Subject: added wake-up event to prevent possible dead-locks by some waiting thread (e. g. for writable events) --- win/tclWinInt.h | 6 ++++-- win/tclWinPipe.c | 35 +++++++++++++++++++++++------------ 2 files changed, 27 insertions(+), 14 deletions(-) diff --git a/win/tclWinInt.h b/win/tclWinInt.h index 8ce4152..67b00a8 100644 --- a/win/tclWinInt.h +++ b/win/tclWinInt.h @@ -110,6 +110,7 @@ typedef struct TclPipeThreadInfo { * used as signal to stop (state set to -1) */ volatile LONG state; /* Indicates current state of the thread */ ClientData clientData; /* Referenced data of the main thread */ + HANDLE evWakeUp; /* Optional wake-up event worker set by shutdown */ } TclPipeThreadInfo; @@ -134,7 +135,8 @@ typedef struct TclPipeThreadInfo { MODULE_SCOPE -TclPipeThreadInfo * TclPipeThreadCreateTI(TclPipeThreadInfo **pipeTIPtr, ClientData clientData); +TclPipeThreadInfo * TclPipeThreadCreateTI(TclPipeThreadInfo **pipeTIPtr, + ClientData clientData, HANDLE wakeEvent); MODULE_SCOPE int TclPipeThreadWaitForSignal(TclPipeThreadInfo **pipeTIPtr); static inline void @@ -147,7 +149,7 @@ TclPipeThreadSignal( } }; -MODULE_SCOPE int TclPipeThreadStopSignal(TclPipeThreadInfo **pipeTIPtr); +MODULE_SCOPE int TclPipeThreadStopSignal(TclPipeThreadInfo **pipeTIPtr, HANDLE wakeEvent); MODULE_SCOPE void TclPipeThreadStop(TclPipeThreadInfo **pipeTIPtr, HANDLE hThread); MODULE_SCOPE void TclPipeThreadExit(TclPipeThreadInfo **pipeTIPtr); diff --git a/win/tclWinPipe.c b/win/tclWinPipe.c index 4b4e68d..528f950 100644 --- a/win/tclWinPipe.c +++ b/win/tclWinPipe.c @@ -1564,7 +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(); @@ -1593,7 +1592,7 @@ TclpCreateCommandChannel( infoPtr->readable = CreateEvent(NULL, TRUE, TRUE, NULL); infoPtr->readThread = CreateThread(NULL, 256, PipeReaderThread, - TclPipeThreadCreateTI(&infoPtr->readTI, infoPtr), 0, &id); + TclPipeThreadCreateTI(&infoPtr->readTI, infoPtr, NULL), 0, NULL); SetThreadPriority(infoPtr->readThread, THREAD_PRIORITY_HIGHEST); infoPtr->validMask |= TCL_READABLE; } else { @@ -1607,7 +1606,8 @@ TclpCreateCommandChannel( infoPtr->writable = CreateEvent(NULL, TRUE, TRUE, NULL); infoPtr->writeThread = CreateThread(NULL, 256, PipeWriterThread, - TclPipeThreadCreateTI(&infoPtr->writeTI, infoPtr), 0, &id); + TclPipeThreadCreateTI(&infoPtr->writeTI, infoPtr, infoPtr->writable), + 0, NULL); SetThreadPriority(infoPtr->writeThread, THREAD_PRIORITY_HIGHEST); infoPtr->validMask |= TCL_WRITABLE; } else { @@ -1835,7 +1835,7 @@ PipeClose2Proc( if ((pipePtr->flags & PIPE_ASYNC) && TclInExit()) { /* give it a chance to leave honorably */ - TclPipeThreadStopSignal(&pipePtr->writeTI); + TclPipeThreadStopSignal(&pipePtr->writeTI, pipePtr->writable); if (WaitForSingleObject(pipePtr->writable, 20) == WAIT_TIMEOUT) { return EWOULDBLOCK; @@ -2840,7 +2840,7 @@ PipeWriterThread( { TclPipeThreadInfo *pipeTI = (TclPipeThreadInfo *)arg; PipeInfo *infoPtr = NULL; /* access info only after success init/wait */ - HANDLE handle = NULL, writable = NULL; + HANDLE handle = NULL; DWORD count, toWrite; char *buf; int done = 0; @@ -2851,16 +2851,12 @@ PipeWriterThread( */ if (!TclPipeThreadWaitForSignal(&pipeTI)) { /* exit */ - if (writable) { - SetEvent(writable); - } break; } if (!infoPtr) { infoPtr = (PipeInfo *)pipeTI->clientData; handle = ((WinFile *) infoPtr->writeFile)->handle; - writable = infoPtr->writable; } buf = infoPtr->writeBuf; @@ -2886,7 +2882,7 @@ PipeWriterThread( * waking up the notifier thread. */ - SetEvent(writable); + SetEvent(infoPtr->writable); /* * Alert the foreground thread. Note that we need to treat this like a @@ -3075,7 +3071,8 @@ TclpOpenTemporaryFile( TclPipeThreadInfo * TclPipeThreadCreateTI( TclPipeThreadInfo **pipeTIPtr, - ClientData clientData) + ClientData clientData, + HANDLE wakeEvent) { TclPipeThreadInfo *pipeTI; #ifndef _PTI_USE_CKALLOC @@ -3086,6 +3083,7 @@ TclPipeThreadCreateTI( pipeTI->evControl = CreateEvent(NULL, FALSE, FALSE, NULL); pipeTI->state = PTI_STATE_IDLE; pipeTI->clientData = clientData; + pipeTI->evWakeUp = wakeEvent; return (*pipeTIPtr = pipeTI); } @@ -3113,10 +3111,13 @@ TclPipeThreadWaitForSignal( 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. */ @@ -3153,6 +3154,11 @@ 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; } @@ -3175,7 +3181,7 @@ end: int TclPipeThreadStopSignal( - TclPipeThreadInfo **pipeTIPtr) + TclPipeThreadInfo **pipeTIPtr, HANDLE wakeEvent) { TclPipeThreadInfo *pipeTI = *pipeTIPtr; HANDLE evControl; @@ -3185,6 +3191,7 @@ TclPipeThreadStopSignal( return 1; } evControl = pipeTI->evControl; + pipeTI->evWakeUp = wakeEvent; switch ( (state = InterlockedCompareExchange(&pipeTI->state, PTI_STATE_STOP, PTI_STATE_IDLE)) @@ -3248,6 +3255,7 @@ TclPipeThreadStop( } pipeTI = *pipeTIPtr; evControl = pipeTI->evControl; + pipeTI->evWakeUp = NULL; /* * Try to sane stop the pipe worker, corresponding its current state */ @@ -3414,6 +3422,9 @@ TclPipeThreadExit( 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 -- cgit v0.12