tclwinpipe.c

这是leon3处理器的交叉编译链

		SetEvent(pipePtr->stopReader);

		/*
		 * Wait at most 10 milliseconds for the reader thread to close.
		 */

		WaitForSingleObject(pipePtr->readThread, 10);
		GetExitCodeThread(pipePtr->readThread, &exitCode);

		if (exitCode == STILL_ACTIVE) {
		    /*
		     * 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);

		    /* Wait for the thread to terminate. */
		    WaitForSingleObject(pipePtr->readThread, INFINITE);

		    Tcl_MutexUnlock(&pipeMutex);
		}
	    }

	    CloseHandle(pipePtr->readThread);
	    CloseHandle(pipePtr->readable);
	    CloseHandle(pipePtr->startReader);
	    CloseHandle(pipePtr->stopReader);
	    pipePtr->readThread = NULL;
	}
	if (TclpCloseFile(pipePtr->readFile) != 0) {
	    errorCode = errno;
	}
	pipePtr->validMask &= ~TCL_READABLE;
	pipePtr->readFile = NULL;
    }
    if ((!flags || (flags & TCL_CLOSE_WRITE))
	    && (pipePtr->writeFile != NULL)) {
	/*
	 * Wait for the writer thread to finish the current buffer, then
	 * terminate the thread and close the handles.  If the channel is
	 * nonblocking, there should be no pending write operations.
	 */

	if (pipePtr->writeThread) {
	    WaitForSingleObject(pipePtr->writable, INFINITE);

	    /*
	     * Forcibly terminate the background thread.  We cannot rely on the
	     * thread to cleanly terminate itself because we have no way of
	     * closing the pipe handle without blocking in the case where the
	     * thread is in the middle of an I/O operation.  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);
	    TerminateThread(pipePtr->writeThread, 0);

	    /*
	     * Wait for the thread to terminate.  This ensures that we are
	     * completely cleaned up before we leave this function. 
	     */

	    WaitForSingleObject(pipePtr->writeThread, INFINITE);
	    Tcl_MutexUnlock(&pipeMutex);


	    CloseHandle(pipePtr->writeThread);
	    CloseHandle(pipePtr->writable);
	    CloseHandle(pipePtr->startWriter);
	    pipePtr->writeThread = NULL;
	}
	if (TclpCloseFile(pipePtr->writeFile) != 0) {
	    if (errorCode == 0) {
		errorCode = errno;
	    }
	}
	pipePtr->validMask &= ~TCL_WRITABLE;
	pipePtr->writeFile = NULL;
    }

    pipePtr->watchMask &= pipePtr->validMask;

    /*
     * Don't free the channel if any of the flags were set.
     */

    if (flags) {
	return errorCode;
    }

    /*
     * Remove the file from the list of watched files.
     */

    for (nextPtrPtr = &(tsdPtr->firstPipePtr), infoPtr = *nextPtrPtr;
	    infoPtr != NULL;
	    nextPtrPtr = &infoPtr->nextPtr, infoPtr = *nextPtrPtr) {
	if (infoPtr == (PipeInfo *)pipePtr) {
	    *nextPtrPtr = infoPtr->nextPtr;
	    break;
	}
    }

    /*
     * Wrap the error file into a channel and give it to the cleanup
     * routine.
     */

    if (pipePtr->errorFile) {
	WinFile *filePtr;

	filePtr = (WinFile*)pipePtr->errorFile;
	errChan = Tcl_MakeFileChannel((ClientData) filePtr->handle,
		TCL_READABLE);
	ckfree((char *) filePtr);
    } else {
        errChan = NULL;
    }

    result = TclCleanupChildren(interp, pipePtr->numPids, pipePtr->pidPtr,
            errChan);

    if (pipePtr->numPids > 0) {
        ckfree((char *) pipePtr->pidPtr);
    }

    if (pipePtr->writeBuf != NULL) {
	ckfree(pipePtr->writeBuf);
    }

    ckfree((char*) pipePtr);

    if (errorCode == 0) {
        return result;
    }
    return errorCode;
}

/*
 *----------------------------------------------------------------------
 *
 * PipeInputProc --
 *
 *	Reads input from the IO channel into the buffer given. Returns
 *	count of how many bytes were actually read, and an error indication.
 *
 * Results:
 *	A count of how many bytes were read is returned and an error
 *	indication is returned in an output argument.
 *
 * Side effects:
 *	Reads input from the actual channel.
 *
 *----------------------------------------------------------------------
 */

static int
PipeInputProc(
    ClientData instanceData,		/* Pipe state. */
    char *buf,				/* Where to store data read. */
    int bufSize,			/* How much space is available
                                         * in the buffer? */
    int *errorCode)			/* Where to store error code. */
{
    PipeInfo *infoPtr = (PipeInfo *) instanceData;
    WinFile *filePtr = (WinFile*) infoPtr->readFile;
    DWORD count, bytesRead = 0;
    int result;

    *errorCode = 0;
    /*
     * Synchronize with the reader thread.
     */

    result = WaitForRead(infoPtr, (infoPtr->flags & PIPE_ASYNC) ? 0 : 1);

    /*
     * If an error occurred, return immediately.
     */

    if (result == -1) {
	*errorCode = errno;
	return -1;
    }

    if (infoPtr->readFlags & PIPE_EXTRABYTE) {
	/*
	 * The reader thread consumed 1 byte as a side effect of
	 * waiting so we need to move it into the buffer.
	 */

	*buf = infoPtr->extraByte;
	infoPtr->readFlags &= ~PIPE_EXTRABYTE;
	buf++;
	bufSize--;
	bytesRead = 1;

	/*
	 * If further read attempts would block, return what we have.
	 */

	if (result == 0) {
	    return bytesRead;
	}
    }

    /*
     * Attempt to read bufSize bytes.  The read will return immediately
     * if there is any data available.  Otherwise it will block until
     * at least one byte is available or an EOF occurs.
     */

    if (ReadFile(filePtr->handle, (LPVOID) buf, (DWORD) bufSize, &count,
	    (LPOVERLAPPED) NULL) == TRUE) {
	return bytesRead + count;
    } else if (bytesRead) {
	/*
	 * Ignore errors if we have data to return.
	 */

	return bytesRead;
    }

    TclWinConvertError(GetLastError());
    if (errno == EPIPE) {
	infoPtr->readFlags |= PIPE_EOF;
	return 0;
    }
    *errorCode = errno;
    return -1;
}

/*
 *----------------------------------------------------------------------
 *
 * PipeOutputProc --
 *
 *	Writes the given output on the IO channel. Returns count of how
 *	many characters were actually written, and an error indication.
 *
 * Results:
 *	A count of how many characters were written is returned and an
 *	error indication is returned in an output argument.
 *
 * Side effects:
 *	Writes output on the actual channel.
 *
 *----------------------------------------------------------------------
 */

static int
PipeOutputProc(
    ClientData instanceData,		/* Pipe state. */
    CONST char *buf,			/* The data buffer. */
    int toWrite,			/* How many bytes to write? */
    int *errorCode)			/* Where to store error code. */
{
    PipeInfo *infoPtr = (PipeInfo *) instanceData;
    WinFile *filePtr = (WinFile*) infoPtr->writeFile;
    DWORD bytesWritten, timeout;
    
    *errorCode = 0;
    timeout = (infoPtr->flags & PIPE_ASYNC) ? 0 : INFINITE;
    if (WaitForSingleObject(infoPtr->writable, timeout) == WAIT_TIMEOUT) {
	/*
	 * The writer thread is blocked waiting for a write to complete
	 * and the channel is in non-blocking mode.
	 */

	errno = EAGAIN;
	goto error;
    }
    
    /*
     * Check for a background error on the last write.
     */

    if (infoPtr->writeError) {
	TclWinConvertError(infoPtr->writeError);
	infoPtr->writeError = 0;
	goto error;
    }

    if (infoPtr->flags & PIPE_ASYNC) {
	/*
	 * The pipe is non-blocking, so copy the data into the output
	 * buffer and restart the writer thread.
	 */

	if (toWrite > infoPtr->writeBufLen) {
	    /*
	     * Reallocate the buffer to be large enough to hold the data.
	     */

	    if (infoPtr->writeBuf) {
		ckfree(infoPtr->writeBuf);
	    }
	    infoPtr->writeBufLen = toWrite;
	    infoPtr->writeBuf = ckalloc((unsigned int) toWrite);
	}
	memcpy(infoPtr->writeBuf, buf, (size_t) toWrite);
	infoPtr->toWrite = toWrite;
	ResetEvent(infoPtr->writable);
	SetEvent(infoPtr->startWriter);
	bytesWritten = toWrite;
    } else {
	/*
	 * In the blocking case, just try to write the buffer directly.
	 * This avoids an unnecessary copy.
	 */

	if (WriteFile(filePtr->handle, (LPVOID) buf, (DWORD) toWrite,
		&bytesWritten, (LPOVERLAPPED) NULL) == FALSE) {
	    TclWinConvertError(GetLastError());
	    goto error;
	}
    }
    return bytesWritten;

    error:
    *errorCode = errno;
    return -1;

}

/*
 *----------------------------------------------------------------------
 *
 * PipeEventProc --
 *
 *	This function is invoked by Tcl_ServiceEvent when a file event
 *	reaches the front of the event queue.  This procedure invokes
 *	Tcl_NotifyChannel on the pipe.
 *
 * Results:
 *	Returns 1 if the event was handled, meaning it should be removed
 *	from the queue.  Returns 0 if the event was not handled, meaning
 *	it should stay on the queue.  The only time the event isn't
 *	handled is if the TCL_FILE_EVENTS flag bit isn't set.
 *
 * Side effects:
 *	Whatever the notifier callback does.
 *
 *----------------------------------------------------------------------
 */

static int
PipeEventProc(
    Tcl_Event *evPtr,		/* Event to service. */
    int flags)			/* Flags that indicate what events to
				 * handle, such as TCL_FILE_EVENTS. */
{
    PipeEvent *pipeEvPtr = (PipeEvent *)evPtr;
    PipeInfo *infoPtr;
    WinFile *filePtr;
    int mask;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    if (!(flags & TCL_FILE_EVENTS)) {
	return 0;
    }

    /*
     * Search through the list of watched pipes for the one whose handle
     * matches the event.  We do this rather than simply dereferencing
     * the handle in the event so that pipes can be deleted while the
     * event is in the queue.
     */

    for (infoPtr = tsdPtr->firstPipePtr; infoPtr != NULL;
	    infoPtr = infoPtr->nextPtr) {
	if (pipeEvPtr->infoPtr == infoPtr) {
	    infoPtr->flags &= ~(PIPE_PENDING);
	    break;
	}
    }

    /*
     * Remove stale events.
     */

    if (!infoPtr) {
	return 1;
    }

    /*
     * Check to see if the pipe is readable.  Note
     * that we can't tell if a pipe is writable, so we always report it
     * as being writable unless we have detected EOF.
     */

    filePtr = (WinFile*) ((PipeInfo*)infoPtr)->writeFile;
    mask = 0;
    if ((infoPtr->watchMask & TCL_WRITABLE) &&
	    (WaitForSingleObject(infoPtr->writable, 0) != WAIT_TIMEOUT)) {
	mask = TCL_WRITABLE;
    }

    filePtr = (WinFile*) ((PipeInfo*)infoPtr)->readFile;
    if ((infoPtr->watchMask & TCL_READABLE) &&
	    (WaitForRead(infoPtr, 0) >= 0)) {
	if (infoPtr->readFlags & PIPE_EOF) {
	    mask = TCL_READABLE;
	} else {
	    mask |= TCL_READABLE;
	}
    }

    /*
     * Inform the channel of the events.
     */

    Tcl_NotifyChannel(infoPtr->channel, infoPtr->watchMask & mask);
    return 1;
}

/*
 *----------------------------------------------------------------------
 *
 * PipeWatchProc --
 *
 *	Called by the notifier to set up to watch for events on this
 *	channel.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static void
PipeWatchProc(
    ClientData instanceData,		/* Pipe state. */
    int mask)				/* What events to watch for, OR-ed
                                         * combination of TCL_READABLE,
                                         * TCL_WRITABLE and TCL_EXCEPTION. */
{
    PipeInfo **nextPtrPtr, *ptr;
    PipeInfo *infoPtr = (PipeInfo *) instanceData;
    int oldMask = infoPtr->watchMask;
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    /*
     * Since most of the work is handled by the background threads,
     * we just need to update the watchMask and then force the notifier
     * to poll once. 
     */

    infoPtr