/* * tclWinConsole.c -- * * This file implements the Windows-specific console functions, and the * "console" channel driver. * * Copyright (c) 1999 by Scriptics Corp. * * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. */ #include "tclWinInt.h" /* * The following variable is used to tell whether this module has been * initialized. */ static int initialized = 0; /* * The consoleMutex locks around access to the initialized variable, and it is * used to protect background threads from being terminated while they are * using APIs that hold locks. */ TCL_DECLARE_MUTEX(consoleMutex) /* * Bit masks used in the flags field of the ConsoleInfo structure below. */ #define CONSOLE_PENDING (1<<0) /* Message is pending in the queue. */ #define CONSOLE_ASYNC (1<<1) /* Channel is non-blocking. */ /* * Bit masks used in the sharedFlags field of the ConsoleInfo structure below. */ #define CONSOLE_EOF (1<<2) /* Console has reached EOF. */ #define CONSOLE_BUFFERED (1<<3) /* Data was read into a buffer by the reader * thread. */ #define CONSOLE_BUFFER_SIZE (8*1024) /* * Structure containing handles associated with one of the special console * threads. */ typedef struct { HANDLE thread; /* Handle to reader or writer thread. */ HANDLE readyEvent; /* Manual-reset event to signal _to_ the main * thread when the worker thread has finished * waiting for its normal work to happen. */ HANDLE startEvent; /* Auto-reset event used by the main thread to * signal when the thread should attempt to do * its normal work. */ HANDLE stopEvent; /* Auto-reset event used by the main thread to * signal when the thread should exit. */ } ConsoleThreadInfo; /* * This structure describes per-instance data for a console based channel. */ typedef struct ConsoleInfo { HANDLE handle; int type; struct ConsoleInfo *nextPtr;/* Pointer to next registered console. */ Tcl_Channel channel; /* Pointer to channel structure. */ int validMask; /* OR'ed combination of TCL_READABLE, * TCL_WRITABLE, or TCL_EXCEPTION: indicates * which operations are valid on the file. */ int watchMask; /* OR'ed combination of TCL_READABLE, * TCL_WRITABLE, or TCL_EXCEPTION: indicates * which events should be reported. */ int flags; /* State flags, see above for a list. */ Tcl_ThreadId threadId; /* Thread to which events should be reported. * This value is used by the reader/writer * threads. */ ConsoleThreadInfo writer; /* A specialized thread for handling * asynchronous writes to the console; the * waiting starts when a start event is sent, * and a reset event is sent back to the main * thread when the write is done. A stop event * is used to terminate the thread. */ ConsoleThreadInfo reader; /* A specialized thread for handling * asynchronous reads from the console; the * waiting starts when a start event is sent, * and a reset event is sent back to the main * thread when input is available. A stop * event is used to terminate the thread. */ 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 * writer thread so access must be * synchronized with the writable object. */ char *writeBuf; /* Current background output buffer. Access is * synchronized with the writable object. */ int writeBufLen; /* Size of write buffer. Access is * synchronized with the writable object. */ int toWrite; /* Current amount to be written. Access is * synchronized with the writable object. */ int readFlags; /* Flags that are shared with the reader * thread. Access is synchronized with the * readable object. */ int bytesRead; /* Number of bytes in the buffer. */ int offset; /* Number of bytes read out of the buffer. */ char buffer[CONSOLE_BUFFER_SIZE]; /* Data consumed by reader thread. */ } ConsoleInfo; typedef struct{ /* * The following pointer refers to the head of the list of consoles that * are being watched for file events. */ ConsoleInfo *firstConsolePtr; } ThreadSpecificData; static Tcl_ThreadDataKey dataKey; /* * The following structure is what is added to the Tcl event queue when * console events are generated. */ typedef struct { Tcl_Event header; /* Information that is standard for all * events. */ ConsoleInfo *infoPtr; /* Pointer to console info structure. Note * that we still have to verify that the * console exists before dereferencing this * pointer. */ } ConsoleEvent; /* * Declarations for functions used only in this file. */ static int ConsoleBlockModeProc(ClientData instanceData, int mode); static void ConsoleCheckProc(ClientData clientData, int flags); static int ConsoleCloseProc(ClientData instanceData, Tcl_Interp *interp); static int ConsoleEventProc(Tcl_Event *evPtr, int flags); static void ConsoleExitHandler(ClientData clientData); static int ConsoleGetHandleProc(ClientData instanceData, int direction, ClientData *handlePtr); static void ConsoleInit(void); static int ConsoleInputProc(ClientData instanceData, char *buf, int toRead, int *errorCode); static int ConsoleOutputProc(ClientData instanceData, const char *buf, int toWrite, int *errorCode); static DWORD WINAPI ConsoleReaderThread(LPVOID arg); static void ConsoleSetupProc(ClientData clientData, int flags); static void ConsoleWatchProc(ClientData instanceData, int mask); static DWORD WINAPI ConsoleWriterThread(LPVOID arg); static void ProcExitHandler(ClientData clientData); static int WaitForRead(ConsoleInfo *infoPtr, int blocking); static void ConsoleThreadActionProc(ClientData instanceData, int action); static BOOL ReadConsoleBytes(HANDLE hConsole, LPVOID lpBuffer, DWORD nbytes, LPDWORD nbytesread); static BOOL WriteConsoleBytes(HANDLE hConsole, const void *lpBuffer, DWORD nbytes, LPDWORD nbyteswritten); static void StartChannelThread(ConsoleInfo *infoPtr, ConsoleThreadInfo *threadInfoPtr, LPTHREAD_START_ROUTINE threadProc); static void StopChannelThread(ConsoleThreadInfo *threadInfoPtr); /* * This structure describes the channel type structure for command console * based IO. */ static const Tcl_ChannelType consoleChannelType = { "console", /* Type name. */ TCL_CHANNEL_VERSION_5, /* v5 channel */ ConsoleCloseProc, /* Close proc. */ ConsoleInputProc, /* Input proc. */ ConsoleOutputProc, /* Output proc. */ NULL, /* Seek proc. */ NULL, /* Set option proc. */ NULL, /* Get option proc. */ ConsoleWatchProc, /* Set up notifier to watch the channel. */ ConsoleGetHandleProc, /* Get an OS handle from channel. */ NULL, /* close2proc. */ ConsoleBlockModeProc, /* Set blocking or non-blocking mode. */ NULL, /* Flush proc. */ NULL, /* Handler proc. */ NULL, /* Wide seek proc. */ ConsoleThreadActionProc, /* Thread action proc. */ NULL /* Truncation proc. */ }; /* *---------------------------------------------------------------------- * * ReadConsoleBytes, WriteConsoleBytes -- * * Wrapper for ReadConsole{A,W}, that takes and returns number of bytes * instead of number of TCHARS. * *---------------------------------------------------------------------- */ static BOOL ReadConsoleBytes( HANDLE hConsole, LPVOID lpBuffer, DWORD nbytes, LPDWORD nbytesread) { DWORD ntchars; BOOL result; int tcharsize = sizeof(TCHAR); result = ReadConsole(hConsole, lpBuffer, nbytes / tcharsize, &ntchars, NULL); if (nbytesread != NULL) { *nbytesread = ntchars * tcharsize; } return result; } static BOOL WriteConsoleBytes( HANDLE hConsole, const void *lpBuffer, DWORD nbytes, LPDWORD nbyteswritten) { DWORD ntchars; BOOL result; int tcharsize = sizeof(TCHAR); result = WriteConsole(hConsole, lpBuffer, nbytes / tcharsize, &ntchars, NULL); if (nbyteswritten != NULL) { *nbyteswritten = ntchars * tcharsize; } return result; } /* *---------------------------------------------------------------------- * * ConsoleInit -- * * This function initializes the static variables for this file. * * Results: * None. * * Side effects: * Creates a new event source. * *---------------------------------------------------------------------- */ static void ConsoleInit(void) { /* * Check the initialized flag first, then check again in the mutex. This * is a speed enhancement. */ if (!initialized) { Tcl_MutexLock(&consoleMutex); if (!initialized) { initialized = 1; Tcl_CreateExitHandler(ProcExitHandler, NULL); } Tcl_MutexUnlock(&consoleMutex); } if (TclThreadDataKeyGet(&dataKey) == NULL) { ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); tsdPtr->firstConsolePtr = NULL; Tcl_CreateEventSource(ConsoleSetupProc, ConsoleCheckProc, NULL); Tcl_CreateThreadExitHandler(ConsoleExitHandler, NULL); } } /* *---------------------------------------------------------------------- * * ConsoleExitHandler -- * * This function is called to cleanup the console module before Tcl is * unloaded. * * Results: * None. * * Side effects: * Removes the console event source. * *---------------------------------------------------------------------- */ static void ConsoleExitHandler( ClientData clientData) /* Old window proc. */ { Tcl_DeleteEventSource(ConsoleSetupProc, ConsoleCheckProc, NULL); } /* *---------------------------------------------------------------------- * * ProcExitHandler -- * * This function is called to cleanup the process list before Tcl is * unloaded. * * Results: * None. * * Side effects: * Resets the process list. * *---------------------------------------------------------------------- */ static void ProcExitHandler( ClientData clientData) /* Old window proc. */ { Tcl_MutexLock(&consoleMutex); initialized = 0; Tcl_MutexUnlock(&consoleMutex); } /* *---------------------------------------------------------------------- * * ConsoleSetupProc -- * * This procedure is invoked before Tcl_DoOneEvent blocks waiting for an * event. * * Results: * None. * * Side effects: * Adjusts the block time if needed. * *---------------------------------------------------------------------- */ void ConsoleSetupProc( ClientData data, /* Not used. */ int flags) /* Event flags as passed to Tcl_DoOneEvent. */ { ConsoleInfo *infoPtr; Tcl_Time blockTime = { 0, 0 }; int block = 1; ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); if (!(flags & TCL_FILE_EVENTS)) { return; } /* * Look to see if any events are already pending. If they are, poll. */ for (infoPtr = tsdPtr->firstConsolePtr; infoPtr != NULL; infoPtr = infoPtr->nextPtr) { if (infoPtr->watchMask & TCL_WRITABLE) { if (WaitForSingleObject(infoPtr->writer.readyEvent, 0) != WAIT_TIMEOUT) { block = 0; } } if (infoPtr->watchMask & TCL_READABLE) { if (WaitForRead(infoPtr, 0) >= 0) { block = 0; } } } if (!block) { Tcl_SetMaxBlockTime(&blockTime); } } /* *---------------------------------------------------------------------- * * ConsoleCheckProc -- * * This procedure is called by Tcl_DoOneEvent to check the console event * source for events. * * Results: * None. * * Side effects: * May queue an event. * *---------------------------------------------------------------------- */ static void ConsoleCheckProc( ClientData data, /* Not used. */ int flags) /* Event flags as passed to Tcl_DoOneEvent. */ { ConsoleInfo *infoPtr; int needEvent; ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); if (!(flags & TCL_FILE_EVENTS)) { return; } /* * Queue events for any ready consoles that don't already have events * queued. */ for (infoPtr = tsdPtr->firstConsolePtr; infoPtr != NULL; infoPtr = infoPtr->nextPtr) { if (infoPtr->flags & CONSOLE_PENDING) { continue; } /* * Queue an event if the console is signaled for reading or writing. */ needEvent = 0; if (infoPtr->watchMask & TCL_WRITABLE) { if (WaitForSingleObject(infoPtr->writer.readyEvent, 0) != WAIT_TIMEOUT) { needEvent = 1; } } if (infoPtr->watchMask & TCL_READABLE) { if (WaitForRead(infoPtr, 0) >= 0) { needEvent = 1; } } if (needEvent) { ConsoleEvent *evPtr = ckalloc(sizeof(ConsoleEvent)); infoPtr->flags |= CONSOLE_PENDING; evPtr->header.proc = ConsoleEventProc; evPtr->infoPtr = infoPtr; Tcl_QueueEvent((Tcl_Event *) evPtr, TCL_QUEUE_TAIL); } } } /* *---------------------------------------------------------------------- * * ConsoleBlockModeProc -- * * Set blocking or non-blocking mode on channel. * * Results: * 0 if successful, errno when failed. * * Side effects: * Sets the device into blocking or non-blocking mode. * *---------------------------------------------------------------------- */ static int ConsoleBlockModeProc( ClientData instanceData, /* Instance data for channel. */ int mode) /* TCL_MODE_BLOCKING or * TCL_MODE_NONBLOCKING. */ { ConsoleInfo *infoPtr = instanceData; /* * Consoles on Windows can not be switched between blocking and * nonblocking, hence we have to emulate the behavior. This is done in the * input function by checking against a bit in the state. We set or unset * the bit here to cause the input function to emulate the correct * behavior. */ if (mode == TCL_MODE_NONBLOCKING) { infoPtr->flags |= CONSOLE_ASYNC; } else { infoPtr->flags &= ~CONSOLE_ASYNC; } return 0; } /* *---------------------------------------------------------------------- * * StartChannelThread, StopChannelThread -- * * Helpers that codify how to ask one of the console service threads to * start and stop. * *---------------------------------------------------------------------- */ static void StartChannelThread( ConsoleInfo *infoPtr, ConsoleThreadInfo *threadInfoPtr, LPTHREAD_START_ROUTINE threadProc) { DWORD id; threadInfoPtr->readyEvent = CreateEvent(NULL, TRUE, TRUE, NULL); threadInfoPtr->startEvent = CreateEvent(NULL, FALSE, FALSE, NULL); threadInfoPtr->stopEvent = CreateEvent(NULL, FALSE, FALSE, NULL); threadInfoPtr->thread = CreateThread(NULL, 256, threadProc, infoPtr, 0, &id); SetThreadPriority(threadInfoPtr->thread, THREAD_PRIORITY_HIGHEST); } static void StopChannelThread( ConsoleThreadInfo *threadInfoPtr) { DWORD exitCode = 0; /* * The thread may already have closed on it's own. Check it's exit * code. */ GetExitCodeThread(threadInfoPtr->thread, &exitCode); if (exitCode == STILL_ACTIVE) { /* * Set the stop event so that if the reader thread is blocked in * ConsoleReaderThread on WaitForMultipleEvents, it will exit cleanly. */ SetEvent(threadInfoPtr->stopEvent); /* * Wait at most 20 milliseconds for the reader thread to close. */ if (WaitForSingleObject(threadInfoPtr->thread, 20) == WAIT_TIMEOUT) { /* * Forcibly terminate the background thread as a last resort. * 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(&consoleMutex); /* BUG: this leaks memory. */ TerminateThread(threadInfoPtr->thread, 0); Tcl_MutexUnlock(&consoleMutex); } } /* * Close all the handles associated with the thread, and set the thread * handle field to NULL to mark that the thread has been cleaned up. */ CloseHandle(threadInfoPtr->thread); CloseHandle(threadInfoPtr->readyEvent); CloseHandle(threadInfoPtr->startEvent); CloseHandle(threadInfoPtr->stopEvent); threadInfoPtr->thread = NULL; } /* *---------------------------------------------------------------------- * * ConsoleCloseProc -- * * Closes a console based IO channel. * * Results: * 0 on success, errno otherwise. * * Side effects: * Closes the physical channel. * *---------------------------------------------------------------------- */ static int ConsoleCloseProc( ClientData instanceData, /* Pointer to ConsoleInfo structure. */ Tcl_Interp *interp) /* For error reporting. */ { ConsoleInfo *consolePtr = instanceData; int errorCode = 0; ConsoleInfo *infoPtr, **nextPtrPtr; ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); /* * 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 * trying to read from the console. */ if (consolePtr->reader.thread) { StopChannelThread(&consolePtr->reader); } consolePtr->validMask &= ~TCL_READABLE; /* * 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 (consolePtr->writer.thread) { if (consolePtr->toWrite) { /* * We only need to wait if there is something to write. This may * prevent infinite wait on exit. [Python Bug 216289] */ WaitForSingleObject(consolePtr->writer.readyEvent, INFINITE); } StopChannelThread(&consolePtr->writer); } consolePtr->validMask &= ~TCL_WRITABLE; /* * Don't close the Win32 handle if the handle is a standard channel during * the thread exit process. Otherwise, one thread may kill the stdio of * another. */ if (!TclInThreadExit() || ((GetStdHandle(STD_INPUT_HANDLE) != consolePtr->handle) && (GetStdHandle(STD_OUTPUT_HANDLE) != consolePtr->handle) && (GetStdHandle(STD_ERROR_HANDLE) != consolePtr->handle))) { if (CloseHandle(consolePtr->handle) == FALSE) { TclWinConvertError(GetLastError()); errorCode = errno; } } consolePtr->watchMask &= consolePtr->validMask; /* * Remove the file from the list of watched files. */ for (nextPtrPtr = &(tsdPtr->firstConsolePtr), infoPtr = *nextPtrPtr; infoPtr != NULL; nextPtrPtr = &infoPtr->nextPtr, infoPtr = *nextPtrPtr) { if (infoPtr == (ConsoleInfo *) consolePtr) { *nextPtrPtr = infoPtr->nextPtr; break; } } if (consolePtr->writeBuf != NULL) { ckfree(consolePtr->writeBuf); consolePtr->writeBuf = 0; } ckfree(consolePtr); return errorCode; } /* *---------------------------------------------------------------------- * * ConsoleInputProc -- * * 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 ConsoleInputProc( ClientData instanceData, /* Console 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. */ { ConsoleInfo *infoPtr = instanceData; DWORD count, bytesRead = 0; int result; *errorCode = 0; /* * Synchronize with the reader thread. */ result = WaitForRead(infoPtr, (infoPtr->flags & CONSOLE_ASYNC) ? 0 : 1); /* * If an error occurred, return immediately. */ if (result == -1) { *errorCode = errno; return -1; } if (infoPtr->readFlags & CONSOLE_BUFFERED) { /* * Data is stored in the buffer. */ if (bufSize < (infoPtr->bytesRead - infoPtr->offset)) { memcpy(buf, &infoPtr->buffer[infoPtr->offset], (size_t) bufSize); bytesRead = bufSize; infoPtr->offset += bufSize; } else { memcpy(buf, &infoPtr->buffer[infoPtr->offset], (size_t) bufSize); bytesRead = infoPtr->bytesRead - infoPtr->offset; /* * Reset the buffer. */ infoPtr->readFlags &= ~CONSOLE_BUFFERED; infoPtr->offset = 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 (ReadConsoleBytes(infoPtr->handle, (LPVOID) buf, (DWORD) bufSize, &count) == TRUE) { /* * TODO: This potentially writes beyond the limits specified * by the caller. In practice this is harmless, since all writes * are into ChannelBuffers, and those have padding, but still * ought to remove this, unless some Windows wizard can give * a reason not to. */ buf[count] = '\0'; return count; } return -1; } /* *---------------------------------------------------------------------- * * ConsoleOutputProc -- * * 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 ConsoleOutputProc( ClientData instanceData, /* Console state. */ const char *buf, /* The data buffer. */ int toWrite, /* How many bytes to write? */ int *errorCode) /* Where to store error code. */ { ConsoleInfo *infoPtr = instanceData; ConsoleThreadInfo *threadInfo = &infoPtr->reader; DWORD bytesWritten, timeout; *errorCode = 0; timeout = (infoPtr->flags & CONSOLE_ASYNC) ? 0 : INFINITE; if (WaitForSingleObject(threadInfo->readyEvent,timeout) == WAIT_TIMEOUT) { /* * The writer thread is blocked waiting for a write to complete and * the channel is in non-blocking mode. */ errno = EWOULDBLOCK; 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 & CONSOLE_ASYNC) { /* * The console 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(toWrite); } memcpy(infoPtr->writeBuf, buf, (size_t) toWrite); infoPtr->toWrite = toWrite; ResetEvent(threadInfo->readyEvent); SetEvent(threadInfo->startEvent); bytesWritten = toWrite; } else { /* * In the blocking case, just try to write the buffer directly. This * avoids an unnecessary copy. */ if (WriteConsoleBytes(infoPtr->handle, buf, (DWORD) toWrite, &bytesWritten) == FALSE) { TclWinConvertError(GetLastError()); goto error; } } return bytesWritten; error: *errorCode = errno; return -1; } /* *---------------------------------------------------------------------- * * ConsoleEventProc -- * * 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 console. * * 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 ConsoleEventProc( Tcl_Event *evPtr, /* Event to service. */ int flags) /* Flags that indicate what events to handle, * such as TCL_FILE_EVENTS. */ { ConsoleEvent *consoleEvPtr = (ConsoleEvent *) evPtr; ConsoleInfo *infoPtr; int mask; ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); if (!(flags & TCL_FILE_EVENTS)) { return 0; } /* * Search through the list of watched consoles for the one whose handle * matches the event. We do this rather than simply dereferencing the * handle in the event so that consoles can be deleted while the event is * in the queue. */ for (infoPtr = tsdPtr->firstConsolePtr; infoPtr != NULL; infoPtr = infoPtr->nextPtr) { if (consoleEvPtr->infoPtr == infoPtr) { infoPtr->flags &= ~CONSOLE_PENDING; break; } } /* * Remove stale events. */ if (!infoPtr) { return 1; } /* * Check to see if the console is readable. Note that we can't tell if a * console is writable, so we always report it as being writable unless we * have detected EOF. */ mask = 0; if (infoPtr->watchMask & TCL_WRITABLE) { if (WaitForSingleObject(infoPtr->writer.readyEvent, 0) != WAIT_TIMEOUT) { mask = TCL_WRITABLE; } } if (infoPtr->watchMask & TCL_READABLE) { if (WaitForRead(infoPtr, 0) >= 0) { if (infoPtr->readFlags & CONSOLE_EOF) { mask = TCL_READABLE; } else { mask |= TCL_READABLE; } } } /* * Inform the channel of the events. */ Tcl_NotifyChannel(infoPtr->channel, infoPtr->watchMask & mask); return 1; } /* *---------------------------------------------------------------------- * * ConsoleWatchProc -- * * Called by the notifier to set up to watch for events on this channel. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ static void ConsoleWatchProc( ClientData instanceData, /* Console state. */ int mask) /* What events to watch for, OR-ed combination * of TCL_READABLE, TCL_WRITABLE and * TCL_EXCEPTION. */ { ConsoleInfo **nextPtrPtr, *ptr; ConsoleInfo *infoPtr = 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->watchMask = mask & infoPtr->validMask; if (infoPtr->watchMask) { Tcl_Time blockTime = { 0, 0 }; if (!oldMask) { infoPtr->nextPtr = tsdPtr->firstConsolePtr; tsdPtr->firstConsolePtr = infoPtr; } Tcl_SetMaxBlockTime(&blockTime); } else if (oldMask) { /* * Remove the console from the list of watched consoles. */ for (nextPtrPtr = &(tsdPtr->firstConsolePtr), ptr = *nextPtrPtr; ptr != NULL; nextPtrPtr = &ptr->nextPtr, ptr = *nextPtrPtr) { if (infoPtr == ptr) { *nextPtrPtr = ptr->nextPtr; break; } } } } /* *---------------------------------------------------------------------- * * ConsoleGetHandleProc -- * * Called from Tcl_GetChannelHandle to retrieve OS handles from inside a * command consoleline based channel. * * Results: * Returns TCL_OK with the fd in handlePtr, or TCL_ERROR if there is no * handle for the specified direction. * * Side effects: * None. * *---------------------------------------------------------------------- */ static int ConsoleGetHandleProc( ClientData instanceData, /* The console state. */ int direction, /* TCL_READABLE or TCL_WRITABLE. */ ClientData *handlePtr) /* Where to store the handle. */ { ConsoleInfo *infoPtr = instanceData; *handlePtr = infoPtr->handle; return TCL_OK; } /* *---------------------------------------------------------------------- * * WaitForRead -- * * Wait until some data is available, the console is at EOF or the reader * thread is blocked waiting for data (if the channel is in non-blocking * mode). * * Results: * Returns 1 if console is readable. Returns 0 if there is no data on the * console, but there is buffered data. Returns -1 if an error occurred. * If an error occurred, the threads may not be synchronized. * * Side effects: * Updates the shared state flags. If no error occurred, the reader * thread is blocked waiting for a signal from the main thread. * *---------------------------------------------------------------------- */ static int WaitForRead( ConsoleInfo *infoPtr, /* Console state. */ int blocking) /* Indicates whether call should be blocking * or not. */ { DWORD timeout, count; HANDLE *handle = infoPtr->handle; ConsoleThreadInfo *threadInfo = &infoPtr->reader; INPUT_RECORD input; while (1) { /* * Synchronize with the reader thread. */ timeout = blocking ? INFINITE : 0; if (WaitForSingleObject(threadInfo->readyEvent, timeout) == WAIT_TIMEOUT) { /* * The reader thread is blocked waiting for data and the channel * is in non-blocking mode. */ errno = EWOULDBLOCK; return -1; } /* * At this point, the two threads are synchronized, so it is safe to * access shared state. */ /* * If the console has hit EOF, it is always readable. */ if (infoPtr->readFlags & CONSOLE_EOF) { return 1; } if (PeekConsoleInput(handle, &input, 1, &count) == FALSE) { /* * Check to see if the peek failed because of EOF. */ TclWinConvertError(GetLastError()); if (errno == EOF) { infoPtr->readFlags |= CONSOLE_EOF; return 1; } /* * Ignore errors if there is data in the buffer. */ if (infoPtr->readFlags & CONSOLE_BUFFERED) { return 0; } else { return -1; } } /* * If there is data in the buffer, the console must be readable (since * it is a line-oriented device). */ if (infoPtr->readFlags & CONSOLE_BUFFERED) { return 1; } /* * There wasn't any data available, so reset the thread and try again. */ ResetEvent(threadInfo->readyEvent); SetEvent(threadInfo->startEvent); } } /* *---------------------------------------------------------------------- * * ConsoleReaderThread -- * * This function runs in a separate thread and waits for input to become * available on a console. * * Results: * None. * * Side effects: * Signals the main thread when input become available. May cause the * main thread to wake up by posting a message. May one line from the * console for each wait operation. * *---------------------------------------------------------------------- */ static DWORD WINAPI ConsoleReaderThread( LPVOID arg) { ConsoleInfo *infoPtr = arg; HANDLE *handle = infoPtr->handle; ConsoleThreadInfo *threadInfo = &infoPtr->reader; DWORD waitResult; HANDLE wEvents[2]; /* * The first event takes precedence. */ wEvents[0] = threadInfo->stopEvent; wEvents[1] = threadInfo->startEvent; for (;;) { /* * Wait for the main thread to signal before attempting to wait. */ waitResult = WaitForMultipleObjects(2, wEvents, FALSE, INFINITE); if (waitResult != (WAIT_OBJECT_0 + 1)) { /* * The start event was not signaled. It must be the stop event or * an error, so exit this thread. */ break; } /* * Look for data on the console, but first ignore any events that are * not KEY_EVENTs. */ if (ReadConsoleBytes(handle, infoPtr->buffer, CONSOLE_BUFFER_SIZE, (LPDWORD) &infoPtr->bytesRead) != FALSE) { /* * Data was stored in the buffer. */ infoPtr->readFlags |= CONSOLE_BUFFERED; } else { DWORD err = GetLastError(); if (err == (DWORD) EOF) { infoPtr->readFlags = CONSOLE_EOF; } } /* * Signal the main thread by signalling the readable event and then * waking up the notifier thread. */ SetEvent(threadInfo->readyEvent); /* * Alert the foreground thread. Note that we need to treat this like a * critical section so the foreground thread does not terminate this * thread while we are holding a mutex in the notifier code. */ Tcl_MutexLock(&consoleMutex); if (infoPtr->threadId != NULL) { /* * TIP #218. When in flight ignore the event, no one will receive * it anyway. */ Tcl_ThreadAlert(infoPtr->threadId); } Tcl_MutexUnlock(&consoleMutex); } return 0; } /* *---------------------------------------------------------------------- * * ConsoleWriterThread -- * * This function runs in a separate thread and writes data onto a * console. * * Results: * Always returns 0. * * Side effects: * Signals the main thread when an output operation is completed. May * cause the main thread to wake up by posting a message. * *---------------------------------------------------------------------- */ static DWORD WINAPI ConsoleWriterThread( LPVOID arg) { ConsoleInfo *infoPtr = arg; HANDLE *handle = infoPtr->handle; ConsoleThreadInfo *threadInfo = &infoPtr->writer; DWORD count, toWrite, waitResult; char *buf; HANDLE wEvents[2]; /* * The first event takes precedence. */ wEvents[0] = threadInfo->stopEvent; wEvents[1] = threadInfo->startEvent; for (;;) { /* * 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 must be the stop event or * an error, so exit this thread. */ break; } buf = infoPtr->writeBuf; toWrite = infoPtr->toWrite; /* * Loop until all of the bytes are written or an error occurs. */ while (toWrite > 0) { if (WriteConsoleBytes(handle, buf, (DWORD) toWrite, &count) == FALSE) { infoPtr->writeError = GetLastError(); break; } toWrite -= count; buf += count; } /* * Signal the main thread by signalling the writable event and then * waking up the notifier thread. */ SetEvent(threadInfo->readyEvent); /* * Alert the foreground thread. Note that we need to treat this like a * critical section so the foreground thread does not terminate this * thread while we are holding a mutex in the notifier code. */ Tcl_MutexLock(&consoleMutex); if (infoPtr->threadId != NULL) { /* * TIP #218. When in flight ignore the event, no one will receive * it anyway. */ Tcl_ThreadAlert(infoPtr->threadId); } Tcl_MutexUnlock(&consoleMutex); } return 0; } /* *---------------------------------------------------------------------- * * TclWinOpenConsoleChannel -- * * Constructs a Console channel for the specified standard OS handle. * This is a helper function to break up the construction of channels * into File, Console, or Serial. * * Results: * Returns the new channel, or NULL. * * Side effects: * May open the channel. * *---------------------------------------------------------------------- */ Tcl_Channel TclWinOpenConsoleChannel( HANDLE handle, char *channelName, int permissions) { char encoding[4 + TCL_INTEGER_SPACE]; ConsoleInfo *infoPtr; DWORD modes; ConsoleInit(); /* * See if a channel with this handle already exists. */ infoPtr = ckalloc(sizeof(ConsoleInfo)); memset(infoPtr, 0, sizeof(ConsoleInfo)); infoPtr->validMask = permissions; infoPtr->handle = handle; infoPtr->channel = (Tcl_Channel) NULL; wsprintfA(encoding, "cp%d", GetConsoleCP()); infoPtr->threadId = Tcl_GetCurrentThread(); /* * Use the pointer for the name of the result channel. This keeps the * channel names unique, since some may share handles (stdin/stdout/stderr * for instance). */ sprintf(channelName, "file%" TCL_I_MODIFIER "x", (size_t) infoPtr); infoPtr->channel = Tcl_CreateChannel(&consoleChannelType, channelName, infoPtr, permissions); if (permissions & TCL_READABLE) { /* * Make sure the console input buffer is ready for only character * input notifications and the buffer is set for line buffering. IOW, * we only want to catch when complete lines are ready for reading. */ GetConsoleMode(infoPtr->handle, &modes); modes &= ~(ENABLE_WINDOW_INPUT | ENABLE_MOUSE_INPUT); modes |= ENABLE_LINE_INPUT; SetConsoleMode(infoPtr->handle, modes); StartChannelThread(infoPtr, &infoPtr->reader, ConsoleReaderThread); } if (permissions & TCL_WRITABLE) { StartChannelThread(infoPtr, &infoPtr->writer, ConsoleWriterThread); } /* * Files have default translation of AUTO and ^Z eof char, which means * that a ^Z will be accepted as EOF when reading. */ Tcl_SetChannelOption(NULL, infoPtr->channel, "-translation", "auto"); Tcl_SetChannelOption(NULL, infoPtr->channel, "-eofchar", "\032 {}"); #ifdef UNICODE Tcl_SetChannelOption(NULL, infoPtr->channel, "-encoding", "unicode"); #else Tcl_SetChannelOption(NULL, infoPtr->channel, "-encoding", encoding); #endif return infoPtr->channel; } /* *---------------------------------------------------------------------- * * ConsoleThreadActionProc -- * * Insert or remove any thread local refs to this channel. * * Results: * None. * * Side effects: * Changes thread local list of valid channels. * *---------------------------------------------------------------------- */ static void ConsoleThreadActionProc( ClientData instanceData, int action) { ConsoleInfo *infoPtr = instanceData; /* * We do not access firstConsolePtr in the thread structures. This is not * for all serials managed by the thread, but only those we are watching. * Removal of the filevent handlers before transfer thus takes care of * this structure. */ Tcl_MutexLock(&consoleMutex); if (action == TCL_CHANNEL_THREAD_INSERT) { /* * We can't copy the thread information from the channel when the * channel is created. At this time the channel back pointer has not * been set yet. However in that case the threadId has already been * set by TclpCreateCommandChannel itself, so the structure is still * good. */ ConsoleInit(); if (infoPtr->channel != NULL) { infoPtr->threadId = Tcl_GetChannelThread(infoPtr->channel); } } else { infoPtr->threadId = NULL; } Tcl_MutexUnlock(&consoleMutex); } /* * Local Variables: * mode: c * c-basic-offset: 4 * fill-column: 78 * End: */