/* * Tclwinserial.c -- * * This file implements the Windows-specific serial port functions, * and the "serial" 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. * * RCS: @(#) $Id: tclWinSerial.c,v 1.4 1999/04/21 21:50:34 rjohnson Exp $ */ #include "tclWinInt.h" #include #include #include #include /* * The following variable is used to tell whether this module has been * initialized. */ static int initialized = 0; /* * The serialMutex 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(serialMutex) /* * Bit masks used in the flags field of the SerialInfo structure below. */ #define SERIAL_PENDING (1<<0) /* Message is pending in the queue. */ #define SERIAL_ASYNC (1<<1) /* Channel is non-blocking. */ /* * Bit masks used in the sharedFlags field of the SerialInfo structure below. */ #define SERIAL_EOF (1<<2) /* Serial has reached EOF. */ #define SERIAL_EXTRABYTE (1<<3) /* Extra byte consumed while waiting for data */ #define SERIAL_ERROR (1<<4) /* * This structure describes per-instance data for a serial based channel. */ typedef struct SerialInfo { HANDLE handle; struct SerialInfo *nextPtr; /* Pointer to next registered serial. */ 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. */ 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 serial. */ HANDLE startReader; /* Auto-reset event used by the main thread to * signal when the reader thread should attempt * to read from the serial. */ 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 writeFlags; /* Flags that are shared with the writer * thread. Access is synchronized with the * readable object. */ int readyMask; /* Events that need to be checked on. */ char extraByte; } SerialInfo; typedef struct ThreadSpecificData { /* * The following pointer refers to the head of the list of serials * that are being watched for file events. */ SerialInfo *firstSerialPtr; } ThreadSpecificData; static Tcl_ThreadDataKey dataKey; /* * The following structure is what is added to the Tcl event queue when * serial events are generated. */ typedef struct SerialEvent { Tcl_Event header; /* Information that is standard for * all events. */ SerialInfo *infoPtr; /* Pointer to serial info structure. Note * that we still have to verify that the * serial exists before dereferencing this * pointer. */ } SerialEvent; /* * Declarations for functions used only in this file. */ static int SerialBlockProc(ClientData instanceData, int mode); static void SerialCheckProc(ClientData clientData, int flags); static int SerialCloseProc(ClientData instanceData, Tcl_Interp *interp); static int SerialEventProc(Tcl_Event *evPtr, int flags); static void SerialExitHandler(ClientData clientData); static int SerialGetHandleProc(ClientData instanceData, int direction, ClientData *handlePtr); static ThreadSpecificData *SerialInit(void); static int SerialInputProc(ClientData instanceData, char *buf, int toRead, int *errorCode); static int SerialOutputProc(ClientData instanceData, char *buf, int toWrite, int *errorCode); static DWORD WINAPI SerialReaderThread(LPVOID arg); static void SerialSetupProc(ClientData clientData, int flags); static void SerialWatchProc(ClientData instanceData, int mask); static DWORD WINAPI SerialWriterThread(LPVOID arg); static void ProcExitHandler(ClientData clientData); static int WaitForRead(SerialInfo *infoPtr, int blocking); static int SerialGetOptionProc _ANSI_ARGS_((ClientData instanceData, Tcl_Interp *interp, char *optionName, Tcl_DString *dsPtr)); static int SerialSetOptionProc _ANSI_ARGS_((ClientData instanceData, Tcl_Interp *interp, char *optionName, char *value)); /* * This structure describes the channel type structure for command serial * based IO. */ static Tcl_ChannelType serialChannelType = { "serial", /* Type name. */ SerialBlockProc, /* Set blocking or non-blocking mode.*/ SerialCloseProc, /* Close proc. */ SerialInputProc, /* Input proc. */ SerialOutputProc, /* Output proc. */ NULL, /* Seek proc. */ SerialSetOptionProc, /* Set option proc. */ SerialGetOptionProc, /* Get option proc. */ SerialWatchProc, /* Set up notifier to watch the channel. */ SerialGetHandleProc, /* Get an OS handle from channel. */ }; /* *---------------------------------------------------------------------- * * SerialInit -- * * This function initializes the static variables for this file. * * Results: * None. * * Side effects: * Creates a new event source. * *---------------------------------------------------------------------- */ static ThreadSpecificData * SerialInit() { ThreadSpecificData *tsdPtr; /* * Check the initialized flag first, then check it again in the mutex. * This is a speed enhancement. */ if (!initialized) { Tcl_MutexLock(&serialMutex); if (!initialized) { initialized = 1; Tcl_CreateExitHandler(ProcExitHandler, NULL); } Tcl_MutexUnlock(&serialMutex); } tsdPtr = (ThreadSpecificData *)TclThreadDataKeyGet(&dataKey); if (tsdPtr == NULL) { tsdPtr = TCL_TSD_INIT(&dataKey); tsdPtr->firstSerialPtr = NULL; Tcl_CreateEventSource(SerialSetupProc, SerialCheckProc, NULL); Tcl_CreateThreadExitHandler(SerialExitHandler, NULL); } return tsdPtr; } /* *---------------------------------------------------------------------- * * SerialExitHandler -- * * This function is called to cleanup the serial module before * Tcl is unloaded. * * Results: * None. * * Side effects: * Removes the serial event source. * *---------------------------------------------------------------------- */ static void SerialExitHandler( ClientData clientData) /* Old window proc */ { Tcl_DeleteEventSource(SerialSetupProc, SerialCheckProc, 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(&serialMutex); initialized = 0; Tcl_MutexUnlock(&serialMutex); } /* *---------------------------------------------------------------------- * * SerialSetupProc -- * * This procedure is invoked before Tcl_DoOneEvent blocks waiting * for an event. * * Results: * None. * * Side effects: * Adjusts the block time if needed. * *---------------------------------------------------------------------- */ void SerialSetupProc( ClientData data, /* Not used. */ int flags) /* Event flags as passed to Tcl_DoOneEvent. */ { SerialInfo *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->firstSerialPtr; infoPtr != NULL; infoPtr = infoPtr->nextPtr) { if (infoPtr->watchMask & TCL_WRITABLE) { if (WaitForSingleObject(infoPtr->writable, 0) != WAIT_TIMEOUT) { block = 0; } } if (infoPtr->watchMask & TCL_READABLE) { if (WaitForRead(infoPtr, 0) >= 0) { block = 0; } } } if (!block) { Tcl_SetMaxBlockTime(&blockTime); } } /* *---------------------------------------------------------------------- * * SerialCheckProc -- * * This procedure is called by Tcl_DoOneEvent to check the serial * event source for events. * * Results: * None. * * Side effects: * May queue an event. * *---------------------------------------------------------------------- */ static void SerialCheckProc( ClientData data, /* Not used. */ int flags) /* Event flags as passed to Tcl_DoOneEvent. */ { SerialInfo *infoPtr; SerialEvent *evPtr; int needEvent; ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); if (!(flags & TCL_FILE_EVENTS)) { return; } /* * Queue events for any ready serials that don't already have events * queued. */ for (infoPtr = tsdPtr->firstSerialPtr; infoPtr != NULL; infoPtr = infoPtr->nextPtr) { if (infoPtr->flags & SERIAL_PENDING) { continue; } /* * Queue an event if the serial is signaled for reading or writing. */ needEvent = 0; if (infoPtr->watchMask & TCL_WRITABLE) { if (WaitForSingleObject(infoPtr->writable, 0) != WAIT_TIMEOUT) { needEvent = 1; } } if (infoPtr->watchMask & TCL_READABLE) { if (WaitForRead(infoPtr, 0) >= 0) { needEvent = 1; } } if (needEvent) { infoPtr->flags |= SERIAL_PENDING; evPtr = (SerialEvent *) ckalloc(sizeof(SerialEvent)); evPtr->header.proc = SerialEventProc; evPtr->infoPtr = infoPtr; Tcl_QueueEvent((Tcl_Event *) evPtr, TCL_QUEUE_TAIL); } } } /* *---------------------------------------------------------------------- * * SerialBlockProc -- * * 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 SerialBlockProc( ClientData instanceData, /* Instance data for channel. */ int mode) /* TCL_MODE_BLOCKING or * TCL_MODE_NONBLOCKING. */ { SerialInfo *infoPtr = (SerialInfo *) instanceData; /* * Serial IO on Windows can not be switched between blocking & 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 |= SERIAL_ASYNC; } else { infoPtr->flags &= ~(SERIAL_ASYNC); } return 0; } /* *---------------------------------------------------------------------- * * SerialCloseProc -- * * Closes a serial based IO channel. * * Results: * 0 on success, errno otherwise. * * Side effects: * Closes the physical channel. * *---------------------------------------------------------------------- */ static int SerialCloseProc( ClientData instanceData, /* Pointer to SerialInfo structure. */ Tcl_Interp *interp) /* For error reporting. */ { SerialInfo *serialPtr = (SerialInfo *) instanceData; int errorCode, result = 0; SerialInfo *infoPtr, **nextPtrPtr; ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); errorCode = 0; if (serialPtr->readThread) { /* * Forcibly terminate the background thread. We cannot rely on the * thread to cleanly terminate itself because we have no way of * closing the 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(&serialMutex); TerminateThread(serialPtr->readThread, 0); Tcl_MutexUnlock(&serialMutex); /* * Wait for the thread to terminate. This ensures that we are * completely cleaned up before we leave this function. */ WaitForSingleObject(serialPtr->readThread, INFINITE); CloseHandle(serialPtr->readThread); CloseHandle(serialPtr->readable); CloseHandle(serialPtr->startReader); serialPtr->readThread = NULL; } serialPtr->validMask &= ~TCL_READABLE; if (serialPtr->writeThread) { WaitForSingleObject(serialPtr->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 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(&serialMutex); TerminateThread(serialPtr->writeThread, 0); Tcl_MutexUnlock(&serialMutex); /* * Wait for the thread to terminate. This ensures that we are * completely cleaned up before we leave this function. */ WaitForSingleObject(serialPtr->writeThread, INFINITE); CloseHandle(serialPtr->writeThread); CloseHandle(serialPtr->writable); CloseHandle(serialPtr->startWriter); serialPtr->writeThread = NULL; } serialPtr->validMask &= ~TCL_WRITABLE; /* * Don't close the Win32 handle if the handle is a standard channel * during the exit process. Otherwise, one thread may kill the stdio * of another. */ if (!TclInExit() || ((GetStdHandle(STD_INPUT_HANDLE) != serialPtr->handle) && (GetStdHandle(STD_OUTPUT_HANDLE) != serialPtr->handle) && (GetStdHandle(STD_ERROR_HANDLE) != serialPtr->handle))) { if (CloseHandle(serialPtr->handle) == FALSE) { TclWinConvertError(GetLastError()); errorCode = errno; } } serialPtr->watchMask &= serialPtr->validMask; /* * Remove the file from the list of watched files. */ for (nextPtrPtr = &(tsdPtr->firstSerialPtr), infoPtr = *nextPtrPtr; infoPtr != NULL; nextPtrPtr = &infoPtr->nextPtr, infoPtr = *nextPtrPtr) { if (infoPtr == (SerialInfo *)serialPtr) { *nextPtrPtr = infoPtr->nextPtr; break; } } /* * Wrap the error file into a channel and give it to the cleanup * routine. */ if (serialPtr->writeBuf != NULL) { ckfree(serialPtr->writeBuf); serialPtr->writeBuf = NULL; } ckfree((char*) serialPtr); if (errorCode == 0) { return result; } return errorCode; } /* *---------------------------------------------------------------------- * * SerialInputProc -- * * 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 SerialInputProc( ClientData instanceData, /* Serial 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. */ { SerialInfo *infoPtr = (SerialInfo *) instanceData; DWORD bytesRead = 0; int result; DWORD err; *errorCode = 0; /* * Synchronize with the reader thread. */ result = WaitForRead(infoPtr, (infoPtr->flags & SERIAL_ASYNC) ? 0 : 1); /* * If an error occurred, return immediately. */ if (result == -1) { *errorCode = errno; return -1; } if (infoPtr->readFlags & SERIAL_EXTRABYTE) { /* * If a byte was consumed waiting, then put it in the buffer. */ *buf = infoPtr->extraByte; infoPtr->readFlags &= ~SERIAL_EXTRABYTE; buf++; bufSize--; bytesRead = 1; if (result == 0) { return bytesRead; } } if (ReadFile(infoPtr->handle, (LPVOID) buf, (DWORD) bufSize, &bytesRead, NULL) == FALSE) { err = GetLastError(); if (err != ERROR_IO_PENDING) { goto error; } } return bytesRead; error: TclWinConvertError(GetLastError()); *errorCode = errno; return -1; } /* *---------------------------------------------------------------------- * * SerialOutputProc -- * * 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 SerialOutputProc( ClientData instanceData, /* Serial state. */ char *buf, /* The data buffer. */ int toWrite, /* How many bytes to write? */ int *errorCode) /* Where to store error code. */ { SerialInfo *infoPtr = (SerialInfo *) instanceData; DWORD bytesWritten, timeout, err; *errorCode = 0; timeout = (infoPtr->flags & SERIAL_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 & SERIAL_ASYNC) { /* * The serial 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, 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(infoPtr->handle, (LPVOID) buf, (DWORD) toWrite, &bytesWritten, NULL) == FALSE) { err = GetLastError(); if (err != ERROR_IO_PENDING) { TclWinConvertError(GetLastError()); goto error; } } } return bytesWritten; error: *errorCode = errno; return -1; } /* *---------------------------------------------------------------------- * * SerialEventProc -- * * 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 serial. * * 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 SerialEventProc( Tcl_Event *evPtr, /* Event to service. */ int flags) /* Flags that indicate what events to * handle, such as TCL_FILE_EVENTS. */ { SerialEvent *serialEvPtr = (SerialEvent *)evPtr; SerialInfo *infoPtr; int mask; ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); if (!(flags & TCL_FILE_EVENTS)) { return 0; } /* * Search through the list of watched serials for the one whose handle * matches the event. We do this rather than simply dereferencing * the handle in the event so that serials can be deleted while the * event is in the queue. */ for (infoPtr = tsdPtr->firstSerialPtr; infoPtr != NULL; infoPtr = infoPtr->nextPtr) { if (serialEvPtr->infoPtr == infoPtr) { infoPtr->flags &= ~(SERIAL_PENDING); break; } } /* * Remove stale events. */ if (!infoPtr) { return 1; } /* * Check to see if the serial is readable. Note * that we can't tell if a serial 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->writable, 0) != WAIT_TIMEOUT) { mask = TCL_WRITABLE; } } if (infoPtr->watchMask & TCL_READABLE) { if (WaitForRead(infoPtr, 0) >= 0) { if (infoPtr->readFlags & SERIAL_EOF) { mask = TCL_READABLE; } else { mask |= TCL_READABLE; } } } /* * Inform the channel of the events. */ Tcl_NotifyChannel(infoPtr->channel, infoPtr->watchMask & mask); return 1; } /* *---------------------------------------------------------------------- * * SerialWatchProc -- * * Called by the notifier to set up to watch for events on this * channel. * * Results: * None. * * Side effects: * None. * *---------------------------------------------------------------------- */ static void SerialWatchProc( ClientData instanceData, /* Serial state. */ int mask) /* What events to watch for, OR-ed * combination of TCL_READABLE, * TCL_WRITABLE and TCL_EXCEPTION. */ { SerialInfo **nextPtrPtr, *ptr; SerialInfo *infoPtr = (SerialInfo *) instanceData; int oldMask = infoPtr->watchMask; ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); /* * Since the file is always ready for events, we set the block time * to zero so we will poll. */ infoPtr->watchMask = mask & infoPtr->validMask; if (infoPtr->watchMask) { Tcl_Time blockTime = { 0, 0 }; if (!oldMask) { infoPtr->nextPtr = tsdPtr->firstSerialPtr; tsdPtr->firstSerialPtr = infoPtr; } Tcl_SetMaxBlockTime(&blockTime); } else { if (oldMask) { /* * Remove the serial port from the list of watched serial ports. */ for (nextPtrPtr = &(tsdPtr->firstSerialPtr), ptr = *nextPtrPtr; ptr != NULL; nextPtrPtr = &ptr->nextPtr, ptr = *nextPtrPtr) { if (infoPtr == ptr) { *nextPtrPtr = ptr->nextPtr; break; } } } } } /* *---------------------------------------------------------------------- * * SerialGetHandleProc -- * * Called from Tcl_GetChannelHandle to retrieve OS handles from * inside a command serial port 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 SerialGetHandleProc( ClientData instanceData, /* The serial state. */ int direction, /* TCL_READABLE or TCL_WRITABLE */ ClientData *handlePtr) /* Where to store the handle. */ { SerialInfo *infoPtr = (SerialInfo *) instanceData; *handlePtr = (ClientData) infoPtr->handle; return TCL_OK; } /* *---------------------------------------------------------------------- * * WaitForRead -- * * Wait until some data is available, the serial is at * EOF or the reader thread is blocked waiting for data (if the * channel is in non-blocking mode). * * Results: * Returns 1 if serial is readable. Returns 0 if there is no data * on the serial, 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 and may consume 1 byte of data * from the serial. If no error occurred, the reader thread is * blocked waiting for a signal from the main thread. * *---------------------------------------------------------------------- */ static int WaitForRead( SerialInfo *infoPtr, /* Serial state. */ int blocking) /* Indicates whether call should be * blocking or not. */ { DWORD timeout; HANDLE *handle = infoPtr->handle; while (1) { /* * Synchronize with the reader thread. */ timeout = blocking ? INFINITE : 0; if (WaitForSingleObject(infoPtr->readable, timeout) == WAIT_TIMEOUT) { /* * The reader thread is blocked waiting for data and the channel * is in non-blocking mode. */ errno = EAGAIN; return -1; } /* * At this point, the two threads are synchronized, so it is safe * to access shared state. This code is not called in the ReaderThread * in blocking mode, so it needs to be checked here. */ /* * If the serial has hit EOF, it is always readable. */ if (infoPtr->readFlags & SERIAL_EOF) { return 1; } /* * if there is an extra byte that was consumed while * waiting, but no data in the queue, return 0 */ if (infoPtr->readFlags & SERIAL_EXTRABYTE) { return 0; } else if ((infoPtr->readFlags & SERIAL_ERROR) == EIO) { return -1; } ResetEvent(infoPtr->readable); SetEvent(infoPtr->startReader); } } /* *---------------------------------------------------------------------- * * SerialReaderThread -- * * This function runs in a separate thread and waits for input * to become available on a serial. * * 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 * consume one byte from the serial for each wait operation. * *---------------------------------------------------------------------- */ static DWORD WINAPI SerialReaderThread(LPVOID arg) { SerialInfo *infoPtr = (SerialInfo *)arg; HANDLE *handle = infoPtr->handle; DWORD count; for (;;) { /* * Wait for the main thread to signal before attempting to wait. */ WaitForSingleObject(infoPtr->startReader, INFINITE); /* * Try waiting for a Comm event. */ WaitCommEvent(handle, NULL, NULL); /* * try to read one byte */ if (ReadFile(handle, &(infoPtr->extraByte), 1, &count, NULL) != FALSE) { /* * one byte was consumed while waiting to read, keep it */ if (count != 0) { infoPtr->readFlags |= SERIAL_EXTRABYTE; } } /* * Signal the main thread by signalling the readable event and * then waking up the notifier thread. */ SetEvent(infoPtr->readable); /* * 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(&serialMutex); Tcl_ThreadAlert(infoPtr->threadId); Tcl_MutexUnlock(&serialMutex); } return 0; /* NOT REACHED */ } /* *---------------------------------------------------------------------- * * SerialWriterThread -- * * This function runs in a separate thread and writes data * onto a serial. * * 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 SerialWriterThread(LPVOID arg) { SerialInfo *infoPtr = (SerialInfo *)arg; HANDLE *handle = infoPtr->handle; DWORD count, toWrite, err; char *buf; for (;;) { /* * Wait for the main thread to signal before attempting to write. */ WaitForSingleObject(infoPtr->startWriter, INFINITE); buf = infoPtr->writeBuf; toWrite = infoPtr->toWrite; /* * Loop until all of the bytes are written or an error occurs. */ while (toWrite > 0) { if (WriteFile(handle, (LPVOID) buf, (DWORD) toWrite, &count, NULL) == FALSE) { err = GetLastError(); if (err != ERROR_IO_PENDING) { TclWinConvertError(GetLastError()); infoPtr->writeError = err; break; } } else { toWrite -= count; buf += count; } } /* * Signal the main thread by signalling the writable event and * then waking up the notifier thread. */ SetEvent(infoPtr->writable); /* * 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(&serialMutex); Tcl_ThreadAlert(infoPtr->threadId); Tcl_MutexUnlock(&serialMutex); } return 0; /* NOT REACHED */ } /* *---------------------------------------------------------------------- * * TclWinOpenSerialChannel -- * * Constructs a Serial port 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 TclWinOpenSerialChannel(handle, channelName, permissions) HANDLE handle; char *channelName; int permissions; { SerialInfo *infoPtr; COMMTIMEOUTS cto; ThreadSpecificData *tsdPtr; DWORD id; tsdPtr = SerialInit(); SetCommMask(handle, EV_RXCHAR); SetupComm(handle, 4096, 4096); PurgeComm(handle, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR); cto.ReadIntervalTimeout = MAXDWORD; cto.ReadTotalTimeoutMultiplier = MAXDWORD; cto.ReadTotalTimeoutConstant = 1; cto.WriteTotalTimeoutMultiplier = 0; cto.WriteTotalTimeoutConstant = 0; SetCommTimeouts(handle, &cto); infoPtr = (SerialInfo *) ckalloc((unsigned) sizeof(SerialInfo)); memset(infoPtr, 0, sizeof(SerialInfo)); infoPtr->validMask = permissions; infoPtr->handle = handle; /* * Use the pointer to keep the channel names unique, in case * the handles are shared between multiple channels (stdin/stdout). */ wsprintfA(channelName, "file%lx", (int) infoPtr); infoPtr->channel = Tcl_CreateChannel(&serialChannelType, channelName, (ClientData) infoPtr, permissions); infoPtr->threadId = Tcl_GetCurrentThread(); if (permissions & TCL_READABLE) { infoPtr->readable = CreateEvent(NULL, TRUE, TRUE, NULL); infoPtr->startReader = CreateEvent(NULL, FALSE, FALSE, NULL); infoPtr->readThread = CreateThread(NULL, 8000, SerialReaderThread, infoPtr, 0, &id); } if (permissions & TCL_WRITABLE) { infoPtr->writable = CreateEvent(NULL, TRUE, TRUE, NULL); infoPtr->startWriter = CreateEvent(NULL, FALSE, FALSE, NULL); infoPtr->writeThread = CreateThread(NULL, 8000, SerialWriterThread, infoPtr, 0, &id); } /* * 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 {}"); return infoPtr->channel; } /* *---------------------------------------------------------------------- * * SerialSetOptionProc -- * * Sets an option on a channel. * * Results: * A standard Tcl result. Also sets the interp's result on error if * interp is not NULL. * * Side effects: * May modify an option on a device. * *---------------------------------------------------------------------- */ static int SerialSetOptionProc(instanceData, interp, optionName, value) ClientData instanceData; /* File state. */ Tcl_Interp *interp; /* For error reporting - can be NULL. */ char *optionName; /* Which option to set? */ char *value; /* New value for option. */ { SerialInfo *infoPtr; DCB dcb; int len; BOOL result; Tcl_DString ds; TCHAR *native; infoPtr = (SerialInfo *) instanceData; len = strlen(optionName); if ((len > 1) && (strncmp(optionName, "-mode", len) == 0)) { if (GetCommState(infoPtr->handle, &dcb)) { native = Tcl_WinUtfToTChar(value, -1, &ds); result = (*tclWinProcs->buildCommDCBProc)(native, &dcb); Tcl_DStringFree(&ds); if ((result == FALSE) || (SetCommState(infoPtr->handle, &dcb) == FALSE)) { /* * one should separate the 2 errors... */ if (interp) { Tcl_AppendResult(interp, "bad value for -mode: should be ", "baud,parity,data,stop", NULL); } return TCL_ERROR; } else { return TCL_OK; } } else { if (interp) { Tcl_AppendResult(interp, "can't get comm state", NULL); } return TCL_ERROR; } } else { return Tcl_BadChannelOption(interp, optionName, "mode"); } } /* *---------------------------------------------------------------------- * * SerialGetOptionProc -- * * Gets a mode associated with an IO channel. If the optionName arg * is non NULL, retrieves the value of that option. If the optionName * arg is NULL, retrieves a list of alternating option names and * values for the given channel. * * Results: * A standard Tcl result. Also sets the supplied DString to the * string value of the option(s) returned. * * Side effects: * The string returned by this function is in static storage and * may be reused at any time subsequent to the call. * *---------------------------------------------------------------------- */ static int SerialGetOptionProc(instanceData, interp, optionName, dsPtr) ClientData instanceData; /* File state. */ Tcl_Interp *interp; /* For error reporting - can be NULL. */ char *optionName; /* Option to get. */ Tcl_DString *dsPtr; /* Where to store value(s). */ { SerialInfo *infoPtr; DCB dcb; int len; infoPtr = (SerialInfo *) instanceData; if (optionName == NULL) { Tcl_DStringAppendElement(dsPtr, "-mode"); len = 0; } else { len = strlen(optionName); } if ((len == 0) || ((len > 1) && (strncmp(optionName, "-mode", len) == 0))) { if (GetCommState(infoPtr->handle, &dcb) == 0) { /* * shouldn't we flag an error instead ? */ Tcl_DStringAppendElement(dsPtr, ""); } else { char parity; char *stop; char buf[2 * TCL_INTEGER_SPACE + 16]; parity = 'n'; if (dcb.Parity < 4) { parity = "noems"[dcb.Parity]; } stop = (dcb.StopBits == ONESTOPBIT) ? "1" : (dcb.StopBits == ONE5STOPBITS) ? "1.5" : "2"; wsprintfA(buf, "%d,%c,%d,%s", dcb.BaudRate, parity, dcb.ByteSize, stop); Tcl_DStringAppendElement(dsPtr, buf); } return TCL_OK; } else { return Tcl_BadChannelOption(interp, optionName, "mode"); } }