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|
/*
* 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 1.1.2.2 1999/03/14 18:55:12 stanton Exp $
*/
#include "tclWinInt.h"
#include <dos.h>
#include <fcntl.h>
#include <io.h>
#include <sys/stat.h>
/*
* The following variable is used to tell whether this module has been
* initialized.
*/
static int initialized = 0;
TCL_DECLARE_MUTEX(procMutex)
/*
* 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. */
/*
* 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. */
} 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(&procMutex);
if (!initialized) {
initialized = 1;
Tcl_CreateExitHandler(ProcExitHandler, NULL);
}
Tcl_MutexUnlock(&procMutex);
}
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(&procMutex);
initialized = 0;
Tcl_MutexUnlock(&procMutex);
}
/*
*----------------------------------------------------------------------
*
* 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;
SerialInfo *infoPtr, **nextPtrPtr;
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
errorCode = 0;
if (serialPtr->readThread) {
TerminateThread(serialPtr->readThread, 0);
/*
* 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);
/*
* Wait for the thread to terminate. This ensures that we are
* completely cleaned up before we leave this function.
*/
WaitForSingleObject(serialPtr->writeThread, INFINITE);
TerminateThread(serialPtr->writeThread, 0);
CloseHandle(serialPtr->writeThread);
CloseHandle(serialPtr->writable);
CloseHandle(serialPtr->startWriter);
serialPtr->writeThread = NULL;
}
serialPtr->validMask &= ~TCL_WRITABLE;
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 errors, err;
DWORD mask = 0;
COMSTAT stat;
*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;
}
infoPtr->readyMask &= ~TCL_READABLE;
if (ClearCommError(infoPtr->handle, &errors, &stat)) {
/*
* If there are errors, then signal an I/O error.
*/
if (errors != 0) {
*errorCode = EIO;
return -1;
}
/*
* Otherwise, it's not that fatal, so check the queue
*/
if (stat.cbInQue != 0) {
/*
* If the buffer is bigger than the data in the queue,
* shrink the buffer size to match.
*/
if ((DWORD) bufSize > stat.cbInQue) {
bufSize = stat.cbInQue;
}
} else {
if (infoPtr->flags & SERIAL_ASYNC) {
errno = *errorCode = EAGAIN;
return -1;
} else {
bufSize = 1;
}
}
}
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, err, mask;
HANDLE *handle = infoPtr->handle;
/*
* 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.
*/
while (1) {
if (WaitCommEvent(handle, &mask, NULL) == FALSE) {
err = GetLastError();
infoPtr->readFlags |= SERIAL_EOF;
break;
}
if (mask & EV_RXCHAR) {
break;
}
ResetEvent(infoPtr->readable);
SetEvent(infoPtr->startReader);
}
/*
* If the serial has hit EOF, it is always readable.
*/
if (infoPtr->readFlags & SERIAL_EOF) {
return 1;
}
return 1;
}
/*
*----------------------------------------------------------------------
*
* 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 mask = EV_RXCHAR;
for (;;) {
/*
* Wait for the main thread to signal before attempting to wait.
*/
WaitForSingleObject(infoPtr->startReader, INFINITE);
/*
* Try waiting for a Comm event.
*/
while (1) {
if (WaitCommEvent(handle, &mask, NULL) == FALSE) {
/*
* There is an error, signal an EOF.
*/
infoPtr->readFlags |= SERIAL_EOF;
break;
}
/*
* Signal the main thread by signalling the readable event and
* then waking up the notifier thread.
*/
if (mask & EV_RXCHAR) {
SetEvent(infoPtr->readable);
Tcl_ThreadAlert(infoPtr->threadId);
break;
}
}
}
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);
Tcl_ThreadAlert(infoPtr->threadId);
}
return 0; /* NOT REACHED */
}
/*
*----------------------------------------------------------------------
*
* TclWinOpenConsoleChannel --
*
* 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 = 0;
cto.ReadTotalTimeoutConstant = 0;
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");
}
}
|