diff options
Diffstat (limited to 'unix')
| -rw-r--r-- | unix/tclXtNotify.c | 1312 |
1 files changed, 656 insertions, 656 deletions
diff --git a/unix/tclXtNotify.c b/unix/tclXtNotify.c index eebb50a..0b5a3b5 100644 --- a/unix/tclXtNotify.c +++ b/unix/tclXtNotify.c @@ -1,656 +1,656 @@ -/*
- * tclXtNotify.c --
- *
- * This file contains the notifier driver implementation for the
- * Xt intrinsics.
- *
- * Copyright (c) 1997 by Sun Microsystems, Inc.
- *
- * See the file "license.terms" for information on usage and redistribution
- * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
- *
- * RCS: @(#) $Id: tclXtNotify.c,v 1.2 1998/09/14 18:40:18 stanton Exp $ - */
-
-#include <X11/Intrinsic.h>
-#include <tclInt.h>
-
-/*
- * This structure is used to keep track of the notifier info for a
- * a registered file.
- */
-
-typedef struct FileHandler {
- int fd;
- int mask; /* Mask of desired events: TCL_READABLE, etc. */
- int readyMask; /* Events that have been seen since the
- last time FileHandlerEventProc was called
- for this file. */
- XtInputId read; /* Xt read callback handle. */
- XtInputId write; /* Xt write callback handle. */
- XtInputId except; /* Xt exception callback handle. */
- Tcl_FileProc *proc; /* Procedure to call, in the style of
- * Tcl_CreateFileHandler. */
- ClientData clientData; /* Argument to pass to proc. */
- struct FileHandler *nextPtr;/* Next in list of all files we care about. */
-} FileHandler;
-
-/*
- * The following structure is what is added to the Tcl event queue when
- * file handlers are ready to fire.
- */
-
-typedef struct FileHandlerEvent {
- Tcl_Event header; /* Information that is standard for
- * all events. */
- int fd; /* File descriptor that is ready. Used
- * to find the FileHandler structure for
- * the file (can't point directly to the
- * FileHandler structure because it could
- * go away while the event is queued). */
-} FileHandlerEvent;
-
-/*
- * The following static structure contains the state information for the
- * Xt based implementation of the Tcl notifier.
- */
-
-static struct NotifierState {
- XtAppContext appContext; /* The context used by the Xt
- * notifier. Can be set with
- * TclSetAppContext. */
- int appContextCreated; /* Was it created by us? */
- XtIntervalId currentTimeout; /* Handle of current timer. */
- FileHandler *firstFileHandlerPtr; /* Pointer to head of file handler
- * list. */
-} notifier;
-
-/*
- * The following static indicates whether this module has been initialized.
- */
-
-static int initialized = 0;
-
-/*
- * Static routines defined in this file.
- */
-
-static int FileHandlerEventProc _ANSI_ARGS_((Tcl_Event *evPtr,
- int flags));
-static void FileProc _ANSI_ARGS_((caddr_t clientData,
- int *source, XtInputId *id));
-static void InitNotifier _ANSI_ARGS_((void));
-static void NotifierExitHandler _ANSI_ARGS_((
- ClientData clientData));
-static void TimerProc _ANSI_ARGS_((caddr_t clientData,
- XtIntervalId *id));
-
-/*
- * Functions defined in this file for use by users of the Xt Notifier:
- */
-
-EXTERN XtAppContext TclSetAppContext _ANSI_ARGS_((XtAppContext ctx));
-
-/*
- *----------------------------------------------------------------------
- *
- * TclSetAppContext --
- *
- * Set the notifier application context.
- *
- * Results:
- * None.
- *
- * Side effects:
- * Sets the application context used by the notifier. Panics if
- * the context is already set when called.
- *
- *----------------------------------------------------------------------
- */
-
-XtAppContext
-TclSetAppContext(appContext)
- XtAppContext appContext;
-{
- if (!initialized) {
- InitNotifier();
- }
-
- /*
- * If we already have a context we check whether we were asked to set a
- * new context. If so, we panic because we try to prevent switching
- * contexts by mistake. Otherwise, we return the one we have.
- */
-
- if (notifier.appContext != NULL) {
- if (appContext != NULL) {
-
- /*
- * We already have a context. We do not allow switching contexts
- * after initialization, so we panic.
- */
-
- panic("TclSetAppContext: multiple application contexts");
-
- }
- } else {
-
- /*
- * If we get here we have not yet gotten a context, so either create
- * one or use the one supplied by our caller.
- */
-
- if (appContext == NULL) {
-
- /*
- * We must create a new context and tell our caller what it is, so
- * she can use it too.
- */
-
- notifier.appContext = XtCreateApplicationContext();
- notifier.appContextCreated = 1;
- } else {
-
- /*
- * Otherwise we remember the context that our caller gave us
- * and use it.
- */
-
- notifier.appContextCreated = 0;
- notifier.appContext = appContext;
- }
- }
-
- return notifier.appContext;
-}
-
-/*
- *----------------------------------------------------------------------
- *
- * InitNotifier --
- *
- * Initializes the notifier state.
- *
- * Results:
- * None.
- *
- * Side effects:
- * Creates a new exit handler.
- *
- *----------------------------------------------------------------------
- */
-
-static void
-InitNotifier(void)
-{
- /*
- * Only reinitialize if we are not in exit handling. The notifier
- * can get reinitialized after its own exit handler has run, because
- * of exit handlers for the I/O and timer sub-systems (order dependency).
- */
-
- if (TclInExit()) {
- return;
- }
-
- /*
- * DO NOT create the application context yet; doing so would prevent
- * external applications from setting it for us to their own ones.
- */
-
- initialized = 1;
- memset(¬ifier, 0, sizeof(notifier));
- Tcl_CreateExitHandler(NotifierExitHandler, NULL);
-}
-
-/*
- *----------------------------------------------------------------------
- *
- * NotifierExitHandler --
- *
- * This function is called to cleanup the notifier state before
- * Tcl is unloaded.
- *
- * Results:
- * None.
- *
- * Side effects:
- * Destroys the notifier window.
- *
- *----------------------------------------------------------------------
- */
-
-static void
-NotifierExitHandler(
- ClientData clientData) /* Not used. */
-{
- if (notifier.currentTimeout != 0) {
- XtRemoveTimeOut(notifier.currentTimeout);
- }
- for (; notifier.firstFileHandlerPtr != NULL; ) {
- Tcl_DeleteFileHandler(notifier.firstFileHandlerPtr->fd);
- }
- if (notifier.appContextCreated) {
- XtDestroyApplicationContext(notifier.appContext);
- notifier.appContextCreated = 0;
- notifier.appContext = NULL;
- }
- initialized = 0;
-}
-
-/*
- *----------------------------------------------------------------------
- *
- * Tcl_SetTimer --
- *
- * This procedure sets the current notifier timeout value.
- *
- * Results:
- * None.
- *
- * Side effects:
- * Replaces any previous timer.
- *
- *----------------------------------------------------------------------
- */
-
-void
-Tcl_SetTimer(timePtr)
- Tcl_Time *timePtr; /* Timeout value, may be NULL. */
-{
- long timeout;
-
- if (!initialized) {
- InitNotifier();
- }
-
- TclSetAppContext(NULL);
- if (notifier.currentTimeout != 0) {
- XtRemoveTimeOut(notifier.currentTimeout);
- }
- if (timePtr) {
- timeout = timePtr->sec * 1000 + timePtr->usec / 1000;
- notifier.currentTimeout =
- XtAppAddTimeOut(notifier.appContext, (unsigned long) timeout,
- TimerProc, NULL);
- } else {
- notifier.currentTimeout = 0;
- }
-}
-
-/*
- *----------------------------------------------------------------------
- *
- * TimerProc --
- *
- * This procedure is the XtTimerCallbackProc used to handle
- * timeouts.
- *
- * Results:
- * None.
- *
- * Side effects:
- * Processes all queued events.
- *
- *----------------------------------------------------------------------
- */
-
-static void
-TimerProc(data, id)
- caddr_t data; /* Not used. */
- XtIntervalId *id;
-{
- if (*id != notifier.currentTimeout) {
- return;
- }
- notifier.currentTimeout = 0;
-
- Tcl_ServiceAll();
-}
-
-/*
- *----------------------------------------------------------------------
- *
- * Tcl_CreateFileHandler --
- *
- * This procedure registers a file handler with the Xt notifier.
- *
- * Results:
- * None.
- *
- * Side effects:
- * Creates a new file handler structure and registers one or more
- * input procedures with Xt.
- *
- *----------------------------------------------------------------------
- */
-
-void
-Tcl_CreateFileHandler(fd, mask, proc, clientData)
- int fd; /* Handle of stream to watch. */
- int mask; /* OR'ed combination of TCL_READABLE,
- * TCL_WRITABLE, and TCL_EXCEPTION:
- * indicates conditions under which
- * proc should be called. */
- Tcl_FileProc *proc; /* Procedure to call for each
- * selected event. */
- ClientData clientData; /* Arbitrary data to pass to proc. */
-{
- FileHandler *filePtr;
-
- if (!initialized) {
- InitNotifier();
- }
-
- TclSetAppContext(NULL);
-
- for (filePtr = notifier.firstFileHandlerPtr; filePtr != NULL;
- filePtr = filePtr->nextPtr) {
- if (filePtr->fd == fd) {
- break;
- }
- }
- if (filePtr == NULL) {
- filePtr = (FileHandler*) ckalloc(sizeof(FileHandler));
- filePtr->fd = fd;
- filePtr->read = 0;
- filePtr->write = 0;
- filePtr->except = 0;
- filePtr->readyMask = 0;
- filePtr->mask = 0;
- filePtr->nextPtr = notifier.firstFileHandlerPtr;
- notifier.firstFileHandlerPtr = filePtr;
- }
- filePtr->proc = proc;
- filePtr->clientData = clientData;
-
- /*
- * Register the file with the Xt notifier, if it hasn't been done yet.
- */
-
- if (mask & TCL_READABLE) {
- if (!(filePtr->mask & TCL_READABLE)) {
- filePtr->read =
- XtAppAddInput(notifier.appContext, fd, XtInputReadMask,
- FileProc, filePtr);
- }
- } else {
- if (filePtr->mask & TCL_READABLE) {
- XtRemoveInput(filePtr->read);
- }
- }
- if (mask & TCL_WRITABLE) {
- if (!(filePtr->mask & TCL_WRITABLE)) {
- filePtr->write =
- XtAppAddInput(notifier.appContext, fd, XtInputWriteMask,
- FileProc, filePtr);
- }
- } else {
- if (filePtr->mask & TCL_WRITABLE) {
- XtRemoveInput(filePtr->write);
- }
- }
- if (mask & TCL_EXCEPTION) {
- if (!(filePtr->mask & TCL_EXCEPTION)) {
- filePtr->except =
- XtAppAddInput(notifier.appContext, fd, XtInputExceptMask,
- FileProc, filePtr);
- }
- } else {
- if (filePtr->mask & TCL_EXCEPTION) {
- XtRemoveInput(filePtr->except);
- }
- }
- filePtr->mask = mask;
-}
-
-/*
- *----------------------------------------------------------------------
- *
- * Tcl_DeleteFileHandler --
- *
- * Cancel a previously-arranged callback arrangement for
- * a file.
- *
- * Results:
- * None.
- *
- * Side effects:
- * If a callback was previously registered on file, remove it.
- *
- *----------------------------------------------------------------------
- */
-
-void
-Tcl_DeleteFileHandler(fd)
- int fd; /* Stream id for which to remove
- * callback procedure. */
-{
- FileHandler *filePtr, *prevPtr;
-
- if (!initialized) {
- InitNotifier();
- }
-
- TclSetAppContext(NULL);
-
- /*
- * Find the entry for the given file (and return if there
- * isn't one).
- */
-
- for (prevPtr = NULL, filePtr = notifier.firstFileHandlerPtr; ;
- prevPtr = filePtr, filePtr = filePtr->nextPtr) {
- if (filePtr == NULL) {
- return;
- }
- if (filePtr->fd == fd) {
- break;
- }
- }
-
- /*
- * Clean up information in the callback record.
- */
-
- if (prevPtr == NULL) {
- notifier.firstFileHandlerPtr = filePtr->nextPtr;
- } else {
- prevPtr->nextPtr = filePtr->nextPtr;
- }
- if (filePtr->mask & TCL_READABLE) {
- XtRemoveInput(filePtr->read);
- }
- if (filePtr->mask & TCL_WRITABLE) {
- XtRemoveInput(filePtr->write);
- }
- if (filePtr->mask & TCL_EXCEPTION) {
- XtRemoveInput(filePtr->except);
- }
- ckfree((char *) filePtr);
-}
-
-/*
- *----------------------------------------------------------------------
- *
- * FileProc --
- *
- * These procedures are called by Xt when a file becomes readable,
- * writable, or has an exception.
- *
- * Results:
- * None.
- *
- * Side effects:
- * Makes an entry on the Tcl event queue if the event is
- * interesting.
- *
- *----------------------------------------------------------------------
- */
-
-static void
-FileProc(clientData, fd, id)
- caddr_t clientData;
- int *fd;
- XtInputId *id;
-{
- FileHandler *filePtr = (FileHandler *)clientData;
- FileHandlerEvent *fileEvPtr;
- int mask = 0;
-
- /*
- * Determine which event happened.
- */
-
- if (*id == filePtr->read) {
- mask = TCL_READABLE;
- } else if (*id == filePtr->write) {
- mask = TCL_WRITABLE;
- } else if (*id == filePtr->except) {
- mask = TCL_EXCEPTION;
- }
-
- /*
- * Ignore unwanted or duplicate events.
- */
-
- if (!(filePtr->mask & mask) || (filePtr->readyMask & mask)) {
- return;
- }
-
- /*
- * This is an interesting event, so put it onto the event queue.
- */
-
- filePtr->readyMask |= mask;
- fileEvPtr = (FileHandlerEvent *) ckalloc(sizeof(FileHandlerEvent));
- fileEvPtr->header.proc = FileHandlerEventProc;
- fileEvPtr->fd = filePtr->fd;
- Tcl_QueueEvent((Tcl_Event *) fileEvPtr, TCL_QUEUE_TAIL);
-
- /*
- * Process events on the Tcl event queue before returning to Xt.
- */
-
- Tcl_ServiceAll();
-}
-
-/*
- *----------------------------------------------------------------------
- *
- * FileHandlerEventProc --
- *
- * This procedure is called by Tcl_ServiceEvent when a file event
- * reaches the front of the event queue. This procedure is
- * responsible for actually handling the event by invoking the
- * callback for the file handler.
- *
- * 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 file handler's callback procedure does.
- *
- *----------------------------------------------------------------------
- */
-
-static int
-FileHandlerEventProc(evPtr, flags)
- Tcl_Event *evPtr; /* Event to service. */
- int flags; /* Flags that indicate what events to
- * handle, such as TCL_FILE_EVENTS. */
-{
- FileHandler *filePtr;
- FileHandlerEvent *fileEvPtr = (FileHandlerEvent *) evPtr;
- int mask;
-
- if (!(flags & TCL_FILE_EVENTS)) {
- return 0;
- }
-
- /*
- * Search through the file handlers to find the one whose handle matches
- * the event. We do this rather than keeping a pointer to the file
- * handler directly in the event, so that the handler can be deleted
- * while the event is queued without leaving a dangling pointer.
- */
-
- for (filePtr = notifier.firstFileHandlerPtr; filePtr != NULL;
- filePtr = filePtr->nextPtr) {
- if (filePtr->fd != fileEvPtr->fd) {
- continue;
- }
-
- /*
- * The code is tricky for two reasons:
- * 1. The file handler's desired events could have changed
- * since the time when the event was queued, so AND the
- * ready mask with the desired mask.
- * 2. The file could have been closed and re-opened since
- * the time when the event was queued. This is why the
- * ready mask is stored in the file handler rather than
- * the queued event: it will be zeroed when a new
- * file handler is created for the newly opened file.
- */
-
- mask = filePtr->readyMask & filePtr->mask;
- filePtr->readyMask = 0;
- if (mask != 0) {
- (*filePtr->proc)(filePtr->clientData, mask);
- }
- break;
- }
- return 1;
-}
-
-/*
- *----------------------------------------------------------------------
- *
- * Tcl_WaitForEvent --
- *
- * This function is called by Tcl_DoOneEvent to wait for new
- * events on the message queue. If the block time is 0, then
- * Tcl_WaitForEvent just polls without blocking.
- *
- * Results:
- * Returns 1 if an event was found, else 0. This ensures that
- * Tcl_DoOneEvent will return 1, even if the event is handled
- * by non-Tcl code.
- *
- * Side effects:
- * Queues file events that are detected by the select.
- *
- *----------------------------------------------------------------------
- */
-
-int
-Tcl_WaitForEvent(
- Tcl_Time *timePtr) /* Maximum block time, or NULL. */
-{
- int timeout;
-
- if (!initialized) {
- InitNotifier();
- }
-
- TclSetAppContext(NULL);
-
- if (timePtr) {
- timeout = timePtr->sec * 1000 + timePtr->usec / 1000;
- if (timeout == 0) {
- if (XtAppPending(notifier.appContext)) {
- goto process;
- } else {
- return 0;
- }
- } else {
- Tcl_SetTimer(timePtr);
- }
- }
-process:
- XtAppProcessEvent(notifier.appContext, XtIMAll);
- return 1;
-}
+/* + * tclXtNotify.c -- + * + * This file contains the notifier driver implementation for the + * Xt intrinsics. + * + * Copyright (c) 1997 by Sun Microsystems, Inc. + * + * See the file "license.terms" for information on usage and redistribution + * of this file, and for a DISCLAIMER OF ALL WARRANTIES. + * + * RCS: @(#) $Id: tclXtNotify.c,v 1.3 1999/02/03 02:59:08 stanton Exp $ + */ + +#include <X11/Intrinsic.h> +#include <tclInt.h> + +/* + * This structure is used to keep track of the notifier info for a + * a registered file. + */ + +typedef struct FileHandler { + int fd; + int mask; /* Mask of desired events: TCL_READABLE, etc. */ + int readyMask; /* Events that have been seen since the + last time FileHandlerEventProc was called + for this file. */ + XtInputId read; /* Xt read callback handle. */ + XtInputId write; /* Xt write callback handle. */ + XtInputId except; /* Xt exception callback handle. */ + Tcl_FileProc *proc; /* Procedure to call, in the style of + * Tcl_CreateFileHandler. */ + ClientData clientData; /* Argument to pass to proc. */ + struct FileHandler *nextPtr;/* Next in list of all files we care about. */ +} FileHandler; + +/* + * The following structure is what is added to the Tcl event queue when + * file handlers are ready to fire. + */ + +typedef struct FileHandlerEvent { + Tcl_Event header; /* Information that is standard for + * all events. */ + int fd; /* File descriptor that is ready. Used + * to find the FileHandler structure for + * the file (can't point directly to the + * FileHandler structure because it could + * go away while the event is queued). */ +} FileHandlerEvent; + +/* + * The following static structure contains the state information for the + * Xt based implementation of the Tcl notifier. + */ + +static struct NotifierState { + XtAppContext appContext; /* The context used by the Xt + * notifier. Can be set with + * TclSetAppContext. */ + int appContextCreated; /* Was it created by us? */ + XtIntervalId currentTimeout; /* Handle of current timer. */ + FileHandler *firstFileHandlerPtr; /* Pointer to head of file handler + * list. */ +} notifier; + +/* + * The following static indicates whether this module has been initialized. + */ + +static int initialized = 0; + +/* + * Static routines defined in this file. + */ + +static int FileHandlerEventProc _ANSI_ARGS_((Tcl_Event *evPtr, + int flags)); +static void FileProc _ANSI_ARGS_((caddr_t clientData, + int *source, XtInputId *id)); +static void InitNotifier _ANSI_ARGS_((void)); +static void NotifierExitHandler _ANSI_ARGS_(( + ClientData clientData)); +static void TimerProc _ANSI_ARGS_((caddr_t clientData, + XtIntervalId *id)); + +/* + * Functions defined in this file for use by users of the Xt Notifier: + */ + +EXTERN XtAppContext TclSetAppContext _ANSI_ARGS_((XtAppContext ctx)); + +/* + *---------------------------------------------------------------------- + * + * TclSetAppContext -- + * + * Set the notifier application context. + * + * Results: + * None. + * + * Side effects: + * Sets the application context used by the notifier. Panics if + * the context is already set when called. + * + *---------------------------------------------------------------------- + */ + +XtAppContext +TclSetAppContext(appContext) + XtAppContext appContext; +{ + if (!initialized) { + InitNotifier(); + } + + /* + * If we already have a context we check whether we were asked to set a + * new context. If so, we panic because we try to prevent switching + * contexts by mistake. Otherwise, we return the one we have. + */ + + if (notifier.appContext != NULL) { + if (appContext != NULL) { + + /* + * We already have a context. We do not allow switching contexts + * after initialization, so we panic. + */ + + panic("TclSetAppContext: multiple application contexts"); + + } + } else { + + /* + * If we get here we have not yet gotten a context, so either create + * one or use the one supplied by our caller. + */ + + if (appContext == NULL) { + + /* + * We must create a new context and tell our caller what it is, so + * she can use it too. + */ + + notifier.appContext = XtCreateApplicationContext(); + notifier.appContextCreated = 1; + } else { + + /* + * Otherwise we remember the context that our caller gave us + * and use it. + */ + + notifier.appContextCreated = 0; + notifier.appContext = appContext; + } + } + + return notifier.appContext; +} + +/* + *---------------------------------------------------------------------- + * + * InitNotifier -- + * + * Initializes the notifier state. + * + * Results: + * None. + * + * Side effects: + * Creates a new exit handler. + * + *---------------------------------------------------------------------- + */ + +static void +InitNotifier(void) +{ + /* + * Only reinitialize if we are not in exit handling. The notifier + * can get reinitialized after its own exit handler has run, because + * of exit handlers for the I/O and timer sub-systems (order dependency). + */ + + if (TclInExit()) { + return; + } + + /* + * DO NOT create the application context yet; doing so would prevent + * external applications from setting it for us to their own ones. + */ + + initialized = 1; + memset(¬ifier, 0, sizeof(notifier)); + Tcl_CreateExitHandler(NotifierExitHandler, NULL); +} + +/* + *---------------------------------------------------------------------- + * + * NotifierExitHandler -- + * + * This function is called to cleanup the notifier state before + * Tcl is unloaded. + * + * Results: + * None. + * + * Side effects: + * Destroys the notifier window. + * + *---------------------------------------------------------------------- + */ + +static void +NotifierExitHandler( + ClientData clientData) /* Not used. */ +{ + if (notifier.currentTimeout != 0) { + XtRemoveTimeOut(notifier.currentTimeout); + } + for (; notifier.firstFileHandlerPtr != NULL; ) { + Tcl_DeleteFileHandler(notifier.firstFileHandlerPtr->fd); + } + if (notifier.appContextCreated) { + XtDestroyApplicationContext(notifier.appContext); + notifier.appContextCreated = 0; + notifier.appContext = NULL; + } + initialized = 0; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_SetTimer -- + * + * This procedure sets the current notifier timeout value. + * + * Results: + * None. + * + * Side effects: + * Replaces any previous timer. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_SetTimer(timePtr) + Tcl_Time *timePtr; /* Timeout value, may be NULL. */ +{ + long timeout; + + if (!initialized) { + InitNotifier(); + } + + TclSetAppContext(NULL); + if (notifier.currentTimeout != 0) { + XtRemoveTimeOut(notifier.currentTimeout); + } + if (timePtr) { + timeout = timePtr->sec * 1000 + timePtr->usec / 1000; + notifier.currentTimeout = + XtAppAddTimeOut(notifier.appContext, (unsigned long) timeout, + TimerProc, NULL); + } else { + notifier.currentTimeout = 0; + } +} + +/* + *---------------------------------------------------------------------- + * + * TimerProc -- + * + * This procedure is the XtTimerCallbackProc used to handle + * timeouts. + * + * Results: + * None. + * + * Side effects: + * Processes all queued events. + * + *---------------------------------------------------------------------- + */ + +static void +TimerProc(data, id) + caddr_t data; /* Not used. */ + XtIntervalId *id; +{ + if (*id != notifier.currentTimeout) { + return; + } + notifier.currentTimeout = 0; + + Tcl_ServiceAll(); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_CreateFileHandler -- + * + * This procedure registers a file handler with the Xt notifier. + * + * Results: + * None. + * + * Side effects: + * Creates a new file handler structure and registers one or more + * input procedures with Xt. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_CreateFileHandler(fd, mask, proc, clientData) + int fd; /* Handle of stream to watch. */ + int mask; /* OR'ed combination of TCL_READABLE, + * TCL_WRITABLE, and TCL_EXCEPTION: + * indicates conditions under which + * proc should be called. */ + Tcl_FileProc *proc; /* Procedure to call for each + * selected event. */ + ClientData clientData; /* Arbitrary data to pass to proc. */ +{ + FileHandler *filePtr; + + if (!initialized) { + InitNotifier(); + } + + TclSetAppContext(NULL); + + for (filePtr = notifier.firstFileHandlerPtr; filePtr != NULL; + filePtr = filePtr->nextPtr) { + if (filePtr->fd == fd) { + break; + } + } + if (filePtr == NULL) { + filePtr = (FileHandler*) ckalloc(sizeof(FileHandler)); + filePtr->fd = fd; + filePtr->read = 0; + filePtr->write = 0; + filePtr->except = 0; + filePtr->readyMask = 0; + filePtr->mask = 0; + filePtr->nextPtr = notifier.firstFileHandlerPtr; + notifier.firstFileHandlerPtr = filePtr; + } + filePtr->proc = proc; + filePtr->clientData = clientData; + + /* + * Register the file with the Xt notifier, if it hasn't been done yet. + */ + + if (mask & TCL_READABLE) { + if (!(filePtr->mask & TCL_READABLE)) { + filePtr->read = + XtAppAddInput(notifier.appContext, fd, XtInputReadMask, + FileProc, filePtr); + } + } else { + if (filePtr->mask & TCL_READABLE) { + XtRemoveInput(filePtr->read); + } + } + if (mask & TCL_WRITABLE) { + if (!(filePtr->mask & TCL_WRITABLE)) { + filePtr->write = + XtAppAddInput(notifier.appContext, fd, XtInputWriteMask, + FileProc, filePtr); + } + } else { + if (filePtr->mask & TCL_WRITABLE) { + XtRemoveInput(filePtr->write); + } + } + if (mask & TCL_EXCEPTION) { + if (!(filePtr->mask & TCL_EXCEPTION)) { + filePtr->except = + XtAppAddInput(notifier.appContext, fd, XtInputExceptMask, + FileProc, filePtr); + } + } else { + if (filePtr->mask & TCL_EXCEPTION) { + XtRemoveInput(filePtr->except); + } + } + filePtr->mask = mask; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_DeleteFileHandler -- + * + * Cancel a previously-arranged callback arrangement for + * a file. + * + * Results: + * None. + * + * Side effects: + * If a callback was previously registered on file, remove it. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_DeleteFileHandler(fd) + int fd; /* Stream id for which to remove + * callback procedure. */ +{ + FileHandler *filePtr, *prevPtr; + + if (!initialized) { + InitNotifier(); + } + + TclSetAppContext(NULL); + + /* + * Find the entry for the given file (and return if there + * isn't one). + */ + + for (prevPtr = NULL, filePtr = notifier.firstFileHandlerPtr; ; + prevPtr = filePtr, filePtr = filePtr->nextPtr) { + if (filePtr == NULL) { + return; + } + if (filePtr->fd == fd) { + break; + } + } + + /* + * Clean up information in the callback record. + */ + + if (prevPtr == NULL) { + notifier.firstFileHandlerPtr = filePtr->nextPtr; + } else { + prevPtr->nextPtr = filePtr->nextPtr; + } + if (filePtr->mask & TCL_READABLE) { + XtRemoveInput(filePtr->read); + } + if (filePtr->mask & TCL_WRITABLE) { + XtRemoveInput(filePtr->write); + } + if (filePtr->mask & TCL_EXCEPTION) { + XtRemoveInput(filePtr->except); + } + ckfree((char *) filePtr); +} + +/* + *---------------------------------------------------------------------- + * + * FileProc -- + * + * These procedures are called by Xt when a file becomes readable, + * writable, or has an exception. + * + * Results: + * None. + * + * Side effects: + * Makes an entry on the Tcl event queue if the event is + * interesting. + * + *---------------------------------------------------------------------- + */ + +static void +FileProc(clientData, fd, id) + caddr_t clientData; + int *fd; + XtInputId *id; +{ + FileHandler *filePtr = (FileHandler *)clientData; + FileHandlerEvent *fileEvPtr; + int mask = 0; + + /* + * Determine which event happened. + */ + + if (*id == filePtr->read) { + mask = TCL_READABLE; + } else if (*id == filePtr->write) { + mask = TCL_WRITABLE; + } else if (*id == filePtr->except) { + mask = TCL_EXCEPTION; + } + + /* + * Ignore unwanted or duplicate events. + */ + + if (!(filePtr->mask & mask) || (filePtr->readyMask & mask)) { + return; + } + + /* + * This is an interesting event, so put it onto the event queue. + */ + + filePtr->readyMask |= mask; + fileEvPtr = (FileHandlerEvent *) ckalloc(sizeof(FileHandlerEvent)); + fileEvPtr->header.proc = FileHandlerEventProc; + fileEvPtr->fd = filePtr->fd; + Tcl_QueueEvent((Tcl_Event *) fileEvPtr, TCL_QUEUE_TAIL); + + /* + * Process events on the Tcl event queue before returning to Xt. + */ + + Tcl_ServiceAll(); +} + +/* + *---------------------------------------------------------------------- + * + * FileHandlerEventProc -- + * + * This procedure is called by Tcl_ServiceEvent when a file event + * reaches the front of the event queue. This procedure is + * responsible for actually handling the event by invoking the + * callback for the file handler. + * + * 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 file handler's callback procedure does. + * + *---------------------------------------------------------------------- + */ + +static int +FileHandlerEventProc(evPtr, flags) + Tcl_Event *evPtr; /* Event to service. */ + int flags; /* Flags that indicate what events to + * handle, such as TCL_FILE_EVENTS. */ +{ + FileHandler *filePtr; + FileHandlerEvent *fileEvPtr = (FileHandlerEvent *) evPtr; + int mask; + + if (!(flags & TCL_FILE_EVENTS)) { + return 0; + } + + /* + * Search through the file handlers to find the one whose handle matches + * the event. We do this rather than keeping a pointer to the file + * handler directly in the event, so that the handler can be deleted + * while the event is queued without leaving a dangling pointer. + */ + + for (filePtr = notifier.firstFileHandlerPtr; filePtr != NULL; + filePtr = filePtr->nextPtr) { + if (filePtr->fd != fileEvPtr->fd) { + continue; + } + + /* + * The code is tricky for two reasons: + * 1. The file handler's desired events could have changed + * since the time when the event was queued, so AND the + * ready mask with the desired mask. + * 2. The file could have been closed and re-opened since + * the time when the event was queued. This is why the + * ready mask is stored in the file handler rather than + * the queued event: it will be zeroed when a new + * file handler is created for the newly opened file. + */ + + mask = filePtr->readyMask & filePtr->mask; + filePtr->readyMask = 0; + if (mask != 0) { + (*filePtr->proc)(filePtr->clientData, mask); + } + break; + } + return 1; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_WaitForEvent -- + * + * This function is called by Tcl_DoOneEvent to wait for new + * events on the message queue. If the block time is 0, then + * Tcl_WaitForEvent just polls without blocking. + * + * Results: + * Returns 1 if an event was found, else 0. This ensures that + * Tcl_DoOneEvent will return 1, even if the event is handled + * by non-Tcl code. + * + * Side effects: + * Queues file events that are detected by the select. + * + *---------------------------------------------------------------------- + */ + +int +Tcl_WaitForEvent( + Tcl_Time *timePtr) /* Maximum block time, or NULL. */ +{ + int timeout; + + if (!initialized) { + InitNotifier(); + } + + TclSetAppContext(NULL); + + if (timePtr) { + timeout = timePtr->sec * 1000 + timePtr->usec / 1000; + if (timeout == 0) { + if (XtAppPending(notifier.appContext)) { + goto process; + } else { + return 0; + } + } else { + Tcl_SetTimer(timePtr); + } + } +process: + XtAppProcessEvent(notifier.appContext, XtIMAll); + return 1; +} |