Experiment after suggestion by Zoran Vasiljevic at comp.lang.tcl to send a script from *any* thread to a thread with a Tcl interpreter. This can be useful for extension developers in C that uses a library that executes callbacks in other threads than the main thread where the Tcl interpreter lives. Most code duplicated from the thread package.
/*
*
*
*
*
*
*/
#if TARGET_API_MAC_CARBON
# include <Tcl/tcl.h>
#else
# include "tcl.h"
#endif
#ifndef TCL_TSD_INIT
#define TCL_TSD_INIT(keyPtr) \
(ThreadSpecificData*)Tcl_GetThreadData((keyPtr),sizeof(ThreadSpecificData))
#endif
/* */
typedef struct ThreadSpecificData {
Tcl_Interp *interp; /* Interp to evaluate scripts */
} ThreadSpecificData;
static Tcl_ThreadDataKey dataKey;
/* */
typedef struct ThreadEvent {
Tcl_Event event; /* Must be first */
struct ThreadSendData *sendData; /* See below */
} ThreadEvent;
typedef int (ThreadSendProc) _ANSI_ARGS_((Tcl_Interp*, ClientData));
typedef void (ThreadSendFree) _ANSI_ARGS_((ClientData));
static ThreadSendProc ThreadSendEval; /* Does a regular Tcl_Eval */
/* */
typedef struct ThreadSendData {
ThreadSendProc *execProc; /* Func to exec in remote thread */
ClientData clientData; /* Ptr to pass to send function */
ThreadSendFree *freeProc; /* Function to free client data */
} ThreadSendData;
static void
ThreadSend _ANSI_ARGS_((Tcl_ThreadId targetId, ThreadSendData *send));
static int
ThreadEventProc _ANSI_ARGS_((Tcl_Event *evPtr, int mask));
static void
ThreadFreeProc _ANSI_ARGS_((ClientData clientData));
/*
*----------------------------------------------------------------------
**
*
*
*
*----------------------------------------------------------------------
*/
void XThread_RegisterThread(Tcl_Interp *interp)
{
ThreadSpecificData* tsdPtr = TCL_TSD_INIT(&dataKey);
tsdPtr->interp = interp;
Tcl_Preserve((ClientData)interp);
}
/*
*----------------------------------------------------------------------
**
*
*
*
*----------------------------------------------------------------------
*/
void XThread_UnregisterThread()
{
ThreadSpecificData* tsdPtr = TCL_TSD_INIT(&dataKey);
if (tsdPtr->interp) {
Tcl_Release((ClientData)tsdPtr->interp);
tsdPtr->interp = NULL;
}
}
/*
*----------------------------------------------------------------------
**
*
*
*
*
*----------------------------------------------------------------------
*/
void XThread_EvalInThread(Tcl_ThreadId threadId, const char *script, int flags)
{
ThreadSendData *sendPtr;
int len = strlen(script);
/*
* Prepare job record for the target thread
*/
sendPtr = (ThreadSendData*)Tcl_Alloc(sizeof(ThreadSendData));
sendPtr->execProc = ThreadSendEval;
sendPtr->freeProc = (ThreadSendFree*)Tcl_Free;
sendPtr->clientData = (ClientData)strcpy(Tcl_Alloc(1+len), script);
ThreadSend((Tcl_ThreadId)threadId, sendPtr);
}
/*
*----------------------------------------------------------------------
**
*
*
*
*----------------------------------------------------------------------
*/
static void
ThreadSend(targetId, send)
Tcl_ThreadId targetId; /* Thread Id of other thread. */
ThreadSendData *send; /* Pointer to structure with work to do */
{
ThreadEvent *eventPtr;
/*
* Create the event for target thread event queue.
*/
eventPtr = (ThreadEvent*)Tcl_Alloc(sizeof(ThreadEvent));
eventPtr->sendData = send;
eventPtr->event.proc = ThreadEventProc;
/*
* Queue the event and poke the other thread's notifier.
* The thread "id" should eventually visit it's event
* loop in order to process this event.
*/
Tcl_ThreadQueueEvent(targetId, (Tcl_Event*)eventPtr, TCL_QUEUE_TAIL);
Tcl_ThreadAlert(targetId);
return;
}
/*
*----------------------------------------------------------------------
**
*
*
*
*----------------------------------------------------------------------
*/
static int
ThreadSendEval(interp, clientData)
Tcl_Interp *interp;
ClientData clientData;
{
ThreadSendData *sendPtr = (ThreadSendData*)clientData;
char *script = (char*)sendPtr->clientData;
return Tcl_EvalEx(interp, script, -1, TCL_EVAL_GLOBAL);
}
/*
*----------------------------------------------------------------------
**
*
*
*
*----------------------------------------------------------------------
*/
static int
ThreadEventProc(evPtr, mask)
Tcl_Event *evPtr; /* Really ThreadEvent */
int mask;
{
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
ThreadEvent *eventPtr = (ThreadEvent*)evPtr;
ThreadSendData *sendPtr = eventPtr->sendData;
if (tsdPtr->interp != NULL) {
if (sendPtr) {
Tcl_CreateThreadExitHandler(ThreadFreeProc, (ClientData)sendPtr);
(*sendPtr->execProc)(tsdPtr->interp, (ClientData)sendPtr);
Tcl_DeleteThreadExitHandler(ThreadFreeProc, (ClientData)sendPtr);
}
}
ThreadFreeProc((ClientData)sendPtr);
return 1;
}
/*
*----------------------------------------------------------------------
**
*
*
*
*----------------------------------------------------------------------
*/
static void
ThreadFreeProc(clientData)
ClientData clientData;
{
ThreadSendData *anyPtr = (ThreadSendData*)clientData;
if (anyPtr) {
if (anyPtr->clientData) {
(*anyPtr->freeProc)(anyPtr->clientData);
}
Tcl_Free((char*)anyPtr);
}
}