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Diffstat (limited to 'generic/tclEvent.c')
| -rw-r--r-- | generic/tclEvent.c | 1627 |
1 files changed, 1627 insertions, 0 deletions
diff --git a/generic/tclEvent.c b/generic/tclEvent.c new file mode 100644 index 0000000..0eabc13 --- /dev/null +++ b/generic/tclEvent.c @@ -0,0 +1,1627 @@ +/* + * tclEvent.c -- + * + * This file implements some general event related interfaces including + * background errors, exit handlers, and the "vwait" and "update" command + * functions. + * + * Copyright (c) 1990-1994 The Regents of the University of California. + * Copyright (c) 1994-1998 Sun Microsystems, Inc. + * Copyright (c) 2004 by Zoran Vasiljevic. + * + * See the file "license.terms" for information on usage and redistribution of + * this file, and for a DISCLAIMER OF ALL WARRANTIES. + */ + +#include "tclInt.h" + +/* + * The data structure below is used to report background errors. One such + * structure is allocated for each error; it holds information about the + * interpreter and the error until an idle handler command can be invoked. + */ + +typedef struct BgError { + Tcl_Obj *errorMsg; /* Copy of the error message (the interp's + * result when the error occurred). */ + Tcl_Obj *returnOpts; /* Active return options when the error + * occurred */ + struct BgError *nextPtr; /* Next in list of all pending error reports + * for this interpreter, or NULL for end of + * list. */ +} BgError; + +/* + * One of the structures below is associated with the "tclBgError" assoc data + * for each interpreter. It keeps track of the head and tail of the list of + * pending background errors for the interpreter. + */ + +typedef struct ErrAssocData { + Tcl_Interp *interp; /* Interpreter in which error occurred. */ + Tcl_Obj *cmdPrefix; /* First word(s) of the handler command */ + BgError *firstBgPtr; /* First in list of all background errors + * waiting to be processed for this + * interpreter (NULL if none). */ + BgError *lastBgPtr; /* Last in list of all background errors + * waiting to be processed for this + * interpreter (NULL if none). */ +} ErrAssocData; + +/* + * For each exit handler created with a call to Tcl_Create(Late)ExitHandler + * there is a structure of the following type: + */ + +typedef struct ExitHandler { + Tcl_ExitProc *proc; /* Function to call when process exits. */ + ClientData clientData; /* One word of information to pass to proc. */ + struct ExitHandler *nextPtr;/* Next in list of all exit handlers for this + * application, or NULL for end of list. */ +} ExitHandler; + +/* + * There is both per-process and per-thread exit handlers. The first list is + * controlled by a mutex. The other is in thread local storage. + */ + +static ExitHandler *firstExitPtr = NULL; + /* First in list of all exit handlers for + * application. */ +static ExitHandler *firstLateExitPtr = NULL; + /* First in list of all late exit handlers for + * application. */ +TCL_DECLARE_MUTEX(exitMutex) + +/* + * This variable is set to 1 when Tcl_Exit is called. The variable is checked + * by TclInExit() to allow different behavior for exit-time processing, e.g., + * in closing of files and pipes. + */ + +static int inExit = 0; + +static int subsystemsInitialized = 0; + +/* + * This variable contains the application wide exit handler. It will be called + * by Tcl_Exit instead of the C-runtime exit if this variable is set to a + * non-NULL value. + */ + +static TCL_NORETURN1 Tcl_ExitProc *appExitPtr = NULL; + +typedef struct ThreadSpecificData { + ExitHandler *firstExitPtr; /* First in list of all exit handlers for this + * thread. */ + int inExit; /* True when this thread is exiting. This is + * used as a hack to decide to close the + * standard channels. */ +} ThreadSpecificData; +static Tcl_ThreadDataKey dataKey; + +#ifdef TCL_THREADS +typedef struct { + Tcl_ThreadCreateProc *proc; /* Main() function of the thread */ + ClientData clientData; /* The one argument to Main() */ +} ThreadClientData; +static Tcl_ThreadCreateType NewThreadProc(ClientData clientData); +#endif /* TCL_THREADS */ + +/* + * Prototypes for functions referenced only in this file: + */ + +static void BgErrorDeleteProc(ClientData clientData, + Tcl_Interp *interp); +static void HandleBgErrors(ClientData clientData); +static char * VwaitVarProc(ClientData clientData, + Tcl_Interp *interp, const char *name1, + const char *name2, int flags); +static void InvokeExitHandlers(void); +static void FinalizeThread(int quick); + +/* + *---------------------------------------------------------------------- + * + * Tcl_BackgroundError -- + * + * This function is invoked to handle errors that occur in Tcl commands + * that are invoked in "background" (e.g. from event or timer bindings). + * + * Results: + * None. + * + * Side effects: + * A handler command is invoked later as an idle handler to process the + * error, passing it the interp result and return options. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_BackgroundError( + Tcl_Interp *interp) /* Interpreter in which an error has + * occurred. */ +{ + Tcl_BackgroundException(interp, TCL_ERROR); +} + +void +Tcl_BackgroundException( + Tcl_Interp *interp, /* Interpreter in which an exception has + * occurred. */ + int code) /* The exception code value */ +{ + BgError *errPtr; + ErrAssocData *assocPtr; + + if (code == TCL_OK) { + return; + } + + errPtr = ckalloc(sizeof(BgError)); + errPtr->errorMsg = Tcl_GetObjResult(interp); + Tcl_IncrRefCount(errPtr->errorMsg); + errPtr->returnOpts = Tcl_GetReturnOptions(interp, code); + Tcl_IncrRefCount(errPtr->returnOpts); + errPtr->nextPtr = NULL; + + (void) TclGetBgErrorHandler(interp); + assocPtr = Tcl_GetAssocData(interp, "tclBgError", NULL); + if (assocPtr->firstBgPtr == NULL) { + assocPtr->firstBgPtr = errPtr; + Tcl_DoWhenIdle(HandleBgErrors, assocPtr); + } else { + assocPtr->lastBgPtr->nextPtr = errPtr; + } + assocPtr->lastBgPtr = errPtr; + Tcl_ResetResult(interp); +} + +/* + *---------------------------------------------------------------------- + * + * HandleBgErrors -- + * + * This function is invoked as an idle handler to process all of the + * accumulated background errors. + * + * Results: + * None. + * + * Side effects: + * Depends on what actions the handler command takes for the errors. + * + *---------------------------------------------------------------------- + */ + +static void +HandleBgErrors( + ClientData clientData) /* Pointer to ErrAssocData structure. */ +{ + ErrAssocData *assocPtr = clientData; + Tcl_Interp *interp = assocPtr->interp; + BgError *errPtr; + + /* + * Not bothering to save/restore the interp state. Assume that any code + * that has interp state it needs to keep will make its own + * Tcl_SaveInterpState call before calling something like Tcl_DoOneEvent() + * that could lead us here. + */ + + Tcl_Preserve(assocPtr); + Tcl_Preserve(interp); + while (assocPtr->firstBgPtr != NULL) { + int code, prefixObjc; + Tcl_Obj **prefixObjv, **tempObjv; + + /* + * Note we copy the handler command prefix each pass through, so we do + * support one handler setting another handler. + */ + + Tcl_Obj *copyObj = TclListObjCopy(NULL, assocPtr->cmdPrefix); + + errPtr = assocPtr->firstBgPtr; + + Tcl_ListObjGetElements(NULL, copyObj, &prefixObjc, &prefixObjv); + tempObjv = ckalloc((prefixObjc+2) * sizeof(Tcl_Obj *)); + memcpy(tempObjv, prefixObjv, prefixObjc*sizeof(Tcl_Obj *)); + tempObjv[prefixObjc] = errPtr->errorMsg; + tempObjv[prefixObjc+1] = errPtr->returnOpts; + Tcl_AllowExceptions(interp); + code = Tcl_EvalObjv(interp, prefixObjc+2, tempObjv, TCL_EVAL_GLOBAL); + + /* + * Discard the command and the information about the error report. + */ + + Tcl_DecrRefCount(copyObj); + Tcl_DecrRefCount(errPtr->errorMsg); + Tcl_DecrRefCount(errPtr->returnOpts); + assocPtr->firstBgPtr = errPtr->nextPtr; + ckfree(errPtr); + ckfree(tempObjv); + + if (code == TCL_BREAK) { + /* + * Break means cancel any remaining error reports for this + * interpreter. + */ + + while (assocPtr->firstBgPtr != NULL) { + errPtr = assocPtr->firstBgPtr; + assocPtr->firstBgPtr = errPtr->nextPtr; + Tcl_DecrRefCount(errPtr->errorMsg); + Tcl_DecrRefCount(errPtr->returnOpts); + ckfree(errPtr); + } + } else if ((code == TCL_ERROR) && !Tcl_IsSafe(interp)) { + Tcl_Channel errChannel = Tcl_GetStdChannel(TCL_STDERR); + + if (errChannel != NULL) { + Tcl_Obj *options = Tcl_GetReturnOptions(interp, code); + Tcl_Obj *keyPtr, *valuePtr = NULL; + + TclNewLiteralStringObj(keyPtr, "-errorinfo"); + Tcl_IncrRefCount(keyPtr); + Tcl_DictObjGet(NULL, options, keyPtr, &valuePtr); + Tcl_DecrRefCount(keyPtr); + + Tcl_WriteChars(errChannel, + "error in background error handler:\n", -1); + if (valuePtr) { + Tcl_WriteObj(errChannel, valuePtr); + } else { + Tcl_WriteObj(errChannel, Tcl_GetObjResult(interp)); + } + Tcl_WriteChars(errChannel, "\n", 1); + Tcl_Flush(errChannel); + Tcl_DecrRefCount(options); + } + } + } + assocPtr->lastBgPtr = NULL; + Tcl_Release(interp); + Tcl_Release(assocPtr); +} + +/* + *---------------------------------------------------------------------- + * + * TclDefaultBgErrorHandlerObjCmd -- + * + * This function is invoked to process the "::tcl::Bgerror" Tcl command. + * It is the default handler command registered with [interp bgerror] for + * the sake of compatibility with older Tcl releases. + * + * Results: + * A standard Tcl object result. + * + * Side effects: + * Depends on what actions the "bgerror" command takes for the errors. + * + *---------------------------------------------------------------------- + */ + +int +TclDefaultBgErrorHandlerObjCmd( + ClientData dummy, /* Not used. */ + Tcl_Interp *interp, /* Current interpreter. */ + int objc, /* Number of arguments. */ + Tcl_Obj *const objv[]) /* Argument objects. */ +{ + Tcl_Obj *keyPtr, *valuePtr; + Tcl_Obj *tempObjv[2]; + int result, code, level; + Tcl_InterpState saved; + + if (objc != 3) { + Tcl_WrongNumArgs(interp, 1, objv, "msg options"); + return TCL_ERROR; + } + + /* + * Check for a valid return options dictionary. + */ + + TclNewLiteralStringObj(keyPtr, "-level"); + Tcl_IncrRefCount(keyPtr); + result = Tcl_DictObjGet(NULL, objv[2], keyPtr, &valuePtr); + Tcl_DecrRefCount(keyPtr); + if (result != TCL_OK || valuePtr == NULL) { + Tcl_SetObjResult(interp, Tcl_NewStringObj( + "missing return option \"-level\"", -1)); + Tcl_SetErrorCode(interp, "TCL", "ARGUMENT", "MISSING", NULL); + return TCL_ERROR; + } + if (Tcl_GetIntFromObj(interp, valuePtr, &level) == TCL_ERROR) { + return TCL_ERROR; + } + TclNewLiteralStringObj(keyPtr, "-code"); + Tcl_IncrRefCount(keyPtr); + result = Tcl_DictObjGet(NULL, objv[2], keyPtr, &valuePtr); + Tcl_DecrRefCount(keyPtr); + if (result != TCL_OK || valuePtr == NULL) { + Tcl_SetObjResult(interp, Tcl_NewStringObj( + "missing return option \"-code\"", -1)); + Tcl_SetErrorCode(interp, "TCL", "ARGUMENT", "MISSING", NULL); + return TCL_ERROR; + } + if (Tcl_GetIntFromObj(interp, valuePtr, &code) == TCL_ERROR) { + return TCL_ERROR; + } + + if (level != 0) { + /* + * We're handling a TCL_RETURN exception. + */ + + code = TCL_RETURN; + } + if (code == TCL_OK) { + /* + * Somehow we got to exception handling with no exception. (Pass + * TCL_OK to Tcl_BackgroundException()?) Just return without doing + * anything. + */ + + return TCL_OK; + } + + /* + * Construct the bgerror command. + */ + + TclNewLiteralStringObj(tempObjv[0], "bgerror"); + Tcl_IncrRefCount(tempObjv[0]); + + /* + * Determine error message argument. Check the return options in case + * a non-error exception brought us here. + */ + + switch (code) { + case TCL_ERROR: + tempObjv[1] = objv[1]; + break; + case TCL_BREAK: + TclNewLiteralStringObj(tempObjv[1], + "invoked \"break\" outside of a loop"); + break; + case TCL_CONTINUE: + TclNewLiteralStringObj(tempObjv[1], + "invoked \"continue\" outside of a loop"); + break; + default: + tempObjv[1] = Tcl_ObjPrintf("command returned bad code: %d", code); + break; + } + Tcl_IncrRefCount(tempObjv[1]); + + if (code != TCL_ERROR) { + Tcl_SetObjResult(interp, tempObjv[1]); + } + + TclNewLiteralStringObj(keyPtr, "-errorcode"); + Tcl_IncrRefCount(keyPtr); + result = Tcl_DictObjGet(NULL, objv[2], keyPtr, &valuePtr); + Tcl_DecrRefCount(keyPtr); + if (result == TCL_OK && valuePtr != NULL) { + Tcl_SetObjErrorCode(interp, valuePtr); + } + + TclNewLiteralStringObj(keyPtr, "-errorinfo"); + Tcl_IncrRefCount(keyPtr); + result = Tcl_DictObjGet(NULL, objv[2], keyPtr, &valuePtr); + Tcl_DecrRefCount(keyPtr); + if (result == TCL_OK && valuePtr != NULL) { + Tcl_AppendObjToErrorInfo(interp, valuePtr); + } + + if (code == TCL_ERROR) { + Tcl_SetObjResult(interp, tempObjv[1]); + } + + /* + * Save interpreter state so we can restore it if multiple handler + * attempts are needed. + */ + + saved = Tcl_SaveInterpState(interp, code); + + /* + * Invoke the bgerror command. + */ + + Tcl_AllowExceptions(interp); + code = Tcl_EvalObjv(interp, 2, tempObjv, TCL_EVAL_GLOBAL); + if (code == TCL_ERROR) { + /* + * If the interpreter is safe, we look for a hidden command named + * "bgerror" and call that with the error information. Otherwise, + * simply ignore the error. The rationale is that this could be an + * error caused by a malicious applet trying to cause an infinite + * barrage of error messages. The hidden "bgerror" command can be used + * by a security policy to interpose on such attacks and e.g. kill the + * applet after a few attempts. + */ + + if (Tcl_IsSafe(interp)) { + Tcl_RestoreInterpState(interp, saved); + TclObjInvoke(interp, 2, tempObjv, TCL_INVOKE_HIDDEN); + } else { + Tcl_Channel errChannel = Tcl_GetStdChannel(TCL_STDERR); + + if (errChannel != NULL) { + Tcl_Obj *resultPtr = Tcl_GetObjResult(interp); + + Tcl_IncrRefCount(resultPtr); + if (Tcl_FindCommand(interp, "bgerror", NULL, + TCL_GLOBAL_ONLY) == NULL) { + Tcl_RestoreInterpState(interp, saved); + Tcl_WriteObj(errChannel, Tcl_GetVar2Ex(interp, + "errorInfo", NULL, TCL_GLOBAL_ONLY)); + Tcl_WriteChars(errChannel, "\n", -1); + } else { + Tcl_DiscardInterpState(saved); + Tcl_WriteChars(errChannel, + "bgerror failed to handle background error.\n",-1); + Tcl_WriteChars(errChannel, " Original error: ", -1); + Tcl_WriteObj(errChannel, tempObjv[1]); + Tcl_WriteChars(errChannel, "\n", -1); + Tcl_WriteChars(errChannel, " Error in bgerror: ", -1); + Tcl_WriteObj(errChannel, resultPtr); + Tcl_WriteChars(errChannel, "\n", -1); + } + Tcl_DecrRefCount(resultPtr); + Tcl_Flush(errChannel); + } else { + Tcl_DiscardInterpState(saved); + } + } + code = TCL_OK; + } else { + Tcl_DiscardInterpState(saved); + } + + Tcl_DecrRefCount(tempObjv[0]); + Tcl_DecrRefCount(tempObjv[1]); + Tcl_ResetResult(interp); + return code; +} + +/* + *---------------------------------------------------------------------- + * + * TclSetBgErrorHandler -- + * + * This function sets the command prefix to be used to handle background + * errors in interp. + * + * Results: + * None. + * + * Side effects: + * Error handler is registered. + * + *---------------------------------------------------------------------- + */ + +void +TclSetBgErrorHandler( + Tcl_Interp *interp, + Tcl_Obj *cmdPrefix) +{ + ErrAssocData *assocPtr = Tcl_GetAssocData(interp, "tclBgError", NULL); + + if (cmdPrefix == NULL) { + Tcl_Panic("TclSetBgErrorHandler: NULL cmdPrefix argument"); + } + if (assocPtr == NULL) { + /* + * First access: initialize. + */ + + assocPtr = ckalloc(sizeof(ErrAssocData)); + assocPtr->interp = interp; + assocPtr->cmdPrefix = NULL; + assocPtr->firstBgPtr = NULL; + assocPtr->lastBgPtr = NULL; + Tcl_SetAssocData(interp, "tclBgError", BgErrorDeleteProc, assocPtr); + } + if (assocPtr->cmdPrefix) { + Tcl_DecrRefCount(assocPtr->cmdPrefix); + } + assocPtr->cmdPrefix = cmdPrefix; + Tcl_IncrRefCount(assocPtr->cmdPrefix); +} + +/* + *---------------------------------------------------------------------- + * + * TclGetBgErrorHandler -- + * + * This function retrieves the command prefix currently used to handle + * background errors in interp. + * + * Results: + * A (Tcl_Obj *) to a list of words (command prefix). + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +Tcl_Obj * +TclGetBgErrorHandler( + Tcl_Interp *interp) +{ + ErrAssocData *assocPtr = Tcl_GetAssocData(interp, "tclBgError", NULL); + + if (assocPtr == NULL) { + Tcl_Obj *bgerrorObj; + + TclNewLiteralStringObj(bgerrorObj, "::tcl::Bgerror"); + TclSetBgErrorHandler(interp, bgerrorObj); + assocPtr = Tcl_GetAssocData(interp, "tclBgError", NULL); + } + return assocPtr->cmdPrefix; +} + +/* + *---------------------------------------------------------------------- + * + * BgErrorDeleteProc -- + * + * This function is associated with the "tclBgError" assoc data for an + * interpreter; it is invoked when the interpreter is deleted in order to + * free the information assoicated with any pending error reports. + * + * Results: + * None. + * + * Side effects: + * Background error information is freed: if there were any pending error + * reports, they are canceled. + * + *---------------------------------------------------------------------- + */ + +static void +BgErrorDeleteProc( + ClientData clientData, /* Pointer to ErrAssocData structure. */ + Tcl_Interp *interp) /* Interpreter being deleted. */ +{ + ErrAssocData *assocPtr = clientData; + BgError *errPtr; + + while (assocPtr->firstBgPtr != NULL) { + errPtr = assocPtr->firstBgPtr; + assocPtr->firstBgPtr = errPtr->nextPtr; + Tcl_DecrRefCount(errPtr->errorMsg); + Tcl_DecrRefCount(errPtr->returnOpts); + ckfree(errPtr); + } + Tcl_CancelIdleCall(HandleBgErrors, assocPtr); + Tcl_DecrRefCount(assocPtr->cmdPrefix); + Tcl_EventuallyFree(assocPtr, TCL_DYNAMIC); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_CreateExitHandler -- + * + * Arrange for a given function to be invoked just before the application + * exits. + * + * Results: + * None. + * + * Side effects: + * Proc will be invoked with clientData as argument when the application + * exits. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_CreateExitHandler( + Tcl_ExitProc *proc, /* Function to invoke. */ + ClientData clientData) /* Arbitrary value to pass to proc. */ +{ + ExitHandler *exitPtr = ckalloc(sizeof(ExitHandler)); + + exitPtr->proc = proc; + exitPtr->clientData = clientData; + Tcl_MutexLock(&exitMutex); + exitPtr->nextPtr = firstExitPtr; + firstExitPtr = exitPtr; + Tcl_MutexUnlock(&exitMutex); +} + +/* + *---------------------------------------------------------------------- + * + * TclCreateLateExitHandler -- + * + * Arrange for a given function to be invoked after all pre-thread + * cleanups. + * + * Results: + * None. + * + * Side effects: + * Proc will be invoked with clientData as argument when the application + * exits. + * + *---------------------------------------------------------------------- + */ + +void +TclCreateLateExitHandler( + Tcl_ExitProc *proc, /* Function to invoke. */ + ClientData clientData) /* Arbitrary value to pass to proc. */ +{ + ExitHandler *exitPtr = ckalloc(sizeof(ExitHandler)); + + exitPtr->proc = proc; + exitPtr->clientData = clientData; + Tcl_MutexLock(&exitMutex); + exitPtr->nextPtr = firstLateExitPtr; + firstLateExitPtr = exitPtr; + Tcl_MutexUnlock(&exitMutex); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_DeleteExitHandler -- + * + * This function cancels an existing exit handler matching proc and + * clientData, if such a handler exits. + * + * Results: + * None. + * + * Side effects: + * If there is an exit handler corresponding to proc and clientData then + * it is canceled; if no such handler exists then nothing happens. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_DeleteExitHandler( + Tcl_ExitProc *proc, /* Function that was previously registered. */ + ClientData clientData) /* Arbitrary value to pass to proc. */ +{ + ExitHandler *exitPtr, *prevPtr; + + Tcl_MutexLock(&exitMutex); + for (prevPtr = NULL, exitPtr = firstExitPtr; exitPtr != NULL; + prevPtr = exitPtr, exitPtr = exitPtr->nextPtr) { + if ((exitPtr->proc == proc) + && (exitPtr->clientData == clientData)) { + if (prevPtr == NULL) { + firstExitPtr = exitPtr->nextPtr; + } else { + prevPtr->nextPtr = exitPtr->nextPtr; + } + ckfree(exitPtr); + break; + } + } + Tcl_MutexUnlock(&exitMutex); + return; +} + +/* + *---------------------------------------------------------------------- + * + * TclDeleteLateExitHandler -- + * + * This function cancels an existing late exit handler matching proc and + * clientData, if such a handler exits. + * + * Results: + * None. + * + * Side effects: + * If there is a late exit handler corresponding to proc and clientData + * then it is canceled; if no such handler exists then nothing happens. + * + *---------------------------------------------------------------------- + */ + +void +TclDeleteLateExitHandler( + Tcl_ExitProc *proc, /* Function that was previously registered. */ + ClientData clientData) /* Arbitrary value to pass to proc. */ +{ + ExitHandler *exitPtr, *prevPtr; + + Tcl_MutexLock(&exitMutex); + for (prevPtr = NULL, exitPtr = firstLateExitPtr; exitPtr != NULL; + prevPtr = exitPtr, exitPtr = exitPtr->nextPtr) { + if ((exitPtr->proc == proc) + && (exitPtr->clientData == clientData)) { + if (prevPtr == NULL) { + firstLateExitPtr = exitPtr->nextPtr; + } else { + prevPtr->nextPtr = exitPtr->nextPtr; + } + ckfree(exitPtr); + break; + } + } + Tcl_MutexUnlock(&exitMutex); + return; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_CreateThreadExitHandler -- + * + * Arrange for a given function to be invoked just before the current + * thread exits. + * + * Results: + * None. + * + * Side effects: + * Proc will be invoked with clientData as argument when the application + * exits. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_CreateThreadExitHandler( + Tcl_ExitProc *proc, /* Function to invoke. */ + ClientData clientData) /* Arbitrary value to pass to proc. */ +{ + ExitHandler *exitPtr; + ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); + + exitPtr = ckalloc(sizeof(ExitHandler)); + exitPtr->proc = proc; + exitPtr->clientData = clientData; + exitPtr->nextPtr = tsdPtr->firstExitPtr; + tsdPtr->firstExitPtr = exitPtr; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_DeleteThreadExitHandler -- + * + * This function cancels an existing exit handler matching proc and + * clientData, if such a handler exits. + * + * Results: + * None. + * + * Side effects: + * If there is an exit handler corresponding to proc and clientData then + * it is canceled; if no such handler exists then nothing happens. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_DeleteThreadExitHandler( + Tcl_ExitProc *proc, /* Function that was previously registered. */ + ClientData clientData) /* Arbitrary value to pass to proc. */ +{ + ExitHandler *exitPtr, *prevPtr; + ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); + + for (prevPtr = NULL, exitPtr = tsdPtr->firstExitPtr; exitPtr != NULL; + prevPtr = exitPtr, exitPtr = exitPtr->nextPtr) { + if ((exitPtr->proc == proc) + && (exitPtr->clientData == clientData)) { + if (prevPtr == NULL) { + tsdPtr->firstExitPtr = exitPtr->nextPtr; + } else { + prevPtr->nextPtr = exitPtr->nextPtr; + } + ckfree(exitPtr); + return; + } + } +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_SetExitProc -- + * + * This function sets the application wide exit handler that will be + * called by Tcl_Exit in place of the C-runtime exit. If the application + * wide exit handler is NULL, the C-runtime exit will be used instead. + * + * Results: + * The previously set application wide exit handler. + * + * Side effects: + * Sets the application wide exit handler to the specified value. + * + *---------------------------------------------------------------------- + */ + +Tcl_ExitProc * +Tcl_SetExitProc( + TCL_NORETURN1 Tcl_ExitProc *proc) /* New exit handler for app or NULL */ +{ + Tcl_ExitProc *prevExitProc; + + /* + * Swap the old exit proc for the new one, saving the old one for our + * return value. + */ + + Tcl_MutexLock(&exitMutex); + prevExitProc = appExitPtr; + appExitPtr = proc; + Tcl_MutexUnlock(&exitMutex); + + return prevExitProc; +} + + +/* + *---------------------------------------------------------------------- + * + * InvokeExitHandlers -- + * + * Call the registered exit handlers. + * + * Results: + * None. + * + * Side effects: + * The exit handlers are invoked, and the ExitHandler struct is + * freed. + * + *---------------------------------------------------------------------- + */ +static void +InvokeExitHandlers(void) +{ + ExitHandler *exitPtr; + + Tcl_MutexLock(&exitMutex); + inExit = 1; + + for (exitPtr = firstExitPtr; exitPtr != NULL; exitPtr = firstExitPtr) { + /* + * Be careful to remove the handler from the list before invoking its + * callback. This protects us against double-freeing if the callback + * should call Tcl_DeleteExitHandler on itself. + */ + + firstExitPtr = exitPtr->nextPtr; + Tcl_MutexUnlock(&exitMutex); + exitPtr->proc(exitPtr->clientData); + ckfree(exitPtr); + Tcl_MutexLock(&exitMutex); + } + firstExitPtr = NULL; + Tcl_MutexUnlock(&exitMutex); +} + + +/* + *---------------------------------------------------------------------- + * + * Tcl_Exit -- + * + * This function is called to terminate the application. + * + * Results: + * None. + * + * Side effects: + * All existing exit handlers are invoked, then the application ends. + * + *---------------------------------------------------------------------- + */ + +TCL_NORETURN void +Tcl_Exit( + int status) /* Exit status for application; typically 0 + * for normal return, 1 for error return. */ +{ + TCL_NORETURN1 Tcl_ExitProc *currentAppExitPtr; + + Tcl_MutexLock(&exitMutex); + currentAppExitPtr = appExitPtr; + Tcl_MutexUnlock(&exitMutex); + + if (currentAppExitPtr) { + /* + * Warning: this code SHOULD NOT return, as there is code that depends + * on Tcl_Exit never returning. In fact, we will Tcl_Panic if anyone + * returns, so critical is this dependcy. + */ + + currentAppExitPtr(INT2PTR(status)); + Tcl_Panic("AppExitProc returned unexpectedly"); + } else { + + if (TclFullFinalizationRequested()) { + + /* + * Thorough finalization for Valgrind et al. + */ + + Tcl_Finalize(); + + } else { + + /* + * Fast and deterministic exit (default behavior) + */ + + InvokeExitHandlers(); + + /* + * Ensure the thread-specific data is initialised as it is used in + * Tcl_FinalizeThread() + */ + + (void) TCL_TSD_INIT(&dataKey); + + /* + * Now finalize the calling thread only (others are not safely + * reachable). Among other things, this triggers a flush of the + * Tcl_Channels that may have data enqueued. + */ + + FinalizeThread(/* quick */ 1); + } + TclpExit(status); + Tcl_Panic("OS exit failed!"); + } +} + +/* + *------------------------------------------------------------------------- + * + * TclInitSubsystems -- + * + * Initialize various subsytems in Tcl. This should be called the first + * time an interp is created, or before any of the subsystems are used. + * This function ensures an order for the initialization of subsystems: + * + * 1. that cannot be initialized in lazy order because they are mutually + * dependent. + * + * 2. so that they can be finalized in a known order w/o causing the + * subsequent re-initialization of a subsystem in the act of shutting + * down another. + * + * Results: + * None. + * + * Side effects: + * Varied, see the respective initialization routines. + * + *------------------------------------------------------------------------- + */ + +void +TclInitSubsystems(void) +{ + if (inExit != 0) { + Tcl_Panic("TclInitSubsystems called while exiting"); + } + + if (subsystemsInitialized == 0) { + /* + * Double check inside the mutex. There are definitly calls back into + * this routine from some of the functions below. + */ + + TclpInitLock(); + if (subsystemsInitialized == 0) { + + /* + * Initialize locks used by the memory allocators before anything + * interesting happens so we can use the allocators in the + * implementation of self-initializing locks. + */ + + TclInitThreadStorage(); /* Creates master hash table for + * thread local storage */ +#if USE_TCLALLOC + TclInitAlloc(); /* Process wide mutex init */ +#endif +#if defined(TCL_THREADS) && defined(USE_THREAD_ALLOC) + TclpInitAllocCache(); +#endif +#ifdef TCL_MEM_DEBUG + TclInitDbCkalloc(); /* Process wide mutex init */ +#endif + + TclpInitPlatform(); /* Creates signal handler(s) */ + TclInitDoubleConversion(); /* Initializes constants for + * converting to/from double. */ + TclInitObjSubsystem(); /* Register obj types, create + * mutexes. */ + TclInitIOSubsystem(); /* Inits a tsd key (noop). */ + TclInitEncodingSubsystem(); /* Process wide encoding init. */ + TclpSetInterfaces(); + TclInitNamespaceSubsystem();/* Register ns obj type (mutexed). */ + subsystemsInitialized = 1; + } + TclpInitUnlock(); + } + TclInitNotifier(); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_Finalize -- + * + * Shut down Tcl. First calls registered exit handlers, then carefully + * shuts down various subsystems. Should be invoked by user before the + * Tcl shared library is being unloaded in an embedded context. + * + * Results: + * None. + * + * Side effects: + * Varied, see the respective finalization routines. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_Finalize(void) +{ + ExitHandler *exitPtr; + + /* + * Invoke exit handlers first. + */ + + InvokeExitHandlers(); + + TclpInitLock(); + if (subsystemsInitialized == 0) { + goto alreadyFinalized; + } + subsystemsInitialized = 0; + + /* + * Ensure the thread-specific data is initialised as it is used in + * Tcl_FinalizeThread() + */ + + (void) TCL_TSD_INIT(&dataKey); + + /* + * Clean up after the current thread now, after exit handlers. In + * particular, the testexithandler command sets up something that writes + * to standard output, which gets closed. Note that there is no + * thread-local storage or IO subsystem after this call. + */ + + Tcl_FinalizeThread(); + + /* + * Now invoke late (process-wide) exit handlers. + */ + + Tcl_MutexLock(&exitMutex); + for (exitPtr = firstLateExitPtr; exitPtr != NULL; + exitPtr = firstLateExitPtr) { + /* + * Be careful to remove the handler from the list before invoking its + * callback. This protects us against double-freeing if the callback + * should call Tcl_DeleteLateExitHandler on itself. + */ + + firstLateExitPtr = exitPtr->nextPtr; + Tcl_MutexUnlock(&exitMutex); + exitPtr->proc(exitPtr->clientData); + ckfree(exitPtr); + Tcl_MutexLock(&exitMutex); + } + firstLateExitPtr = NULL; + Tcl_MutexUnlock(&exitMutex); + + /* + * Now finalize the Tcl execution environment. Note that this must be done + * after the exit handlers, because there are order dependencies. + */ + + TclFinalizeEvaluation(); + TclFinalizeExecution(); + TclFinalizeEnvironment(); + + /* + * Finalizing the filesystem must come after anything which might + * conceivably interact with the 'Tcl_FS' API. + */ + + TclFinalizeFilesystem(); + + /* + * Undo all Tcl_ObjType registrations, and reset the master list of free + * Tcl_Obj's. After this returns, no more Tcl_Obj's should be allocated or + * freed. + * + * Note in particular that TclFinalizeObjects() must follow + * TclFinalizeFilesystem() because TclFinalizeFilesystem free's the + * Tcl_Obj that holds the path of the current working directory. + */ + + TclFinalizeObjects(); + + /* + * We must be sure the encoding finalization doesn't need to examine the + * filesystem in any way. Since it only needs to clean up internal data + * structures, this is fine. + */ + + TclFinalizeEncodingSubsystem(); + + /* + * Repeat finalization of the thread local storage once more. Although + * this step is already done by the Tcl_FinalizeThread call above, series + * of events happening afterwards may re-initialize TSD slots. Those need + * to be finalized again, otherwise we're leaking memory chunks. Very + * important to note is that things happening afterwards should not + * reference anything which may re-initialize TSD's. This includes freeing + * Tcl_Objs's, among other things. + * + * This fixes the Tcl Bug #990552. + */ + + TclFinalizeThreadData(/* quick */ 0); + + /* + * Now we can free constants for conversions to/from double. + */ + + TclFinalizeDoubleConversion(); + + /* + * There have been several bugs in the past that cause exit handlers to be + * established during Tcl_Finalize processing. Such exit handlers leave + * malloc'ed memory, and Tcl_FinalizeMemorySubsystem or + * Tcl_FinalizeThreadAlloc will result in a corrupted heap. The result can + * be a mysterious crash on process exit. Check here that nobody's done + * this. + */ + + if (firstExitPtr != NULL) { + Tcl_Panic("exit handlers were created during Tcl_Finalize"); + } + + TclFinalizePreserve(); + + /* + * Free synchronization objects. There really should only be one thread + * alive at this moment. + */ + + TclFinalizeSynchronization(); + + /* + * Close down the thread-specific object allocator. + */ + +#if defined(TCL_THREADS) && defined(USE_THREAD_ALLOC) + TclFinalizeThreadAlloc(); +#endif + + /* + * We defer unloading of packages until very late to avoid memory access + * issues. Both exit callbacks and synchronization variables may be stored + * in packages. + * + * Note that TclFinalizeLoad unloads packages in the reverse of the order + * they were loaded in (i.e. last to be loaded is the first to be + * unloaded). This can be important for correct unloading when + * dependencies exist. + * + * Once load has been finalized, we will have deleted any temporary copies + * of shared libraries and can therefore reset the filesystem to its + * original state. + */ + + TclFinalizeLoad(); + TclResetFilesystem(); + + /* + * At this point, there should no longer be any ckalloc'ed memory. + */ + + TclFinalizeMemorySubsystem(); + + alreadyFinalized: + TclFinalizeLock(); +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_FinalizeThread -- + * + * Runs the exit handlers to allow Tcl to clean up its state about a + * particular thread. + * + * Results: + * None. + * + * Side effects: + * Varied, see the respective finalization routines. + * + *---------------------------------------------------------------------- + */ + +void +Tcl_FinalizeThread(void) +{ + FinalizeThread(/* quick */ 0); +} + +void +FinalizeThread( + int quick) +{ + ExitHandler *exitPtr; + ThreadSpecificData *tsdPtr; + + /* + * We use TclThreadDataKeyGet here, rather than Tcl_GetThreadData, because + * we don't want to initialize the data block if it hasn't been + * initialized already. + */ + + tsdPtr = TclThreadDataKeyGet(&dataKey); + if (tsdPtr != NULL) { + tsdPtr->inExit = 1; + + for (exitPtr = tsdPtr->firstExitPtr; exitPtr != NULL; + exitPtr = tsdPtr->firstExitPtr) { + /* + * Be careful to remove the handler from the list before invoking + * its callback. This protects us against double-freeing if the + * callback should call Tcl_DeleteThreadExitHandler on itself. + */ + + tsdPtr->firstExitPtr = exitPtr->nextPtr; + exitPtr->proc(exitPtr->clientData); + ckfree(exitPtr); + } + TclFinalizeIOSubsystem(); + TclFinalizeNotifier(); + TclFinalizeAsync(); + TclFinalizeThreadObjects(); + } + + /* + * Blow away all thread local storage blocks. + * + * Note that Tcl API allows creation of threads which do not use any Tcl + * interp or other Tcl subsytems. Those threads might, however, use thread + * local storage, so we must unconditionally finalize it. + * + * Fix [Bug #571002] + */ + TclFinalizeThreadData(quick); +} + +/* + *---------------------------------------------------------------------- + * + * TclInExit -- + * + * Determines if we are in the middle of exit-time cleanup. + * + * Results: + * If we are in the middle of exiting, 1, otherwise 0. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +int +TclInExit(void) +{ + return inExit; +} + +/* + *---------------------------------------------------------------------- + * + * TclInThreadExit -- + * + * Determines if we are in the middle of thread exit-time cleanup. + * + * Results: + * If we are in the middle of exiting this thread, 1, otherwise 0. + * + * Side effects: + * None. + * + *---------------------------------------------------------------------- + */ + +int +TclInThreadExit(void) +{ + ThreadSpecificData *tsdPtr = TclThreadDataKeyGet(&dataKey); + + if (tsdPtr == NULL) { + return 0; + } + return tsdPtr->inExit; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_VwaitObjCmd -- + * + * This function is invoked to process the "vwait" Tcl command. See the + * user documentation for details on what it does. + * + * Results: + * A standard Tcl result. + * + * Side effects: + * See the user documentation. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +int +Tcl_VwaitObjCmd( + ClientData clientData, /* Not used. */ + Tcl_Interp *interp, /* Current interpreter. */ + int objc, /* Number of arguments. */ + Tcl_Obj *const objv[]) /* Argument objects. */ +{ + int done, foundEvent; + const char *nameString; + + if (objc != 2) { + Tcl_WrongNumArgs(interp, 1, objv, "name"); + return TCL_ERROR; + } + nameString = Tcl_GetString(objv[1]); + if (Tcl_TraceVar2(interp, nameString, NULL, + TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS, + VwaitVarProc, &done) != TCL_OK) { + return TCL_ERROR; + }; + done = 0; + foundEvent = 1; + while (!done && foundEvent) { + foundEvent = Tcl_DoOneEvent(TCL_ALL_EVENTS); + if (Tcl_Canceled(interp, TCL_LEAVE_ERR_MSG) == TCL_ERROR) { + break; + } + if (Tcl_LimitExceeded(interp)) { + Tcl_ResetResult(interp); + Tcl_SetObjResult(interp, Tcl_NewStringObj("limit exceeded", -1)); + break; + } + } + Tcl_UntraceVar2(interp, nameString, NULL, + TCL_GLOBAL_ONLY|TCL_TRACE_WRITES|TCL_TRACE_UNSETS, + VwaitVarProc, &done); + + if (!foundEvent) { + Tcl_ResetResult(interp); + Tcl_SetObjResult(interp, Tcl_ObjPrintf( + "can't wait for variable \"%s\": would wait forever", + nameString)); + Tcl_SetErrorCode(interp, "TCL", "EVENT", "NO_SOURCES", NULL); + return TCL_ERROR; + } + if (!done) { + /* + * The interpreter's result was already set to the right error message + * prior to exiting the loop above. + */ + + return TCL_ERROR; + } + + /* + * Clear out the interpreter's result, since it may have been set by event + * handlers. + */ + + Tcl_ResetResult(interp); + return TCL_OK; +} + + /* ARGSUSED */ +static char * +VwaitVarProc( + ClientData clientData, /* Pointer to integer to set to 1. */ + Tcl_Interp *interp, /* Interpreter containing variable. */ + const char *name1, /* Name of variable. */ + const char *name2, /* Second part of variable name. */ + int flags) /* Information about what happened. */ +{ + int *donePtr = clientData; + + *donePtr = 1; + Tcl_UntraceVar(interp, name1, TCL_TRACE_WRITES|TCL_TRACE_UNSETS, + VwaitVarProc, clientData); + return NULL; +} + +/* + *---------------------------------------------------------------------- + * + * Tcl_UpdateObjCmd -- + * + * This function is invoked to process the "update" Tcl command. See the + * user documentation for details on what it does. + * + * Results: + * A standard Tcl result. + * + * Side effects: + * See the user documentation. + * + *---------------------------------------------------------------------- + */ + + /* ARGSUSED */ +int +Tcl_UpdateObjCmd( + ClientData clientData, /* Not used. */ + Tcl_Interp *interp, /* Current interpreter. */ + int objc, /* Number of arguments. */ + Tcl_Obj *const objv[]) /* Argument objects. */ +{ + int optionIndex; + int flags = 0; /* Initialized to avoid compiler warning. */ + static const char *const updateOptions[] = {"idletasks", NULL}; + enum updateOptions {OPT_IDLETASKS}; + + if (objc == 1) { + flags = TCL_ALL_EVENTS|TCL_DONT_WAIT; + } else if (objc == 2) { + if (Tcl_GetIndexFromObj(interp, objv[1], updateOptions, + "option", 0, &optionIndex) != TCL_OK) { + return TCL_ERROR; + } + switch ((enum updateOptions) optionIndex) { + case OPT_IDLETASKS: + flags = TCL_WINDOW_EVENTS|TCL_IDLE_EVENTS|TCL_DONT_WAIT; + break; + default: + Tcl_Panic("Tcl_UpdateObjCmd: bad option index to UpdateOptions"); + } + } else { + Tcl_WrongNumArgs(interp, 1, objv, "?idletasks?"); + return TCL_ERROR; + } + + while (Tcl_DoOneEvent(flags) != 0) { + if (Tcl_Canceled(interp, TCL_LEAVE_ERR_MSG) == TCL_ERROR) { + return TCL_ERROR; + } + if (Tcl_LimitExceeded(interp)) { + Tcl_ResetResult(interp); + Tcl_SetObjResult(interp, Tcl_NewStringObj("limit exceeded", -1)); + return TCL_ERROR; + } + } + + /* + * Must clear the interpreter's result because event handlers could have + * executed commands. + */ + + Tcl_ResetResult(interp); + return TCL_OK; +} + +#ifdef TCL_THREADS +/* + *---------------------------------------------------------------------- + * + * NewThreadProc -- + * + * Bootstrap function of a new Tcl thread. + * + * Results: + * None. + * + * Side Effects: + * Initializes Tcl notifier for the current thread. + * + *---------------------------------------------------------------------- + */ + +static Tcl_ThreadCreateType +NewThreadProc( + ClientData clientData) +{ + ThreadClientData *cdPtr = clientData; + ClientData threadClientData; + Tcl_ThreadCreateProc *threadProc; + + threadProc = cdPtr->proc; + threadClientData = cdPtr->clientData; + ckfree(clientData); /* Allocated in Tcl_CreateThread() */ + + threadProc(threadClientData); + + TCL_THREAD_CREATE_RETURN; +} +#endif + +/* + *---------------------------------------------------------------------- + * + * Tcl_CreateThread -- + * + * This function creates a new thread. This actually belongs to the + * tclThread.c file but since we use some private data structures local + * to this file, it is placed here. + * + * Results: + * TCL_OK if the thread could be created. The thread ID is returned in a + * parameter. + * + * Side effects: + * A new thread is created. + * + *---------------------------------------------------------------------- + */ + +int +Tcl_CreateThread( + Tcl_ThreadId *idPtr, /* Return, the ID of the thread */ + Tcl_ThreadCreateProc *proc, /* Main() function of the thread */ + ClientData clientData, /* The one argument to Main() */ + int stackSize, /* Size of stack for the new thread */ + int flags) /* Flags controlling behaviour of the new + * thread. */ +{ +#ifdef TCL_THREADS + ThreadClientData *cdPtr = ckalloc(sizeof(ThreadClientData)); + int result; + + cdPtr->proc = proc; + cdPtr->clientData = clientData; + result = TclpThreadCreate(idPtr, NewThreadProc, cdPtr, stackSize, flags); + if (result != TCL_OK) { + ckfree(cdPtr); + } + return result; +#else + return TCL_ERROR; +#endif /* TCL_THREADS */ +} + +/* + * Local Variables: + * mode: c + * c-basic-offset: 4 + * fill-column: 78 + * End: + */ |