tclwinthrd.c

这是leon3处理器的交叉编译链

 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Will allocate memory the first time this process calls for
 *	this key.  In this case it modifies its argument
 *	to hold the pointer to information about the key.
 *
 *----------------------------------------------------------------------
 */

void
TclpThreadDataKeyInit(keyPtr)
    Tcl_ThreadDataKey *keyPtr;	/* Identifier for the data chunk,
				 * really (DWORD **) */
{
    DWORD *indexPtr;

    MASTER_LOCK;
    if (*keyPtr == NULL) {
	indexPtr = (DWORD *)ckalloc(sizeof(DWORD));
	*indexPtr = TlsAlloc();
	*keyPtr = (Tcl_ThreadDataKey)indexPtr;
	TclRememberDataKey(keyPtr);
    }
    MASTER_UNLOCK;
}


/*
 *----------------------------------------------------------------------
 *
 * TclpThreadDataKeyGet --
 *
 *	This procedure returns a pointer to a block of thread local storage.
 *
 * Results:
 *	A thread-specific pointer to the data structure, or NULL
 *	if the memory has not been assigned to this key for this thread.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

VOID *
TclpThreadDataKeyGet(keyPtr)
    Tcl_ThreadDataKey *keyPtr;	/* Identifier for the data chunk,
				 * really (DWORD **) */
{
    DWORD *indexPtr = *(DWORD **)keyPtr;
    if (indexPtr == NULL) {
	return NULL;
    } else {
	return (VOID *) TlsGetValue(*indexPtr);
    }
}


/*
 *----------------------------------------------------------------------
 *
 * TclpThreadDataKeySet --
 *
 *	This procedure sets the pointer to a block of thread local storage.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Sets up the thread so future calls to TclpThreadDataKeyGet with
 *	this key will return the data pointer.
 *
 *----------------------------------------------------------------------
 */

void
TclpThreadDataKeySet(keyPtr, data)
    Tcl_ThreadDataKey *keyPtr;	/* Identifier for the data chunk,
				 * really (pthread_key_t **) */
    VOID *data;			/* Thread local storage */
{
    DWORD *indexPtr = *(DWORD **)keyPtr;
    TlsSetValue(*indexPtr, (void *)data);
}


/*
 *----------------------------------------------------------------------
 *
 * TclpFinalizeThreadData --
 *
 *	This procedure cleans up the thread-local storage.  This is
 *	called once for each thread.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Frees up the memory.
 *
 *----------------------------------------------------------------------
 */

void
TclpFinalizeThreadData(keyPtr)
    Tcl_ThreadDataKey *keyPtr;
{
    VOID *result;
    DWORD *indexPtr;

#ifdef USE_THREAD_ALLOC
    TclWinFreeAllocCache();
#endif
    if (*keyPtr != NULL) {
	indexPtr = *(DWORD **)keyPtr;
	result = (VOID *)TlsGetValue(*indexPtr);
	if (result != NULL) {
	    ckfree((char *)result);
	    TlsSetValue(*indexPtr, (void *)NULL);
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TclpFinalizeThreadDataKey --
 *
 *	This procedure is invoked to clean up one key.  This is a
 *	process-wide storage identifier.  The thread finalization code
 *	cleans up the thread local storage itself.
 *
 *	This assumes the master lock is held.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The key is deallocated.
 *
 *----------------------------------------------------------------------
 */

void
TclpFinalizeThreadDataKey(keyPtr)
    Tcl_ThreadDataKey *keyPtr;
{
    DWORD *indexPtr;
    if (*keyPtr != NULL) {
	indexPtr = *(DWORD **)keyPtr;
	TlsFree(*indexPtr);
	ckfree((char *)indexPtr);
	*keyPtr = NULL;
    }
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_ConditionWait --
 *
 *	This procedure is invoked to wait on a condition variable.
 *	The mutex is atomically released as part of the wait, and
 *	automatically grabbed when the condition is signaled.
 *
 *	The mutex must be held when this procedure is called.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	May block the current thread.  The mutex is aquired when
 *	this returns.  Will allocate memory for a HANDLE
 *	and initialize this the first time this Tcl_Condition is used.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_ConditionWait(condPtr, mutexPtr, timePtr)
    Tcl_Condition *condPtr;	/* Really (WinCondition **) */
    Tcl_Mutex *mutexPtr;	/* Really (CRITICAL_SECTION **) */
    Tcl_Time *timePtr;		/* Timeout on waiting period */
{
    WinCondition *winCondPtr;	/* Per-condition queue head */
    CRITICAL_SECTION *csPtr;	/* Caller's Mutex, after casting */
    DWORD wtime;		/* Windows time value */
    int timeout;		/* True if we got a timeout */
    int doExit = 0;		/* True if we need to do exit setup */
    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);

    if (tsdPtr->flags & WIN_THREAD_DEAD) {
	/*
	 * No more per-thread event on which to wait.
	 */

	return;
    }

    /*
     * Self initialize the two parts of the condition.
     * The per-condition and per-thread parts need to be
     * handled independently.
     */

    if (tsdPtr->flags == WIN_THREAD_UNINIT) {
	MASTER_LOCK;

	/* 
	 * Create the per-thread event and queue pointers.
	 */

	if (tsdPtr->flags == WIN_THREAD_UNINIT) {
	    tsdPtr->condEvent = CreateEvent(NULL, TRUE /* manual reset */,
			FALSE /* non signaled */, NULL);
	    tsdPtr->nextPtr = NULL;
	    tsdPtr->prevPtr = NULL;
	    tsdPtr->flags = WIN_THREAD_RUNNING;
	    doExit = 1;
	}
	MASTER_UNLOCK;

	if (doExit) {
	    /*
	     * Create a per-thread exit handler to clean up the condEvent.
	     * We must be careful to do this outside the Master Lock
	     * because Tcl_CreateThreadExitHandler uses its own
	     * ThreadSpecificData, and initializing that may drop
	     * back into the Master Lock.
	     */
	    
	    Tcl_CreateThreadExitHandler(FinalizeConditionEvent,
		    (ClientData) tsdPtr);
	}
    }

    if (*condPtr == NULL) {
	MASTER_LOCK;

	/*
	 * Initialize the per-condition queue pointers and Mutex.
	 */

	if (*condPtr == NULL) {
	    winCondPtr = (WinCondition *)ckalloc(sizeof(WinCondition));
	    InitializeCriticalSection(&winCondPtr->condLock);
	    winCondPtr->firstPtr = NULL;
	    winCondPtr->lastPtr = NULL;
	    *condPtr = (Tcl_Condition)winCondPtr;
	    TclRememberCondition(condPtr);
	}
	MASTER_UNLOCK;
    }
    csPtr = *((CRITICAL_SECTION **)mutexPtr);
    winCondPtr = *((WinCondition **)condPtr);
    if (timePtr == NULL) {
	wtime = INFINITE;
    } else {
	wtime = timePtr->sec * 1000 + timePtr->usec / 1000;
    }

    /*
     * Queue the thread on the condition, using
     * the per-condition lock for serialization.
     */

    tsdPtr->flags = WIN_THREAD_BLOCKED;
    tsdPtr->nextPtr = NULL;
    EnterCriticalSection(&winCondPtr->condLock);
    tsdPtr->prevPtr = winCondPtr->lastPtr;		/* A: */
    winCondPtr->lastPtr = tsdPtr;
    if (tsdPtr->prevPtr != NULL) {
        tsdPtr->prevPtr->nextPtr = tsdPtr;
    }
    if (winCondPtr->firstPtr == NULL) {
        winCondPtr->firstPtr = tsdPtr;
    }

    /*
     * Unlock the caller's mutex and wait for the condition, or a timeout.
     * There is a minor issue here in that we don't count down the
     * timeout if we get notified, but another thread grabs the condition
     * before we do.  In that race condition we'll wait again for the
     * full timeout.  Timed waits are dubious anyway.  Either you have
     * the locking protocol wrong and are masking a deadlock,
     * or you are using conditions to pause your thread.
     */
    
    LeaveCriticalSection(csPtr);
    timeout = 0;
    while (!timeout && (tsdPtr->flags & WIN_THREAD_BLOCKED)) {
	ResetEvent(tsdPtr->condEvent);
	LeaveCriticalSection(&winCondPtr->condLock);
	if (WaitForSingleObject(tsdPtr->condEvent, wtime) == WAIT_TIMEOUT) {
	    timeout = 1;
	}
	EnterCriticalSection(&winCondPtr->condLock);
    }

    /*
     * Be careful on timeouts because the signal might arrive right around
     * time time limit and someone else could have taken us off the queue.
     */
    
    if (timeout) {
	if (tsdPtr->flags & WIN_THREAD_RUNNING) {
	    timeout = 0;
	} else {
	    /*
	     * When dequeuing, we can leave the tsdPtr->nextPtr
	     * and tsdPtr->prevPtr with dangling pointers because
	     * they are reinitialilzed w/out reading them when the
	     * thread is enqueued later.
	     */

            if (winCondPtr->firstPtr == tsdPtr) {
                winCondPtr->firstPtr = tsdPtr->nextPtr;
            } else {
                tsdPtr->prevPtr->nextPtr = tsdPtr->nextPtr;
            }
            if (winCondPtr->lastPtr == tsdPtr) {
                winCondPtr->lastPtr = tsdPtr->prevPtr;
            } else {
                tsdPtr->nextPtr->prevPtr = tsdPtr->prevPtr;
            }
            tsdPtr->flags = WIN_THREAD_RUNNING;
	}
    }

    LeaveCriticalSection(&winCondPtr->condLock);
    EnterCriticalSection(csPtr);
}


/*
 *----------------------------------------------------------------------
 *
 * Tcl_ConditionNotify --
 *
 *	This procedure is invoked to signal a condition variable.
 *
 *	The mutex must be held during this call to avoid races,
 *	but this interface does not enforce that.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	May unblock another thread.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_ConditionNotify(condPtr)
    Tcl_Condition *condPtr;
{
    WinCondition *winCondPtr;
    ThreadSpecificData *tsdPtr;
    if (condPtr != NULL) {
	winCondPtr = *((WinCondition **)condPtr);

	/*
	 * Loop through all the threads waiting on the condition
	 * and notify them (i.e., broadcast semantics).  The queue
	 * manipulation is guarded by the per-condition coordinating mutex.
	 */

	EnterCriticalSection(&winCondPtr->condLock);
	while (winCondPtr->firstPtr != NULL) {
	    tsdPtr = winCondPtr->firstPtr;
	    winCondPtr->firstPtr = tsdPtr->nextPtr;
	    if (winCondPtr->lastPtr == tsdPtr) {
		winCondPtr->lastPtr = NULL;
	    }
	    tsdPtr->flags = WIN_THREAD_RUNNING;
	    tsdPtr->nextPtr = NULL;
	    tsdPtr->prevPtr = NULL;	/* Not strictly necessary, see A: */
	    SetEvent(tsdPtr->condEvent);
	}
	LeaveCriticalSection(&winCondPtr->condLock);
    } else {
	/*
	 * Noone has used the condition variable, so there are no waiters.
	 */
    }
}


/*
 *----------------------------------------------------------------------
 *
 * FinalizeConditionEvent --
 *
 *	This procedure is invoked to clean up the per-thread
 *	event used to implement condition waiting.
 *	This is only safe to call at the end of time.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The per-thread event is closed.
 *
 *----------------------------------------------------------------------
 */

static void
FinalizeConditionEvent(data)
    ClientData data;
{
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *)data;
    tsdPtr->flags = WIN_THREAD_DEAD;
    CloseHandle(tsdPtr->condEvent);
}

/*
 *----------------------------------------------------------------------
 *
 * TclpFinalizeCondition --
 *
 *	This procedure is invoked to clean up a condition variable.
 *	This is only safe to call at the end of time.
 *
 *	This assumes the Master Lock is held.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The condition variable is deallocated.
 *
 *----------------------------------------------------------------------
 */

void
TclpFinalizeCondition(condPtr)
    Tcl_Condition *condPtr;
{
    WinCondition *winCondPtr = *(WinCondition **)condPtr;

    /*
     * Note - this is called long after the thread-local storage is
     * reclaimed.  The per-thread condition waiting event is
     * reclaimed earlier in a per-thread exit handler, which is
     * called before thread local storage is reclaimed.
     */

    if (winCondPtr != NULL) {
	DeleteCriticalSection(&winCondPtr->condLock);
	ckfree((char *)winCondPtr);
	*condPtr = NULL;
    }
}

/*
 * Additions by AOL for specialized thread memory allocator.
 */
#ifdef USE_THREAD_ALLOC
static DWORD key;

Tcl_Mutex *
TclpNewAllocMutex(void)
{
    struct lock {
        Tcl_Mutex        tlock;
        CRITICAL_SECTION wlock;
    } *lockPtr;

    lockPtr = malloc(sizeof(struct lock));
    if (lockPtr == NULL) {
	panic("could not allocate lock");
    }
    lockPtr->tlock = (Tcl_Mutex) &lockPtr->wlock;
    InitializeCriticalSection(&lockPtr->wlock);
    return &lockPtr->tlock;
}

void *
TclpGetAllocCache(void)
{
    static int once = 0;

    if (!once) {
	/*
	 * We need to make sure that TclWinFreeAllocCache is called
	 * on each thread that calls this, but only on threads that
	 * call this.
	 */
    	key = TlsAlloc();
	once = 1;
	if (key == TLS_OUT_OF_INDEXES) {
	    panic("could not allocate thread local storage");
	}
    }
    return TlsGetValue(key);
}

void
TclpSetAllocCache(void *ptr)
{
    TlsSetValue(key, ptr);
}

void
TclWinFreeAllocCache(void)
{
    void *ptr;

    ptr = TlsGetValue(key);
    if (ptr != NULL) {
	TlsSetValue(key, NULL);
	TclFreeAllocCache(ptr);
    }
}

#endif /* USE_THREAD_ALLOC */
#endif /* TCL_THREADS */