/*
* tclThread.c --
*
* This file implements Platform independent thread operations. Most of
* the real work is done in the platform dependent files.
*
* Copyright (c) 1998 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: tclThread.c,v 1.19 2007/12/13 15:23:20 dgp Exp $
*/
#include "tclInt.h"
/*
* There are three classes of synchronization objects: mutexes, thread data
* keys, and condition variables. The following are used to record the memory
* used for these objects so they can be finalized.
*
* These statics are guarded by the mutex in the caller of
* TclRememberThreadData, e.g., TclpThreadDataKeyInit
*/
typedef struct {
int num; /* Number of objects remembered */
int max; /* Max size of the array */
char **list; /* List of pointers */
} SyncObjRecord;
static SyncObjRecord keyRecord = {0, 0, NULL};
static SyncObjRecord mutexRecord = {0, 0, NULL};
static SyncObjRecord condRecord = {0, 0, NULL};
/*
* Prototypes of functions used only in this file.
*/
static void ForgetSyncObject(char *objPtr, SyncObjRecord *recPtr);
static void RememberSyncObject(char *objPtr,
SyncObjRecord *recPtr);
/*
* Several functions are #defined to nothing in tcl.h if TCL_THREADS is not
* specified. Here we undo that so the functions are defined in the stubs
* table.
*/
#ifndef TCL_THREADS
#undef Tcl_MutexLock
#undef Tcl_MutexUnlock
#undef Tcl_MutexFinalize
#undef Tcl_ConditionNotify
#undef Tcl_ConditionWait
#undef Tcl_ConditionFinalize
#endif
/*
*----------------------------------------------------------------------
*
* Tcl_GetThreadData --
*
* This function allocates and initializes a chunk of thread local
* storage.
*
* Results:
* A thread-specific pointer to the data structure.
*
* Side effects:
* Will allocate memory the first time this thread calls for this chunk
* of storage.
*
*----------------------------------------------------------------------
*/
void *
Tcl_GetThreadData(
Tcl_ThreadDataKey *keyPtr, /* Identifier for the data chunk */
int size) /* Size of storage block */
{
void *result;
#ifdef TCL_THREADS
/*
* Initialize the key for this thread.
*/
result = TclpThreadDataKeyGet(keyPtr);
if (result == NULL) {
result = ckalloc((size_t) size);
memset(result, 0, (size_t) size);
TclpThreadDataKeySet(keyPtr, result);
}
#else /* TCL_THREADS */
if (*keyPtr == NULL) {
result = ckalloc((size_t) size);
memset(result, 0, (size_t) size);
*keyPtr = (Tcl_ThreadDataKey)result;
RememberSyncObject((char *) keyPtr, &keyRecord);
}
result = * (void **) keyPtr;
#endif /* TCL_THREADS */
return result;
}
/*
*----------------------------------------------------------------------
*
* TclThreadDataKeyGet --
*
* This function 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 *
TclThreadDataKeyGet(
Tcl_ThreadDataKey *keyPtr) /* Identifier for the data chunk, really
* (pthread_key_t **) */
{
#ifdef TCL_THREADS
return TclpThreadDataKeyGet(keyPtr);
#else /* TCL_THREADS */
char *result = *(char **) keyPtr;
return result;
#endif /* TCL_THREADS */
}
/*
*----------------------------------------------------------------------
*
* RememberSyncObject
*
* Keep a list of (mutexes/condition variable/data key) used during
* finalization.
*
* Assume master lock is held.
*
* Results:
* None.
*
* Side effects:
* Add to the appropriate list.
*
*----------------------------------------------------------------------
*/
static void
RememberSyncObject(
char *objPtr, /* Pointer to sync object */
SyncObjRecord *recPtr) /* Record of sync objects */
{
char **newList;
int i, j;
/*
* Reuse any free slot in the list.
*/
for (i=0 ; i < recPtr->num ; ++i) {
if (recPtr->list[i] == NULL) {
recPtr->list[i] = objPtr;
return;
}
}
/*
* Grow the list of pointers if necessary, copying only non-NULL
* pointers to the new list.
*/
if (recPtr->num >= recPtr->max) {
recPtr->max += 8;
newList = (char **) ckalloc(recPtr->max * sizeof(char *));
for (i=0,j=0 ; i<recPtr->num ; i++) {
if (recPtr->list[i] != NULL) {
newList[j++] = recPtr->list[i];
}
}
if (recPtr->list != NULL) {
ckfree((char *) recPtr->list);
}
recPtr->list = newList;
recPtr->num = j;
}
recPtr->list[recPtr->num] = objPtr;
recPtr->num++;
}
/*
*----------------------------------------------------------------------
*
* ForgetSyncObject
*
* Remove a single object from the list.
* Assume master lock is held.
*
* Results:
* None.
*
* Side effects:
* Remove from the appropriate list.
*
*----------------------------------------------------------------------
*/
static void
ForgetSyncObject(
char *objPtr, /* Pointer to sync object */
SyncObjRecord *recPtr) /* Record of sync objects */
{
int i;
for (i=0 ; i<recPtr->num ; i++) {
if (objPtr == recPtr->list[i]) {
recPtr->list[i] = NULL;
return;
}
}
}
/*
*----------------------------------------------------------------------
*
* TclRememberMutex
*
* Keep a list of mutexes used during finalization.
* Assume master lock is held.
*
* Results:
* None.
*
* Side effects:
* Add to the mutex list.
*
*----------------------------------------------------------------------
*/
void
TclRememberMutex(
Tcl_Mutex *mutexPtr)
{
RememberSyncObject((char *)mutexPtr, &mutexRecord);
}
/*
*----------------------------------------------------------------------
*
* Tcl_MutexFinalize --
*
* Finalize a single mutex and remove it from the list of remembered
* objects.
*
* Results:
* None.
*
* Side effects:
* Remove the mutex from the list.
*
*----------------------------------------------------------------------
*/
void
Tcl_MutexFinalize(
Tcl_Mutex *mutexPtr)
{
#ifdef TCL_THREADS
TclpFinalizeMutex(mutexPtr);
#endif
TclpMasterLock();
ForgetSyncObject((char *) mutexPtr, &mutexRecord);
TclpMasterUnlock();
}
/*
*----------------------------------------------------------------------
*
* TclRememberCondition
*
* Keep a list of condition variables used during finalization.
* Assume master lock is held.
*
* Results:
* None.
*
* Side effects:
* Add to the condition variable list.
*
*----------------------------------------------------------------------
*/
void
TclRememberCondition(
Tcl_Condition *condPtr)
{
RememberSyncObject((char *) condPtr, &condRecord);
}
/*
*----------------------------------------------------------------------
*
* Tcl_ConditionFinalize --
*
* Finalize a single condition variable and remove it from the list of
* remembered objects.
*
* Results:
* None.
*
* Side effects:
* Remove the condition variable from the list.
*
*----------------------------------------------------------------------
*/
void
Tcl_ConditionFinalize(
Tcl_Condition *condPtr)
{
#ifdef TCL_THREADS
TclpFinalizeCondition(condPtr);
#endif
TclpMasterLock();
ForgetSyncObject((char *) condPtr, &condRecord);
TclpMasterUnlock();
}
/*
*----------------------------------------------------------------------
*
* TclFinalizeThreadData --
*
* This function cleans up the thread-local storage. This is called once
* for each thread.
*
* Results:
* None.
*
* Side effects:
* Frees up all thread local storage.
*
*----------------------------------------------------------------------
*/
void
TclFinalizeThreadData(void)
{
TclpFinalizeThreadDataThread();
}
/*
*----------------------------------------------------------------------
*
* TclFinalizeSynchronization --
*
* This function cleans up all synchronization objects: mutexes,
* condition variables, and thread-local storage.
*
* Results:
* None.
*
* Side effects:
* Frees up the memory.
*
*----------------------------------------------------------------------
*/
void
TclFinalizeSynchronization(void)
{
int i;
void *blockPtr;
Tcl_ThreadDataKey *keyPtr;
#ifdef TCL_THREADS
Tcl_Mutex *mutexPtr;
Tcl_Condition *condPtr;
TclpMasterLock();
#endif
/*
* If we're running unthreaded, the TSD blocks are simply stored inside
* their thread data keys. Free them here.
*/
if (keyRecord.list != NULL) {
for (i=0 ; i<keyRecord.num ; i++) {
keyPtr = (Tcl_ThreadDataKey *) keyRecord.list[i];
blockPtr = (void *) *keyPtr;
ckfree(blockPtr);
}
ckfree((char *) keyRecord.list);
keyRecord.list = NULL;
}
keyRecord.max = 0;
keyRecord.num = 0;
#ifdef TCL_THREADS
/*
* Call thread storage master cleanup.
*/
TclFinalizeThreadStorage();
for (i=0 ; i<mutexRecord.num ; i++) {
mutexPtr = (Tcl_Mutex *)mutexRecord.list[i];
if (mutexPtr != NULL) {
TclpFinalizeMutex(mutexPtr);
}
}
if (mutexRecord.list != NULL) {
ckfree((char *) mutexRecord.list);
mutexRecord.list = NULL;
}
mutexRecord.max = 0;
mutexRecord.num = 0;
for (i=0 ; i<condRecord.num ; i++) {
condPtr = (Tcl_Condition *) condRecord.list[i];
if (condPtr != NULL) {
TclpFinalizeCondition(condPtr);
}
}
if (condRecord.list != NULL) {
ckfree((char *) condRecord.list);
condRecord.list = NULL;
}
condRecord.max = 0;
condRecord.num = 0;
TclpMasterUnlock();
#endif /* TCL_THREADS */
}
/*
*----------------------------------------------------------------------
*
* Tcl_ExitThread --
*
* This function is called to terminate the current thread. This should
* be used by extensions that create threads with additional interpreters
* in them.
*
* Results:
* None.
*
* Side effects:
* All thread exit handlers are invoked, then the thread dies.
*
*----------------------------------------------------------------------
*/
void
Tcl_ExitThread(
int status)
{
Tcl_FinalizeThread();
#ifdef TCL_THREADS
TclpThreadExit(status);
#endif
}
#ifndef TCL_THREADS
/*
*----------------------------------------------------------------------
*
* Tcl_ConditionWait, et al. --
*
* These noop functions are provided so the stub table does not have to
* be conditionalized for threads. The real implementations of these
* functions live in the platform specific files.
*
* Results:
* None.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
#undef Tcl_ConditionWait
void
Tcl_ConditionWait(
Tcl_Condition *condPtr, /* Really (pthread_cond_t **) */
Tcl_Mutex *mutexPtr, /* Really (pthread_mutex_t **) */
Tcl_Time *timePtr) /* Timeout on waiting period */
{
}
#undef Tcl_ConditionNotify
void
Tcl_ConditionNotify(
Tcl_Condition *condPtr)
{
}
#undef Tcl_MutexLock
void
Tcl_MutexLock(
Tcl_Mutex *mutexPtr)
{
}
#undef Tcl_MutexUnlock
void
Tcl_MutexUnlock(
Tcl_Mutex *mutexPtr)
{
}
#endif /* !TCL_THREADS */
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/
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