/*
* tclUnixThrd.c --
*
* This file implements the UNIX-specific thread support.
*
* Copyright (c) 1991-1994 The Regents of the University of California.
* Copyright (c) 1994-1997 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution
* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* SCCS: @(#) tclUnixThrd.c 1.18 98/02/19 14:24:12
*/
#include "tclInt.h"
#ifdef TCL_THREADS
#include "tclPort.h"
#include "pthread.h"
/*
* masterLock is used to serialize creation of mutexes, condition
* variables, and thread local storage.
* This is the only place that can count on the ability to statically
* initialize the mutex.
*/
static pthread_mutex_t masterLock = PTHREAD_MUTEX_INITIALIZER;
/*
* initLock is used to serialize initialization and finalization
* of Tcl. It cannot use any dyamically allocated storage.
*/
static pthread_mutex_t initLock = PTHREAD_MUTEX_INITIALIZER;
/*
* allocLock is used to serialize memory allocation.
*/
static pthread_mutex_t allocLock = PTHREAD_MUTEX_INITIALIZER;
TCL_DECLARE_MUTEX(allocMutex)
/*
* These are for the critical sections inside this file.
*/
#define MASTER_LOCK pthread_mutex_lock(&masterLock)
#define MASTER_UNLOCK pthread_mutex_unlock(&masterLock)
#endif /* TCL_THREADS */
/*
*----------------------------------------------------------------------
*
* TclpMutexBootstrap --
*
* This procedure gives out a pointer to a pre-allocated mutex.
* This is used by memory allocators for their own mutex.
*
* Results:
* None.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
Tcl_Mutex *
TclpMutexBootstrap()
{
#ifdef TCL_THREADS
pthread_mutex_init(&allocLock, NULL);
allocMutex = (Tcl_Mutex)&allocLock;
return &allocMutex;
#else
return NULL;
#endif
}
#ifdef TCL_THREADS
/*
*----------------------------------------------------------------------
*
* TclpThreadCreate --
*
* This procedure creates a new thread.
*
* 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
TclpThreadCreate(idPtr, proc, clientData)
Tcl_ThreadId *idPtr; /* Return, the ID of the thread */
Tcl_ThreadCreateProc proc; /* Main() function of the thread */
ClientData clientData; /* The one argument to Main() */
{
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);
if (pthread_create((pthread_t *)idPtr, &attr, (void * (*)())proc, (void *)clientData) < 0) {
return TCL_ERROR;
} else {
return TCL_OK;
}
}
/*
*----------------------------------------------------------------------
*
* TclpThreadExit --
*
* This procedure terminates the current thread.
*
* Results:
* None.
*
* Side effects:
* This procedure terminates the current thread.
*
*----------------------------------------------------------------------
*/
void
TclpThreadExit(status)
int status;
{
pthread_exit((VOID *)status);
}
#endif /* TCL_THREADS */
/*
*----------------------------------------------------------------------
*
* Tcl_GetCurrentThread --
*
* This procedure returns the ID of the currently running thread.
*
* Results:
* A thread ID.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
Tcl_ThreadId
Tcl_GetCurrentThread()
{
#ifdef TCL_THREADS
return (Tcl_ThreadId) pthread_self();
#else
return (Tcl_ThreadId) 0;
#endif
}
/*
*----------------------------------------------------------------------
*
* TclpInitLock
*
* This procedure is used to grab a lock that serializes initialization
* and finalization of Tcl. On some platforms this may also initialize
* the mutex used to serialize creation of more mutexes and thread
* local storage keys.
*
* Results:
* None.
*
* Side effects:
* Acquire the initialization mutex.
*
*----------------------------------------------------------------------
*/
void
TclpInitLock()
{
#ifdef TCL_THREADS
pthread_mutex_lock(&initLock);
#endif
}
/*
*----------------------------------------------------------------------
*
* TclpInitUnlock
*
* This procedure is used to release a lock that serializes initialization
* and finalization of Tcl.
*
* Results:
* None.
*
* Side effects:
* Release the initialization mutex.
*
*----------------------------------------------------------------------
*/
void
TclpInitUnlock()
{
#ifdef TCL_THREADS
pthread_mutex_unlock(&initLock);
#endif
}
/*
*----------------------------------------------------------------------
*
* TclpMasterLock
*
* This procedure is used to grab a lock that serializes creation
* and finalization of serialization objects. This interface is
* only needed in finalization; it is hidden during
* creation of the objects.
*
* This lock must be different than the initLock because the
* initLock is held during creation of syncronization objects.
*
* Results:
* None.
*
* Side effects:
* Acquire the master mutex.
*
*----------------------------------------------------------------------
*/
void
TclpMasterLock()
{
#ifdef TCL_THREADS
pthread_mutex_lock(&masterLock);
#endif
}
/*
*----------------------------------------------------------------------
*
* TclpMasterUnlock
*
* This procedure is used to release a lock that serializes creation
* and finalization of synchronization objects.
*
* Results:
* None.
*
* Side effects:
* Release the master mutex.
*
*----------------------------------------------------------------------
*/
void
TclpMasterUnlock()
{
#ifdef TCL_THREADS
pthread_mutex_unlock(&masterLock);
#endif
}
#ifdef TCL_THREADS
/*
*----------------------------------------------------------------------
*
* TclpMutexInit --
* TclpMutexLock --
* TclpMutexUnlock --
*
* These procedures use an explicitly initialized mutex.
* These are used by memory allocators for their own mutex.
*
* Results:
* None.
*
* Side effects:
* Initialize, Lock, and Unlock the mutex.
*
*----------------------------------------------------------------------
*/
void
TclpMutexInit(mPtr)
TclpMutex *mPtr;
{
pthread_mutex_init((pthread_mutex_t *)mPtr, NULL);
}
void
TclpMutexLock(mPtr)
TclpMutex *mPtr;
{
pthread_mutex_lock((pthread_mutex_t *)mPtr);
}
void
TclpMutexUnlock(mPtr)
TclpMutex *mPtr;
{
pthread_mutex_unlock((pthread_mutex_t *)mPtr);
}
/*
*----------------------------------------------------------------------
*
* Tcl_MutexLock --
*
* This procedure is invoked to lock a mutex. This procedure
* handles initializing the mutex, if necessary. The caller
* can rely on the fact that Tcl_Mutex is an opaque pointer.
* This routine will change that pointer from NULL after first use.
*
* Results:
* None.
*
* Side effects:
* May block the current thread. The mutex is aquired when
* this returns. Will allocate memory for a pthread_mutex_t
* and initialize this the first time this Tcl_Mutex is used.
*
*----------------------------------------------------------------------
*/
void
Tcl_MutexLock(mutexPtr)
Tcl_Mutex *mutexPtr; /* Really (pthread_mutex_t **) */
{
pthread_mutex_t *pmutexPtr;
if (*mutexPtr == NULL) {
MASTER_LOCK;
if (*mutexPtr == NULL) {
/*
* Double inside master lock check to avoid a race.
*/
pmutexPtr = (pthread_mutex_t *)ckalloc(sizeof(pthread_mutex_t));
pthread_mutex_init(pmutexPtr, NULL);
*mutexPtr = (Tcl_Mutex)pmutexPtr;
TclRememberMutex(mutexPtr);
}
MASTER_UNLOCK;
}
pmutexPtr = *((pthread_mutex_t **)mutexPtr);
pthread_mutex_lock(pmutexPtr);
}
/*
*----------------------------------------------------------------------
*
* TclpMutexUnlock --
*
* This procedure is invoked to unlock a mutex. The mutex must
* have been locked by Tcl_MutexLock.
*
* Results:
* None.
*
* Side effects:
* The mutex is released when this returns.
*
*----------------------------------------------------------------------
*/
void
Tcl_MutexUnlock(mutexPtr)
Tcl_Mutex *mutexPtr; /* Really (pthread_mutex_t **) */
{
pthread_mutex_t *pmutexPtr = *(pthread_mutex_t **)mutexPtr;
pthread_mutex_unlock(pmutexPtr);
}
/*
*----------------------------------------------------------------------
*
* TclpFinalizeMutex --
*
* This procedure is invoked to clean up one mutex. This is only
* safe to call at the end of time.
*
* This assumes the Master Lock is held.
*
* Results:
* None.
*
* Side effects:
* The mutex list is deallocated.
*
*----------------------------------------------------------------------
*/
void
TclpFinalizeMutex(mutexPtr)
Tcl_Mutex *mutexPtr;
{
pthread_mutex_t *pmutexPtr = *(pthread_mutex_t **)mutexPtr;
if (pmutexPtr != NULL) {
ckfree((char *)pmutexPtr);
*mutexPtr = NULL;
}
}
/*
*----------------------------------------------------------------------
*
* TclpThreadDataKeyInit --
*
* This procedure initializes a thread specific data block key.
* Each thread has table of pointers to thread specific data.
* all threads agree on which table entry is used by each module.
* this is remembered in a "data key", that is just an index into
* this table. To allow self initialization, the interface
* passes a pointer to this key and the first thread to use
* the key fills in the pointer to the key. The key should be
* a process-wide static.
*
* 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 (pthread_key_t **) */
{
pthread_key_t *pkeyPtr;
MASTER_LOCK;
if (*keyPtr == NULL) {
pkeyPtr = (pthread_key_t *)ckalloc(sizeof(pthread_key_t));
pthread_key_create(pkeyPtr, NULL);
*keyPtr = (Tcl_ThreadDataKey)pkeyPtr;
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 (pthread_key_t **) */
{
pthread_key_t *pkeyPtr = *(pthread_key_t **)keyPtr;
if (pkeyPtr == NULL) {
return NULL;
} else {
return (VOID *)pthread_getspecific(*pkeyPtr);
}
}
/*
*----------------------------------------------------------------------
*
* 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 */
{
pthread_key_t *pkeyPtr = *(pthread_key_t **)keyPtr;
pthread_setspecific(*pkeyPtr, data);
}
/*
*----------------------------------------------------------------------
*
* TclpFinalizeThreadData --
*
* This procedure cleans up the thread-local storage. This is
* called once for each thread.
*
* Results:
* None.
*
* Side effects:
* Frees up all thread local storage.
*
*----------------------------------------------------------------------
*/
void
TclpFinalizeThreadData(keyPtr)
Tcl_ThreadDataKey *keyPtr;
{
VOID *result;
pthread_key_t *pkeyPtr;
if (*keyPtr != NULL) {
pkeyPtr = *(pthread_key_t **)keyPtr;
result = (VOID *)pthread_getspecific(*pkeyPtr);
if (result != NULL) {
ckfree((char *)result);
pthread_setspecific(*pkeyPtr, (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;
{
pthread_key_t *pkeyPtr;
if (*keyPtr != NULL) {
pkeyPtr = *(pthread_key_t **)keyPtr;
pthread_key_delete(*pkeyPtr);
ckfree((char *)pkeyPtr);
*keyPtr = NULL;
}
}
/*
*----------------------------------------------------------------------
*
* Tcl_ConditionWait --
*
* This procedure is invoked to wait on a condition variable.
* The mutex is automically 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 pthread_mutex_t
* and initialize this the first time this Tcl_Mutex is used.
*
*----------------------------------------------------------------------
*/
void
Tcl_ConditionWait(condPtr, mutexPtr, timePtr)
Tcl_Condition *condPtr; /* Really (pthread_cond_t **) */
Tcl_Mutex *mutexPtr; /* Really (pthread_mutex_t **) */
Tcl_Time *timePtr; /* Timeout on waiting period */
{
pthread_cond_t *pcondPtr;
pthread_mutex_t *pmutexPtr;
struct timespec ptime;
if (*condPtr == NULL) {
MASTER_LOCK;
/*
* Double check inside mutex to avoid race,
* then initialize condition variable if necessary.
*/
if (*condPtr == NULL) {
pcondPtr = (pthread_cond_t *)ckalloc(sizeof(pthread_cond_t));
pthread_cond_init(pcondPtr, NULL);
*condPtr = (Tcl_Condition)pcondPtr;
TclRememberCondition(condPtr);
}
MASTER_UNLOCK;
}
pmutexPtr = *((pthread_mutex_t **)mutexPtr);
pcondPtr = *((pthread_cond_t **)condPtr);
if (timePtr == NULL) {
pthread_cond_wait(pcondPtr, pmutexPtr);
} else {
ptime.tv_sec = timePtr->sec + TclpGetSeconds();
ptime.tv_nsec = 1000 * timePtr->usec;
pthread_cond_timedwait(pcondPtr, pmutexPtr, &ptime);
}
}
/*
*----------------------------------------------------------------------
*
* 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;
{
pthread_cond_t *pcondPtr = *((pthread_cond_t **)condPtr);
if (pcondPtr != NULL) {
pthread_cond_broadcast(pcondPtr);
} else {
/*
* Noone has used the condition variable, so there are no waiters.
*/
}
}
/*
*----------------------------------------------------------------------
*
* 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;
{
pthread_cond_t *pcondPtr = *(pthread_cond_t **)condPtr;
if (pcondPtr != NULL) {
pthread_cond_destroy(pcondPtr);
ckfree((char *)pcondPtr);
*condPtr = NULL;
}
}
#endif /* TCL_THREADS */