/*
* 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.
*
* RCS: @(#) $Id: tclUnixThrd.c,v 1.57 2008/01/11 11:53:02 msofer Exp $
*/
#include "tclInt.h"
#ifdef TCL_THREADS
#include "pthread.h"
typedef struct ThreadSpecificData {
char nabuf[16];
} ThreadSpecificData;
static Tcl_ThreadDataKey dataKey;
/*
* 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 by Tcl's version of malloc for synchronization. For
* obvious reasons, cannot use any dyamically allocated storage.
*/
static pthread_mutex_t allocLock = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t *allocLockPtr = &allocLock;
/*
* 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 */
/*
*----------------------------------------------------------------------
*
* 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(
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
pthread_attr_t attr;
pthread_t theThread;
int result;
pthread_attr_init(&attr);
pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);
#ifdef HAVE_PTHREAD_ATTR_SETSTACKSIZE
if (stackSize != TCL_THREAD_STACK_DEFAULT) {
pthread_attr_setstacksize(&attr, (size_t) stackSize);
#ifdef TCL_THREAD_STACK_MIN
} else {
/*
* Certain systems define a thread stack size that by default is too
* small for many operations. The user has the option of defining
* TCL_THREAD_STACK_MIN to a value large enough to work for their
* needs. This would look like (for 128K min stack):
* make MEM_DEBUG_FLAGS=-DTCL_THREAD_STACK_MIN=131072L
*
* This solution is not optimal, as we should allow the user to
* specify a size at runtime, but we don't want to slow this function
* down, and that would still leave the main thread at the default.
*/
size_t size;
result = pthread_attr_getstacksize(&attr, &size);
if (!result && (size < TCL_THREAD_STACK_MIN)) {
pthread_attr_setstacksize(&attr, (size_t) TCL_THREAD_STACK_MIN);
}
#endif
}
#endif
if (! (flags & TCL_THREAD_JOINABLE)) {
pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
}
if (pthread_create(&theThread, &attr,
(void * (*)(void *))proc, (void *)clientData) &&
pthread_create(&theThread, NULL,
(void * (*)(void *))proc, (void *)clientData)) {
result = TCL_ERROR;
} else {
*idPtr = (Tcl_ThreadId)theThread;
result = TCL_OK;
}
pthread_attr_destroy(&attr);
return result;
#else
return TCL_ERROR;
#endif /* TCL_THREADS */
}
/*
*----------------------------------------------------------------------
*
* Tcl_JoinThread --
*
* This procedure waits upon the exit of the specified thread.
*
* Results:
* TCL_OK if the wait was successful, TCL_ERROR else.
*
* Side effects:
* The result area is set to the exit code of the thread we waited upon.
*
*----------------------------------------------------------------------
*/
int
Tcl_JoinThread(
Tcl_ThreadId threadId, /* Id of the thread to wait upon. */
int *state) /* Reference to the storage the result of the
* thread we wait upon will be written into.
* May be NULL. */
{
#ifdef TCL_THREADS
int result;
unsigned long retcode, *retcodePtr = &retcode;
result = pthread_join((pthread_t) threadId, (void**) retcodePtr);
if (state) {
*state = (int) retcode;
}
return (result == 0) ? TCL_OK : TCL_ERROR;
#else
return TCL_ERROR;
#endif
}
#ifdef TCL_THREADS
/*
*----------------------------------------------------------------------
*
* TclpThreadExit --
*
* This procedure terminates the current thread.
*
* Results:
* None.
*
* Side effects:
* This procedure terminates the current thread.
*
*----------------------------------------------------------------------
*/
void
TclpThreadExit(
int status)
{
pthread_exit(INT2PTR(status));
}
#endif /* TCL_THREADS */
#ifdef TCL_THREADS
/*
*----------------------------------------------------------------------
*
* TclpThreadGetStackSize --
*
* This procedure returns the size of the current thread's stack.
*
* Results:
* Stack size (in bytes?) or -1 for error or 0 for undeterminable.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
size_t
TclpThreadGetStackSize(void)
{
size_t stackSize = 0;
#if defined(HAVE_PTHREAD_ATTR_SETSTACKSIZE) && defined(TclpPthreadGetAttrs)
pthread_attr_t threadAttr; /* This will hold the thread attributes for
* the current thread. */
#ifdef __GLIBC__
/*
* Fix for [Bug 1815573]
*
* DESCRIPTION:
* On linux TclpPthreadGetAttrs (which is pthread_attr_get_np) may return
* bogus values on the initial thread.
*
* ASSUMPTIONS:
* There seems to be no api to determine if we are on the initial
* thread. The simple scheme implemented here assumes:
* 1. The first Tcl interp to be created lives in the initial thread. If
* this assumption is not true, the fix is to call
* TclpThreadGetStackSize from the initial thread previous to
* creating any Tcl interpreter. In this case, especially if another
* Tcl interpreter may be created in the initial thread, it might be
* better to enable the second branch in the #if below
* 2. There will be no races in creating the first Tcl interp - ie, the
* second Tcl interp will be created only after the first call to
* Tcl_CreateInterp returns.
*
* These assumptions are satisfied by tclsh. Embedders on linux may want
* to check their validity, and possibly adapt the code on failing to meet
* them.
*/
static int initialized = 0;
if (!initialized) {
initialized = 1;
return 0;
} else {
#else
{
#endif
if (pthread_attr_init(&threadAttr) != 0) {
return -1;
}
if (TclpPthreadGetAttrs(pthread_self(), &threadAttr) != 0) {
pthread_attr_destroy(&threadAttr);
return (size_t)-1;
}
}
if (pthread_attr_getstacksize(&threadAttr, &stackSize) != 0) {
pthread_attr_destroy(&threadAttr);
return (size_t)-1;
}
pthread_attr_destroy(&threadAttr);
#elif defined(HAVE_PTHREAD_GET_STACKSIZE_NP)
#ifdef __APPLE__
/*
* On Darwin, the API below does not return the correct stack size for the
* main thread (which is not a real pthread), so fallback to getrlimit().
*/
if (!pthread_main_np())
#endif
stackSize = pthread_get_stacksize_np(pthread_self());
#else
/*
* Cannot determine the real stack size of this thread. The caller might
* want to try looking at the process accounting limits instead.
*/
#endif
return stackSize;
}
#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(void)
{
#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(void)
{
#ifdef TCL_THREADS
pthread_mutex_lock(&initLock);
#endif
}
/*
*----------------------------------------------------------------------
*
* TclpFinalizeLock
*
* This procedure is used to destroy all private resources used in this
* file.
*
* Results:
* None.
*
* Side effects:
* Destroys everything private. TclpInitLock must be held entering this
* function.
*
*----------------------------------------------------------------------
*/
void
TclFinalizeLock(void)
{
#ifdef TCL_THREADS
/*
* You do not need to destroy mutexes that were created with the
* PTHREAD_MUTEX_INITIALIZER macro. These mutexes do not need any
* destruction: masterLock, allocLock, and initLock.
*/
pthread_mutex_unlock(&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(void)
{
#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(void)
{
#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(void)
{
#ifdef TCL_THREADS
pthread_mutex_unlock(&masterLock);
#endif
}
/*
*----------------------------------------------------------------------
*
* Tcl_GetAllocMutex
*
* This procedure returns a pointer to a statically initialized mutex for
* use by the memory allocator. The alloctor must use this lock, because
* all other locks are allocated...
*
* Results:
* A pointer to a mutex that is suitable for passing to Tcl_MutexLock and
* Tcl_MutexUnlock.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
Tcl_Mutex *
Tcl_GetAllocMutex(void)
{
#ifdef TCL_THREADS
pthread_mutex_t **allocLockPtrPtr = &allocLockPtr;
return (Tcl_Mutex *) allocLockPtrPtr;
#else
return NULL;
#endif
}
#ifdef TCL_THREADS
/*
*----------------------------------------------------------------------
*
* 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(
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 condition.
*/
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);
}
/*
*----------------------------------------------------------------------
*
* Tcl_MutexUnlock --
*
* 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(
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(
Tcl_Mutex *mutexPtr)
{
pthread_mutex_t *pmutexPtr = *(pthread_mutex_t **)mutexPtr;
if (pmutexPtr != NULL) {
pthread_mutex_destroy(pmutexPtr);
ckfree((char *) pmutexPtr);
*mutexPtr = 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(
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 {
Tcl_Time now;
/*
* Make sure to take into account the microsecond component of the
* current time, including possible overflow situations. [Bug #411603]
*/
Tcl_GetTime(&now);
ptime.tv_sec = timePtr->sec + now.sec +
(timePtr->usec + now.usec) / 1000000;
ptime.tv_nsec = 1000 * ((timePtr->usec + now.usec) % 1000000);
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(
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(
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 */
/*
*----------------------------------------------------------------------
*
* TclpReaddir, TclpLocaltime, TclpGmtime, TclpInetNtoa --
*
* These procedures replace core C versions to be used in a threaded
* environment.
*
* Results:
* See documentation of C functions.
*
* Side effects:
* See documentation of C functions.
*
* Notes:
* TclpReaddir is no longer used by the core (see 1095909), but it
* appears in the internal stubs table (see #589526).
*
*----------------------------------------------------------------------
*/
Tcl_DirEntry *
TclpReaddir(
DIR * dir)
{
return TclOSreaddir(dir);
}
char *
TclpInetNtoa(
struct in_addr addr)
{
#ifdef TCL_THREADS
ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey);
unsigned char *b = (unsigned char*) &addr.s_addr;
sprintf(tsdPtr->nabuf, "%u.%u.%u.%u", b[0], b[1], b[2], b[3]);
return tsdPtr->nabuf;
#else
return inet_ntoa(addr);
#endif
}
#ifdef TCL_THREADS
/*
* Additions by AOL for specialized thread memory allocator.
*/
#ifdef USE_THREAD_ALLOC
static volatile int initialized = 0;
static pthread_key_t key;
typedef struct allocMutex {
Tcl_Mutex tlock;
pthread_mutex_t plock;
} allocMutex;
Tcl_Mutex *
TclpNewAllocMutex(void)
{
struct allocMutex *lockPtr;
register pthread_mutex_t *plockPtr;
lockPtr = malloc(sizeof(struct allocMutex));
if (lockPtr == NULL) {
Tcl_Panic("could not allocate lock");
}
plockPtr = &lockPtr->plock;
lockPtr->tlock = (Tcl_Mutex) plockPtr;
pthread_mutex_init(&lockPtr->plock, NULL);
return &lockPtr->tlock;
}
void
TclpFreeAllocMutex(
Tcl_Mutex *mutex) /* The alloc mutex to free. */
{
allocMutex* lockPtr = (allocMutex*) mutex;
if (!lockPtr) {
return;
}
pthread_mutex_destroy(&lockPtr->plock);
free(lockPtr);
}
void
TclpFreeAllocCache(
void *ptr)
{
if (ptr != NULL) {
/*
* Called by the pthread lib when a thread exits
*/
TclFreeAllocCache(ptr);
} else if (initialized) {
/*
* Called by us in TclFinalizeThreadAlloc() during the library
* finalization initiated from Tcl_Finalize()
*/
pthread_key_delete(key);
initialized = 0;
}
}
void *
TclpGetAllocCache(void)
{
if (!initialized) {
pthread_mutex_lock(allocLockPtr);
if (!initialized) {
pthread_key_create(&key, TclpFreeAllocCache);
initialized = 1;
}
pthread_mutex_unlock(allocLockPtr);
}
return pthread_getspecific(key);
}
void
TclpSetAllocCache(
void *arg)
{
pthread_setspecific(key, arg);
}
#endif /* USE_THREAD_ALLOC */
#endif /* TCL_THREADS */
/*
* Local Variables:
* mode: c
* c-basic-offset: 4
* fill-column: 78
* End:
*/
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