diff options
Diffstat (limited to 'gcc/objc/thr-pthreads.c')
| -rw-r--r-- | gcc/objc/thr-pthreads.c | 157 |
1 files changed, 131 insertions, 26 deletions
diff --git a/gcc/objc/thr-pthreads.c b/gcc/objc/thr-pthreads.c index 112f1131d05..cbd997c79fb 100644 --- a/gcc/objc/thr-pthreads.c +++ b/gcc/objc/thr-pthreads.c @@ -1,5 +1,5 @@ /* GNU Objective C Runtime Thread Implementation for PCThreads under Linux. - Copyright (C) 1996 Free Software Foundation, Inc. + Copyright (C) 1996, 1997 Free Software Foundation, Inc. Contributed by Scott Christley <scottc@net-community.com> This file is part of GNU CC. @@ -37,13 +37,18 @@ static pthread_key_t _objc_thread_storage; * provided by the system. We augment it with depth and current owner id * fields to implement and re-entrant lock. */ -struct _objc_mutex +struct objc_mutex { - volatile _objc_thread_t owner; /* Id of thread that owns. */ + volatile objc_thread_t owner; /* Id of thread that owns. */ volatile int depth; /* # of acquires. */ pthread_mutex_t mutex; /* PCThread mutex */ }; +struct objc_condition +{ + pthread_cond_t condition; /* cthread condition */ +}; + /******** * Initialize the threads subsystem. Returns 0 if successful, or -1 if no * thread support is available. @@ -71,17 +76,17 @@ __objc_fini_thread_system(void) * Create a new thread of execution and return its id. Return NULL if fails. * The new thread starts in "func" with the given argument. */ -_objc_thread_t +objc_thread_t objc_thread_create(void (*func)(void *arg), void *arg) { - _objc_thread_t thread_id; + objc_thread_t thread_id; pthread_t new_thread_handle; objc_mutex_lock(__objc_runtime_mutex); if ( !(pthread_create(&new_thread_handle, NULL, (void *)func, arg)) ) { - thread_id = *(_objc_thread_t *)&new_thread_handle; + thread_id = *(objc_thread_t *)&new_thread_handle; __objc_runtime_threads_alive++; } else @@ -99,7 +104,7 @@ int objc_thread_set_priority(int priority) { /* Not implemented yet */ - return -1; /* Failed. */ + return -1; /* Failed. */ } /******** @@ -109,7 +114,7 @@ int objc_thread_get_priority(void) { /* Not implemented yet */ - return OBJC_THREAD_INTERACTIVE_PRIORITY; /* Highest priority. */ + return OBJC_THREAD_INTERACTIVE_PRIORITY; /* Highest priority. */ } /******** @@ -134,7 +139,7 @@ objc_thread_exit(void) __objc_runtime_threads_alive--; objc_mutex_unlock(__objc_runtime_mutex); - pthread_exit(&__objc_thread_exit_status); /* Terminate thread. */ + pthread_exit(&__objc_thread_exit_status); /* Terminate thread. */ return -1; } @@ -142,12 +147,12 @@ objc_thread_exit(void) * Returns an integer value which uniquely describes a thread. Must not be * NULL which is reserved as a marker for "no thread". */ -_objc_thread_t +objc_thread_t objc_thread_id(void) { pthread_t self = pthread_self(); - return *(_objc_thread_t *)&self; /* Return thread handle. */ + return *(objc_thread_t *)&self; /* Return thread handle. */ } /******** @@ -178,12 +183,12 @@ objc_thread_get_data(void) * Allocate a mutex. Return the mutex pointer if successful or NULL if the * allocation failed for any reason. */ -_objc_mutex_t +objc_mutex_t objc_mutex_allocate(void) { - _objc_mutex_t mutex; + objc_mutex_t mutex; - if (!(mutex = (_objc_mutex_t) objc_malloc(sizeof(struct _objc_mutex)))) + if (!(mutex = (objc_mutex_t)objc_malloc(sizeof(struct objc_mutex)))) return NULL; /* Abort if malloc failed. */ /* Create PCThread mutex */ @@ -207,7 +212,7 @@ objc_mutex_allocate(void) * Returns the number of locks on the thread. (1 for deallocate). */ int -objc_mutex_deallocate(_objc_mutex_t mutex) +objc_mutex_deallocate(objc_mutex_t mutex) { int depth; /* # of locks on mutex. */ @@ -229,9 +234,9 @@ objc_mutex_deallocate(_objc_mutex_t mutex) * Returns the lock count on the mutex held by this thread. */ int -objc_mutex_lock(_objc_mutex_t mutex) +objc_mutex_lock(objc_mutex_t mutex) { - _objc_thread_t thread_id; /* Cache our thread id. */ + objc_thread_t thread_id; /* Cache our thread id. */ int status; if (!mutex) /* Is argument bad? */ @@ -259,9 +264,9 @@ objc_mutex_lock(_objc_mutex_t mutex) * thread has a lock on the mutex returns -1. */ int -objc_mutex_trylock(_objc_mutex_t mutex) +objc_mutex_trylock(objc_mutex_t mutex) { - _objc_thread_t thread_id; /* Cache our thread id. */ + objc_thread_t thread_id; /* Cache our thread id. */ int status; if (!mutex) /* Is argument bad? */ @@ -280,16 +285,16 @@ objc_mutex_trylock(_objc_mutex_t mutex) } /******** - * Decrements the lock count on this mutex by one. If the lock count reaches - * zero, release the lock on the mutex. Returns the lock count on the mutex. - * It is an error to attempt to unlock a mutex which this thread doesn't hold - * in which case return -1 and the mutex is unaffected. - * Will also return -1 if the mutex free fails. + * Decrements the lock count on this mutex by one. If the lock count reaches + * zero, release the lock on the mutex. Returns the lock count on the mutex. + * It is an error to attempt to unlock a mutex which this thread doesn't hold + * in which case return -1 and the mutex is unaffected. + * Will also return -1 if the mutex free fails. */ int -objc_mutex_unlock(_objc_mutex_t mutex) +objc_mutex_unlock(objc_mutex_t mutex) { - _objc_thread_t thread_id; /* Cache our thread id. */ + objc_thread_t thread_id; /* Cache our thread id. */ int status; if (!mutex) /* Is argument bad? */ @@ -310,4 +315,104 @@ objc_mutex_unlock(_objc_mutex_t mutex) return 0; /* No, return success. */ } +/******** + * Allocate a condition. Return the condition pointer if successful or NULL + * if the allocation failed for any reason. + */ +objc_condition_t +objc_condition_allocate(void) +{ + objc_condition_t condition; + + if (!(condition = (objc_condition_t)objc_malloc( + sizeof(struct objc_condition)))) + return NULL; /* Abort if malloc failed. */ + + if ( pthread_cond_init(&(condition->condition), NULL) ) { + objc_free(condition); + return NULL; + } + + return condition; /* Return condition handle. */ +} + +/******** + * Deallocate a condition. Note that this includes an implicit + * condition_broadcast to insure that waiting threads have the opportunity + * to wake. It is legal to dealloc a condition only if no other + * thread is/will be using it. Here we do NOT check for other threads + * waiting but just wake them up. + */ +int +objc_condition_deallocate(objc_condition_t condition) +{ + pthread_cond_broadcast(&(condition->condition)); + pthread_cond_destroy(&(condition->condition)); + objc_free(condition); + return 0; +} + +/******** + * Wait on the condition unlocking the mutex until objc_condition_signal() + * or objc_condition_broadcast() are called for the same condition. The + * given mutex *must* have the depth set to 1 so that it can be unlocked + * here, so that someone else can lock it and signal/broadcast the condition. + * The mutex is used to lock access to the shared data that make up the + * "condition" predicate. + */ +int +objc_condition_wait(objc_condition_t condition, objc_mutex_t mutex) +{ + objc_thread_t thread_id; /* Cache our thread id. */ + + if (!mutex || !condition) /* Is argument bad? */ + return -1; /* Yes, abort. */ + + thread_id = objc_thread_id(); /* Get this thread's id. */ + if (mutex->owner != thread_id) /* Does some else own lock? */ + return -1; /* Yes, abort. */ + if (mutex->depth > 1) /* Locked more than once ? */ + return -1; /* YES, return error */ + /* mutex will be unlocked */ + mutex->depth = 0; /* Yes, reset depth to 0. */ + mutex->owner = (objc_thread_t) -1; /* Set owner to "no thread".*/ + + pthread_cond_wait(&(condition->condition), + &(mutex->mutex)); /* unlock, wait ..., lock */ + + mutex->owner = thread_id; /* Mark thread as owner. */ + mutex->depth = 1; /* Increment depth to end. */ + return 0; /* Return success. */ +} + +/******** + * Wake up all threads waiting on this condition. It is recommended that + * the called would lock the same mutex as the threads in objc_condition_wait + * before changing the "condition predicate" and make this call and unlock it + * right away after this call. + */ +int +objc_condition_broadcast(objc_condition_t condition) +{ + if (!condition) + return -1; + pthread_cond_broadcast(&(condition->condition)); + return 0; +} + +/******** + * Wake up one thread waiting on this condition. It is recommended that + * the called would lock the same mutex as the threads in objc_condition_wait + * before changing the "condition predicate" and make this call and unlock it + * right away after this call. + */ +int +objc_condition_signal(objc_condition_t condition) +{ + if (!condition) + return -1; + pthread_cond_signal(&(condition->condition)); + return 0; +} + /* End of File */ |
