Completely rework according to new interface.

From-SVN: r14310

1 files changed, 170 insertions, 322 deletions

diff --git a/gcc/objc/thr-mach.c b/gcc/objc/thr-mach.c
index 1f43fc5..6f54ada 100644
--- a/gcc/objc/thr-mach.c
+++ b/gcc/objc/thr-mach.c
@@ -31,434 +31,282 @@ Boston, MA 02111-1307, USA.  */
 #include <objc/thr.h>
 #include "runtime.h"
 
-/********
- *  This structure represents a single mutual exclusion lock.  Lock semantics
- *  are detailed with the subsequent functions.  We use whatever lock is
- *  provided by the system.  We augment it with depth and current owner id
- *  fields to implement and re-entrant lock.
- */
-struct objc_mutex 
+/*
+  Obtain the maximum thread priority that can set for t.  Under the
+  mach threading model, it is possible for the developer to adjust the
+  maximum priority downward only-- cannot be raised without superuser
+  priviledges.  Once lowered, it cannot be raised.
+  */
+static int __mach_get_max_thread_priority(cthread_t t, int *base)
 {
-    volatile objc_thread_t     owner;          /* Id of thread that owns.  */
-    volatile int                depth;          /* # of acquires.           */
-    struct mutex                lock;           /* cthread mutex            */
-};
-
-struct objc_condition 
-{
-    struct condition            condition;      /* cthread condition        */
-};
-
-/********
- * obtain the maximum thread priority that can set for t.  Under the
- * mach threading model, it is possible for the developer to adjust the
- * maximum priority downward only-- cannot be raised without superuser
- * priviledges.  Once lowered, it cannot be raised.
- */
-static int __mach_get_max_thread_priority(cthread_t t, int *base) {
-    thread_t   		      threadP;
-    kern_return_t             error;
-    struct thread_sched_info  info;
-    unsigned int              info_count=THREAD_SCHED_INFO_COUNT;
+  thread_t threadP;
+  kern_return_t error;
+  struct thread_sched_info info;
+  unsigned int info_count=THREAD_SCHED_INFO_COUNT;
     
-    if (t == NULL)
-	return -1;
+  if (t == NULL)
+    return -1;
 
-    threadP  = cthread_thread(t); 	/* get thread underlying */
+  threadP  = cthread_thread(t); 	/* get thread underlying */
 
-    error=thread_info(threadP, THREAD_SCHED_INFO, 
-		      (thread_info_t)&info, &info_count);
+  error=thread_info(threadP, THREAD_SCHED_INFO, 
+		    (thread_info_t)&info, &info_count);
 
-    if (error != KERN_SUCCESS)
-	return -1;
+  if (error != KERN_SUCCESS)
+    return -1;
 
-    if (base != NULL)
-	*base = info.base_priority;
+  if (base != NULL)
+    *base = info.base_priority;
 
-    return info.max_priority;
+  return info.max_priority;
 }
 	
-/********
- *  Initialize the threads subsystem.  Returns 0 if successful, or -1 if no
- *  thread support is available.
- */
+/* Backend initialization functions */
+
+/* Initialize the threads subsystem. */
 int
 __objc_init_thread_system(void)
 {
-    DEBUG_PRINTF("__objc_init_thread_system\n");
-    return 0;                                    /* Succeeded.       */
+  return 0;
 }
 
-
+/* Close the threads subsystem. */
 int
-__objc_fini_thread_system(void)
+__objc_close_thread_system(void)
 {
   return 0;
 }
 
-/********
- *  Create a new thread of execution and return its id.  Return NULL if fails.
- *  The new thread starts in "func" with the given argument.
- */
+/* Backend thread functions */
+
+/* Create a new thread of execution. */
 objc_thread_t
-objc_thread_create(void (*func)(void *arg), void *arg)
+__objc_thread_detach(void (*func)(void *arg), void *arg)
 {
-    objc_thread_t      thread_id = NULL;       /* Detached thread id.      */
-    cthread_t           new_thread_handle;      /* cthread handle.          */
+  objc_thread_t thread_id;
+  cthread_t new_thread_handle;
 
-    objc_mutex_lock(__objc_runtime_mutex);
-    
-    /* create thread */
-    new_thread_handle = cthread_fork((cthread_fn_t)func, arg);
+  /* create thread */
+  new_thread_handle = cthread_fork((cthread_fn_t)func, arg);
 
-    if(new_thread_handle) {
+  if(new_thread_handle)
+    {
       /* this is not terribly portable */
-        thread_id = *(objc_thread_t *)&new_thread_handle; 
-        cthread_detach(new_thread_handle);      /* fully detach thread */
-        __objc_runtime_threads_alive++;         /* increment thread count */
+      thread_id = *(objc_thread_t *)&new_thread_handle; 
+      cthread_detach(new_thread_handle);
     }
-    
-    objc_mutex_unlock(__objc_runtime_mutex);
-    return thread_id;
+  else
+    thread_id = NULL;
+  
+  return thread_id;
 }
 
-/********
- *  Set the current thread's priority.
- */
+/* Set the current thread's priority. */
 int
-objc_thread_set_priority(int priority)
+__objc_thread_set_priority(int priority)
 {
-    objc_thread_t   *t	     = objc_thread_id();
-    cthread_t        cT	     = (cthread_t) t; 
-    int 	     maxPriority  = __mach_get_max_thread_priority(cT, NULL);
-    int              sys_priority = 0;
+  objc_thread_t *t = objc_thread_id();
+  cthread_t cT = (cthread_t) t; 
+  int maxPriority = __mach_get_max_thread_priority(cT, NULL);
+  int sys_priority = 0;
 
-    if (maxPriority == -1)
-	return -1;
+  if (maxPriority == -1)
+    return -1;
 
-    switch (priority) {
+  switch (priority)
+    {
     case OBJC_THREAD_INTERACTIVE_PRIORITY:
-        sys_priority = maxPriority;
-        break;
+      sys_priority = maxPriority;
+      break;
     case OBJC_THREAD_BACKGROUND_PRIORITY:
-        sys_priority = (maxPriority * 2) / 3;
-        break;
+      sys_priority = (maxPriority * 2) / 3;
+      break;
     case OBJC_THREAD_LOW_PRIORITY:
-        sys_priority = maxPriority / 3;
-        break;
+      sys_priority = maxPriority / 3;
+      break;
     default:
-	return -1;
+      return -1;
     }
 
-    if (sys_priority == 0)
-	return -1;
-    
-    if (cthread_priority(cT, sys_priority, 0) == KERN_SUCCESS)
-        return 0;                               /* Changed priority. End.   */
-    
-    return -1;                                  /* Failed.                  */
+  if (sys_priority == 0)
+    return -1;
+
+  /* Change the priority */
+  if (cthread_priority(cT, sys_priority, 0) == KERN_SUCCESS)
+    return 0;
+  else
+    return -1;
 }
 
-/********
- *  Return the current thread's priority [well, whatever it is closest to].
- */
+/* Return the current thread's priority. */
 int
-objc_thread_get_priority(void)
+__objc_thread_get_priority(void)
 {
-    objc_thread_t *t	        = objc_thread_id();
-    cthread_t      cT	        = (cthread_t) t; /* see objc_thread_id() */
-    int 	   basePriority;
-    int 	   maxPriority;
-    int            sys_priority = 0;
-
-    int interactiveT, backgroundT, lowT; /* threasholds */
-
-    maxPriority = __mach_get_max_thread_priority(cT, &basePriority);
-
-    if(maxPriority == -1)
-	return -1;
-
-    if (basePriority > ( (maxPriority * 2) / 3))
-	return OBJC_THREAD_INTERACTIVE_PRIORITY; /* interactive priority
-						 */
-    if (basePriority > ( maxPriority / 3))
-	return OBJC_THREAD_BACKGROUND_PRIORITY; /* background priority
-						 */
-    return OBJC_THREAD_LOW_PRIORITY; /* everything else is low */
+  objc_thread_t *t = objc_thread_id();
+  cthread_t cT = (cthread_t) t; /* see objc_thread_id() */
+  int basePriority;
+  int maxPriority;
+  int sys_priority = 0;
+
+  int interactiveT, backgroundT, lowT; /* threasholds */
+
+  maxPriority = __mach_get_max_thread_priority(cT, &basePriority);
+
+  if(maxPriority == -1)
+    return -1;
+
+  if (basePriority > ( (maxPriority * 2) / 3))
+    return OBJC_THREAD_INTERACTIVE_PRIORITY;
+
+  if (basePriority > ( maxPriority / 3))
+    return OBJC_THREAD_BACKGROUND_PRIORITY;
+
+  return OBJC_THREAD_LOW_PRIORITY;
 }
 
-/********
- *  Yield our process time to another thread.  Any BUSY waiting that is done
- *  by a thread should use this function to make sure that other threads can
- *  make progress even on a lazy uniprocessor system.
- */
+/* Yield our process time to another thread. */
 void
-objc_thread_yield(void)
+__objc_thread_yield(void)
 {
-    cthread_yield();                            /* Yield to equal thread.   */
+  cthread_yield();
 }
 
-/********
- *  Terminate the current tread.  Doesn't return anything.  Doesn't return.
- *  Actually, if it failed returns -1.
- */
+/* Terminate the current thread. */
 int
-objc_thread_exit(void)
+__objc_thread_exit(void)
 {
-  objc_mutex_lock(__objc_runtime_mutex);
-  __objc_runtime_threads_alive--;
-  objc_mutex_unlock(__objc_runtime_mutex);
-      
-  cthread_exit(&__objc_thread_exit_status);     /* Terminate thread.        */
+  /* exit the thread */
+  cthread_exit(&__objc_thread_exit_status);
+
+  /* Failed if we reached here */
   return -1;
 }
 
-/********
- *  Returns an integer value which uniquely describes a thread.  Must not be
- *  NULL which is reserved as a marker for "no thread".
- */
+/* Returns an integer value which uniquely describes a thread. */
 objc_thread_t
-objc_thread_id(void)
+__objc_thread_id(void)
 {
   cthread_t self = cthread_self();
-  return (objc_thread_t)self;
-}
 
-/********
- *  Sets the thread's local storage pointer.  Returns 0 if successful or -1
- *  if failed.
- */
+  return *(objc_thread_t *)&self;
+}
 
+/* Sets the thread's local storage pointer. */
 int
-objc_thread_set_data(void *value)
+__objc_thread_set_data(void *value)
 {
   cthread_set_data(cthread_self(), (any_t) value);
   return 0;
 }
 
-/********
- *  Returns the thread's local storage pointer.  Returns NULL on failure.
- */
+/* Returns the thread's local storage pointer. */
 void *
-objc_thread_get_data(void)
+__objc_thread_get_data(void)
 {
   return (void *) cthread_data(cthread_self());
 }
 
-/********
- *  Allocate a mutex.  Return the mutex pointer if successful or NULL if the
- *  allocation failed for any reason.
- */
-objc_mutex_t
-objc_mutex_allocate(void)
+/* Backend mutex functions */
+
+/* Allocate a mutex. */
+int
+__objc_mutex_allocate(objc_mutex_t mutex)
 {
-    objc_mutex_t mutex;
-    int         err = 0;
-    
-    if (!(mutex = (objc_mutex_t)objc_malloc(sizeof(struct objc_mutex))))
-        return NULL;                            /* Abort if malloc failed.  */
+  int err = 0;
+  mutex->backend = objc_malloc(sizeof(struct mutex));
 
-    err = mutex_init(&(mutex->lock));
-    
-    if (err != 0) {                             /* System init failed?      */
-        objc_free(mutex);                       /* Yes, free local memory.  */
-        return NULL;                            /* Abort.                   */
+  err = mutex_init((mutex_t)(mutex->backend));
+
+  if (err != 0)
+    {
+      objc_free(mutex->backend);
+      return -1;
     }
-    mutex->owner = (objc_thread_t) -1;         /* No owner.                */
-    mutex->depth = 0;                           /* No locks.                */
-    return mutex;                               /* Return mutex handle.     */
+  else
+    return 0;
 }
 
-/********
- *  Deallocate a mutex.  Note that this includes an implicit mutex_lock to
- *  insure that no one else is using the lock.  It is legal to deallocate
- *  a lock if we have a lock on it, but illegal to deallocate a lock held
- *  by anyone else.
- *  Returns the number of locks on the thread.  (1 for deallocate).
- */
+/* Deallocate a mutex. */
 int
-objc_mutex_deallocate(objc_mutex_t mutex)
+__objc_mutex_deallocate(objc_mutex_t mutex)
 {
-    int         depth;                          /* # of locks on mutex.     */
+  mutex_clear((mutex_t)(mutex->backend));
 
-    if (!mutex)                                 /* Is argument bad?         */
-        return -1;                              /* Yes, abort.              */
-    depth = objc_mutex_lock(mutex);             /* Must have lock.          */
-    
-    mutex_unlock(&(mutex->lock));               /* Must unlock system mutex.*/
-    mutex_clear(&(mutex->lock));                /* Free system mutex.       */
-    
-    objc_free(mutex);                           /* Free memory.             */
-    return depth;                               /* Return last depth.       */
+  objc_free(mutex->backend);
+  mutex->backend = NULL;
+  return 0;
 }
 
-/********
- *  Grab a lock on a mutex.  If this thread already has a lock on this mutex
- *  then we increment the lock count.  If another thread has a lock on the 
- *  mutex we block and wait for the thread to release the lock.
- *  Returns the lock count on the mutex held by this thread.
- */
+/* Grab a lock on a mutex. */
 int
-objc_mutex_lock(objc_mutex_t mutex)
+__objc_mutex_lock(objc_mutex_t mutex)
 {
-    objc_thread_t thread_id;                  /* Cache our thread id.     */
-
-    if (!mutex)                                 /* Is argument bad?         */
-        return -1;                              /* Yes, abort.              */
-    thread_id = objc_thread_id();               /* Get this thread's id.    */
-    if (mutex->owner == thread_id)              /* Already own lock?        */
-        return ++mutex->depth;                  /* Yes, increment depth.    */
-
-    mutex_lock(&(mutex->lock));                 /* Lock cthread mutex.      */
-    
-    mutex->owner = thread_id;                   /* Mark thread as owner.    */
-    return mutex->depth = 1;                    /* Increment depth to end.  */
+  mutex_lock((mutex_t)(mutex->backend));
+  return 0;
 }
 
-/********
- *  Try to grab a lock on a mutex.  If this thread already has a lock on
- *  this mutex then we increment the lock count and return it.  If another
- *  thread has a lock on the mutex returns -1.
- */
+/* Try to grab a lock on a mutex. */
 int
-objc_mutex_trylock(objc_mutex_t mutex)
+__objc_mutex_trylock(objc_mutex_t mutex)
 {
-    objc_thread_t         thread_id;           /* Cache our thread id.     */
-
-    if (!mutex)                                 /* Is argument bad?         */
-        return -1;                              /* Yes, abort.              */
-    thread_id = objc_thread_id();               /* Get this thread's id.    */
-    if (mutex->owner == thread_id)              /* Already own lock?        */
-        return ++mutex->depth;                  /* Yes, increment depth.    */
-    
-    if (mutex_try_lock(&(mutex->lock)) == 0)    /* Lock cthread mutex.      */
-        return -1;                              /* Failed, abort.           */
-    
-    mutex->owner = thread_id;                   /* Mark thread as owner.    */
-    return mutex->depth = 1;                    /* Increment depth to end.  */
+  if (mutex_try_lock((mutex_t)(mutex->backend)) == 0)
+    return -1;
+  else
+    return 0;
 }
 
-/********
- *  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.
- */
+/* Unlock the mutex */
 int
-objc_mutex_unlock(objc_mutex_t mutex)
+__objc_mutex_unlock(objc_mutex_t mutex)
 {
-    objc_thread_t    thread_id;                /* Cache our thread id.     */
-    
-    if (!mutex)                                 /* 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)                       /* Released last lock?      */
-        return --mutex->depth;                  /* No, Decrement depth, end.*/
-    mutex->depth = 0;                           /* Yes, reset depth to 0.   */
-    mutex->owner = (objc_thread_t) -1;         /* Set owner to "no thread".*/
-    
-    mutex_unlock(&(mutex->lock));               /* unlock cthread mutex.    */
-    
-    return 0;                                   /* No, return success.      */
+  mutex_unlock((mutex_t)(mutex->backend));
+  return 0;
 }
 
-/********
- *  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.  */
+/* Backend condition mutex functions */
 
-    condition_init(&(condition->condition));
-    
-    return condition;                           /* Return mutex handle.     */
+/* Allocate a condition. */
+int
+__objc_condition_allocate(objc_condition_t condition)
+{
+  condition->backend = objc_malloc(sizeof(struct condition));
+  condition_init((condition_t)(condition->backend));
+  return 0;
 }
 
-/********
- *  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.
- */
+/* Deallocate a condition. */
 int
-objc_condition_deallocate(objc_condition_t condition)
+__objc_condition_deallocate(objc_condition_t condition)
 {
-	condition_broadcast(&(condition->condition));
-	condition_clear(&(condition->condition));
-	objc_free(condition);
-	return 0;
+  condition_clear((condition_t)(condition->backend));
+  objc_free(condition->backend);
+  condition->backend = NULL;
+  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.
- */
+/* Wait on the condition */
 int
-objc_condition_wait(objc_condition_t condition, objc_mutex_t mutex)
+__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".*/
-    
-    condition_wait(&(condition->condition),
-		&(mutex->lock));                        /* unlock, wait ..., lock   */
-    
-    mutex->owner = thread_id;                   /* Mark thread as owner.    */
-    mutex->depth = 1;                           /* Increment depth to end.  */
-    return 0;                                   /* Return success.          */
+  condition_wait((condition_t)(condition->backend),
+		 (mutex_t)(mutex->backend));
+  return 0;
 }
 
-/********
- *  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.
- */
+/* Wake up all threads waiting on this condition. */
 int
-objc_condition_broadcast(objc_condition_t condition)
+__objc_condition_broadcast(objc_condition_t condition)
 {
-    if (!condition)
-		return -1;
-	condition_broadcast(&(condition->condition));
-	return 0;
+  condition_broadcast((condition_t)(condition->backend));
+  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.
- */
+/* Wake up one thread waiting on this condition. */
 int
-objc_condition_signal(objc_condition_t condition)
+__objc_condition_signal(objc_condition_t condition)
 {
-    if (!condition)
-		return -1;
-	condition_signal(&(condition->condition));
-	return 0;
+  condition_signal((condition_t)(condition->backend));
+  return 0;
 }
 
+/* End of File */