1998-09-21 Ben Elliston <bje@cygnus.com>

* New directory.  Moved files from ../gcc/objc.

From-SVN: r22514

libobjc/thr-mach.c

@@ -0,0 +1,312 @@
+/* GNU Objective C Runtime Thread Implementation
+   Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+   Contributed by Galen C. Hunt (gchunt@cs.rochester.edu)
+   Modified for Mach threads by Bill Bumgarner <bbum@friday.com>
+   Condition functions added by Mircea Oancea <mircea@first.elcom.pub.ro>
+
+This file is part of GNU CC.
+
+GNU CC is free software; you can redistribute it and/or modify it under the
+terms of the GNU General Public License as published by the Free Software
+Foundation; either version 2, or (at your option) any later version.
+
+GNU CC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+details.
+
+You should have received a copy of the GNU General Public License
+along with GNU CC; see the file COPYING.  If not, write to
+the Free Software Foundation, 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+/* As a special exception, if you link this library with files compiled with
+   GCC to produce an executable, this does not cause the resulting executable
+   to be covered by the GNU General Public License. This exception does not
+   however invalidate any other reasons why the executable file might be
+   covered by the GNU General Public License.  */
+
+#include <mach/mach.h>
+#include <mach/cthreads.h>
+#include <objc/thr.h>
+#include "runtime.h"
+
+/*
+  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
+  privileges.  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;
+    
+  if (t == NULL)
+    return -1;
+
+  threadP  = cthread_thread(t); 	/* get thread underlying */
+
+  error=thread_info(threadP, THREAD_SCHED_INFO, 
+		    (thread_info_t)&info, &info_count);
+
+  if (error != KERN_SUCCESS)
+    return -1;
+
+  if (base != NULL)
+    *base = info.base_priority;
+
+  return info.max_priority;
+}
+	
+/* Backend initialization functions */
+
+/* Initialize the threads subsystem. */
+int
+__objc_init_thread_system(void)
+{
+  return 0;
+}
+
+/* Close the threads subsystem. */
+int
+__objc_close_thread_system(void)
+{
+  return 0;
+}
+
+/* Backend thread functions */
+
+/* Create a new thread of execution. */
+objc_thread_t
+__objc_thread_detach(void (*func)(void *arg), void *arg)
+{
+  objc_thread_t thread_id;
+  cthread_t new_thread_handle;
+
+  /* create thread */
+  new_thread_handle = cthread_fork((cthread_fn_t)func, arg);
+
+  if(new_thread_handle)
+    {
+      /* this is not terribly portable */
+      thread_id = *(objc_thread_t *)&new_thread_handle; 
+      cthread_detach(new_thread_handle);
+    }
+  else
+    thread_id = NULL;
+  
+  return thread_id;
+}
+
+/* Set the current thread's priority. */
+int
+__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;
+
+  if (maxPriority == -1)
+    return -1;
+
+  switch (priority)
+    {
+    case OBJC_THREAD_INTERACTIVE_PRIORITY:
+      sys_priority = maxPriority;
+      break;
+    case OBJC_THREAD_BACKGROUND_PRIORITY:
+      sys_priority = (maxPriority * 2) / 3;
+      break;
+    case OBJC_THREAD_LOW_PRIORITY:
+      sys_priority = maxPriority / 3;
+      break;
+    default:
+      return -1;
+    }
+
+  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. */
+int
+__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; /* thresholds */
+
+  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. */
+void
+__objc_thread_yield(void)
+{
+  cthread_yield();
+}
+
+/* Terminate the current thread. */
+int
+__objc_thread_exit(void)
+{
+  /* 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. */
+objc_thread_t
+__objc_thread_id(void)
+{
+  cthread_t self = cthread_self();
+
+  return *(objc_thread_t *)&self;
+}
+
+/* Sets the thread's local storage pointer. */
+int
+__objc_thread_set_data(void *value)
+{
+  cthread_set_data(cthread_self(), (any_t) value);
+  return 0;
+}
+
+/* Returns the thread's local storage pointer. */
+void *
+__objc_thread_get_data(void)
+{
+  return (void *) cthread_data(cthread_self());
+}
+
+/* Backend mutex functions */
+
+/* Allocate a mutex. */
+int
+__objc_mutex_allocate(objc_mutex_t mutex)
+{
+  int err = 0;
+  mutex->backend = objc_malloc(sizeof(struct mutex));
+
+  err = mutex_init((mutex_t)(mutex->backend));
+
+  if (err != 0)
+    {
+      objc_free(mutex->backend);
+      return -1;
+    }
+  else
+    return 0;
+}
+
+/* Deallocate a mutex. */
+int
+__objc_mutex_deallocate(objc_mutex_t mutex)
+{
+  mutex_clear((mutex_t)(mutex->backend));
+
+  objc_free(mutex->backend);
+  mutex->backend = NULL;
+  return 0;
+}
+
+/* Grab a lock on a mutex. */
+int
+__objc_mutex_lock(objc_mutex_t mutex)
+{
+  mutex_lock((mutex_t)(mutex->backend));
+  return 0;
+}
+
+/* Try to grab a lock on a mutex. */
+int
+__objc_mutex_trylock(objc_mutex_t mutex)
+{
+  if (mutex_try_lock((mutex_t)(mutex->backend)) == 0)
+    return -1;
+  else
+    return 0;
+}
+
+/* Unlock the mutex */
+int
+__objc_mutex_unlock(objc_mutex_t mutex)
+{
+  mutex_unlock((mutex_t)(mutex->backend));
+  return 0;
+}
+
+/* Backend condition mutex functions */
+
+/* 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. */
+int
+__objc_condition_deallocate(objc_condition_t condition)
+{
+  condition_clear((condition_t)(condition->backend));
+  objc_free(condition->backend);
+  condition->backend = NULL;
+  return 0;
+}
+
+/* Wait on the condition */
+int
+__objc_condition_wait(objc_condition_t condition, objc_mutex_t mutex)
+{
+  condition_wait((condition_t)(condition->backend),
+		 (mutex_t)(mutex->backend));
+  return 0;
+}
+
+/* Wake up all threads waiting on this condition. */
+int
+__objc_condition_broadcast(objc_condition_t condition)
+{
+  condition_broadcast((condition_t)(condition->backend));
+  return 0;
+}
+
+/* Wake up one thread waiting on this condition. */
+int
+__objc_condition_signal(objc_condition_t condition)
+{
+  condition_signal((condition_t)(condition->backend));
+  return 0;
+}
+
+/* End of File */