/* Threads compatibility routines for libgcc2 and libobjc.  */
/* Compile this one with gcc.  */
/* Copyright (C) 1997, 1999, 2000 Free Software Foundation, Inc.

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 other files,
   some of which are compiled with GCC, to produce an executable,
   this library does not by itself 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.  */

#ifndef __gthr_solaris_h
#define __gthr_solaris_h

/* Solaris threads as found in Solaris 2.[456].
   Actually these are Unix International (UI) threads, but I don't
   know if anyone else implements these. */

#define __GTHREADS 1

#include <thread.h>
#include <errno.h>

typedef thread_key_t __gthread_key_t;
typedef struct
{
  mutex_t mutex;
  int once;
} __gthread_once_t;
typedef mutex_t __gthread_mutex_t;

#define __GTHREAD_ONCE_INIT { DEFAULTMUTEX, 0 }
#define __GTHREAD_MUTEX_INIT DEFAULTMUTEX

#if SUPPORTS_WEAK && GTHREAD_USE_WEAK

#pragma weak thr_keycreate
#pragma weak thr_getspecific
#pragma weak thr_setspecific
#pragma weak thr_create

#pragma weak mutex_lock
#pragma weak mutex_trylock
#pragma weak mutex_unlock

#ifdef _LIBOBJC
#pragma weak thr_exit
#pragma weak thr_keycreate
#pragma weak thr_getprio
#pragma weak thr_self
#pragma weak thr_setprio
#pragma weak thr_yield

#pragma weak cond_init
#pragma weak cond_destroy
#pragma weak cond_wait
#pragma weak cond_broadcast
#pragma weak cond_signal

#pragma weak mutex_init
#pragma weak mutex_destroy
#endif

/* This will not actually work in Solaris 2.5, since libc contains
   dummy symbols of all thr_* routines. */

static void *__gthread_active_ptr = (void *) &thr_create;

static inline int
__gthread_active_p (void)
{
  return __gthread_active_ptr != 0;
}

#else /* not SUPPORTS_WEAK */

static inline int
__gthread_active_p (void)
{
  return 1;
}

#endif /* SUPPORTS_WEAK */

#ifdef _LIBOBJC

/* Key structure for maintaining thread specific storage */
static thread_key_t _objc_thread_storage;

/* Thread local storage for a single thread */
static void *thread_local_storage = NULL;

/* Backend initialization functions */

/* Initialize the threads subsystem. */
static inline int
__gthread_objc_init_thread_system(void)
{
  /* Initialize the thread storage key */
  if (__gthread_active_p ()
      && thr_keycreate(&_objc_thread_storage, NULL) == 0)
    return 0;

  return -1;
}

/* Close the threads subsystem. */
static inline int
__gthread_objc_close_thread_system(void)
{
  if (__gthread_active_p ())
    return 0;
  else
    return -1;
}

/* Backend thread functions */

/* Create a new thread of execution. */
static inline objc_thread_t
__gthread_objc_thread_detach(void (*func)(void *), void *arg)
{
  objc_thread_t thread_id;
  thread_t new_thread_id = 0;

  if (!__gthread_active_p ())
    return NULL;
 
  if (thr_create(NULL, 0, (void *)func, arg,
  		 THR_DETACHED | THR_NEW_LWP,
		 &new_thread_id) == 0)
    thread_id = *(objc_thread_t *)&new_thread_id;
  else
    thread_id = NULL;
  
  return thread_id;
}

/* Set the current thread's priority. */
static inline int
__gthread_objc_thread_set_priority(int priority)
{
  int sys_priority = 0;

  if (!__gthread_active_p ())
    return -1;

  switch (priority)
    {
    case OBJC_THREAD_INTERACTIVE_PRIORITY:
      sys_priority = 300;
      break;
    default:
    case OBJC_THREAD_BACKGROUND_PRIORITY:
      sys_priority = 200;
      break;
    case OBJC_THREAD_LOW_PRIORITY:
      sys_priority = 1000;
      break;
    }

  /* Change priority */
  if (thr_setprio(thr_self(), sys_priority) == 0)
    return 0;
  else
    return -1;
}

/* Return the current thread's priority. */
static inline int
__gthread_objc_thread_get_priority(void)
{
  int sys_priority;

  if (!__gthread_active_p ())
    return OBJC_THREAD_INTERACTIVE_PRIORITY;
                                                   
  if (thr_getprio(thr_self(), &sys_priority) == 0)
    {
      if (sys_priority >= 250)
	return OBJC_THREAD_INTERACTIVE_PRIORITY;
      else if (sys_priority >= 150)
	return OBJC_THREAD_BACKGROUND_PRIORITY;
      return OBJC_THREAD_LOW_PRIORITY;
    }

  /* Couldn't get priority. */
  return -1;
}

/* Yield our process time to another thread. */
static inline void
__gthread_objc_thread_yield(void)
{
  if (__gthread_active_p ())
    thr_yield();
}

/* Terminate the current thread. */
static inline int
__gthread_objc_thread_exit(void)
{
  if (__gthread_active_p ())
    /* exit the thread */
    thr_exit(&__objc_thread_exit_status);

  /* Failed if we reached here */
  return -1;
}

/* Returns an integer value which uniquely describes a thread. */
static inline objc_thread_t
__gthread_objc_thread_id(void)
{
  if (__gthread_active_p ())
    return (objc_thread_t)thr_self();
  else
    return (objc_thread_t)1;
}

/* Sets the thread's local storage pointer. */
static inline int
__gthread_objc_thread_set_data(void *value)
{
  if (__gthread_active_p ())
    {
      if (thr_setspecific(_objc_thread_storage, value) == 0)
	return 0;
      else
	return -1;
    }
  else
    {
      thread_local_storage = value;
      return 0;
    }
}

/* Returns the thread's local storage pointer. */
static inline void *
__gthread_objc_thread_get_data(void)
{
  void *value = NULL;

  if (__gthread_active_p ())
    {
      if (thr_getspecific(_objc_thread_storage, &value) == 0)
	return value;
      else
	return NULL;
    }
  else
    return thread_local_storage;
}

/* Backend mutex functions */

/* Allocate a mutex. */
static inline int
__gthread_objc_mutex_allocate(objc_mutex_t mutex)
{
  if (__gthread_active_p ()
      && mutex_init( (mutex_t *)(&(mutex->backend)), USYNC_THREAD, 0))
    return -1;

  return 0;
}

/* Deallocate a mutex. */
static inline int
__gthread_objc_mutex_deallocate(objc_mutex_t mutex)
{
  if (__gthread_active_p ())
    mutex_destroy((mutex_t *)(&(mutex->backend)));

  return 0;
}

/* Grab a lock on a mutex. */
static inline int
__gthread_objc_mutex_lock(objc_mutex_t mutex)
{
  if (__gthread_active_p ()
      && mutex_lock((mutex_t *)(&(mutex->backend))) != 0)
    return -1;

  return 0;
}

/* Try to grab a lock on a mutex. */
static inline int
__gthread_objc_mutex_trylock(objc_mutex_t mutex)
{
  if (__gthread_active_p ()
      && mutex_trylock((mutex_t *)(&(mutex->backend))) != 0)
    return -1;

  return 0;
}

/* Unlock the mutex */
static inline int
__gthread_objc_mutex_unlock(objc_mutex_t mutex)
{
  if (__gthread_active_p ()
      && mutex_unlock((mutex_t *)(&(mutex->backend))) != 0)
    return -1;

  return 0;
}

/* Backend condition mutex functions */

/* Allocate a condition. */
static inline int
__gthread_objc_condition_allocate(objc_condition_t condition)
{
  if (__gthread_active_p ())
    return cond_init((cond_t *)(&(condition->backend)), USYNC_THREAD,
    		     NULL);
  else
    return 0;
}

/* Deallocate a condition. */
static inline int
__gthread_objc_condition_deallocate(objc_condition_t condition)
{
  if (__gthread_active_p ())
    return cond_destroy((cond_t *)(&(condition->backend)));
  else
    return 0;
}

/* Wait on the condition */
static inline int
__gthread_objc_condition_wait(objc_condition_t condition, objc_mutex_t mutex)
{
  if (__gthread_active_p ())
    return cond_wait((cond_t *)(&(condition->backend)),
    		     (mutex_t *)(&(mutex->backend)));
  else
    return 0;
}

/* Wake up all threads waiting on this condition. */
static inline int
__gthread_objc_condition_broadcast(objc_condition_t condition)
{
  if (__gthread_active_p ())
    return cond_broadcast((cond_t *)(&(condition->backend)));
  else
    return 0;
}

/* Wake up one thread waiting on this condition. */
static inline int
__gthread_objc_condition_signal(objc_condition_t condition)
{
  if (__gthread_active_p ())
    return cond_signal((cond_t *)(&(condition->backend)));
  else
    return 0;
}

#else /* _LIBOBJC */

static inline int
__gthread_once (__gthread_once_t *once, void (*func) (void))
{
  if (! __gthread_active_p ())
    return -1;

  if (once == 0 || func == 0)
    return EINVAL;

  if (once->once == 0)
    {
      int status = mutex_lock (&once->mutex);
      if (status != 0)
	return status;
      if (once->once == 0)
	{
	  (*func) ();
	  once->once ++;
	}
      mutex_unlock (&once->mutex);
    }
  return 0;
}

static inline int
__gthread_key_create (__gthread_key_t *key, void (*dtor) (void *))
{
  /* Solaris 2.5 contains thr_* routines no-op in libc, so test if we actually
     got a reasonable key value, and if not, fail. */
  *key = -1;
  if (thr_keycreate (key, dtor) != 0 || *key == -1)
    return -1;
  else
    return 0;
}

static inline int
__gthread_key_dtor (__gthread_key_t key, void *ptr)
{
  /* Nothing needed. */
  return 0;
}

static inline int
__gthread_key_delete (__gthread_key_t key)
{
  /* Not possible. */
  return -1;
}

static inline void *
__gthread_getspecific (__gthread_key_t key)
{
  void *ptr;
  if (thr_getspecific (key, &ptr) == 0)
    return ptr;
  else
    return 0;
}

static inline int
__gthread_setspecific (__gthread_key_t key, const void *ptr)
{
  return thr_setspecific (key, (void *) ptr);
}

static inline int
__gthread_mutex_lock (__gthread_mutex_t *mutex)
{
  if (__gthread_active_p ())
    return mutex_lock (mutex);
  else
    return 0;
}

static inline int
__gthread_mutex_trylock (__gthread_mutex_t *mutex)
{
  if (__gthread_active_p ())
    return mutex_trylock (mutex);
  else
    return 0;
}

static inline int
__gthread_mutex_unlock (__gthread_mutex_t *mutex)
{
  if (__gthread_active_p ())
    return mutex_unlock (mutex);
  else
    return 0;
}

#endif /* _LIBOBJC */

#endif /* not __gthr_solaris_h */
