pthread_support.c

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      GC_release_mark_lock();
#   endif
    GC_remove_all_threads_but_me();
#   ifdef PARALLEL_MARK
      /* Turn off parallel marking in the child, since we are probably 	*/
      /* just going to exec, and we would have to restart mark threads.	*/
        GC_markers = 1;
        GC_parallel = FALSE;
#   endif /* PARALLEL_MARK */
    UNLOCK();
}
#endif /* HANDLE_FORK */

#if defined(GC_DGUX386_THREADS)
/* Return the number of processors, or i<= 0 if it can't be determined. */
int GC_get_nprocs()
{
    /* <[e-mail]> */
    int numCpus;
    struct dg_sys_info_pm_info pm_sysinfo;
    int status =0;

    status = dg_sys_info((long int *) &pm_sysinfo,
	DG_SYS_INFO_PM_INFO_TYPE, DG_SYS_INFO_PM_CURRENT_VERSION);
    if (status < 0)
       /* set -1 for error */
       numCpus = -1;
    else
      /* Active CPUs */
      numCpus = pm_sysinfo.idle_vp_count;

#  ifdef DEBUG_THREADS
    GC_printf1("Number of active CPUs in this system: %d\n", numCpus);
#  endif
    return(numCpus);
}
#endif /* GC_DGUX386_THREADS */

/* We hold the allocation lock.	*/
void GC_thr_init()
{
#   ifndef GC_DARWIN_THREADS
      int dummy;
#   endif
    GC_thread t;

    if (GC_thr_initialized) return;
    GC_thr_initialized = TRUE;
    
#   ifdef HANDLE_FORK
      /* Prepare for a possible fork.	*/
        pthread_atfork(GC_fork_prepare_proc, GC_fork_parent_proc,
	  	       GC_fork_child_proc);
#   endif /* HANDLE_FORK */
    /* Add the initial thread, so we can stop it.	*/
      t = GC_new_thread(pthread_self());
#     ifdef GC_DARWIN_THREADS
         t -> stop_info.mach_thread = mach_thread_self();
#     else
         t -> stop_info.stack_ptr = (ptr_t)(&dummy);
#     endif
      t -> flags = DETACHED | MAIN_THREAD;

    GC_stop_init();

    /* Set GC_nprocs.  */
      {
	char * nprocs_string = GETENV("GC_NPROCS");
	GC_nprocs = -1;
	if (nprocs_string != NULL) GC_nprocs = atoi(nprocs_string);
      }
      if (GC_nprocs <= 0) {
#       if defined(GC_HPUX_THREADS)
	  GC_nprocs = pthread_num_processors_np();
#       endif
#	if defined(GC_OSF1_THREADS) || defined(GC_AIX_THREADS)
	  GC_nprocs = sysconf(_SC_NPROCESSORS_ONLN);
	  if (GC_nprocs <= 0) GC_nprocs = 1;
#	endif
#       if defined(GC_IRIX_THREADS)
	  GC_nprocs = sysconf(_SC_NPROC_ONLN);
	  if (GC_nprocs <= 0) GC_nprocs = 1;
#       endif
#       if defined(GC_DARWIN_THREADS) || defined(GC_FREEBSD_THREADS)
	  int ncpus = 1;
	  size_t len = sizeof(ncpus);
	  sysctl((int[2]) {CTL_HW, HW_NCPU}, 2, &ncpus, &len, NULL, 0);
	  GC_nprocs = ncpus;
#       endif
#	if defined(GC_LINUX_THREADS) || defined(GC_DGUX386_THREADS)
          GC_nprocs = GC_get_nprocs();
#	endif
      }
      if (GC_nprocs <= 0) {
	WARN("GC_get_nprocs() returned %ld\n", GC_nprocs);
	GC_nprocs = 2;
#	ifdef PARALLEL_MARK
	  GC_markers = 1;
#	endif
      } else {
#	ifdef PARALLEL_MARK
          {
	    char * markers_string = GETENV("GC_MARKERS");
	    if (markers_string != NULL) {
	      GC_markers = atoi(markers_string);
	    } else {
	      GC_markers = GC_nprocs;
	    }
          }
#	endif
      }
#   ifdef PARALLEL_MARK
#     ifdef CONDPRINT
        if (GC_print_stats) {
          GC_printf2("Number of processors = %ld, "
		 "number of marker threads = %ld\n", GC_nprocs, GC_markers);
	}
#     endif
      if (GC_markers == 1) {
	GC_parallel = FALSE;
#	ifdef CONDPRINT
	  if (GC_print_stats) {
	    GC_printf0("Single marker thread, turning off parallel marking\n");
	  }
#	endif
      } else {
	GC_parallel = TRUE;
	/* Disable true incremental collection, but generational is OK.	*/
	GC_time_limit = GC_TIME_UNLIMITED;
      }
      /* If we are using a parallel marker, actually start helper threads.  */
        if (GC_parallel) start_mark_threads();
#   endif
}


/* Perform all initializations, including those that	*/
/* may require allocation.				*/
/* Called without allocation lock.			*/
/* Must be called before a second thread is created.	*/
/* Called without allocation lock.			*/
void GC_init_parallel()
{
    if (parallel_initialized) return;
    parallel_initialized = TRUE;

    /* GC_init() calls us back, so set flag first.	*/
    if (!GC_is_initialized) GC_init();
    /* Initialize thread local free lists if used.	*/
#   if defined(THREAD_LOCAL_ALLOC) && !defined(DBG_HDRS_ALL)
      LOCK();
      GC_init_thread_local(GC_lookup_thread(pthread_self()));
      UNLOCK();
#   endif
}


#if !defined(GC_DARWIN_THREADS)
int WRAP_FUNC(pthread_sigmask)(int how, const sigset_t *set, sigset_t *oset)
{
    sigset_t fudged_set;
    
    if (set != NULL && (how == SIG_BLOCK || how == SIG_SETMASK)) {
        fudged_set = *set;
        sigdelset(&fudged_set, SIG_SUSPEND);
        set = &fudged_set;
    }
    return(REAL_FUNC(pthread_sigmask)(how, set, oset));
}
#endif /* !GC_DARWIN_THREADS */

/* Wrappers for functions that are likely to block for an appreciable	*/
/* length of time.  Must be called in pairs, if at all.			*/
/* Nothing much beyond the system call itself should be executed	*/
/* between these.							*/

void GC_start_blocking(void) {
#   define SP_SLOP 128
    GC_thread me;
    LOCK();
    me = GC_lookup_thread(pthread_self());
    GC_ASSERT(!(me -> thread_blocked));
#   ifdef SPARC
	me -> stop_info.stack_ptr = (ptr_t)GC_save_regs_in_stack();
#   else
#   ifndef GC_DARWIN_THREADS
	me -> stop_info.stack_ptr = (ptr_t)GC_approx_sp();
#   endif
#   endif
#   ifdef IA64
	me -> backing_store_ptr = (ptr_t)GC_save_regs_in_stack() + SP_SLOP;
#   endif
    /* Add some slop to the stack pointer, since the wrapped call may 	*/
    /* end up pushing more callee-save registers.			*/
#   ifndef GC_DARWIN_THREADS
#   ifdef STACK_GROWS_UP
	me -> stop_info.stack_ptr += SP_SLOP;
#   else
	me -> stop_info.stack_ptr -= SP_SLOP;
#   endif
#   endif
    me -> thread_blocked = TRUE;
    UNLOCK();
}

void GC_end_blocking(void) {
    GC_thread me;
    LOCK();   /* This will block if the world is stopped.	*/
    me = GC_lookup_thread(pthread_self());
    GC_ASSERT(me -> thread_blocked);
    me -> thread_blocked = FALSE;
    UNLOCK();
}
    
#if defined(GC_DGUX386_THREADS)
#define __d10_sleep sleep
#endif /* GC_DGUX386_THREADS */

/* A wrapper for the standard C sleep function	*/
int WRAP_FUNC(sleep) (unsigned int seconds)
{
    int result;

    GC_start_blocking();
    result = REAL_FUNC(sleep)(seconds);
    GC_end_blocking();
    return result;
}

struct start_info {
    void *(*start_routine)(void *);
    void *arg;
    word flags;
    sem_t registered;   	/* 1 ==> in our thread table, but 	*/
				/* parent hasn't yet noticed.		*/
};

/* Called at thread exit.				*/
/* Never called for main thread.  That's OK, since it	*/
/* results in at most a tiny one-time leak.  And 	*/
/* linuxthreads doesn't reclaim the main threads 	*/
/* resources or id anyway.				*/
void GC_thread_exit_proc(void *arg)
{
    GC_thread me;

    LOCK();
    me = GC_lookup_thread(pthread_self());
    GC_destroy_thread_local(me);
    if (me -> flags & DETACHED) {
    	GC_delete_thread(pthread_self());
    } else {
	me -> flags |= FINISHED;
    }
#   if defined(THREAD_LOCAL_ALLOC) && !defined(USE_PTHREAD_SPECIFIC) \
       && !defined(USE_COMPILER_TLS) && !defined(DBG_HDRS_ALL)
      GC_remove_specific(GC_thread_key);
#   endif
    /* The following may run the GC from "nonexistent" thread.	*/
    GC_wait_for_gc_completion(FALSE);
    UNLOCK();
}

int WRAP_FUNC(pthread_join)(pthread_t thread, void **retval)
{
    int result;
    GC_thread thread_gc_id;
    
    LOCK();
    thread_gc_id = GC_lookup_thread(thread);
    /* This is guaranteed to be the intended one, since the thread id	*/
    /* cant have been recycled by pthreads.				*/
    UNLOCK();
    result = REAL_FUNC(pthread_join)(thread, retval);
# if defined (GC_FREEBSD_THREADS)
    /* On FreeBSD, the wrapped pthread_join() sometimes returns (what
       appears to be) a spurious EINTR which caused the test and real code
       to gratuitously fail.  Having looked at system pthread library source
       code, I see how this return code may be generated.  In one path of
       code, pthread_join() just returns the errno setting of the thread
       being joined.  This does not match the POSIX specification or the
       local man pages thus I have taken the liberty to catch this one
       spurious return value properly conditionalized on GC_FREEBSD_THREADS. */
    if (result == EINTR) result = 0;
# endif
    if (result == 0) {
        LOCK();
        /* Here the pthread thread id may have been recycled. */
        GC_delete_gc_thread(thread, thread_gc_id);
        UNLOCK();
    }
    return result;
}

int
WRAP_FUNC(pthread_detach)(pthread_t thread)
{
    int result;
    GC_thread thread_gc_id;
    
    LOCK();
    thread_gc_id = GC_lookup_thread(thread);
    UNLOCK();
    result = REAL_FUNC(pthread_detach)(thread);
    if (result == 0) {
      LOCK();
      thread_gc_id -> flags |= DETACHED;
      /* Here the pthread thread id may have been recycled. */
      if (thread_gc_id -> flags & FINISHED) {
        GC_delete_gc_thread(thread, thread_gc_id);
      }
      UNLOCK();
    }
    return result;
}

GC_bool GC_in_thread_creation = FALSE;

void * GC_start_routine(void * arg)
{
    int dummy;
    struct start_info * si = arg;
    void * result;
    GC_thread me;
    pthread_t my_pthread;
    void *(*start)(void *);
    void *start_arg;

    my_pthread = pthread_self();
#   ifdef DEBUG_THREADS
        GC_printf1("Starting thread 0x%lx\n", my_pthread);
        GC_printf1("pid = %ld\n", (long) getpid());
        GC_printf1("sp = 0x%lx\n", (long) &arg);
#   endif
    LOCK();
    GC_in_thread_creation = TRUE;
    me = GC_new_thread(my_pthread);
    GC_in_thread_creation = FALSE;
#ifdef GC_DARWIN_THREADS
    me -> stop_info.mach_thread = mach_thread_self();
#else
    me -> stop_info.stack_ptr = 0;
#endif
    me -> flags = si -> flags;
    /* me -> stack_end = GC_linux_stack_base(); -- currently (11/99)	*/
    /* doesn't work because the stack base in /proc/self/stat is the 	*/
    /* one for the main thread.  There is a strong argument that that's	*/
    /* a kernel bug, but a pervasive one.				*/
#   ifdef STACK_GROWS_DOWN
      me -> stack_end = (ptr_t)(((word)(&dummy) + (GC_page_size - 1))
		                & ~(GC_page_size - 1));
#	  ifndef GC_DARWIN_THREADS
        me -> stop_info.stack_ptr = me -> stack_end - 0x10;
#	  endif
	/* Needs to be plausible, since an asynchronous stack mark	*/
	/* should not crash.						*/
#   else
      me -> stack_end = (ptr_t)((word)(&dummy) & ~(GC_page_size - 1));
      me -> stop_info.stack_ptr = me -> stack_end + 0x10;
#   endif
    /* This is dubious, since we may be more than a page into the stack, */
    /* and hence skip some of it, though it's not clear that matters.	 */
#   ifdef IA64
      me -> backing_store_end = (ptr_t)
			(GC_save_regs_in_stack() & ~(GC_page_size - 1));
      /* This is also < 100% convincing.  We should also read this 	*/
      /* from /proc, but the hook to do so isn't there yet.		*/
#   endif /* IA64 */
    UNLOCK();
    start = si -> start_routine;
#   ifdef DEBUG_THREADS
	GC_printf1("start_routine = 0x%lx\n", start);
#   endif
    start_arg = si -> arg;
    sem_post(&(si -> registered));	/* Last action on si.	*/
    					/* OK to deallocate.	*/
    pthread_cleanup_push(GC_thread_exit_proc, 0);
#   if defined(THREAD_LOCAL_ALLOC) && !defined(DBG_HDRS_ALL)
 	LOCK();
        GC_init_thread_local(me);
	UNLOCK();
#   endif
    result = (*start)(start_arg);
#if DEBUG_THREADS
        GC_printf1("Finishing thread 0x%x\n", pthread_self());
#endif
    me -> status = result;
    pthread_cleanup_pop(1);
    /* Cleanup acquires lock, ensuring that we can't exit		*/
    /* while a collection that thinks we're alive is trying to stop     */
    /* us.								*/
    return(result);
}

int
WRAP_FUNC(pthread_create)(pthread_t *new_thread,
		  const pthread_attr_t *attr,
                  void *(*start_routine)(void *), void *arg)
{
    int result;