Finish user stack support. Change locking code to be safe in situations with different priorities.

1998-06-25 19:27  Ulrich Drepper  <drepper@cygnus.com>

	* attr.c: Finish user stack support.  Change locking code to be safe
	in situations with different priorities.
	* cancel.c: Likewise.
	* condvar.c: Likewise.
	* internals.h: Likewise.
	* join.c: Likewise.
	* manager.c: Likewise.
	* mutex.c: Likewise.
	* pthread.c: Likewise.
	* ptlongjmp.c: Likewise.
	* queue.h: Likewise.
	* rwlock.c: Likewise.
	* semaphore.c: Likewise.
	* semaphore.h: Likewise.
	* signals.c: Likewise.
	* spinlock.c: Likewise.
	* spinlock.h: Likewise.
	Patches by Xavier leroy.

1998-06-25  Ulrich Drepper  <drepper@cygnus.com>

	* sysdeps/pthread/pthread.h: Make [sg]et_stacksize and
	[sg]et_stackaddr prototypes always available.

	* sysdeps/unix/sysv/linux/bits/posix_opt.h: Define
	_POSIX_THREAD_ATTR_STACKSIZE and _POSIX_THREAD_ATTR_STACKADDR.

1 files changed, 25 insertions, 32 deletions

diff --git a/linuxthreads/queue.h b/linuxthreads/queue.h
index 60039cce6e..fa8c5d861d 100644
--- a/linuxthreads/queue.h
+++ b/linuxthreads/queue.h
@@ -14,49 +14,42 @@
 
 /* Waiting queues */
 
-typedef struct _pthread_queue pthread_queue;
+/* Waiting queues are represented by lists of thread descriptors
+   linked through their p_nextwaiting field.  The lists are kept
+   sorted by decreasing priority, and then decreasing waiting time. */
 
-static inline void queue_init(pthread_queue * q)
+static inline void enqueue(pthread_descr * q, pthread_descr th)
 {
-  q->head = q->tail = NULL;
-}
-
-static inline void enqueue(pthread_queue * q, pthread_descr th)
-{
-  int prio;
-  pthread_descr * elt;
-
+  int prio = th->p_priority;
   ASSERT(th->p_nextwaiting == NULL);
-  if (q->tail == NULL) {
-    q->head = th;
-    q->tail = th;
-    return;
-  }
-  prio = th->p_priority;
-  if (prio > 0) {
-    /* Insert in queue according to priority order */
-    for (elt = &(q->head); *elt != NULL; elt = &((*elt)->p_nextwaiting)) {
-      if (prio > (*elt)->p_priority) {
-        th->p_nextwaiting = *elt;
-        *elt = th;
-        return;
-      }
+  for (; *q != NULL; q = &((*q)->p_nextwaiting)) {
+    if (prio > (*q)->p_priority) {
+      th->p_nextwaiting = *q;
+      *q = th;
+      return;
     }
   }
-  /* Priority is no greater than any thread in the queue.
-     Insert at end of queue */
-  q->tail->p_nextwaiting = th;
-  q->tail = th;
+  *q = th;
 }
 
-static inline pthread_descr dequeue(pthread_queue * q)
+static inline pthread_descr dequeue(pthread_descr * q)
 {
   pthread_descr th;
-  th = q->head;
+  th = *q;
   if (th != NULL) {
-    q->head = th->p_nextwaiting;
-    if (q->head == NULL) q->tail = NULL;
+    *q = th->p_nextwaiting;
     th->p_nextwaiting = NULL;
   }
   return th;
 }
+
+static inline void remove_from_queue(pthread_descr * q, pthread_descr th)
+{
+  for (; *q != NULL; q = &((*q)->p_nextwaiting)) {
+    if (*q == th) {
+      *q = th->p_nextwaiting;
+      th->p_nextwaiting = NULL;
+      return;
+    }
+  }
+}