Changeset b5e68c8 in mainline for kernel/generic/src/synch/waitq.c

Timestamp:

2011-05-12T16:49:44Z (14 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

f36787d7

Parents:

e80329d6 (diff), 750636a (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge mainline changes.

File:

• kernel/generic/src/synch/waitq.c (modified) (6 diffs)

kernel/generic/src/synch/waitq.c

@@ -127 +127 @@
 /** Interrupt sleeping thread.
  *
- * This routine attempts to interrupt a thread from its sleep in a waitqueue.
- * If the thread is not found sleeping, no action is taken.
+ * This routine attempts to interrupt a thread from its sleep in
+ * a waitqueue. If the thread is not found sleeping, no action
+ * is taken.
+ *
+ * The threads_lock must be already held and interrupts must be
+ * disabled upon calling this function.
  *
  * @param thread Thread to be interrupted.
@@ -138 +142 @@
         DEADLOCK_PROBE_INIT(p_wqlock);
         
-        irq_spinlock_lock(&threads_lock, true);
-        if (!thread_exists(thread))
-                goto out;
+        /*
+         * The thread is quaranteed to exist because
+         * threads_lock is held.
+         */
         
 grab_locks:
@@ -150 +155 @@
                         /*
                          * The sleep cannot be interrupted.
-                         *
                          */
                         irq_spinlock_unlock(&thread->lock, false);
-                        goto out;
+                        return;
                 }
                 
                 if (!irq_spinlock_trylock(&wq->lock)) {
+                        /* Avoid deadlock */
                         irq_spinlock_unlock(&thread->lock, false);
                         DEADLOCK_PROBE(p_wqlock, DEADLOCK_THRESHOLD);
-                        /* Avoid deadlock */
                         goto grab_locks;
                 }
@@ -173 +177 @@
                 irq_spinlock_unlock(&wq->lock, false);
         }
+        
         irq_spinlock_unlock(&thread->lock, false);
         
         if (do_wakeup)
                 thread_ready(thread);
-        
-out:
-        irq_spinlock_unlock(&threads_lock, true);
 }
 
@@ -370 +372 @@
                  * If the thread was already interrupted,
                  * don't go to sleep at all.
-                 *
                  */
                 if (THREAD->interrupted) {
@@ -381 +382 @@
                  * Set context that will be restored if the sleep
                  * of this thread is ever interrupted.
-                 *
                  */
                 THREAD->sleep_interruptible = true;