Changes in kernel/generic/src/synch/waitq.c [9fe9d296:9d58539] in mainline

File:

• kernel/generic/src/synch/waitq.c (modified) (4 diffs)

kernel/generic/src/synch/waitq.c

@@ -57 +57 @@
 
 static void waitq_sleep_timed_out(void *);
-static void waitq_complete_wakeup(waitq_t *);
-
 
 /** Initialize wait queue
@@ -332 +330 @@
                 break;
         default:
-                /* 
-                 * Wait for a waitq_wakeup() or waitq_unsleep() to complete
-                 * before returning from waitq_sleep() to the caller. Otherwise
-                 * the caller might expect that the wait queue is no longer used 
-                 * and deallocate it (although the wakeup on a another cpu has 
-                 * not yet completed and is using the wait queue). 
-                 * 
-                 * Note that we have to do this for ESYNCH_OK_BLOCKED and
-                 * ESYNCH_INTERRUPTED, but not necessarily for ESYNCH_TIMEOUT
-                 * where the timeout handler stops using the waitq before waking 
-                 * us up. To be on the safe side, ensure the waitq is not in use 
-                 * anymore in this case as well.
-                 */
-                waitq_complete_wakeup(wq);
                 break;
         }
@@ -373 +357 @@
         } else {
                 if (PARAM_NON_BLOCKING(flags, usec)) {
-                        /* Return immediately instead of going to sleep */
+                        /* Return immediatelly instead of going to sleep */
                         return ESYNCH_WOULD_BLOCK;
                 }
@@ -458 +442 @@
         irq_spinlock_unlock(&wq->lock, true);
 }
-
-/** If there is a wakeup in progress actively waits for it to complete.
- * 
- * The function returns once the concurrently running waitq_wakeup()
- * exits. It returns immediately if there are no concurrent wakeups 
- * at the time.
- * 
- * Interrupts must be disabled.
- * 
- * Example usage:
- * @code
- * void callback(waitq *wq)
- * {
- *     // Do something and notify wait_for_completion() that we're done.
- *     waitq_wakeup(wq);
- * }
- * void wait_for_completion(void) 
- * {
- *     waitq wg;
- *     waitq_initialize(&wq);
- *     // Run callback() in the background, pass it wq.
- *     do_asynchronously(callback, &wq);
- *     // Wait for callback() to complete its work.
- *     waitq_sleep(&wq);
- *     // callback() completed its work, but it may still be accessing 
- *     // wq in waitq_wakeup(). Therefore it is not yet safe to return 
- *     // from waitq_sleep() or it would clobber up our stack (where wq 
- *     // is stored). waitq_sleep() ensures the wait queue is no longer
- *     // in use by invoking waitq_complete_wakeup() internally.
- *     
- *     // waitq_sleep() returned, it is safe to free wq.
- * }
- * @endcode
- * 
- * @param wq  Pointer to a wait queue.
- */
-static void waitq_complete_wakeup(waitq_t *wq)
-{
-        ASSERT(interrupts_disabled());
-        
-        irq_spinlock_lock(&wq->lock, false);
-        irq_spinlock_unlock(&wq->lock, false);
-}
-
 
 /** Internal SMP- and IRQ-unsafe version of waitq_wakeup()