Changes in kernel/generic/src/time/timeout.c [583c2a3:eda43238] in mainline

File:

• kernel/generic/src/time/timeout.c (modified) (5 diffs)

kernel/generic/src/time/timeout.c

@@ -1 +1 @@
 /*
  * Copyright (c) 2001-2004 Jakub Jermar
+ * Copyright (c) 2022 Jiří Zárevúcky
  * All rights reserved.
  *
@@ -57 +58 @@
 }
 
-/** Reinitialize timeout
- *
- * Initialize all members except the lock.
- *
- * @param timeout Timeout to be initialized.
- *
- */
-void timeout_reinitialize(timeout_t *timeout)
-{
-        timeout->cpu = NULL;
-        timeout->ticks = 0;
-        timeout->handler = NULL;
-        timeout->arg = NULL;
-        link_initialize(&timeout->link);
-}
-
 /** Initialize timeout
  *
@@ -82 +67 @@
 void timeout_initialize(timeout_t *timeout)
 {
-        irq_spinlock_initialize(&timeout->lock, "timeout_t_lock");
-        timeout_reinitialize(timeout);
+        link_initialize(&timeout->link);
+        timeout->cpu = NULL;
 }
 
@@ -102 +87 @@
 {
         irq_spinlock_lock(&CPU->timeoutlock, true);
-        irq_spinlock_lock(&timeout->lock, false);
 
-        if (timeout->cpu)
-                panic("Unexpected: timeout->cpu != 0.");
+        assert(!link_in_use(&timeout->link));
 
         timeout->cpu = CPU;
-        timeout->ticks = us2ticks(time);
-
+        timeout->deadline = CPU->current_clock_tick + us2ticks(time);
         timeout->handler = handler;
         timeout->arg = arg;
 
-        /*
-         * Insert timeout into the active timeouts list according to timeout->ticks.
-         */
-        uint64_t sum = 0;
-        timeout_t *target = NULL;
-        link_t *cur, *prev;
-        prev = NULL;
-        for (cur = list_first(&CPU->timeout_active_list);
-            cur != NULL; cur = list_next(cur, &CPU->timeout_active_list)) {
-                target = list_get_instance(cur, timeout_t, link);
-                irq_spinlock_lock(&target->lock, false);
+        /* Insert timeout into the active timeouts list according to timeout->deadline. */
 
-                if (timeout->ticks < sum + target->ticks) {
-                        irq_spinlock_unlock(&target->lock, false);
-                        break;
+        link_t *last = list_last(&CPU->timeout_active_list);
+        if (last == NULL || timeout->deadline >= list_get_instance(last, timeout_t, link)->deadline) {
+                list_append(&timeout->link, &CPU->timeout_active_list);
+        } else {
+                for (link_t *cur = list_first(&CPU->timeout_active_list); cur != NULL;
+                    cur = list_next(cur, &CPU->timeout_active_list)) {
+
+                        if (timeout->deadline < list_get_instance(cur, timeout_t, link)->deadline) {
+                                list_insert_before(&timeout->link, cur);
+                                break;
+                        }
                 }
-
-                sum += target->ticks;
-                irq_spinlock_unlock(&target->lock, false);
-                prev = cur;
         }
 
-        if (prev == NULL)
-                list_prepend(&timeout->link, &CPU->timeout_active_list);
-        else
-                list_insert_after(&timeout->link, prev);
-
-        /*
-         * Adjust timeout->ticks according to ticks
-         * accumulated in target's predecessors.
-         */
-        timeout->ticks -= sum;
-
-        /*
-         * Decrease ticks of timeout's immediate succesor by timeout->ticks.
-         */
-        if (cur != NULL) {
-                irq_spinlock_lock(&target->lock, false);
-                target->ticks -= timeout->ticks;
-                irq_spinlock_unlock(&target->lock, false);
-        }
-
-        irq_spinlock_unlock(&timeout->lock, false);
         irq_spinlock_unlock(&CPU->timeoutlock, true);
 }
@@ -170 +125 @@
 bool timeout_unregister(timeout_t *timeout)
 {
-        DEADLOCK_PROBE_INIT(p_tolock);
+        assert(timeout->cpu);
 
-grab_locks:
-        irq_spinlock_lock(&timeout->lock, true);
-        if (!timeout->cpu) {
-                irq_spinlock_unlock(&timeout->lock, true);
-                return false;
+        irq_spinlock_lock(&timeout->cpu->timeoutlock, true);
+
+        bool success = link_in_use(&timeout->link);
+        if (success) {
+                list_remove(&timeout->link);
         }
 
-        if (!irq_spinlock_trylock(&timeout->cpu->timeoutlock)) {
-                irq_spinlock_unlock(&timeout->lock, true);
-                DEADLOCK_PROBE(p_tolock, DEADLOCK_THRESHOLD);
-                goto grab_locks;
-        }
-
-        /*
-         * Now we know for sure that timeout hasn't been activated yet
-         * and is lurking in timeout->cpu->timeout_active_list.
-         */
-
-        link_t *cur = list_next(&timeout->link,
-            &timeout->cpu->timeout_active_list);
-        if (cur != NULL) {
-                timeout_t *tmp = list_get_instance(cur, timeout_t, link);
-                irq_spinlock_lock(&tmp->lock, false);
-                tmp->ticks += timeout->ticks;
-                irq_spinlock_unlock(&tmp->lock, false);
-        }
-
-        list_remove(&timeout->link);
-        irq_spinlock_unlock(&timeout->cpu->timeoutlock, false);
-
-        timeout_reinitialize(timeout);
-        irq_spinlock_unlock(&timeout->lock, true);
-
-        return true;
+        irq_spinlock_unlock(&timeout->cpu->timeoutlock, true);
+        return success;
 }