Changes in kernel/generic/src/proc/task.c [07d4271:40eab9f] in mainline

File:

• kernel/generic/src/proc/task.c (modified) (14 diffs)

kernel/generic/src/proc/task.c

@@ -158 +158 @@
                 return rc;
 
+        atomic_store(&task->refcount, 0);
         atomic_store(&task->lifecount, 0);
 
@@ -200 +201 @@
         if (!task)
                 return NULL;
-
-        refcount_init(&task->refcount);
 
         task_create_arch(task);
@@ -269 +268 @@
  *
  */
-static void task_destroy(task_t *task)
+void task_destroy(task_t *task)
 {
         /*
@@ -300 +299 @@
 void task_hold(task_t *task)
 {
-        refcount_up(&task->refcount);
+        atomic_inc(&task->refcount);
 }
 
@@ -312 +311 @@
 void task_release(task_t *task)
 {
-        if (refcount_down(&task->refcount))
+        if ((atomic_predec(&task->refcount)) == 0)
                 task_destroy(task);
 }
@@ -417 +416 @@
 /** Find task structure corresponding to task ID.
  *
+ * The tasks_lock must be already held by the caller of this function and
+ * interrupts must be disabled.
+ *
  * @param id Task ID.
  *
- * @return Task reference or NULL if there is no such task ID.
+ * @return Task structure address or NULL if there is no such task ID.
  *
  */
 task_t *task_find_by_id(task_id_t id)
 {
-        task_t *task = NULL;
-
-        irq_spinlock_lock(&tasks_lock, true);
+        assert(interrupts_disabled());
+        assert(irq_spinlock_locked(&tasks_lock));
 
         odlink_t *odlink = odict_find_eq(&tasks, &id, NULL);
-        if (odlink != NULL) {
-                task = odict_get_instance(odlink, task_t, ltasks);
-
-                /*
-                 * The directory of tasks can't hold a reference, since that would
-                 * prevent task from ever being destroyed. That means we have to
-                 * check for the case where the task is already being destroyed, but
-                 * not yet removed from the directory.
-                 */
-                if (!refcount_try_up(&task->refcount))
-                        task = NULL;
-        }
-
-        irq_spinlock_unlock(&tasks_lock, true);
-
-        return task;
+        if (odlink != NULL)
+                return odict_get_instance(odlink, task_t, ltasks);
+
+        return NULL;
 }
 
@@ -517 +506 @@
         /* Current values of threads */
         list_foreach(task->threads, th_link, thread_t, thread) {
+                irq_spinlock_lock(&thread->lock, false);
+
                 /* Process only counted threads */
                 if (!thread->uncounted) {
@@ -524 +515 @@
                         }
 
-                        uret += atomic_time_read(&thread->ucycles);
-                        kret += atomic_time_read(&thread->kcycles);
+                        uret += thread->ucycles;
+                        kret += thread->kcycles;
                 }
+
+                irq_spinlock_unlock(&thread->lock, false);
         }
 
@@ -535 +528 @@
 static void task_kill_internal(task_t *task)
 {
-        irq_spinlock_lock(&task->lock, true);
+        irq_spinlock_lock(&task->lock, false);
 
         /*
@@ -545 +538 @@
         }
 
-        irq_spinlock_unlock(&task->lock, true);
+        irq_spinlock_unlock(&task->lock, false);
 }
 
@@ -563 +556 @@
                 return EPERM;
 
+        irq_spinlock_lock(&tasks_lock, true);
+
         task_t *task = task_find_by_id(id);
-        if (!task)
+        if (!task) {
+                irq_spinlock_unlock(&tasks_lock, true);
                 return ENOENT;
+        }
 
         task_kill_internal(task);
-        task_release(task);
+        irq_spinlock_unlock(&tasks_lock, true);
+
         return EOK;
 }
@@ -598 +596 @@
         }
 
+        irq_spinlock_lock(&tasks_lock, true);
         task_kill_internal(TASK);
+        irq_spinlock_unlock(&tasks_lock, true);
+
         thread_exit();
 }
@@ -627 +628 @@
         if (additional)
                 printf("%-8" PRIu64 " %9zu", task->taskid,
-                    atomic_load(&task->lifecount));
+                    atomic_load(&task->refcount));
         else
                 printf("%-8" PRIu64 " %-14s %-5" PRIu32 " %10p %10p"
@@ -639 +640 @@
                 printf("%-8" PRIu64 " %9" PRIu64 "%c %9" PRIu64 "%c "
                     "%9zu\n", task->taskid, ucycles, usuffix, kcycles,
-                    ksuffix, atomic_load(&task->lifecount));
+                    ksuffix, atomic_load(&task->refcount));
         else
                 printf("%-8" PRIu64 " %-14s %-5" PRIu32 " %18p %18p\n",