sched: Rename task->error to tast->status.

[paraslash.git] / sched.c

diff --git a/sched.c b/sched.c
index 6b8e09108308336676e48c4d8c9e84eb6e388431..b92774fa95d4d1a0e4870c6e58a42130bc9bbe5b 100644 (file)
--- a/sched.c
+++ b/sched.c
@@ -18,6 +18,25 @@
 #include "time.h"
 #include "error.h"
 
+struct task {
+       /** The task name supplied when the task was registered(). */
+       char name[255];
+       /** Copied from the task_info struct during task_register(). */
+       void (*pre_select)(struct sched *s, struct task *t);
+       /** Copied from the task_info struct during task_register(). */
+       int (*post_select)(struct sched *s, struct task *t);
+       /** Whether this task is active (>=0) or in error state (<0). */
+       int status;
+       /** Position of the task in the task list of the scheduler. */
+       struct list_head node;
+       /** If less than zero, the task was notified by another task. */
+       int notification;
+       /** True if task is in error state and exit status has been queried. */
+       bool dead;
+       /** Usually a pointer to the struct containing this task. */
+       void *context;
+};
+
 static struct timeval now_struct;
 struct timeval *now = &now_struct;
 
@@ -32,7 +51,7 @@ static void sched_preselect(struct sched *s)
        struct task *t, *tmp;
 
        list_for_each_entry_safe(t, tmp, &s->task_list, node) {
-               if (t->error < 0)
+               if (t->status < 0)
                        continue;
                if (t->notification != 0)
                        sched_min_delay(s);
@@ -43,29 +62,28 @@ static void sched_preselect(struct sched *s)
 
 static void unlink_and_free_task(struct task *t)
 {
-       PARA_INFO_LOG("freeing task %s\n", t->status);
+       PARA_INFO_LOG("freeing task %s\n", t->name);
        list_del(&t->node);
-       if (t->owned_by_sched)
-               free(t);
+       free(t);
 }
 
 //#define SCHED_DEBUG 1
 static inline void call_post_select(struct sched *s, struct task *t)
 {
 #ifndef SCHED_DEBUG
-       t->error = t->post_select(s, t);
+       t->status = t->post_select(s, t);
 #else
        struct timeval t1, t2, diff;
        unsigned long pst;
 
        clock_get_realtime(&t1);
-       t->error = t->post_select(s, t);
+       t->status = t->post_select(s, t);
        clock_get_realtime(&t2);
        tv_diff(&t1, &t2, &diff);
        pst = tv2ms(&diff);
        if (pst > 50)
                PARA_WARNING_LOG("%s: post_select time: %lums\n",
-                       t->status, pst);
+                       t->name, pst);
 #endif
 }
 
@@ -75,17 +93,14 @@ static unsigned sched_post_select(struct sched *s)
        unsigned num_running_tasks = 0;
 
        list_for_each_entry_safe(t, tmp, &s->task_list, node) {
-               if (t->error < 0) {
+               if (t->status < 0) {
                        if (t->dead) /* task has been reaped */
                                unlink_and_free_task(t);
                        continue;
                }
                call_post_select(s, t);
                t->notification = 0;
-               if (t->error < 0) {
-                       if (!t->owned_by_sched)
-                               list_del(&t->node);
-               } else
+               if (t->status >= 0)
                        num_running_tasks++;
        }
        return num_running_tasks;
@@ -169,9 +184,7 @@ int task_reap(struct task **tptr)
        t = *tptr;
        if (!t)
                return 0;
-       if (!t->owned_by_sched)
-               return 0;
-       if (t->error >= 0)
+       if (t->status >= 0)
                return 0;
        if (t->dead) /* will be freed in sched_post_select() */
                return 0;
@@ -185,7 +198,7 @@ int task_reap(struct task **tptr)
         */
        t->dead = true;
        *tptr = NULL;
-       return t->error;
+       return t->status;
 }
 
 /**
@@ -200,33 +213,14 @@ void sched_shutdown(struct sched *s)
        struct task *t, *tmp;
 
        list_for_each_entry_safe(t, tmp, &s->task_list, node) {
-               if (t->error >= 0)
+               if (t->status >= 0)
                        /* The task list should contain only terminated tasks. */
                        PARA_WARNING_LOG("shutting down running task %s\n",
-                               t->status);
+                               t->name);
                unlink_and_free_task(t);
        }
 }
 
-/**
- * Add a task to the scheduler. Deprecated.
- *
- * \param t The task to add.
- * \param s The scheduler instance to add the task to.
- *
- * \sa task::pre_select, task::post_select
- */
-void register_task(struct sched *s, struct task *t)
-{
-       PARA_INFO_LOG("registering %s (%p)\n", t->status, t);
-       assert(t->post_select);
-       t->notification = 0;
-       t->owned_by_sched = false;
-       if (!s->task_list.next)
-               INIT_LIST_HEAD(&s->task_list);
-       list_add_tail(&t->node, &s->task_list);
-}
-
 /**
  * Add a task to the scheduler task list.
  *
@@ -245,15 +239,14 @@ struct task *task_register(struct task_info *info, struct sched *s)
        if (!s->task_list.next)
                INIT_LIST_HEAD(&s->task_list);
 
-       snprintf(t->status, sizeof(t->status) - 1, "%s", info->name);
-       t->status[sizeof(t->status) - 1] = '\0';
+       snprintf(t->name, sizeof(t->name) - 1, "%s", info->name);
+       t->name[sizeof(t->name) - 1] = '\0';
        t->notification = 0;
-       t->error = 0;
+       t->status = 0;
        t->dead = false;
        t->pre_select = info->pre_select;
        t->post_select = info->post_select;
        t->context = info->context;
-       t->owned_by_sched = true;
        list_add_tail(&t->node, &s->task_list);
        return t;
 }
@@ -268,7 +261,6 @@ struct task *task_register(struct task_info *info, struct sched *s)
  */
 void *task_context(struct task *t)
 {
-       assert(t->owned_by_sched);
        return t->context;
 }
 
@@ -290,8 +282,8 @@ char *get_task_list(struct sched *s)
        list_for_each_entry_safe(t, tmp, &s->task_list, node) {
                char *tmp_msg;
                tmp_msg = make_message("%s%p\t%s\t%s\n", msg? msg : "", t,
-                       t->error < 0? (t->dead? "dead" : "zombie") : "running",
-                       t->status);
+                       t->status < 0? (t->dead? "dead" : "zombie") : "running",
+                       t->name);
                free(msg);
                msg = tmp_msg;
        }
@@ -322,7 +314,7 @@ void task_notify(struct task *t, int err)
        assert(err > 0);
        if (t->notification == -err) /* ignore subsequent notifications */
                return;
-       PARA_INFO_LOG("notifying task %s: %s\n", t->status, para_strerror(err));
+       PARA_INFO_LOG("notifying task %s: %s\n", t->name, para_strerror(err));
        t->notification = -err;
 }
 
@@ -342,6 +334,25 @@ int task_get_notification(const struct task *t)
        return t->notification;
 }
 
+/**
+ * Return the status value of a task.
+ *
+ * \param t The task to get the status value from.
+ *
+ * \return Zero if task does not exist, one if task is running, negative error
+ * code if task has terminated.
+ */
+int task_status(const struct task *t)
+{
+       if (!t)
+               return 0;
+       if (t->dead)
+               return 0;
+       if (t->status >= 0)
+               return 1;
+       return t->status;
+}
+
 /**
  * Set the notification value of all tasks of a scheduler instance.
  *