From 0a5226b8f6b9131024893f35de615d0b829afe27 Mon Sep 17 00:00:00 2001
From: Andre Noll <maan@systemlinux.org>
Date: Sun, 20 Feb 2011 18:41:02 +0100
Subject: [PATCH] Kill TASK_UNREGISTERED error code.

Currently the scheduler sets t->error to -E_TASK_UNREGISTERED when
it has unregistered a task. This deprives the applications from doing
post-mortem error checking.

The condition (task.error != -E_TASK_UNREGISTERED) is now equivalent
to task.error >= 0, so use this test everywhere.
---
 audiod.c      | 12 ++++++------
 error.h       |  2 +-
 grab_client.c |  2 +-
 sched.c       | 13 ++++++++-----
 4 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/audiod.c b/audiod.c
index 8b17d95f..486a33ff 100644
--- a/audiod.c
+++ b/audiod.c
@@ -1097,17 +1097,17 @@ static void try_to_close_slot(int slot_num)
 
 	if (s->format < 0)
 		return;
-	if (s->receiver_node && s->receiver_node->task.error != -E_TASK_UNREGISTERED)
+	if (s->receiver_node && s->receiver_node->task.error >= 0)
 		return;
 	for (i = 0; i < a->num_filters; i++)
-		if (s->fns && s->fns[i].task.error != -E_TASK_UNREGISTERED)
+		if (s->fns && s->fns[i].task.error >= 0)
 			return;
 	if (a->num_writers > 0) {
 		for (i = 0; i < a->num_writers; i++)
-			if (s->wns && s->wns[i].task.error != -E_TASK_UNREGISTERED)
+			if (s->wns && s->wns[i].task.error >= 0)
 				return;
 	} else {
-		if (s->wns && s->wns[0].task.error != -E_TASK_UNREGISTERED)
+		if (s->wns && s->wns[0].task.error >= 0)
 			return;
 	}
 	PARA_INFO_LOG("closing slot %d\n", slot_num);
@@ -1188,7 +1188,7 @@ static void status_post_select(__a_unused struct sched *s, struct task *t)
 			kill_btrn(st->ct->btrn, &st->ct->task, -E_AUDIOD_OFF);
 			goto out;
 		}
-		if (st->ct->task.error != -E_TASK_UNREGISTERED)
+		if (st->ct->task.error >= 0)
 			goto out;
 		close_stat_pipe();
 		st->clock_diff_count = conf.clock_diff_count_arg;
@@ -1199,7 +1199,7 @@ static void status_post_select(__a_unused struct sched *s, struct task *t)
 		size_t sz;
 		int ret;
 		if (st->ct->task.error < 0) {
-			if (st->ct->task.error != -E_TASK_UNREGISTERED)
+			if (st->ct->task.error >= 0)
 				goto out;
 			close_stat_pipe();
 			goto out;
diff --git a/error.h b/error.h
index 5a2e39b4..ed905a10 100644
--- a/error.h
+++ b/error.h
@@ -231,9 +231,9 @@ extern const char **para_errlist[];
 
 #define SCHED_ERRORS \
 	PARA_ERROR(TASK_KILLED, "task killed"), \
-	PARA_ERROR(TASK_UNREGISTERED, "task has been unscheduled"), \
 	PARA_ERROR(NO_SUCH_TASK, "task not found"), \
 	PARA_ERROR(NOT_INITIALIZED, "scheduler not yet initialized"), \
+	PARA_ERROR(SCHED_SHUTDOWN, "scheduler was shut down"), \
 
 
 #define NET_ERRORS \
diff --git a/grab_client.c b/grab_client.c
index 8e671503..c410b3b9 100644
--- a/grab_client.c
+++ b/grab_client.c
@@ -156,7 +156,7 @@ void activate_grab_clients(void)
 	struct grab_client *gc, *tmp;
 
 	list_for_each_entry_safe(gc, tmp, &inactive_grab_client_list, node) {
-		if (gc->task.error == -E_TASK_UNREGISTERED) {
+		if (gc->task.error < 0) {
 			list_del(&gc->node);
 			free(gc);
 			continue;
diff --git a/sched.c b/sched.c
index b0e9ce12..7d91797a 100644
--- a/sched.c
+++ b/sched.c
@@ -38,16 +38,15 @@ static void unregister_task(struct task *t)
 {
 	if (!initialized)
 		return;
+	assert(t->error < 0);
 	PARA_INFO_LOG("unregistering %s (%s)\n", t->status,
-		t->error <0? para_strerror(-t->error) : "shutdown");
+		para_strerror(-t->error));
 	if (t->pre_select)
 		list_del(&t->pre_select_node);
 	if (t->post_select)
 		list_del(&t->post_select_node);
-	t->error = -E_TASK_UNREGISTERED;
 }
 
-
 static void sched_preselect(struct sched *s)
 {
 	struct task *t, *tmp;
@@ -207,10 +206,14 @@ void sched_shutdown(void)
 
 	if (!initialized)
 		return;
-	list_for_each_entry_safe(t, tmp, &pre_select_list, pre_select_node)
+	list_for_each_entry_safe(t, tmp, &pre_select_list, pre_select_node) {
+		t->error = -E_SCHED_SHUTDOWN;
 		unregister_task(t);
-	list_for_each_entry_safe(t, tmp, &post_select_list, post_select_node)
+	}
+	list_for_each_entry_safe(t, tmp, &post_select_list, post_select_node) {
+		t->error = -E_SCHED_SHUTDOWN;
 		unregister_task(t);
+	}
 	initialized = 0;
 }
 
-- 
2.39.5