resource: new sync resource

new resources that ensure an atomic : signal and wait sequence
With 2 tasks that wake up each, we can have the situation that the wakee
preempts the waker before the later waits on condition.
This leads to a situation where both tasks are waiting to be woken up by
the other one

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>

5 files changed, 65 insertions, 49 deletions

diff --git a/doc/taskset.json b/doc/taskset.json
index 25b39e0..8f5d6e6 100644
--- a/doc/taskset.json
+++ b/doc/taskset.json
@@ -1,68 +1,71 @@
 {
 	/*"resources" : 4,*/
 	"resources" : {
-		"m0" : { "type" : "mutex" },
-		"sync_mutex" : { "type" : "mutex" },
-		"wait" : { "type" : "wait" },
-		"trig" : { "type" : "signal", "target" : "wait" },
-		"m1" : { "type" : "mutex" },
-		"wake" : { "type" : "wait" },
-		"broad" : { "type" : "broadcast", "target" : "wake"  },
-		"m2" : { "type" : "mutex" },
-		"s1" : { "type" : "sleep" },
-		"s2" : { "type" : "sleep" },
-		"r1" : { "type" : "run" },
-		"r2" : { "type" : "run" },
+		"trig1_mutex" : { "type" : "mutex" },
+		"wait1" : { "type" : "wait" },
+		"trig1" : { "type" : "signal", "target" : "wait1" },
+		"trig2_mutex" : { "type" : "mutex" },
+		"wait2" : { "type" : "wait" },
+		"trig2" : { "type" : "signal", "target" : "wait2" },
+		"trig3_mutex" : { "type" : "mutex" },
+		"wait3" : { "type" : "wait" },
+		"trig3" : { "type" : "signal", "target" : "wait3" },
+		"sync3" : { "type" : "sync", "target" : "wait3" },
+		"trig4_mutex" : { "type" : "mutex" },
+		"wait4" : { "type" : "wait" },
+		"trig4" : { "type" : "signal", "target" : "wait4" },
+		"r0" : { "type" : "run" },
 	},
 	"tasks" : {
-		"thread0" : { 
-		       "exec" : 1000,
-		       "period" : 20000,
-		       "deadline" : 8000,
-			   "cpus" : [0],
-		       "lock_order" : ["r1", "m0", "trig"],
+		"AudioOut" : { 
+		       "exec" : 5000,
+		       "period" : 24000,
+		       "deadline" : 24000,
+			   "priority" : -19,
+			   "cpus": [0],
+			   "lock_order" : ["r0", "trig1"],
 		       "resources" : {
-			   "r1" : { "duration" : 200 },
-			   "m0" : { "duration" : 500 },
-			   "trig" : { "duration" : 0, "access": ["sync_mutex"] },
+			   "r0" : { "duration" : 275 },
+			   "trig1" : { "duration" : 0 },
 		       }
 		},
-		"thread1" : { 
-		       "exec" : 5000,
-		       "period" : 20000,
+		"AudioTrack" : { 
+		       "exec" : 300,
+		       "period" : 24000,
+		       "deadline" : 24000,
+			   "priority" : -16,
 			   "sleep" : false,
-		       "lock_order" : ["wait", "m0", "broad", "r1", "broad"],
+		       "lock_order" : ["wait1", "r0", "trig2"],
 		       "resources" : {
-			   "wait" : { "duration" : 0, "access": ["sync_mutex"] },
-			   "m0" : { "duration" : 1000 },
-			   "broad" : { "duration" : 0},
-			   "r1" : { "duration" : 1000 },
+			   "wait1" : { "duration" : 0, "access": ["trig1_mutex"] },
+			   "r0" : { "duration" : 300 },
+			   "trig2" : { "duration" : 0 },
 		       }
 		},
-		"thread2" : {
-			   "loop" : 100,
-		       "exec" : 1000, 
-		       "period" : 20000, 
+		"mp3.decoder" : {
+		       "exec" : 1150, 
+		       "period" : 24000,
+		       "deadline" : 24000,
+			   "priority" : -2,
 			   "sleep" : false,
-		       "lock_order" : ["wake", "m2", "wake", "m2"],
+		       "lock_order" : ["wait2", "r0", "sync3"],
 		       "resources" : {
-			   "wake" : { "duration" : 0, "access": ["m1"] },
-			   "m2" : { "duration" : 200 },
+			   "wait2" : { "duration" : 0, "access": ["trig2_mutex"] },
+			   "r0" : { "duration" : 1000 },
+			   "sync3" : { "duration" : 0, "access": ["trig3_mutex"] },
 		       }
 		},
-		"thread3" : { 
-		       "exec" : 1000, 
-		       "period" : 20000, 
-		       "deadline" : 15000,
-			   "delay" : 15000,
-			   "sleep" : true,
-		       "lock_order" : ["r1", "s1", "r1", "s2", "r2" ],
+		"OMXCall" : {
+		       "exec" : 300, 
+		       "period" : 24000,
+		       "deadline" : 24000,
+			   "priority" : -2,
+			   "sleep" : false,
+		       "lock_order" : ["wait3", "r0", "trig3"],
 		       "resources" : {
-			   "wake" : { "duration" : 0, "access": ["m1"] },
-			   "r1" : { "duration" : 200 },
-			   "s1" : { "duration" : 2000 },
-			   "r2" : { "duration" : 200 },
-			   "s2" : { "duration" : 1000 },
+			   "wait3" : { "duration" : 0, "access": ["trig3_mutex"] },
+			   "r0" : { "duration" : 300 },
+			   "trig3" : { "duration" : 0, "access": ["trig3_mutex"] },
 		       }
 		},
 	},
diff --git a/src/rt-app.c b/src/rt-app.c
index c8d509e..682750d 100644
--- a/src/rt-app.c
+++ b/src/rt-app.c
@@ -132,6 +132,11 @@ int get_resource(rtapp_resource_access_list_t *lock, struct timespec *usage)
 	case rtapp_signal:
 		pthread_cond_signal(lock->res->res.signal.target);
 		break;
+	case rtapp_sig_and_wait:
+		pthread_cond_signal(lock->res->res.signal.target);
+		prev = lock->prev;
+		pthread_cond_wait(lock->res->res.signal.target, &(prev->res->res.mtx.obj));
+		break;
 	case rtapp_broadcast:
 		pthread_cond_broadcast(lock->res->res.signal.target);
 		break;
@@ -219,6 +224,7 @@ shutdown(int sig)
 
 	for (i = 0; i <  opts.nresources; i++) {
 		switch (opts.resources[i].type) {
+		case rtapp_sig_and_wait:
 		case rtapp_signal:
 		case rtapp_broadcast:
 			pthread_cond_broadcast(opts.resources[i].res.signal.target);
diff --git a/src/rt-app_parse_config.c b/src/rt-app_parse_config.c
index 4fdb2a6..41b6941 100644
--- a/src/rt-app_parse_config.c
+++ b/src/rt-app_parse_config.c
@@ -232,6 +232,7 @@ parse_resource_data(char *name, struct json_object *obj, int idx,
 			break;
 		case rtapp_signal:
 		case rtapp_broadcast:
+		case rtapp_sig_and_wait:
 			target = get_string_value_from(obj, "target", FALSE, NULL);
 			init_signal_resource(data, opts, target);
 			break;
diff --git a/src/rt-app_types.h b/src/rt-app_types.h
index a14bd5b..d7587ae 100644
--- a/src/rt-app_types.h
+++ b/src/rt-app_types.h
@@ -62,7 +62,8 @@ typedef enum resource_t
 	rtapp_signal,
 	rtapp_broadcast,
 	rtapp_sleep,
-	rtapp_run
+	rtapp_run,
+	rtapp_sig_and_wait,
 } resource_t;
 
 struct _rtapp_mutex {
diff --git a/src/rt-app_utils.c b/src/rt-app_utils.c
index 354cdb5..0b1ef48 100644
--- a/src/rt-app_utils.c
+++ b/src/rt-app_utils.c
@@ -228,6 +228,8 @@ string_to_resource(const char *name, resource_t *resource)
 		*resource =  rtapp_wait;
 	else if (strcmp(name, "broadcast") == 0)
 		*resource =  rtapp_broadcast;
+	else if (strcmp(name, "sync") == 0)
+		*resource =  rtapp_sig_and_wait;
 	else if (strcmp(name, "sleep") == 0)
 		*resource =  rtapp_sleep;
 	else if (strcmp(name, "run") == 0)
@@ -253,6 +255,9 @@ resource_to_string(resource_t resource, char *resource_name)
 		case rtapp_broadcast:
 			strcpy(resource_name, "broadcast");
 			break;
+		case rtapp_sig_and_wait:
+			strcpy(resource_name, "sync");
+			break;
 		case rtapp_sleep:
 			strcpy(resource_name, "sleep");
 			break;