ws-server-threads-smp: modernize

READMEs/README.lws_system.md

@@ -207,6 +207,7 @@ The generic states defined are:
 |`LWS_SYSTATE_AUTH2`|Optional second access token for different services|
 |`LWS_SYSTATE_OPERATIONAL`|The system is ready for user code to work normally|
 |`LWS_SYSTATE_POLICY_INVALID`|All connections are being dropped because policy information is changing.  It will transition back to `LWS_SYSTATE_INITIALIZED` and onward to `OPERATIONAL` again afterwards with the new policy|
+|`LWS_SYSTATE_CONTEXT_DESTROYING`|Context is going down and smd with it|
 
 ### Inserting a notifier
 

include/libwebsockets/lws-system.h

@@ -139,6 +139,7 @@ typedef enum { /* keep system_state_names[] in sync in context.c */
 					  * drop everything done with old
 					  * policy, switch to new then enter
 					  * LWS_SYSTATE_POLICY_VALID */
+	LWS_SYSTATE_CONTEXT_DESTROYING,	 /* Context is being destroyed */
 } lws_system_states_t;
 
 /* Captive Portal Detect -related */

lib/core-net/vhost.c

@@ -1286,6 +1286,7 @@ void
 lws_vhost_destroy1(struct lws_vhost *vh)
 {
 	struct lws_context *context = vh->context;
+	int n;
 
 	lwsl_vhost_info(vh, "\n");
 
@@ -1294,6 +1295,14 @@ lws_vhost_destroy1(struct lws_vhost *vh)
 	if (vh->being_destroyed)
 		goto out;
 
+	/*
+	 * let's lock all the pts, to enforce pt->vh order... pt is refcounted
+	 * so it's OK if we acquire it later inside this
+	 */
+
+	for (n = 0; n < context->count_threads; n++)
+		lws_pt_lock((&context->pt[n]), __func__);
+
 	lws_vhost_lock(vh); /* -------------- vh { */
 
 #if defined(LWS_WITH_TLS_SESSIONS) && defined(LWS_WITH_TLS)
@@ -1390,6 +1399,9 @@ lws_vhost_destroy1(struct lws_vhost *vh)
 
 	lws_vhost_unlock(vh); /* } vh -------------- */
 
+	for (n = 0; n < context->count_threads; n++)
+		lws_pt_unlock((&context->pt[n]));
+
 out:
 	lws_context_unlock(context); /* --------------------------- context { */
 }
@@ -1525,7 +1537,7 @@ __lws_vhost_destroy2(struct lws_vhost *vh)
 #endif
 
 #if LWS_MAX_SMP > 1
-	lws_mutex_refcount_destroy(&context->mr);
+	lws_mutex_refcount_destroy(&vh->mr);
 #endif
 
 #if defined(LWS_WITH_UNIX_SOCK)

lib/core/context.c

@@ -75,7 +75,8 @@ static const char * system_state_names[] = {
 	"AUTH1",
 	"AUTH2",
 	"OPERATIONAL",
-	"POLICY_INVALID"
+	"POLICY_INVALID",
+	"DESTROYING"
 };
 
 
@@ -2084,6 +2085,9 @@ next:
 		if (context->event_loop_ops->destroy_context2)
 			context->event_loop_ops->destroy_context2(context);
 
+		lws_state_transition_steps(&context->mgr_system,
+					   LWS_SYSTATE_CONTEXT_DESTROYING);
+
 		/*
 		 * finalize destroy of pt and things hanging off it
 		 */

minimal-examples/ws-server/minimal-ws-server-threads-smp/minimal-ws-server.c

@@ -41,7 +41,8 @@ static struct lws_protocols protocols[] = {
 };
 
 static struct lws_context *context;
-static int interrupted;
+static int interrupted, started;
+static pthread_t pthread_service[COUNT_THREADS];
 
 static const struct lws_http_mount mount = {
 	/* .mount_next */		NULL,		/* linked-list "next" */
@@ -98,18 +99,58 @@ void *thread_service(void *threadid)
 	return NULL;
 }
 
+static int
+system_notify_cb(lws_state_manager_t *mgr, lws_state_notify_link_t *link,
+		   int current, int target)
+{
+	struct lws_context *context = mgr->parent;
+	void *retval;
+
+	if (current != target)
+		return 0;
+
+	switch (current) {
+	case LWS_SYSTATE_OPERATIONAL:
+		lwsl_notice("  Service threads: %d\n",
+			    lws_get_count_threads(context));
+
+		/* start all the service threads */
+
+		for (started = 1; started < lws_get_count_threads(context);
+		     started++)
+			if (pthread_create(&pthread_service[started], NULL,
+					   thread_service,
+					   (void *)(lws_intptr_t)started))
+				lwsl_err("Failed to start service thread\n");
+		break;
+	case LWS_SYSTATE_CONTEXT_DESTROYING:
+		/* wait for all the service threads to exit */
+
+		while ((--started) >= 1)
+			pthread_join(pthread_service[started], &retval);
+
+		break;
+	}
+
+	return 0;
+}
+
+lws_state_notify_link_t notifier = { { NULL, NULL, NULL },
+				     system_notify_cb, "app" };
+lws_state_notify_link_t *na[] = { &notifier, NULL };
+
 void sigint_handler(int sig)
 {
 	interrupted = 1;
+	lws_cancel_service(context);
 }
 
 int main(int argc, const char **argv)
 {
-	int n, logs = LLL_USER | LLL_ERR | LLL_WARN | LLL_NOTICE;
-	pthread_t pthread_service[COUNT_THREADS];
+	int logs = LLL_USER | LLL_ERR | LLL_WARN | LLL_NOTICE;
 	struct lws_context_creation_info info;
 	const char *p;
-	void *retval;
+	int n = 0;
 
 	signal(SIGINT, sigint_handler);
 
@@ -125,6 +166,7 @@ int main(int argc, const char **argv)
 	info.protocols = protocols;
 	info.pvo = &pvo; /* per-vhost options */
 	info.count_threads = COUNT_THREADS;
+	info.register_notifier_list = na;
 	info.options =
 		LWS_SERVER_OPTION_HTTP_HEADERS_SECURITY_BEST_PRACTICES_ENFORCE;
 
@@ -134,19 +176,8 @@ int main(int argc, const char **argv)
 		return 1;
 	}
 
-	lwsl_notice("  Service threads: %d\n", lws_get_count_threads(context));
-
-	/* start all the service threads */
-
-	for (n = 0; n < lws_get_count_threads(context); n++)
-		if (pthread_create(&pthread_service[n], NULL, thread_service,
-				   (void *)(lws_intptr_t)n))
-			lwsl_err("Failed to start service thread\n");
-
-	/* wait for all the service threads to exit */
-
-	while ((--n) >= 0)
-		pthread_join(pthread_service[n], &retval);
+	while (n >= 0 && !interrupted)
+		n = lws_service(context, 0);
 
 	lws_context_destroy(context);