From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Sun, 2 Dec 2018 21:20:16 +0000 (-0500)
Subject: Launch agent management thread using lttng_thread
X-Git-Tag: v2.12.0-rc1~717
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=8a7e45909a46d4aab3c3debde8f5ce2006c7d306

Launch agent management thread using lttng_thread

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/src/bin/lttng-sessiond/agent-thread.c b/src/bin/lttng-sessiond/agent-thread.c
index 51221c4c6..e648eda1e 100644
--- a/src/bin/lttng-sessiond/agent-thread.c
+++ b/src/bin/lttng-sessiond/agent-thread.c
@@ -31,6 +31,7 @@
 #include "lttng-sessiond.h"
 #include "session.h"
 #include "utils.h"
+#include "thread.h"
 
 static int agent_tracing_enabled = -1;
 
@@ -295,12 +296,14 @@ static int write_agent_port(uint16_t port)
 /*
  * This thread manage application notify communication.
  */
-void *agent_thread_manage_registration(void *data)
+static void *thread_agent_management(void *data)
 {
 	int i, ret, pollfd;
 	uint32_t revents, nb_fd;
 	struct lttng_poll_event events;
 	struct lttcomm_sock *reg_sock;
+	struct lttng_pipe *quit_pipe = data;
+	const int quit_pipe_read_fd = lttng_pipe_get_readfd(quit_pipe);
 
 	DBG("[agent-thread] Manage agent application registration.");
 
@@ -310,13 +313,18 @@ void *agent_thread_manage_registration(void *data)
 	/* Agent initialization call MUST be called before starting the thread. */
 	assert(agent_apps_ht_by_sock);
 
-	/* Create pollset with size 2, quit pipe and socket. */
-	ret = sessiond_set_thread_pollset(&events, 2);
+	/* Create pollset with size 2, quit pipe and registration socket. */
+	ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
 	if (ret < 0) {
-		sessiond_notify_ready();
 		goto error_poll_create;
 	}
 
+	ret = lttng_poll_add(&events, quit_pipe_read_fd,
+			LPOLLIN | LPOLLERR);
+	if (ret < 0) {
+		goto error_tcp_socket;
+	}
+
 	reg_sock = init_tcp_socket();
 	if (reg_sock) {
 		uint16_t port;
@@ -381,8 +389,7 @@ restart:
 			}
 
 			/* Thread quit pipe has been closed. Killing thread. */
-			ret = sessiond_check_thread_quit_pipe(pollfd, revents);
-			if (ret) {
+			if (pollfd == quit_pipe_read_fd) {
 				goto exit;
 			}
 
@@ -446,9 +453,41 @@ error_tcp_socket:
 	lttng_poll_clean(&events);
 error_poll_create:
 	uatomic_set(&agent_tracing_enabled, 0);
-	DBG("[agent-thread] is cleaning up and stopping.");
-
+	DBG("[agent-thread] Cleaning up and stopping.");
+	lttng_pipe_destroy(quit_pipe);
 	rcu_thread_offline();
 	rcu_unregister_thread();
 	return NULL;
 }
+
+static bool shutdown_agent_management_thread(void *data)
+{
+	struct lttng_pipe *quit_pipe = data;
+	const int write_fd = lttng_pipe_get_writefd(quit_pipe);
+
+	return notify_thread_pipe(write_fd) == 1;
+}
+
+bool launch_agent_registration_thread(void)
+{
+	struct lttng_pipe *quit_pipe;
+	struct lttng_thread *thread;
+
+	quit_pipe = lttng_pipe_open(FD_CLOEXEC);
+	if (!quit_pipe) {
+		goto error;
+	}
+	thread = lttng_thread_create("Agent management",
+			thread_agent_management,
+			shutdown_agent_management_thread,
+			quit_pipe);
+	if (!thread) {
+		goto error;
+	}
+
+	lttng_thread_put(thread);
+	return true;
+error:
+	lttng_pipe_destroy(quit_pipe);
+	return false;
+}
diff --git a/src/bin/lttng-sessiond/agent-thread.h b/src/bin/lttng-sessiond/agent-thread.h
index 4bed47b37..7c33eddc9 100644
--- a/src/bin/lttng-sessiond/agent-thread.h
+++ b/src/bin/lttng-sessiond/agent-thread.h
@@ -22,17 +22,17 @@
 
 #ifdef HAVE_LIBLTTNG_UST_CTL
 
-void *agent_thread_manage_registration(void *data);
+bool launch_agent_management_thread(void);
 bool agent_tracing_is_enabled(void);
 
 #else /* HAVE_LIBLTTNG_UST_CTL */
 
 static inline
-void *agent_thread_manage_registration(void *data)
+bool launch_agent_management_thread(void)
 {
-	sessiond_notify_ready();
-	return NULL;
+	return true;
 }
+
 static inline
 bool agent_tracing_is_enabled(void)
 {
diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c
index 39800b51c..56d932da9 100644
--- a/src/bin/lttng-sessiond/main.c
+++ b/src/bin/lttng-sessiond/main.c
@@ -146,7 +146,6 @@ static int apps_cmd_notify_pipe[2] = { -1, -1 };
 
 /* Pthread, Mutexes and Semaphores */
 static pthread_t kernel_thread;
-static pthread_t agent_reg_thread;
 static pthread_t load_session_thread;
 
 /*
@@ -2447,14 +2446,9 @@ int main(int argc, char **argv)
 		goto exit_apps_notify;
 	}
 
-	/* Create agent registration thread. */
-	ret = pthread_create(&agent_reg_thread, default_pthread_attr(),
-			agent_thread_manage_registration, (void *) NULL);
-	if (ret) {
-		errno = ret;
-		PERROR("pthread_create agent");
+	/* Create agent management thread. */
+	if (!launch_agent_management_thread()) {
 		retval = -1;
-		stop_threads();
 		goto exit_agent_reg;
 	}
 
@@ -2520,13 +2514,6 @@ exit_load_session:
 		}
 	}
 exit_kernel:
-
-	ret = pthread_join(agent_reg_thread, &status);
-	if (ret) {
-		errno = ret;
-		PERROR("pthread_join agent");
-		retval = -1;
-	}
 exit_agent_reg:
 exit_apps_notify:
 exit_apps: