Remove the sessiond "ready" counter mechanism

[lttng-tools.git] / src / bin / lttng-sessiond / agent-thread.c

diff --git a/src/bin/lttng-sessiond/agent-thread.c b/src/bin/lttng-sessiond/agent-thread.c
index 9c98d30ab4e71accd303a442d41b45feeee212b6..3ee383389d5e35927b9787e221fc3e51a0cf2b03 100644 (file)
--- a/src/bin/lttng-sessiond/agent-thread.c
+++ b/src/bin/lttng-sessiond/agent-thread.c
@@ -33,6 +33,11 @@
 #include "utils.h"
 #include "thread.h"
 
+struct thread_notifiers {
+       struct lttng_pipe *quit_pipe;
+       sem_t ready;
+};
+
 static int agent_tracing_enabled = -1;
 
 /*
@@ -293,6 +298,21 @@ static int write_agent_port(uint16_t port)
                        config.agent_port_file_path.value);
 }
 
+static
+void mark_thread_as_ready(struct thread_notifiers *notifiers)
+{
+       DBG("Marking agent management thread as ready");
+       sem_post(&notifiers->ready);
+}
+
+static
+void wait_until_thread_is_ready(struct thread_notifiers *notifiers)
+{
+       DBG("Waiting for agent management thread to be ready");
+       sem_wait(&notifiers->ready);
+       DBG("Agent management thread is ready");
+}
+
 /*
  * This thread manage application notify communication.
  */
@@ -302,8 +322,9 @@ static void *thread_agent_management(void *data)
        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);
+       struct thread_notifiers *notifiers = data;
+       const int quit_pipe_read_fd = lttng_pipe_get_readfd(
+                       notifiers->quit_pipe);
 
        DBG("[agent-thread] Manage agent application registration.");
 
@@ -335,12 +356,12 @@ static void *thread_agent_management(void *data)
                if (ret) {
                        ERR("[agent-thread] Failed to create agent port file: agent tracing will be unavailable");
                        /* Don't prevent the launch of the sessiond on error. */
-                       sessiond_notify_ready();
+                       mark_thread_as_ready(notifiers);
                        goto error;
                }
        } else {
                /* Don't prevent the launch of the sessiond on error. */
-               sessiond_notify_ready();
+               mark_thread_as_ready(notifiers);
                goto error_tcp_socket;
        }
 
@@ -349,7 +370,7 @@ static void *thread_agent_management(void *data)
         * may start to query whether or not agent tracing is enabled.
         */
        uatomic_set(&agent_tracing_enabled, 1);
-       sessiond_notify_ready();
+       mark_thread_as_ready(notifiers);
 
        /* Add TCP socket to poll set. */
        ret = lttng_poll_add(&events, reg_sock->fd,
@@ -461,40 +482,48 @@ error_poll_create:
 
 static bool shutdown_agent_management_thread(void *data)
 {
-       struct lttng_pipe *quit_pipe = data;
-       const int write_fd = lttng_pipe_get_writefd(quit_pipe);
+       struct thread_notifiers *notifiers = data;
+       const int write_fd = lttng_pipe_get_writefd(notifiers->quit_pipe);
 
        return notify_thread_pipe(write_fd) == 1;
 }
 
 static void cleanup_agent_management_thread(void *data)
 {
-       struct lttng_pipe *quit_pipe = data;
+       struct thread_notifiers *notifiers = data;
 
-       lttng_pipe_destroy(quit_pipe);
+       lttng_pipe_destroy(notifiers->quit_pipe);
+       sem_destroy(&notifiers->ready);
+       free(notifiers);
 }
 
 bool launch_agent_management_thread(void)
 {
-       struct lttng_pipe *quit_pipe;
+       struct thread_notifiers *notifiers;
        struct lttng_thread *thread;
 
-       quit_pipe = lttng_pipe_open(FD_CLOEXEC);
-       if (!quit_pipe) {
+       notifiers = zmalloc(sizeof(*notifiers));
+       if (!notifiers) {
+               goto error;
+       }
+
+       sem_init(&notifiers->ready, 0, 0);
+       notifiers->quit_pipe = lttng_pipe_open(FD_CLOEXEC);
+       if (!notifiers->quit_pipe) {
                goto error;
        }
        thread = lttng_thread_create("Agent management",
                        thread_agent_management,
                        shutdown_agent_management_thread,
                        cleanup_agent_management_thread,
-                       quit_pipe);
+                       notifiers);
        if (!thread) {
                goto error;
        }
-
+       wait_until_thread_is_ready(notifiers);
        lttng_thread_put(thread);
        return true;
 error:
-       cleanup_agent_management_thread(quit_pipe);
+       cleanup_agent_management_thread(notifiers);
        return false;
 }