Cleanup: use CMM accessors for consumer_quit variable

Use CMM_LOAD_SHARED and CMM_STORE_SHARED, which are strictly
equivalent to a volatile variable, in line with the rest of the
lttng-tools project.

Also move its declaration to a header, rather than having multiple
declarations in C files, now following our coding style.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/src/common/consumer/consumer.c b/src/common/consumer/consumer.c
index d07e5b4925317f026fbe8b9483b54eae19c7ae77..9834322cf589d0c00c0ffef796e0ebb461291964 100644 (file)
--- a/src/common/consumer/consumer.c
+++ b/src/common/consumer/consumer.c
@@ -76,7 +76,7 @@ int data_consumption_paused;
  * Also updated by the signal handler (consumer_should_exit()). Read by the
  * polling threads.
  */
-volatile int consumer_quit;
+int consumer_quit;
 
 /*
  * Global hash table containing respectively metadata and data streams. The
@@ -1227,7 +1227,7 @@ void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx)
 {
        ssize_t ret;
 
-       consumer_quit = 1;
+       CMM_STORE_SHARED(consumer_quit, 1);
        ret = lttng_write(ctx->consumer_should_quit[1], "4", 1);
        if (ret < 1) {
                PERROR("write consumer quit");
@@ -2526,7 +2526,7 @@ void *consumer_thread_data_poll(void *data)
                pthread_mutex_unlock(&consumer_data.lock);
 
                /* No FDs and consumer_quit, consumer_cleanup the thread */
-               if (nb_fd == 0 && consumer_quit == 1) {
+               if (nb_fd == 0 && CMM_LOAD_SHARED(consumer_quit) == 1) {
                        err = 0;        /* All is OK */
                        goto end;
                }
@@ -3203,7 +3203,7 @@ void *consumer_thread_sessiond_poll(void *data)
                        err = 0;
                        goto end;
                }
-               if (consumer_quit) {
+               if (CMM_LOAD_SHARED(consumer_quit)) {
                        DBG("consumer_thread_receive_fds received quit from signal");
                        err = 0;        /* All is OK */
                        goto end;
@@ -3228,7 +3228,7 @@ end:
         * when all fds have hung up, the polling thread
         * can exit cleanly
         */
-       consumer_quit = 1;
+       CMM_STORE_SHARED(consumer_quit, 1);
 
        /*
         * Notify the data poll thread to poll back again and test the

diff --git a/src/common/consumer/consumer.h b/src/common/consumer/consumer.h
index 7375373c76113ab791a5e06027e8f0599a1494f6..220dbb4a294b0b608a88391bc72f08365d64fad5 100644 (file)
--- a/src/common/consumer/consumer.h
+++ b/src/common/consumer/consumer.h
@@ -604,6 +604,12 @@ struct lttng_consumer_global_data {
        struct lttng_ht *stream_per_chan_id_ht;
 };
 
+/*
+ * Set to nonzero when the consumer is exiting. Updated by signal
+ * handler and thread exit, read by threads.
+ */
+extern int consumer_quit;
+
 /* Flag used to temporarily pause data consumption from testpoints. */
 extern int data_consumption_paused;
 

diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index b5afc73aa5fb167071145b35e6d8a16a4291cbc6..8d00a0d46bd0c6edb2ab991b21bde1af448d70b0 100644 (file)
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -48,7 +48,6 @@
 
 extern struct lttng_consumer_global_data consumer_data;
 extern int consumer_poll_timeout;
-extern volatile int consumer_quit;
 
 /*
  * Take a snapshot for a specific fd

diff --git a/src/common/ust-consumer/ust-consumer.c b/src/common/ust-consumer/ust-consumer.c
index 99803a693f95b0beffaff9eef4313b521ce2f2e9..4297d60cffbaaf5a82d3d575e30eea964ff9713b 100644 (file)
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -51,7 +51,6 @@
 
 extern struct lttng_consumer_global_data consumer_data;
 extern int consumer_poll_timeout;
-extern volatile int consumer_quit;
 
 /*
  * Free channel object and all streams associated with it. This MUST be used