Store the version of the tracer in the UID registry

[lttng-tools.git] / src / bin / lttng-sessiond / ht-cleanup.c

diff --git a/src/bin/lttng-sessiond/ht-cleanup.c b/src/bin/lttng-sessiond/ht-cleanup.c
index 4eb0c003437574e8790fa95ce02d7cac3ef09ec2..4a4bfc41b11a003be69ad6985654d55e18583a47 100644 (file)
--- a/src/bin/lttng-sessiond/ht-cleanup.c
+++ b/src/bin/lttng-sessiond/ht-cleanup.c
@@ -15,7 +15,7 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <assert.h>
 
 #include <common/hashtable/hashtable.h>
@@ -24,10 +24,12 @@
 
 #include "lttng-sessiond.h"
 #include "health-sessiond.h"
+#include "testpoint.h"
 
 void *thread_ht_cleanup(void *data)
 {
        int ret, i, pollfd, err = -1;
+       ssize_t size_ret;
        uint32_t revents, nb_fd;
        struct lttng_poll_event events;
 
@@ -36,31 +38,39 @@ void *thread_ht_cleanup(void *data)
        rcu_register_thread();
        rcu_thread_online();
 
-       health_register(health_sessiond, HEALTH_TYPE_HT_CLEANUP);
+       health_register(health_sessiond, HEALTH_SESSIOND_TYPE_HT_CLEANUP);
+
+       if (testpoint(sessiond_thread_ht_cleanup)) {
+               DBG("[ht-thread] testpoint.");
+               goto error_testpoint;
+       }
 
        health_code_update();
 
-       ret = sessiond_set_thread_pollset(&events, 2);
+       ret = sessiond_set_ht_cleanup_thread_pollset(&events, 2);
        if (ret < 0) {
+               DBG("[ht-thread] sessiond_set_ht_cleanup_thread_pollset error %d.", ret);
                goto error_poll_create;
        }
 
        /* Add pipe to the pollset. */
        ret = lttng_poll_add(&events, ht_cleanup_pipe[0], LPOLLIN | LPOLLERR);
        if (ret < 0) {
+               DBG("[ht-thread] lttng_poll_add error %d.", ret);
                goto error;
        }
 
        health_code_update();
 
        while (1) {
-               DBG3("[ht-thread] Polling on %d fds.",
-                       LTTNG_POLL_GETNB(&events));
+               DBG3("[ht-thread] Polling.");
 
                /* Inifinite blocking call, waiting for transmission */
 restart:
                health_poll_entry();
                ret = lttng_poll_wait(&events, -1);
+               DBG3("[ht-thread] Returning from poll on %d fds.",
+                       LTTNG_POLL_GETNB(&events));
                health_poll_exit();
                if (ret < 0) {
                        /*
@@ -83,41 +93,65 @@ restart:
                        revents = LTTNG_POLL_GETEV(&events, i);
                        pollfd = LTTNG_POLL_GETFD(&events, i);
 
-                       /* Thread quit pipe has been closed. Killing thread. */
-                       ret = sessiond_check_thread_quit_pipe(pollfd, revents);
-                       if (ret) {
-                               err = 0;
-                               goto exit;
+                       if (!revents) {
+                               /* No activity for this FD (poll implementation). */
+                               continue;
                        }
-                       assert(pollfd == ht_cleanup_pipe[0]);
 
-                       if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
-                               ERR("ht cleanup pipe error");
-                               goto error;
-                       } else if (!(revents & LPOLLIN)) {
-                               /* No POLLIN and not a catched error, stop the thread. */
-                               ERR("ht cleanup failed. revent: %u", revents);
-                               goto error;
+                       if (pollfd != ht_cleanup_pipe[0]) {
+                               continue;
                        }
 
-                       do {
+                       if (revents & LPOLLIN) {
                                /* Get socket from dispatch thread. */
-                               ret = read(ht_cleanup_pipe[0], &ht, sizeof(ht));
-                       } while (ret < 0 && errno == EINTR);
-                       if (ret < 0 || ret < sizeof(ht)) {
-                               PERROR("ht cleanup notify pipe");
+                               size_ret = lttng_read(ht_cleanup_pipe[0], &ht,
+                                               sizeof(ht));
+                               if (size_ret < sizeof(ht)) {
+                                       PERROR("ht cleanup notify pipe");
+                                       goto error;
+                               }
+                               health_code_update();
+                               /*
+                                * The whole point of this thread is to call
+                                * lttng_ht_destroy from a context that is NOT:
+                                * 1) a read-side RCU lock,
+                                * 2) a call_rcu thread.
+                                */
+                               lttng_ht_destroy(ht);
+
+                               health_code_update();
+                       } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+                               ERR("ht cleanup pipe error");
+                               goto error;
+                       } else {
+                               ERR("Unexpected poll events %u for sock %d", revents, pollfd);
                                goto error;
                        }
-                       health_code_update();
-                       /*
-                        * The whole point of this thread is to call
-                        * lttng_ht_destroy from a context that is NOT:
-                        * 1) a read-side RCU lock,
-                        * 2) a call_rcu thread.
-                        */
-                       lttng_ht_destroy(ht);
+               }
 
+               for (i = 0; i < nb_fd; i++) {
                        health_code_update();
+
+                       /* Fetch once the poll data */
+                       revents = LTTNG_POLL_GETEV(&events, i);
+                       pollfd = LTTNG_POLL_GETFD(&events, i);
+
+                       if (!revents) {
+                               /* No activity for this FD (poll implementation). */
+                               continue;
+                       }
+
+                       if (pollfd == ht_cleanup_pipe[0]) {
+                               continue;
+                       }
+
+                       /* Thread quit pipe has been closed. Killing thread. */
+                       ret = sessiond_check_ht_cleanup_quit(pollfd, revents);
+                       if (ret) {
+                               err = 0;
+                               DBG("[ht-cleanup] quit.");
+                               goto exit;
+                       }
                }
        }
 
@@ -125,9 +159,8 @@ exit:
 error:
        lttng_poll_clean(&events);
 error_poll_create:
-       utils_close_pipe(ht_cleanup_pipe);
-       ht_cleanup_pipe[0] = ht_cleanup_pipe[1] = -1;
-       DBG("[ust-thread] cleanup complete.");
+error_testpoint:
+       DBG("[ht-cleanup] Thread terminates.");
        if (err) {
                health_error();
                ERR("Health error occurred in %s", __func__);