* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
#include <assert.h>
#include <common/hashtable/hashtable.h>
#include <common/common.h>
#include <common/utils.h>
+#include <pthread.h>
#include "lttng-sessiond.h"
#include "health-sessiond.h"
+#include "testpoint.h"
+#include "utils.h"
+#include "ht-cleanup.h"
-void *thread_ht_cleanup(void *data)
+static int ht_cleanup_quit_pipe[2] = { -1, -1 };
+
+/*
+ * Check if the ht_cleanup thread quit pipe was triggered.
+ *
+ * Return true if it was triggered else false;
+ */
+static bool check_quit_pipe(int fd, uint32_t events)
+{
+ return (fd == ht_cleanup_quit_pipe[0] && (events & LPOLLIN));
+}
+
+static int init_pipe(int *pipe_fds)
+{
+ int ret, i;
+
+ ret = pipe(pipe_fds);
+ if (ret < 0) {
+ PERROR("ht_cleanup thread quit pipe");
+ goto error;
+ }
+
+ for (i = 0; i < 2; i++) {
+ ret = fcntl(pipe_fds[i], F_SETFD, FD_CLOEXEC);
+ if (ret < 0) {
+ PERROR("fcntl ht_cleanup_quit_pipe");
+ goto error;
+ }
+ }
+error:
+ return ret;
+}
+
+/*
+ * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set.
+ */
+static int set_pollset(struct lttng_poll_event *events, size_t size)
+{
+ int ret;
+
+ ret = lttng_poll_create(events, size, LTTNG_CLOEXEC);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = lttng_poll_add(events, ht_cleanup_quit_pipe[0],
+ LPOLLIN | LPOLLERR);
+ if (ret < 0) {
+ goto error;
+ }
+
+ 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;
+ }
+
+ return 0;
+
+error:
+ return ret;
+}
+
+static void cleanup_ht_cleanup_thread(void *data)
+{
+ utils_close_pipe(ht_cleanup_quit_pipe);
+ utils_close_pipe(ht_cleanup_pipe);
+}
+
+static 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;
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 = set_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) {
- goto error;
- }
-
health_code_update();
while (1) {
- DBG3("[ht-thread] Polling on %d fds.",
- LTTNG_POLL_GETNB(&events));
-
- /* Inifinite blocking call, waiting for transmission */
-restart:
+ restart:
+ DBG3("[ht-thread] Polling.");
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) {
/*
* Restart interrupted system call.
*/
if (errno == EINTR) {
- goto restart;
+ continue;
}
goto error;
}
nb_fd = ret;
-
for (i = 0; i < nb_fd; i++) {
struct lttng_ht *ht;
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 (pollfd != ht_cleanup_pipe[0]) {
+ continue;
}
- assert(pollfd == ht_cleanup_pipe[0]);
- if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ if (revents & LPOLLIN) {
+ /* Get socket from dispatch thread. */
+ 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();
+
+ /*
+ * Ensure that we never process the quit pipe
+ * event while there is still data available
+ * on the ht clean pipe.
+ */
+ goto restart;
+ } else 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);
+ } else {
+ ERR("Unexpected poll events %u for sock %d", revents, pollfd);
goto error;
}
+ }
- do {
- /* 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");
- goto error;
- }
+ for (i = 0; i < nb_fd; i++) {
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();
+ /* 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 = check_quit_pipe(pollfd, revents);
+ if (ret) {
+ err = 0;
+ DBG("[ht-cleanup] quit.");
+ goto 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__);
rcu_unregister_thread();
return NULL;
}
+
+static bool shutdown_ht_cleanup_thread(void *data)
+{
+ int ret;
+
+ ret = notify_thread_pipe(ht_cleanup_quit_pipe[1]);
+ if (ret < 0) {
+ ERR("write error on ht_cleanup quit pipe");
+ goto end;
+ }
+end:
+ return ret;
+}
+
+struct lttng_thread *launch_ht_cleanup_thread(void)
+{
+ int ret;
+ struct lttng_thread *thread;
+
+ ret = init_pipe(ht_cleanup_pipe);
+ if (ret) {
+ goto error;
+ }
+
+ ret = init_pipe(ht_cleanup_quit_pipe);
+ if (ret) {
+ goto error;
+ }
+
+ thread = lttng_thread_create("HT cleanup",
+ thread_ht_cleanup,
+ shutdown_ht_cleanup_thread,
+ cleanup_ht_cleanup_thread,
+ NULL);
+ if (!thread) {
+ goto error;
+ }
+ return thread;
+error:
+ cleanup_ht_cleanup_thread(NULL);
+ return NULL;
+}
projects / lttng-tools.git / blobdiff