X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fht-cleanup.c;h=f5aab3309280daa9c4550b967334ebe8f6449278;hp=890c9a8215e26967c5ff6b42b5cf171295cdc306;hb=f2e086eddce40fb3b772f50f4cd8023f2cc2a10f;hpb=6c71277b0dc97ce8a4ac6b8d359b4b349c04b658 diff --git a/src/bin/lttng-sessiond/ht-cleanup.c b/src/bin/lttng-sessiond/ht-cleanup.c index 890c9a821..f5aab3309 100644 --- a/src/bin/lttng-sessiond/ht-cleanup.c +++ b/src/bin/lttng-sessiond/ht-cleanup.c @@ -15,19 +15,93 @@ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ -#define _GNU_SOURCE +#define _LGPL_SOURCE #include #include #include #include +#include #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; @@ -38,42 +112,40 @@ void *thread_ht_cleanup(void *data) 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; @@ -83,41 +155,67 @@ 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 (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; + } } } @@ -125,9 +223,8 @@ 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__); @@ -137,3 +234,45 @@ error_poll_create: 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; +}