summary |
shortlog |
log |
commit | commitdiff |
tree
raw |
patch |
inline | side by side (from parent 1:
06c7582)
The select(2) system call is an ancient ABI limited to processes
containing at most FD_SETSIZE file descriptors overall (typically
1024).
This select call will fail if the target file descriptor is above
FD_SETSIZE in a session daemon containing many file descriptors.
This is unlikely to happen in normal use given than
sessiond_init_thread_quit_pipe() is called early by main(). Odd
scenarios could trigger this, for instance if the parent process leaves
a large number of file descriptors open, or if a library which
allocates file descriptors is LD_PRELOADed with the sessiond.
Never use select, use the lttng epoll/poll wrapper instead.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
int sessiond_init_thread_quit_pipe(void);
int sessiond_check_thread_quit_pipe(int fd, uint32_t events);
int sessiond_init_thread_quit_pipe(void);
int sessiond_check_thread_quit_pipe(int fd, uint32_t events);
-int sessiond_wait_for_quit_pipe(unsigned int timeout_us);
+int sessiond_wait_for_quit_pipe(int timeout_ms);
int sessiond_notify_quit_pipe(void);
void sessiond_close_quit_pipe(void);
int sessiond_notify_quit_pipe(void);
void sessiond_close_quit_pipe(void);
*/
/* Initiate teardown once activity occurs on the quit pipe. */
*/
/* Initiate teardown once activity occurs on the quit pipe. */
- sessiond_wait_for_quit_pipe(-1U);
+ sessiond_wait_for_quit_pipe(-1);
* Returns 1 if the caller should quit, 0 if the timeout was reached, and
* -1 if an error was encountered.
*/
* Returns 1 if the caller should quit, 0 if the timeout was reached, and
* -1 if an error was encountered.
*/
-int sessiond_wait_for_quit_pipe(unsigned int timeout_us)
+int sessiond_wait_for_quit_pipe(int timeout_ms)
- fd_set read_fds;
- struct timeval timeout;
-
- FD_ZERO(&read_fds);
- FD_SET(thread_quit_pipe[0], &read_fds);
- memset(&timeout, 0, sizeof(timeout));
- timeout.tv_sec = timeout_us / USEC_PER_SEC;
- timeout.tv_usec = timeout_us % USEC_PER_SEC;
-
- while (true) {
- ret = select(thread_quit_pipe[0] + 1, &read_fds, NULL, NULL,
- timeout_us != -1U ? &timeout : NULL);
- if (ret < 0 && errno == EINTR) {
- /* Retry on interrupt. */
- continue;
- } else {
- break;
- }
- }
+ struct lttng_poll_event events;
+ ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC);
+ if (ret < 0) {
+ PERROR("Failed to initialize poll/epoll set");
+ ret = -1;
+ goto end;
+ }
+ ret = lttng_poll_add(&events, thread_quit_pipe[0], LPOLLIN | LPOLLERR);
+ if (ret < 0) {
+ PERROR("Failed to add file descriptor to poll/epoll set");
+ ret = -1;
+ goto end_clean_poll;
+ }
+ ret = lttng_poll_wait(&events, timeout_ms);
if (ret > 0) {
/* Should quit. */
ret = 1;
} else if (ret < 0 && errno != EINTR) {
/* Unknown error. */
if (ret > 0) {
/* Should quit. */
ret = 1;
} else if (ret < 0 && errno != EINTR) {
/* Unknown error. */
- PERROR("Failed to select() thread quit pipe");
+ PERROR("Failed to epoll()/poll() thread quit pipe");
ret = -1;
} else {
/* Timeout reached. */
ret = 0;
}
ret = -1;
} else {
/* Timeout reached. */
ret = 0;
}
+end_clean_poll:
+ lttng_poll_clean(&events);
+end: