sd-event: return 1 in sd_event_run() when we hit EINTR

[elogind.git] / src / libsystemd-bus / sd-event.c

diff --git a/src/libsystemd-bus/sd-event.c b/src/libsystemd-bus/sd-event.c
index 6af52ecb3cdf45325d91e74d91c0a4801397dbc9..a1baac52aaaa324a5b372d05583d30293ad18502 100644 (file)
--- a/src/libsystemd-bus/sd-event.c
+++ b/src/libsystemd-bus/sd-event.c
@@ -34,7 +34,7 @@
 
 #include "sd-event.h"
 
-#define EPOLL_QUEUE_MAX 64
+#define EPOLL_QUEUE_MAX 512U
 #define DEFAULT_ACCURACY_USEC (250 * USEC_PER_MSEC)
 
 typedef enum EventSourceType {
@@ -151,6 +151,8 @@ struct sd_event {
         sd_event **default_event_ptr;
 
         usec_t watchdog_last, watchdog_period;
+
+        unsigned n_sources;
 };
 
 static int pending_prioq_compare(const void *a, const void *b) {
@@ -316,6 +318,7 @@ static int exit_prioq_compare(const void *a, const void *b) {
 
 static void event_free(sd_event *e) {
         assert(e);
+        assert(e->n_sources == 0);
 
         if (e->default_event_ptr)
                 *(e->default_event_ptr) = NULL;
@@ -470,6 +473,8 @@ static void source_free(sd_event_source *s) {
         assert(s);
 
         if (s->event) {
+                assert(s->event->n_sources > 0);
+
                 switch (s->type) {
 
                 case SOURCE_IO:
@@ -521,6 +526,9 @@ static void source_free(sd_event_source *s) {
                 case SOURCE_EXIT:
                         prioq_remove(s->event->exit, s, &s->exit.prioq_index);
                         break;
+
+                case SOURCE_WATCHDOG:
+                        assert_not_reached("Wut? I shouldn't exist.");
                 }
 
                 if (s->pending)
@@ -529,6 +537,7 @@ static void source_free(sd_event_source *s) {
                 if (s->prepare)
                         prioq_remove(s->event->prepare, s, &s->prepare_index);
 
+                s->event->n_sources--;
                 sd_event_unref(s->event);
         }
 
@@ -582,6 +591,8 @@ static sd_event_source *source_new(sd_event *e, EventSourceType type) {
         s->type = type;
         s->pending_index = s->prepare_index = PRIOQ_IDX_NULL;
 
+        e->n_sources ++;
+
         return s;
 }
 
@@ -1036,6 +1047,42 @@ _public_ int sd_event_source_get_io_fd(sd_event_source *s) {
         return s->io.fd;
 }
 
+_public_ int sd_event_source_set_io_fd(sd_event_source *s, int fd) {
+        int r;
+
+        assert_return(s, -EINVAL);
+        assert_return(fd >= 0, -EINVAL);
+        assert_return(s->type == SOURCE_IO, -EDOM);
+        assert_return(!event_pid_changed(s->event), -ECHILD);
+
+        if (s->io.fd == fd)
+                return 0;
+
+        if (s->enabled == SD_EVENT_OFF) {
+                s->io.fd = fd;
+                s->io.registered = false;
+        } else {
+                int saved_fd;
+
+                saved_fd = s->io.fd;
+                assert(s->io.registered);
+
+                s->io.fd = fd;
+                s->io.registered = false;
+
+                r = source_io_register(s, s->enabled, s->io.events);
+                if (r < 0) {
+                        s->io.fd = saved_fd;
+                        s->io.registered = true;
+                        return r;
+                }
+
+                epoll_ctl(s->event->epoll_fd, EPOLL_CTL_DEL, saved_fd, NULL);
+        }
+
+        return 0;
+}
+
 _public_ int sd_event_source_get_io_events(sd_event_source *s, uint32_t* events) {
         assert_return(s, -EINVAL);
         assert_return(events, -EINVAL);
@@ -1192,6 +1239,9 @@ _public_ int sd_event_source_set_enabled(sd_event_source *s, int m) {
                 case SOURCE_DEFER:
                         s->enabled = m;
                         break;
+
+                case SOURCE_WATCHDOG:
+                        assert_not_reached("Wut? I shouldn't exist.");
                 }
 
         } else {
@@ -1247,6 +1297,9 @@ _public_ int sd_event_source_set_enabled(sd_event_source *s, int m) {
                 case SOURCE_DEFER:
                         s->enabled = m;
                         break;
+
+                case SOURCE_WATCHDOG:
+                        assert_not_reached("Wut? I shouldn't exist.");
                 }
         }
 
@@ -1371,6 +1424,17 @@ _public_ void* sd_event_source_get_userdata(sd_event_source *s) {
         return s->userdata;
 }
 
+_public_ void *sd_event_source_set_userdata(sd_event_source *s, void *userdata) {
+        void *ret;
+
+        assert_return(s, NULL);
+
+        ret = s->userdata;
+        s->userdata = userdata;
+
+        return ret;
+}
+
 static usec_t sleep_between(sd_event *e, usec_t a, usec_t b) {
         usec_t c;
         assert(e);
@@ -1505,12 +1569,21 @@ static int event_arm_timer(
         return 0;
 }
 
-static int process_io(sd_event *e, sd_event_source *s, uint32_t events) {
+static int process_io(sd_event *e, sd_event_source *s, uint32_t revents) {
         assert(e);
         assert(s);
         assert(s->type == SOURCE_IO);
 
-        s->io.revents = events;
+        /* If the event source was already pending, we just OR in the
+         * new revents, otherwise we reset the value. The ORing is
+         * necessary to handle EPOLLONESHOT events properly where
+         * readability might happen independently of writability, and
+         * we need to keep track of both */
+
+        if (s->pending)
+                s->io.revents |= revents;
+        else
+                s->io.revents = revents;
 
         return source_set_pending(s, true);
 }
@@ -1532,7 +1605,7 @@ static int flush_timer(sd_event *e, int fd, uint32_t events, usec_t *next) {
                 return -errno;
         }
 
-        if (ss != sizeof(x))
+        if (_unlikely_(ss != sizeof(x)))
                 return -EIO;
 
         if (next)
@@ -1660,7 +1733,7 @@ static int process_signal(sd_event *e, uint32_t events) {
                         return -errno;
                 }
 
-                if (ss != sizeof(si))
+                if (_unlikely_(ss != sizeof(si)))
                         return -EIO;
 
                 read_one = true;
@@ -1746,6 +1819,9 @@ static int source_dispatch(sd_event_source *s) {
         case SOURCE_EXIT:
                 r = s->exit.callback(s, s->userdata);
                 break;
+
+        case SOURCE_WATCHDOG:
+                assert_not_reached("Wut? I shouldn't exist.");
         }
 
         s->dispatching = false;
@@ -1873,7 +1949,8 @@ static int process_watchdog(sd_event *e) {
 }
 
 _public_ int sd_event_run(sd_event *e, uint64_t timeout) {
-        struct epoll_event ev_queue[EPOLL_QUEUE_MAX];
+        struct epoll_event *ev_queue;
+        unsigned ev_queue_max;
         sd_event_source *p;
         int r, i, m;
 
@@ -1903,11 +1980,13 @@ _public_ int sd_event_run(sd_event *e, uint64_t timeout) {
 
         if (event_next_pending(e) || e->need_process_child)
                 timeout = 0;
+        ev_queue_max = CLAMP(e->n_sources, 1U, EPOLL_QUEUE_MAX);
+        ev_queue = newa(struct epoll_event, ev_queue_max);
 
-        m = epoll_wait(e->epoll_fd, ev_queue, EPOLL_QUEUE_MAX,
+        m = epoll_wait(e->epoll_fd, ev_queue, ev_queue_max,
                        timeout == (uint64_t) -1 ? -1 : (int) ((timeout + USEC_PER_MSEC - 1) / USEC_PER_MSEC));
         if (m < 0) {
-                r = errno == EAGAIN || errno == EINTR ? 0 : -errno;
+                r = errno == EAGAIN || errno == EINTR ? 1 : -errno;
                 goto finish;
         }
 
@@ -2037,7 +2116,7 @@ _public_ int sd_event_get_now_monotonic(sd_event *e, uint64_t *usec) {
 
 _public_ int sd_event_default(sd_event **ret) {
 
-        static __thread sd_event *default_event = NULL;
+        static thread_local sd_event *default_event = NULL;
         sd_event *e;
         int r;
 
@@ -2078,6 +2157,7 @@ _public_ int sd_event_set_watchdog(sd_event *e, int b) {
         int r;
 
         assert_return(e, -EINVAL);
+        assert_return(!event_pid_changed(e), -ECHILD);
 
         if (e->watchdog == !!b)
                 return e->watchdog;
@@ -2133,3 +2213,10 @@ fail:
         e->watchdog_fd = -1;
         return r;
 }
+
+_public_ int sd_event_get_watchdog(sd_event *e) {
+        assert_return(e, -EINVAL);
+        assert_return(!event_pid_changed(e), -ECHILD);
+
+        return e->watchdog;
+}