From: David Strauss <david@davidstrauss.net>
Date: Mon, 21 Oct 2013 23:39:13 +0000 (-0700)
Subject: sd-event: EPOLLONESHOT only disables event reporting after an event. The fd is still... 
X-Git-Tag: v209~1799
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=9ec9694ce3dbc137735b2992dfa305d0e5948815

sd-event: EPOLLONESHOT only disables event reporting after an event. The fd is still registered.
---

diff --git a/src/libsystemd-bus/sd-event.c b/src/libsystemd-bus/sd-event.c
index 19fa982ed..b3a6c5b08 100644
--- a/src/libsystemd-bus/sd-event.c
+++ b/src/libsystemd-bus/sd-event.c
@@ -1430,15 +1430,6 @@ static int process_io(sd_event *e, sd_event_source *s, uint32_t events) {
 
         s->io.revents = events;
 
-        /*
-           If this is a oneshot event source, then we added it to the
-           epoll with EPOLLONESHOT, hence we know it's not registered
-           anymore. We can save a syscall here...
-        */
-
-        if (s->enabled == SD_EVENT_ONESHOT)
-                s->io.registered = false;
-
         return source_set_pending(s, true);
 }
 
diff --git a/src/libsystemd-bus/test-event.c b/src/libsystemd-bus/test-event.c
index 80aa28eb2..60194b99a 100644
--- a/src/libsystemd-bus/test-event.c
+++ b/src/libsystemd-bus/test-event.c
@@ -29,6 +29,7 @@ static int prepare_handler(sd_event_source *s, void *userdata) {
 }
 
 static bool got_a, got_b, got_c;
+static unsigned got_d;
 
 static int io_handler(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 
@@ -41,6 +42,12 @@ static int io_handler(sd_event_source *s, int fd, uint32_t revents, void *userda
         } else if (userdata == INT_TO_PTR('b')) {
                 assert_se(!got_b);
                 got_b = true;
+        } else if (userdata == INT_TO_PTR('d')) {
+                got_d++;
+                if (got_d < 2)
+                        assert_se(sd_event_source_set_enabled(s, SD_EVENT_ONESHOT) >= 0);
+                else
+                        assert_se(sd_event_source_set_enabled(s, SD_EVENT_OFF) >= 0);
         } else
                 assert_not_reached("Yuck!");
 
@@ -148,16 +155,28 @@ static int quit_handler(sd_event_source *s, void *userdata) {
 
 int main(int argc, char *argv[]) {
         sd_event *e = NULL;
-        sd_event_source *x = NULL, *y = NULL, *z = NULL, *q = NULL;
+        sd_event_source *w = NULL, *x = NULL, *y = NULL, *z = NULL, *q = NULL;
         static const char ch = 'x';
-        int a[2] = { -1, -1 }, b[2] = { -1, -1};
+        int a[2] = { -1, -1 }, b[2] = { -1, -1}, d[2] = { -1, -1};
 
         assert_se(pipe(a) >= 0);
         assert_se(pipe(b) >= 0);
+        assert_se(pipe(d) >= 0);
 
         assert_se(sd_event_new(&e) >= 0);
 
-        got_a = false, got_b = false, got_c = false;
+        got_a = false, got_b = false, got_c = false, got_d = 0;
+
+        /* Add a oneshot handler, trigger it, re-enable it, and trigger
+         * it again. */
+        assert_se(sd_event_add_io(e, d[0], EPOLLIN, io_handler, INT_TO_PTR('d'), &w) >= 0);
+        assert_se(sd_event_source_set_enabled(w, SD_EVENT_ONESHOT) >= 0);
+        assert_se(write(d[1], &ch, 1) >= 0);
+        assert_se(sd_event_run(e, (uint64_t) -1) >= 1);
+        assert_se(got_d == 1);
+        assert_se(write(d[1], &ch, 1) >= 0);
+        assert_se(sd_event_run(e, (uint64_t) -1) >= 1);
+        assert_se(got_d == 2);
 
         assert_se(sd_event_add_io(e, a[0], EPOLLIN, io_handler, INT_TO_PTR('a'), &x) >= 0);
         assert_se(sd_event_add_io(e, b[0], EPOLLIN, io_handler, INT_TO_PTR('b'), &y) >= 0);