Fix: poll and epoll fd set reallocation

[lttng-tools.git] / src / common / compat / poll.h

diff --git a/src/common/compat/poll.h b/src/common/compat/poll.h
index cfde4fc8381d36786f23683de1ffa7cc3f9e40f8..2cfad9a25fa1c7e0339ff8e810796c58f1b5b552 100644 (file)
--- a/src/common/compat/poll.h
+++ b/src/common/compat/poll.h
@@ -78,7 +78,8 @@ enum {
 struct compat_epoll_event {
        int epfd;
        uint32_t nb_fd;       /* Current number of fd in events */
-       uint32_t events_size; /* Size of events array */
+       uint32_t alloc_size; /* Size of events array */
+       uint32_t init_size;     /* Initial size of events array */
        struct epoll_event *events;
 };
 #define lttng_poll_event compat_epoll_event
@@ -202,21 +203,40 @@ enum {
        LTTNG_CLOEXEC = 0xdead,
 };
 
-struct compat_poll_event {
+struct compat_poll_event_array {
        uint32_t nb_fd;       /* Current number of fd in events */
-       uint32_t events_size; /* Size of events array */
+       uint32_t alloc_size; /* Size of events array */
+       /* Initial size of the pollset. We never shrink below that. */
+       uint32_t init_size;
        struct pollfd *events;
 };
+
+struct compat_poll_event {
+       /*
+        * Modified by the wait action. Updated using current fields if the
+        * need_update flag is set.
+        */
+       struct compat_poll_event_array wait;
+       /*
+        * This is modified by add/del actions being the _current_ flow of
+        * execution before a poll wait is done.
+        */
+       struct compat_poll_event_array current;
+       /* Indicate if wait.events needs to be realloc. */
+       int need_realloc:1;
+       /* Indicate if wait.events need to be updated from current. */
+       int need_update:1;
+};
 #define lttng_poll_event compat_poll_event
 
 /*
  * For the following calls, consider 'e' to be a lttng_poll_event pointer and i
  * being the index of the events array.
  */
-#define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->events[i].fd
-#define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->events[i].revents
-#define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->nb_fd
-#define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->events_size
+#define LTTNG_POLL_GETFD(e, i) LTTNG_REF(e)->wait.events[i].fd
+#define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->wait.events[i].revents
+#define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->wait.nb_fd
+#define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->wait.events_size
 
 /*
  * Create a pollfd structure of size 'size'.
@@ -270,7 +290,8 @@ static inline void lttng_poll_reset(struct lttng_poll_event *events)
 static inline void lttng_poll_clean(struct lttng_poll_event *events)
 {
        if (events) {
-               __lttng_poll_free((void *) events->events);
+               __lttng_poll_free((void *) events->wait.events);
+               __lttng_poll_free((void *) events->current.events);
        }
 }