Fix: lttng_poll_mod calls compat_(e)poll_add

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

diff --git a/src/common/compat/poll.h b/src/common/compat/poll.h
index e69d59b42d054efbc900fd5412db093362fc5190..fde54ddb91331c46a28ce75c590b060d338ef845 100644 (file)
--- a/src/common/compat/poll.h
+++ b/src/common/compat/poll.h
@@ -52,6 +52,8 @@ static inline void __lttng_poll_free(void *events)
 #ifdef HAVE_EPOLL
 #include <sys/epoll.h>
 #include <stdio.h>
+#include <features.h>
+#include <common/compat/fcntl.h>
 
 /* See man epoll(7) for this define path */
 #define COMPAT_EPOLL_PROC_PATH "/proc/sys/fs/epoll/max_user_watches"
@@ -71,7 +73,17 @@ enum {
        LPOLLNVAL = EPOLLHUP,
        LPOLLRDHUP = EPOLLRDHUP,
        /* Close on exec feature of epoll */
+#if defined(HAVE_EPOLL_CREATE1) && defined(EPOLL_CLOEXEC)
        LTTNG_CLOEXEC = EPOLL_CLOEXEC,
+#else
+       /*
+        * EPOLL_CLOEXEC was added in glibc 2.8 (usually used in conjunction with
+        * epoll_create1(..)), but since neither EPOLL_CLOEXEC exists nor
+        * epoll_create1(..), we set it to FD_CLOEXEC so that we can pass it
+        * directly to fcntl(..) instead.
+        */
+       LTTNG_CLOEXEC = FD_CLOEXEC,
+#endif
 };
 
 struct compat_epoll_event {
@@ -115,6 +127,27 @@ extern int compat_epoll_create(struct lttng_poll_event *events,
 #define lttng_poll_create(events, size, flags) \
        compat_epoll_create(events, size, flags)
 
+#if defined(HAVE_EPOLL_CREATE1) && defined(EPOLL_CLOEXEC)
+static inline int compat_glibc_epoll_create(int size __attribute__((unused)),
+               int flags)
+{
+       return epoll_create1(flags);
+}
+#else
+static inline int compat_glibc_epoll_create(int size, int flags)
+{
+       /*
+        * epoll_create1 was added in glibc 2.9, but unfortunatly reverting to
+        * epoll_create(..) also means that we lose the possibility to
+        * directly set the EPOLL_CLOEXEC, so try and do it anyway but through
+        * fcntl(..).
+        */
+       int efd = epoll_create(size);
+       assert(fcntl(efd, F_SETFD, flags) != -1);
+       return efd;
+}
+#endif
+
 /*
  * Wait on epoll set with the number of fd registered to the lttng_poll_event
  * data structure (events).
@@ -138,10 +171,18 @@ extern int compat_epoll_del(struct lttng_poll_event *events, int fd);
 #define lttng_poll_del(events, fd) \
        compat_epoll_del(events, fd)
 
+/*
+ * Modify an fd's events in the epoll set.
+ */
+extern int compat_epoll_mod(struct lttng_poll_event *events,
+               int fd, uint32_t req_events);
+#define lttng_poll_mod(events, fd, req_events) \
+       compat_epoll_mod(events, fd, req_events)
+
 /*
  * Set up the poll set limits variable poll_max_size
  */
-extern void compat_epoll_set_max_size(void);
+extern int compat_epoll_set_max_size(void);
 #define lttng_poll_set_max_size() \
        compat_epoll_set_max_size()
 
@@ -158,6 +199,17 @@ static inline void lttng_poll_reset(struct lttng_poll_event *events)
        }
 }
 
+/*
+ * Initialize an already allocated poll event data structure. For epoll(), the
+ * epfd is set to -1 to indicate that it's not usable.
+ */
+static inline void lttng_poll_init(struct lttng_poll_event *events)
+{
+       memset(events, 0, sizeof(struct lttng_poll_event));
+       /* Set fd to -1 so if clean before created, we don't close 0. */
+       events->epfd = -1;
+}
+
 /*
  * Clean the events structure of a lttng_poll_event. It's the caller
  * responsability to free the lttng_poll_event memory.
@@ -173,7 +225,7 @@ static inline void lttng_poll_clean(struct lttng_poll_event *events)
        if (events->epfd >= 0) {
                ret = close(events->epfd);
                if (ret) {
-                       perror("close");
+                       PERROR("close");
                }
        }
 
@@ -210,7 +262,7 @@ enum {
 #if __linux__
        LPOLLMSG = POLLMSG,
        LPOLLRDHUP = POLLRDHUP,
-#elif (defined(__FreeBSD__) || defined(__CYGWIN__))
+#elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__))
        LPOLLMSG = 0,
        LPOLLRDHUP = 0,
 #else
@@ -241,8 +293,7 @@ struct compat_poll_event {
         * 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;
 };
@@ -304,10 +355,18 @@ extern int compat_poll_del(struct lttng_poll_event *events, int fd);
 #define lttng_poll_del(events, fd) \
        compat_poll_del(events, fd)
 
+/*
+ * Modify an fd's events in the epoll set.
+ */
+extern int compat_poll_mod(struct lttng_poll_event *events,
+               int fd, uint32_t req_events);
+#define lttng_poll_mod(events, fd, req_events) \
+       compat_poll_mod(events, fd, req_events)
+
 /*
  * Set up the poll set limits variable poll_max_size
  */
-extern void compat_poll_set_max_size(void);
+extern int compat_poll_set_max_size(void);
 #define lttng_poll_set_max_size() \
        compat_poll_set_max_size()
 
@@ -317,6 +376,14 @@ extern void compat_poll_set_max_size(void);
 static inline void lttng_poll_reset(struct lttng_poll_event *events)
 {}
 
+/*
+ * Initialize an already allocated poll event data structure.
+ */
+static inline void lttng_poll_init(struct lttng_poll_event *events)
+{
+       memset(events, 0, sizeof(struct lttng_poll_event));
+}
+
 /*
  * Clean the events structure of a lttng_poll_event. It's the caller
  * responsability to free the lttng_poll_event memory.