X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fcompat%2Fpoll.h;h=fde54ddb91331c46a28ce75c590b060d338ef845;hp=2cfad9a25fa1c7e0339ff8e810796c58f1b5b552;hb=2a85be8e0e679da996b48252b1d9aebb9bb29126;hpb=d21b0d71990ac6ec4272c1f80f0ca544103628b3

diff --git a/src/common/compat/poll.h b/src/common/compat/poll.h
index 2cfad9a25..fde54ddb9 100644
--- a/src/common/compat/poll.h
+++ b/src/common/compat/poll.h
@@ -18,6 +18,7 @@
 #ifndef _LTT_POLL_H
 #define _LTT_POLL_H
 
+#include <assert.h>
 #include <string.h>
 #include <unistd.h>
 
@@ -42,9 +43,7 @@ extern unsigned int poll_max_size;
  */
 static inline void __lttng_poll_free(void *events)
 {
-	if (events) {
-		free(events);
-	}
+	free(events);
 }
 
 /*
@@ -53,6 +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"
@@ -72,7 +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 {
@@ -84,6 +95,19 @@ struct compat_epoll_event {
 };
 #define lttng_poll_event compat_epoll_event
 
+static inline int __lttng_epoll_get_prev_fd(struct lttng_poll_event *events,
+		int index, uint32_t nb_fd)
+{
+	assert(events);
+	assert(index != nb_fd);
+
+	if (index == 0 || nb_fd == 0) {
+		return -1;
+	} else {
+		return events->events[index - 1].data.fd;
+	}
+}
+
 /*
  * For the following calls, consider 'e' to be a lttng_poll_event pointer and i
  * being the index of the events array.
@@ -92,6 +116,8 @@ struct compat_epoll_event {
 #define LTTNG_POLL_GETEV(e, i) LTTNG_REF(e)->events[i].events
 #define LTTNG_POLL_GETNB(e) LTTNG_REF(e)->nb_fd
 #define LTTNG_POLL_GETSZ(e) LTTNG_REF(e)->events_size
+#define LTTNG_POLL_GET_PREV_FD(e, i, nb_fd) \
+	__lttng_epoll_get_prev_fd(LTTNG_REF(e), i, nb_fd)
 
 /*
  * Create the epoll set. No memory allocation is done here.
@@ -101,6 +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).
@@ -124,10 +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()
 
@@ -144,6 +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.
@@ -152,13 +218,18 @@ static inline void lttng_poll_clean(struct lttng_poll_event *events)
 {
 	int ret;
 
-	if (events) {
+	if (!events) {
+		return;
+	}
+
+	if (events->epfd >= 0) {
 		ret = close(events->epfd);
 		if (ret) {
-			perror("close");
+			PERROR("close");
 		}
-		__lttng_poll_free((void *) events->events);
 	}
+
+	__lttng_poll_free((void *) events->events);
 }
 
 #else	/* HAVE_EPOLL */
@@ -191,7 +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
@@ -222,13 +293,25 @@ 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;
 };
 #define lttng_poll_event compat_poll_event
 
+static inline int __lttng_poll_get_prev_fd(struct lttng_poll_event *events,
+		int index, uint32_t nb_fd)
+{
+	assert(events);
+	assert(index != nb_fd);
+
+	if (index == 0 || nb_fd == 0) {
+		return -1;
+	} else {
+		return events->current.events[index - 1].fd;
+	}
+}
+
 /*
  * For the following calls, consider 'e' to be a lttng_poll_event pointer and i
  * being the index of the events array.
@@ -237,6 +320,8 @@ struct compat_poll_event {
 #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
+#define LTTNG_POLL_GET_PREV_FD(e, i, nb_fd) \
+	__lttng_poll_get_prev_fd(LTTNG_REF(e), i, nb_fd)
 
 /*
  * Create a pollfd structure of size 'size'.
@@ -270,10 +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()
 
@@ -283,6 +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.