X-Git-Url: http://git.lttng.org/?p=ust.git;a=blobdiff_plain;f=libustcomm%2Fmultipoll.c;fp=libustcomm%2Fmultipoll.c;h=1210b93dd9d3714ddcb7e9dd17ce2741c2927aa0;hp=1ac51a58bfacbcbde590acffce61ea95d30a06a7;hb=93e5ce29599beb7b32858b3074b8433dfffdab34;hpb=223f2e7ce070406f507856fa8f0de508d8a05ad3

diff --git a/libustcomm/multipoll.c b/libustcomm/multipoll.c
index 1ac51a5..1210b93 100644
--- a/libustcomm/multipoll.c
+++ b/libustcomm/multipoll.c
@@ -18,6 +18,10 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  */
 
+/* Multipoll is a framework to poll on several file descriptors and to call
+ * a specific callback depending on the fd that had activity.
+ */
+
 #include <poll.h>
 #include <stdlib.h>
 #include "multipoll.h"
@@ -25,6 +29,11 @@
 
 #define INITIAL_N_AVAIL 16
 
+/* multipoll_init
+ *
+ * Initialize an mpentries struct, which is initially empty of any fd.
+ */
+
 int multipoll_init(struct mpentries *ent)
 {
 	ent->n_used = 0;
@@ -36,6 +45,9 @@ int multipoll_init(struct mpentries *ent)
 	return 0;
 }
 
+/* multipoll_destroy: free a struct mpentries
+ */
+
 int multipoll_destroy(struct mpentries *ent)
 {
 	int i;
@@ -52,6 +64,19 @@ int multipoll_destroy(struct mpentries *ent)
 	return 0;
 }
 
+/* multipoll_add
+ *
+ * Add a file descriptor to be waited on in a struct mpentries.
+ *
+ * @ent: the struct mpentries to add an fd to
+ * @fd: the fd to wait on
+ * @events: a mask of the types of events to wait on, see the poll(2) man page
+ * @func: the callback function to be called if there is activity on the fd
+ * @priv: the private pointer to pass to func
+ * @destroy_priv: a callback to destroy the priv pointer when the mpentries
+                  is destroyed; may be NULL
+ */
+
 int multipoll_add(struct mpentries *ent, int fd, short events, int (*func)(void *priv, int fd, short events), void *priv, int (*destroy_priv)(void *))
 {
 	int cur;
@@ -74,6 +99,16 @@ int multipoll_add(struct mpentries *ent, int fd, short events, int (*func)(void
 	return 0;
 }
 
+/* multipoll_poll: do the actual poll on a struct mpentries
+ *
+ * File descriptors should have been already added with multipoll_add().
+ *
+ * A struct mpentries may be reused for multiple multipoll_poll calls.
+ *
+ * @ent: the struct mpentries to poll on.
+ * @timeout: the timeout after which to return if there was no activity.
+ */
+
 int multipoll_poll(struct mpentries *ent, int timeout)
 {
 	int result;