libperf: Adopt perf_evlist__filter_pollfd() from tools/perf

Introduce the perf_evlist__filter_pollfd function and export it in the
perf/evlist.h header, so that libperf users can check if the descriptor
is still alive.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20191007125344.14268-27-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/lib/evlist.c

@@ -313,6 +313,21 @@ int perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd,
 	return pos;
 }
 
+static void perf_evlist__munmap_filtered(struct fdarray *fda, int fd,
+					 void *arg __maybe_unused)
+{
+	struct perf_mmap *map = fda->priv[fd].ptr;
+
+	if (map)
+		perf_mmap__put(map);
+}
+
+int perf_evlist__filter_pollfd(struct perf_evlist *evlist, short revents_and_mask)
+{
+	return fdarray__filter(&evlist->pollfd, revents_and_mask,
+			       perf_evlist__munmap_filtered, NULL);
+}
+
 int perf_evlist__poll(struct perf_evlist *evlist, int timeout)
 {
 	return fdarray__poll(&evlist->pollfd, timeout);

tools/perf/lib/include/perf/evlist.h

@@ -32,6 +32,8 @@ LIBPERF_API void perf_evlist__set_maps(struct perf_evlist *evlist,
 				       struct perf_cpu_map *cpus,
 				       struct perf_thread_map *threads);
 LIBPERF_API int perf_evlist__poll(struct perf_evlist *evlist, int timeout);
+LIBPERF_API int perf_evlist__filter_pollfd(struct perf_evlist *evlist,
+					   short revents_and_mask);
 
 LIBPERF_API int perf_evlist__mmap(struct perf_evlist *evlist, int pages);
 LIBPERF_API void perf_evlist__munmap(struct perf_evlist *evlist);

tools/perf/lib/libperf.map

@@ -42,6 +42,7 @@ LIBPERF_0.0.1 {
 		perf_evlist__poll;
 		perf_evlist__mmap;
 		perf_evlist__munmap;
+		perf_evlist__filter_pollfd;
 		perf_mmap__consume;
 		perf_mmap__read_init;
 		perf_mmap__read_done;

tools/perf/util/evlist.c

@@ -423,19 +423,9 @@ int evlist__add_pollfd(struct evlist *evlist, int fd)
 	return perf_evlist__add_pollfd(&evlist->core, fd, NULL, POLLIN);
 }
 
-static void perf_evlist__munmap_filtered(struct fdarray *fda, int fd,
-					 void *arg __maybe_unused)
-{
-	struct perf_mmap *map = fda->priv[fd].ptr;
-
-	if (map)
-		perf_mmap__put(map);
-}
-
 int evlist__filter_pollfd(struct evlist *evlist, short revents_and_mask)
 {
-	return fdarray__filter(&evlist->core.pollfd, revents_and_mask,
-			       perf_evlist__munmap_filtered, NULL);
+	return perf_evlist__filter_pollfd(&evlist->core, revents_and_mask);
 }
 
 int evlist__poll(struct evlist *evlist, int timeout)