[PATCH v2 5/8] libperf: Add perf_evsel__has_fd() functions

[Charlie Jenkins <charlie@xxxxxxxxxxxx>]

From: Shunsuke Nakamura <nakamura.shun@xxxxxxxxxxx>

Add the following functions:

  perf_evsel__has_fd

to check for perf events with the file descriptor specified in the
argument.
This function can be used in signal handlers to check overflow.

Signed-off-by: Shunsuke Nakamura <nakamura.shun@xxxxxxxxxxx>
Signed-off-by: Charlie Jenkins <charlie@xxxxxxxxxxxx>
---
 tools/lib/perf/Documentation/libperf.txt |  1 +
 tools/lib/perf/evsel.c                   | 18 ++++++++++++++++++
 tools/lib/perf/include/perf/evsel.h      |  1 +
 tools/lib/perf/libperf.map               |  1 +
 4 files changed, 21 insertions(+)

diff --git a/tools/lib/perf/Documentation/libperf.txt b/tools/lib/perf/Documentation/libperf.txt
index bb99534d5855..f1bfe6b6e78a 100644
--- a/tools/lib/perf/Documentation/libperf.txt
+++ b/tools/lib/perf/Documentation/libperf.txt
@@ -161,6 +161,7 @@ SYNOPSIS
   int perf_evsel__enable_cpu(struct perf_evsel *evsel, int cpu_map_idx);
   int perf_evsel__disable(struct perf_evsel *evsel);
   int perf_evsel__disable_cpu(struct perf_evsel *evsel, int cpu_map_idx);
+  bool perf_evsel__has_fd(struct perf_evsel *evsel, int fd);
   struct perf_cpu_map *perf_evsel__cpus(struct perf_evsel *evsel);
   struct perf_thread_map *perf_evsel__threads(struct perf_evsel *evsel);
   struct perf_event_attr *perf_evsel__attr(struct perf_evsel *evsel);
diff --git a/tools/lib/perf/evsel.c b/tools/lib/perf/evsel.c
index 17d3d9a88c23..6b98cba6eb4f 100644
--- a/tools/lib/perf/evsel.c
+++ b/tools/lib/perf/evsel.c
@@ -658,3 +658,21 @@ int perf_evsel__open_opts(struct perf_evsel *evsel, struct perf_cpu_map *cpus,
 
 	return err;
 }
+
+bool perf_evsel__has_fd(struct perf_evsel *evsel, int fd)
+{
+	int cpu_map_idx;
+	int thread;
+	int *evsel_fd;
+
+	for (cpu_map_idx = 0; cpu_map_idx < xyarray__max_x(evsel->fd); ++cpu_map_idx) {
+		for (thread = 0; thread < xyarray__max_y(evsel->fd); ++thread) {
+			evsel_fd = FD(evsel, cpu_map_idx, thread);
+
+			if (fd == *evsel_fd)
+				return true;
+		}
+	}
+
+	return false;
+}
diff --git a/tools/lib/perf/include/perf/evsel.h b/tools/lib/perf/include/perf/evsel.h
index 344808f23371..77816a35c383 100644
--- a/tools/lib/perf/include/perf/evsel.h
+++ b/tools/lib/perf/include/perf/evsel.h
@@ -73,5 +73,6 @@ LIBPERF_API int perf_evsel__open_opts(struct perf_evsel *evsel,
 				      struct perf_cpu_map *cpus,
 				      struct perf_thread_map *threads,
 				      struct perf_evsel_open_opts *opts);
+LIBPERF_API bool perf_evsel__has_fd(struct perf_evsel *evsel, int fd);
 
 #endif /* __LIBPERF_EVSEL_H */
diff --git a/tools/lib/perf/libperf.map b/tools/lib/perf/libperf.map
index 84fed76621cb..f68519e17885 100644
--- a/tools/lib/perf/libperf.map
+++ b/tools/lib/perf/libperf.map
@@ -38,6 +38,7 @@ LIBPERF_0.0.1 {
 		perf_evsel__cpus;
 		perf_evsel__threads;
 		perf_evsel__attr;
+		perf_evsel__has_fd;
 		perf_evlist__new;
 		perf_evlist__delete;
 		perf_evlist__open;

-- 
2.44.0