libperf: Add perf_evlist__enable/disable test

Add simple perf_evlist enable/disable test together with evlist counter
reading interface.

Committer testing:

  # make -C tools/perf/lib tests
  make: Entering directory '/home/acme/git/perf/tools/perf/lib'
    LINK     test-cpumap-a
    LINK     test-threadmap-a
    LINK     test-evlist-a
    LINK     test-evsel-a
    LINK     test-cpumap-so
    LINK     test-threadmap-so
    LINK     test-evlist-so
    LINK     test-evsel-so
  running static:
  - running test-cpumap.c...OK
  - running test-threadmap.c...OK
  - running test-evlist.c...OK
  - running test-evsel.c...OK
  running dynamic:
  - running test-cpumap.c...OK
  - running test-threadmap.c...OK
  - running test-evlist.c...OK
  - running test-evsel.c...OK
  make: Leaving directory '/home/acme/git/perf/tools/perf/lib'
  #
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190721112506.12306-78-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/lib/tests/test-evlist.c

@@ -111,12 +111,75 @@ static int test_stat_thread(void)
 	return 0;
 }
 
+static int test_stat_thread_enable(void)
+{
+	struct perf_counts_values counts = { .val = 0 };
+	struct perf_thread_map *threads;
+	struct perf_evlist *evlist;
+	struct perf_evsel *evsel;
+	struct perf_event_attr attr1 = {
+		.type	  = PERF_TYPE_SOFTWARE,
+		.config	  = PERF_COUNT_SW_CPU_CLOCK,
+		.disabled = 1,
+	};
+	struct perf_event_attr attr2 = {
+		.type	  = PERF_TYPE_SOFTWARE,
+		.config	  = PERF_COUNT_SW_TASK_CLOCK,
+		.disabled = 1,
+	};
+	int err;
+
+	threads = perf_thread_map__new_dummy();
+	__T("failed to create threads", threads);
+
+	perf_thread_map__set_pid(threads, 0, 0);
+
+	evlist = perf_evlist__new();
+	__T("failed to create evlist", evlist);
+
+	evsel = perf_evsel__new(&attr1);
+	__T("failed to create evsel1", evsel);
+
+	perf_evlist__add(evlist, evsel);
+
+	evsel = perf_evsel__new(&attr2);
+	__T("failed to create evsel2", evsel);
+
+	perf_evlist__add(evlist, evsel);
+
+	perf_evlist__set_maps(evlist, NULL, threads);
+
+	err = perf_evlist__open(evlist);
+	__T("failed to open evsel", err == 0);
+
+	perf_evlist__for_each_evsel(evlist, evsel) {
+		perf_evsel__read(evsel, 0, 0, &counts);
+		__T("failed to read value for evsel", counts.val == 0);
+	}
+
+	perf_evlist__enable(evlist);
+
+	perf_evlist__for_each_evsel(evlist, evsel) {
+		perf_evsel__read(evsel, 0, 0, &counts);
+		__T("failed to read value for evsel", counts.val != 0);
+	}
+
+	perf_evlist__disable(evlist);
+
+	perf_evlist__close(evlist);
+	perf_evlist__delete(evlist);
+
+	perf_thread_map__put(threads);
+	return 0;
+}
+
 int main(int argc, char **argv)
 {
 	__T_START;
 
 	test_stat_cpu();
 	test_stat_thread();
+	test_stat_thread_enable();
 
 	__T_OK;
 	return 0;