libperf: Add API for allocating new thread map array

The existing API perf_thread_map__new_dummy() allocates new thread map
for one thread. I couldn't find a way to reallocate the map with more
threads, or to allocate a new map for more than one thread.

Having multiple threads in a thread map is essential for some use cases.
That's why a new API is proposed, which allocates a new thread map for
given number of threads: perf_thread_map__new_array()

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/linux-perf-users/20220221102628.43904-1-tz.stoyanov@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 41 insertions, 0 deletions

diff --git a/tools/lib/perf/tests/test-threadmap.c b/tools/lib/perf/tests/test-threadmap.c
index 5e2a0291e94c..f728ad7002bb 100644
--- a/tools/lib/perf/tests/test-threadmap.c
+++ b/tools/lib/perf/tests/test-threadmap.c
@@ -11,9 +11,43 @@ static int libperf_print(enum libperf_print_level level,
 	return vfprintf(stderr, fmt, ap);
 }
 
+static int test_threadmap_array(int nr, pid_t *array)
+{
+	struct perf_thread_map *threads;
+	int i;
+
+	threads = perf_thread_map__new_array(nr, array);
+	__T("Failed to allocate new thread map", threads);
+
+	__T("Unexpected number of threads", perf_thread_map__nr(threads) == nr);
+
+	for (i = 0; i < nr; i++) {
+		__T("Unexpected initial value of thread",
+		    perf_thread_map__pid(threads, i) == (array ? array[i] : -1));
+	}
+
+	for (i = 1; i < nr; i++)
+		perf_thread_map__set_pid(threads, i, i * 100);
+
+	__T("Unexpected value of thread 0",
+	    perf_thread_map__pid(threads, 0) == (array ? array[0] : -1));
+
+	for (i = 1; i < nr; i++) {
+		__T("Unexpected thread value",
+		    perf_thread_map__pid(threads, i) == i * 100);
+	}
+
+	perf_thread_map__put(threads);
+
+	return 0;
+}
+
+#define THREADS_NR	10
 int test_threadmap(int argc, char **argv)
 {
 	struct perf_thread_map *threads;
+	pid_t thr_array[THREADS_NR];
+	int i;
 
 	__T_START;
 
@@ -27,6 +61,13 @@ int test_threadmap(int argc, char **argv)
 	perf_thread_map__put(threads);
 	perf_thread_map__put(threads);
 
+	test_threadmap_array(THREADS_NR, NULL);
+
+	for (i = 0; i < THREADS_NR; i++)
+		thr_array[i] = i + 100;
+
+	test_threadmap_array(THREADS_NR, thr_array);
+
 	__T_END;
 	return tests_failed == 0 ? 0 : -1;
 }