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linux/tools/lib/perf/threadmap.c
Tzvetomir Stoyanov (VMware) 56dce86819 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>
2022-02-23 14:40:23 -03:00

102 lines
2.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <perf/threadmap.h>
#include <stdlib.h>
#include <linux/refcount.h>
#include <internal/threadmap.h>
#include <string.h>
#include <asm/bug.h>
#include <stdio.h>
static void perf_thread_map__reset(struct perf_thread_map *map, int start, int nr)
{
size_t size = (nr - start) * sizeof(map->map[0]);
memset(&map->map[start], 0, size);
map->err_thread = -1;
}
struct perf_thread_map *perf_thread_map__realloc(struct perf_thread_map *map, int nr)
{
size_t size = sizeof(*map) + sizeof(map->map[0]) * nr;
int start = map ? map->nr : 0;
map = realloc(map, size);
/*
* We only realloc to add more items, let's reset new items.
*/
if (map)
perf_thread_map__reset(map, start, nr);
return map;
}
#define thread_map__alloc(__nr) perf_thread_map__realloc(NULL, __nr)
void perf_thread_map__set_pid(struct perf_thread_map *map, int idx, pid_t pid)
{
map->map[idx].pid = pid;
}
char *perf_thread_map__comm(struct perf_thread_map *map, int idx)
{
return map->map[idx].comm;
}
struct perf_thread_map *perf_thread_map__new_array(int nr_threads, pid_t *array)
{
struct perf_thread_map *threads = thread_map__alloc(nr_threads);
int i;
if (!threads)
return NULL;
for (i = 0; i < nr_threads; i++)
perf_thread_map__set_pid(threads, i, array ? array[i] : -1);
threads->nr = nr_threads;
refcount_set(&threads->refcnt, 1);
return threads;
}
struct perf_thread_map *perf_thread_map__new_dummy(void)
{
return perf_thread_map__new_array(1, NULL);
}
static void perf_thread_map__delete(struct perf_thread_map *threads)
{
if (threads) {
int i;
WARN_ONCE(refcount_read(&threads->refcnt) != 0,
"thread map refcnt unbalanced\n");
for (i = 0; i < threads->nr; i++)
free(perf_thread_map__comm(threads, i));
free(threads);
}
}
struct perf_thread_map *perf_thread_map__get(struct perf_thread_map *map)
{
if (map)
refcount_inc(&map->refcnt);
return map;
}
void perf_thread_map__put(struct perf_thread_map *map)
{
if (map && refcount_dec_and_test(&map->refcnt))
perf_thread_map__delete(map);
}
int perf_thread_map__nr(struct perf_thread_map *threads)
{
return threads ? threads->nr : 1;
}
pid_t perf_thread_map__pid(struct perf_thread_map *map, int idx)
{
return map->map[idx].pid;
}