linux/tools/perf/util/thread_map.c

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#include <dirent.h>
#include <limits.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include "strlist.h"
#include <string.h>
#include <api/fs/fs.h>
#include "asm/bug.h"
#include "thread_map.h"
#include "util.h"
#include "debug.h"
#include "event.h"
/* Skip "." and ".." directories */
static int filter(const struct dirent *dir)
{
if (dir->d_name[0] == '.')
return 0;
else
return 1;
}
static void thread_map__reset(struct thread_map *map, int start, int nr)
{
size_t size = (nr - start) * sizeof(map->map[0]);
memset(&map->map[start], 0, size);
}
static struct thread_map *thread_map__realloc(struct 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)
thread_map__reset(map, start, nr);
return map;
}
#define thread_map__alloc(__nr) thread_map__realloc(NULL, __nr)
struct thread_map *thread_map__new_by_pid(pid_t pid)
{
struct thread_map *threads;
char name[256];
int items;
struct dirent **namelist = NULL;
int i;
sprintf(name, "/proc/%d/task", pid);
items = scandir(name, &namelist, filter, NULL);
if (items <= 0)
return NULL;
threads = thread_map__alloc(items);
if (threads != NULL) {
for (i = 0; i < items; i++)
thread_map__set_pid(threads, i, atoi(namelist[i]->d_name));
threads->nr = items;
atomic_set(&threads->refcnt, 1);
}
for (i=0; i<items; i++)
zfree(&namelist[i]);
free(namelist);
return threads;
}
struct thread_map *thread_map__new_by_tid(pid_t tid)
{
struct thread_map *threads = thread_map__alloc(1);
if (threads != NULL) {
thread_map__set_pid(threads, 0, tid);
threads->nr = 1;
atomic_set(&threads->refcnt, 1);
}
return threads;
}
struct thread_map *thread_map__new_by_uid(uid_t uid)
{
DIR *proc;
int max_threads = 32, items, i;
char path[256];
struct dirent *dirent, **namelist = NULL;
struct thread_map *threads = thread_map__alloc(max_threads);
if (threads == NULL)
goto out;
proc = opendir("/proc");
if (proc == NULL)
goto out_free_threads;
threads->nr = 0;
atomic_set(&threads->refcnt, 1);
while ((dirent = readdir(proc)) != NULL) {
char *end;
bool grow = false;
struct stat st;
pid_t pid = strtol(dirent->d_name, &end, 10);
if (*end) /* only interested in proper numerical dirents */
continue;
snprintf(path, sizeof(path), "/proc/%s", dirent->d_name);
if (stat(path, &st) != 0)
continue;
if (st.st_uid != uid)
continue;
snprintf(path, sizeof(path), "/proc/%d/task", pid);
items = scandir(path, &namelist, filter, NULL);
if (items <= 0)
goto out_free_closedir;
while (threads->nr + items >= max_threads) {
max_threads *= 2;
grow = true;
}
if (grow) {
struct thread_map *tmp;
tmp = thread_map__realloc(threads, max_threads);
if (tmp == NULL)
goto out_free_namelist;
threads = tmp;
}
for (i = 0; i < items; i++) {
thread_map__set_pid(threads, threads->nr + i,
atoi(namelist[i]->d_name));
}
for (i = 0; i < items; i++)
zfree(&namelist[i]);
free(namelist);
threads->nr += items;
}
out_closedir:
closedir(proc);
out:
return threads;
out_free_threads:
free(threads);
return NULL;
out_free_namelist:
for (i = 0; i < items; i++)
zfree(&namelist[i]);
free(namelist);
out_free_closedir:
zfree(&threads);
goto out_closedir;
}
struct thread_map *thread_map__new(pid_t pid, pid_t tid, uid_t uid)
{
if (pid != -1)
return thread_map__new_by_pid(pid);
if (tid == -1 && uid != UINT_MAX)
return thread_map__new_by_uid(uid);
return thread_map__new_by_tid(tid);
}
static struct thread_map *thread_map__new_by_pid_str(const char *pid_str)
{
struct thread_map *threads = NULL, *nt;
char name[256];
int items, total_tasks = 0;
struct dirent **namelist = NULL;
int i, j = 0;
pid_t pid, prev_pid = INT_MAX;
char *end_ptr;
struct str_node *pos;
struct strlist_config slist_config = { .dont_dupstr = true, };
struct strlist *slist = strlist__new(pid_str, &slist_config);
if (!slist)
return NULL;
strlist__for_each_entry(pos, slist) {
pid = strtol(pos->s, &end_ptr, 10);
if (pid == INT_MIN || pid == INT_MAX ||
(*end_ptr != '\0' && *end_ptr != ','))
goto out_free_threads;
if (pid == prev_pid)
continue;
sprintf(name, "/proc/%d/task", pid);
items = scandir(name, &namelist, filter, NULL);
if (items <= 0)
goto out_free_threads;
total_tasks += items;
nt = thread_map__realloc(threads, total_tasks);
if (nt == NULL)
goto out_free_namelist;
threads = nt;
for (i = 0; i < items; i++) {
thread_map__set_pid(threads, j++, atoi(namelist[i]->d_name));
zfree(&namelist[i]);
}
threads->nr = total_tasks;
free(namelist);
}
out:
strlist__delete(slist);
if (threads)
atomic_set(&threads->refcnt, 1);
return threads;
out_free_namelist:
for (i = 0; i < items; i++)
zfree(&namelist[i]);
free(namelist);
out_free_threads:
zfree(&threads);
goto out;
}
struct thread_map *thread_map__new_dummy(void)
{
struct thread_map *threads = thread_map__alloc(1);
if (threads != NULL) {
thread_map__set_pid(threads, 0, -1);
threads->nr = 1;
atomic_set(&threads->refcnt, 1);
}
return threads;
}
struct thread_map *thread_map__new_by_tid_str(const char *tid_str)
{
struct thread_map *threads = NULL, *nt;
int ntasks = 0;
pid_t tid, prev_tid = INT_MAX;
char *end_ptr;
struct str_node *pos;
struct strlist_config slist_config = { .dont_dupstr = true, };
struct strlist *slist;
/* perf-stat expects threads to be generated even if tid not given */
if (!tid_str)
return thread_map__new_dummy();
slist = strlist__new(tid_str, &slist_config);
if (!slist)
return NULL;
strlist__for_each_entry(pos, slist) {
tid = strtol(pos->s, &end_ptr, 10);
if (tid == INT_MIN || tid == INT_MAX ||
(*end_ptr != '\0' && *end_ptr != ','))
goto out_free_threads;
if (tid == prev_tid)
continue;
ntasks++;
nt = thread_map__realloc(threads, ntasks);
if (nt == NULL)
goto out_free_threads;
threads = nt;
thread_map__set_pid(threads, ntasks - 1, tid);
threads->nr = ntasks;
}
out:
if (threads)
atomic_set(&threads->refcnt, 1);
return threads;
out_free_threads:
zfree(&threads);
strlist__delete(slist);
goto out;
}
struct thread_map *thread_map__new_str(const char *pid, const char *tid,
uid_t uid)
{
if (pid)
return thread_map__new_by_pid_str(pid);
if (!tid && uid != UINT_MAX)
return thread_map__new_by_uid(uid);
return thread_map__new_by_tid_str(tid);
}
static void thread_map__delete(struct thread_map *threads)
{
if (threads) {
int i;
WARN_ONCE(atomic_read(&threads->refcnt) != 0,
"thread map refcnt unbalanced\n");
for (i = 0; i < threads->nr; i++)
free(thread_map__comm(threads, i));
free(threads);
}
}
struct thread_map *thread_map__get(struct thread_map *map)
{
if (map)
atomic_inc(&map->refcnt);
return map;
}
void thread_map__put(struct thread_map *map)
{
if (map && atomic_dec_and_test(&map->refcnt))
thread_map__delete(map);
}
size_t thread_map__fprintf(struct thread_map *threads, FILE *fp)
{
int i;
size_t printed = fprintf(fp, "%d thread%s: ",
threads->nr, threads->nr > 1 ? "s" : "");
for (i = 0; i < threads->nr; ++i)
printed += fprintf(fp, "%s%d", i ? ", " : "", thread_map__pid(threads, i));
return printed + fprintf(fp, "\n");
}
static int get_comm(char **comm, pid_t pid)
{
char *path;
size_t size;
int err;
if (asprintf(&path, "%s/%d/comm", procfs__mountpoint(), pid) == -1)
return -ENOMEM;
err = filename__read_str(path, comm, &size);
if (!err) {
/*
* We're reading 16 bytes, while filename__read_str
* allocates data per BUFSIZ bytes, so we can safely
* mark the end of the string.
*/
(*comm)[size] = 0;
rtrim(*comm);
}
free(path);
return err;
}
static void comm_init(struct thread_map *map, int i)
{
pid_t pid = thread_map__pid(map, i);
char *comm = NULL;
/* dummy pid comm initialization */
if (pid == -1) {
map->map[i].comm = strdup("dummy");
return;
}
/*
* The comm name is like extra bonus ;-),
* so just warn if we fail for any reason.
*/
if (get_comm(&comm, pid))
pr_warning("Couldn't resolve comm name for pid %d\n", pid);
map->map[i].comm = comm;
}
void thread_map__read_comms(struct thread_map *threads)
{
int i;
for (i = 0; i < threads->nr; ++i)
comm_init(threads, i);
}
static void thread_map__copy_event(struct thread_map *threads,
struct thread_map_event *event)
{
unsigned i;
threads->nr = (int) event->nr;
for (i = 0; i < event->nr; i++) {
thread_map__set_pid(threads, i, (pid_t) event->entries[i].pid);
threads->map[i].comm = strndup(event->entries[i].comm, 16);
}
atomic_set(&threads->refcnt, 1);
}
struct thread_map *thread_map__new_event(struct thread_map_event *event)
{
struct thread_map *threads;
threads = thread_map__alloc(event->nr);
if (threads)
thread_map__copy_event(threads, event);
return threads;
}
bool thread_map__has(struct thread_map *threads, pid_t pid)
{
int i;
for (i = 0; i < threads->nr; ++i) {
if (threads->map[i].pid == pid)
return true;
}
return false;
}