platform_bionic/libc/bionic/pthread_setname_np.cpp
Elliott Hughes bcb152903a Revert "Stop checking the global thread list in several trivial cases."
This reverts commit f5a4992b71.

Breaks OMX_ImgEnc in cameraserver (http://b/35088254).

Change-Id: I6dcf12706a184b0b8b72451584567a42dfa1bb4f
2017-02-07 21:05:30 +00:00

109 lines
3.4 KiB
C++

/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <pthread.h>
#include <fcntl.h>
#include <stdio.h> // For snprintf.
#include <string.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "private/ErrnoRestorer.h"
#include "pthread_internal.h"
// This value is not exported by kernel headers.
#define MAX_TASK_COMM_LEN 16
static int __open_task_comm_fd(pthread_t t, int flags) {
pthread_internal_t* thread = __pthread_internal_find(t);
if (thread == nullptr) {
errno = ENOENT;
return -1;
}
char comm_name[64];
snprintf(comm_name, sizeof(comm_name), "/proc/self/task/%d/comm", thread->tid);
return open(comm_name, O_CLOEXEC | flags);
}
int pthread_getname_np(pthread_t t, char* buf, size_t buf_size) {
ErrnoRestorer errno_restorer;
if (buf_size < MAX_TASK_COMM_LEN) return ERANGE;
// Getting our own name is an easy special case.
if (t == pthread_self()) {
return prctl(PR_GET_NAME, buf) ? errno : 0;
}
// We have to get another thread's name.
int fd = __open_task_comm_fd(t, O_RDONLY);
if (fd == -1) return errno;
ssize_t n = TEMP_FAILURE_RETRY(read(fd, buf, buf_size));
close(fd);
if (n == -1) return errno;
// The kernel adds a trailing '\n' to the /proc file,
// so this is actually the normal case for short names.
if (n > 0 && buf[n - 1] == '\n') {
buf[n - 1] = '\0';
return 0;
}
if (n == static_cast<ssize_t>(buf_size)) return ERANGE;
buf[n] = '\0';
return 0;
}
int pthread_setname_np(pthread_t t, const char* thread_name) {
ErrnoRestorer errno_restorer;
size_t thread_name_len = strlen(thread_name);
if (thread_name_len >= MAX_TASK_COMM_LEN) return ERANGE;
// Setting our own name is an easy special case.
if (t == pthread_self()) {
return prctl(PR_SET_NAME, thread_name) ? errno : 0;
}
// We have to set another thread's name.
int fd = __open_task_comm_fd(t, O_WRONLY);
if (fd == -1) return errno;
ssize_t n = TEMP_FAILURE_RETRY(write(fd, thread_name, thread_name_len));
close(fd);
if (n == -1) return errno;
if (n != static_cast<ssize_t>(thread_name_len)) return EIO;
return 0;
}