rhubarb-lip-sync/lib/webrtc-8d2248ff/webrtc/base/posix.cc

132 lines
3.8 KiB
C++

/*
* Copyright 2004 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "webrtc/base/posix.h"
#include <sys/wait.h>
#include <errno.h>
#include <unistd.h>
#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
#include "webrtc/base/linuxfdwalk.h"
#endif
#include "webrtc/base/logging.h"
namespace rtc {
#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
static void closefds(void *close_errors, int fd) {
if (fd <= 2) {
// We leave stdin/out/err open to the browser's terminal, if any.
return;
}
if (close(fd) < 0) {
*static_cast<bool *>(close_errors) = true;
}
}
#endif
enum {
EXIT_FLAG_CHDIR_ERRORS = 1 << 0,
#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
EXIT_FLAG_FDWALK_ERRORS = 1 << 1,
EXIT_FLAG_CLOSE_ERRORS = 1 << 2,
#endif
EXIT_FLAG_SECOND_FORK_FAILED = 1 << 3,
};
bool RunAsDaemon(const char *file, const char *const argv[]) {
// Fork intermediate child to daemonize.
pid_t pid = fork();
if (pid < 0) {
LOG_ERR(LS_ERROR) << "fork()";
return false;
} else if (!pid) {
// Child.
// We try to close all fds and change directory to /, but if that fails we
// keep going because it's not critical.
int exit_code = 0;
if (chdir("/") < 0) {
exit_code |= EXIT_FLAG_CHDIR_ERRORS;
}
#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
bool close_errors = false;
if (fdwalk(&closefds, &close_errors) < 0) {
exit_code |= EXIT_FLAG_FDWALK_ERRORS;
}
if (close_errors) {
exit_code |= EXIT_FLAG_CLOSE_ERRORS;
}
#endif
// Fork again to become a daemon.
pid = fork();
// It is important that everything here use _exit() and not exit(), because
// exit() would call the destructors of all global variables in the whole
// process, which is both unnecessary and unsafe.
if (pid < 0) {
exit_code |= EXIT_FLAG_SECOND_FORK_FAILED;
_exit(exit_code); // if second fork failed
} else if (!pid) {
// Child.
// Successfully daemonized. Run command.
// WEBRTC_POSIX requires the args to be typed as non-const for historical
// reasons, but it mandates that the actual implementation be const, so
// the cast is safe.
execvp(file, const_cast<char *const *>(argv));
_exit(255); // if execvp failed
}
// Parent.
// Successfully spawned process, but report any problems to the parent where
// we can log them.
_exit(exit_code);
}
// Parent. Reap intermediate child.
int status;
pid_t child = waitpid(pid, &status, 0);
if (child < 0) {
LOG_ERR(LS_ERROR) << "Error in waitpid()";
return false;
}
if (child != pid) {
// Should never happen (see man page).
LOG(LS_ERROR) << "waitpid() chose wrong child???";
return false;
}
if (!WIFEXITED(status)) {
LOG(LS_ERROR) << "Intermediate child killed uncleanly"; // Probably crashed
return false;
}
int exit_code = WEXITSTATUS(status);
if (exit_code & EXIT_FLAG_CHDIR_ERRORS) {
LOG(LS_WARNING) << "Child reported probles calling chdir()";
}
#if defined(WEBRTC_LINUX) && !defined(WEBRTC_ANDROID)
if (exit_code & EXIT_FLAG_FDWALK_ERRORS) {
LOG(LS_WARNING) << "Child reported problems calling fdwalk()";
}
if (exit_code & EXIT_FLAG_CLOSE_ERRORS) {
LOG(LS_WARNING) << "Child reported problems calling close()";
}
#endif
if (exit_code & EXIT_FLAG_SECOND_FORK_FAILED) {
LOG(LS_ERROR) << "Failed to daemonize";
// This means the command was not launched, so failure.
return false;
}
return true;
}
} // namespace rtc