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/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "workload.h"
#include <errno.h>
#include <fcntl.h>
#include <sched.h>
#include <sys/prctl.h>
#include <sys/wait.h>
#include <unistd.h>
#include <android-base/logging.h>
#include <android-base/strings.h>
#include "environment.h"
namespace simpleperf {
std::unique_ptr<Workload> Workload::CreateWorkload(const std::vector<std::string>& args) {
#if defined(__ANDROID__)
if (IsInAppUid()) {
LOG(ERROR) << "Running child command in app uid isn't allowed.";
return nullptr;
}
#endif
std::unique_ptr<Workload> workload(new Workload(args, std::function<void()>()));
if (workload != nullptr && workload->CreateNewProcess()) {
return workload;
}
return nullptr;
}
std::unique_ptr<Workload> Workload::CreateWorkload(const std::function<void()>& function) {
std::unique_ptr<Workload> workload(new Workload(std::vector<std::string>(), function));
if (workload != nullptr && workload->CreateNewProcess()) {
return workload;
}
return nullptr;
}
bool Workload::RunCmd(const std::vector<std::string>& args, bool report_error) {
std::string arg_str = android::base::Join(args, ' ');
int ret = system(arg_str.c_str());
if (ret != 0 && report_error) {
LOG(ERROR) << "Failed to run cmd " << arg_str << ", exitcode " << ret;
return false;
}
return ret == 0;
}
Workload::Workload(const std::vector<std::string>& args, const std::function<void()>& function)
: work_state_(NotYetCreateNewProcess),
child_proc_args_(args),
child_proc_function_(function),
work_pid_(-1),
start_signal_fd_(-1),
exec_child_fd_(-1) {
kill_function_ = [](pid_t pid) { kill(pid, SIGKILL); };
}
Workload::~Workload() {
if (work_pid_ != -1 && work_state_ != NotYetCreateNewProcess) {
if (!Workload::WaitChildProcess(false, false, nullptr)) {
kill_function_(work_pid_);
Workload::WaitChildProcess(true, true, nullptr);
}
}
if (start_signal_fd_ != -1) {
close(start_signal_fd_);
}
if (exec_child_fd_ != -1) {
close(exec_child_fd_);
}
}
bool Workload::CreateNewProcess() {
CHECK_EQ(work_state_, NotYetCreateNewProcess);
int start_signal_pipe[2];
if (pipe2(start_signal_pipe, O_CLOEXEC) != 0) {
PLOG(ERROR) << "pipe2() failed";
return false;
}
int exec_child_pipe[2];
if (pipe2(exec_child_pipe, O_CLOEXEC) != 0) {
PLOG(ERROR) << "pipe2() failed";
close(start_signal_pipe[0]);
close(start_signal_pipe[1]);
return false;
}
pid_t pid = fork();
if (pid == -1) {
PLOG(ERROR) << "fork() failed";
close(start_signal_pipe[0]);
close(start_signal_pipe[1]);
close(exec_child_pipe[0]);
close(exec_child_pipe[1]);
return false;
} else if (pid == 0) {
// In child process.
close(start_signal_pipe[1]);
close(exec_child_pipe[0]);
ChildProcessFn(start_signal_pipe[0], exec_child_pipe[1]);
_exit(0);
}
// In parent process.
close(start_signal_pipe[0]);
close(exec_child_pipe[1]);
start_signal_fd_ = start_signal_pipe[1];
exec_child_fd_ = exec_child_pipe[0];
work_pid_ = pid;
work_state_ = NotYetStartNewProcess;
return true;
}
void Workload::ChildProcessFn(int start_signal_fd, int exec_child_fd) {
// Die if parent exits.
prctl(PR_SET_PDEATHSIG, SIGHUP, 0, 0, 0);
char start_signal = 0;
ssize_t nread = TEMP_FAILURE_RETRY(read(start_signal_fd, &start_signal, 1));
if (nread == 1 && start_signal == 1) {
close(start_signal_fd);
if (child_proc_function_) {
close(exec_child_fd);
child_proc_function_();
} else {
char* argv[child_proc_args_.size() + 1];
for (size_t i = 0; i < child_proc_args_.size(); ++i) {
argv[i] = &child_proc_args_[i][0];
}
argv[child_proc_args_.size()] = nullptr;
execvp(argv[0], argv);
// If execvp() succeed, we will not arrive here. But if it failed, we need to
// report the failure to the parent process by writing 1 to exec_child_fd.
int saved_errno = errno;
char exec_child_failed = 1;
TEMP_FAILURE_RETRY(write(exec_child_fd, &exec_child_failed, 1));
close(exec_child_fd);
errno = saved_errno;
PLOG(ERROR) << "child process failed to execvp(" << argv[0] << ")";
}
} else {
PLOG(ERROR) << "child process failed to receive start_signal, nread = " << nread;
}
}
bool Workload::SetCpuAffinity(int cpu) {
CHECK_EQ(work_state_, NotYetStartNewProcess);
cpu_set_t mask;
CPU_ZERO(&mask);
CPU_SET(cpu, &mask);
if (sched_setaffinity(GetPid(), sizeof(mask), &mask) != 0) {
PLOG(WARNING) << "sched_setaffinity failed";
return false;
}
return true;
}
bool Workload::Start() {
CHECK_EQ(work_state_, NotYetStartNewProcess);
char start_signal = 1;
ssize_t nwrite = TEMP_FAILURE_RETRY(write(start_signal_fd_, &start_signal, 1));
if (nwrite != 1) {
PLOG(ERROR) << "write start signal failed";
return false;
}
char exec_child_failed;
ssize_t nread = TEMP_FAILURE_RETRY(read(exec_child_fd_, &exec_child_failed, 1));
if (nread != 0) {
if (nread == -1) {
PLOG(ERROR) << "failed to receive error message from child process";
} else {
LOG(ERROR) << "received error message from child process";
}
return false;
}
work_state_ = Started;
return true;
}
bool Workload::WaitChildProcess(bool wait_forever, int* exit_code) {
return WaitChildProcess(wait_forever, false, exit_code);
}
bool Workload::WaitChildProcess(bool wait_forever, bool is_child_killed, int* exit_code) {
if (work_state_ == Finished) {
return true;
}
bool finished = false;
int status;
pid_t result = TEMP_FAILURE_RETRY(waitpid(work_pid_, &status, (wait_forever ? 0 : WNOHANG)));
if (result == work_pid_) {
finished = true;
work_state_ = Finished;
if (WIFSIGNALED(status)) {
if (!(is_child_killed && WTERMSIG(status) == SIGKILL)) {
LOG(WARNING) << "child process was terminated by signal " << strsignal(WTERMSIG(status));
}
} else if (WIFEXITED(status)) {
if (exit_code != nullptr) {
*exit_code = WEXITSTATUS(status);
} else if (WEXITSTATUS(status) != 0) {
LOG(WARNING) << "child process exited with exit code " << WEXITSTATUS(status);
}
}
} else if (result == -1) {
PLOG(ERROR) << "waitpid() failed";
}
return finished;
}
} // namespace simpleperf
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