1 //===-- ExecuteFunction implementation for Unix-like Systems --------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "ExecuteFunction.h" 10 #include <cassert> 11 #include <cstdlib> 12 #include <cstring> 13 #include <iostream> 14 #include <memory> 15 #include <poll.h> 16 #include <signal.h> 17 #include <sys/wait.h> 18 #include <unistd.h> 19 20 namespace __llvm_libc { 21 namespace testutils { 22 23 bool ProcessStatus::exited_normally() { return WIFEXITED(platform_defined); } 24 25 int ProcessStatus::get_exit_code() { 26 assert(exited_normally() && "Abnormal termination, no exit code"); 27 return WEXITSTATUS(platform_defined); 28 } 29 30 int ProcessStatus::get_fatal_signal() { 31 if (exited_normally()) 32 return 0; 33 return WTERMSIG(platform_defined); 34 } 35 36 ProcessStatus invoke_in_subprocess(FunctionCaller *func, unsigned timeout_ms) { 37 std::unique_ptr<FunctionCaller> X(func); 38 int pipe_fds[2]; 39 if (::pipe(pipe_fds) == -1) 40 return ProcessStatus::error("pipe(2) failed"); 41 42 // Don't copy the buffers into the child process and print twice. 43 std::cout.flush(); 44 std::cerr.flush(); 45 pid_t pid = ::fork(); 46 if (pid == -1) 47 return ProcessStatus::error("fork(2) failed"); 48 49 if (!pid) { 50 (*func)(); 51 std::exit(0); 52 } 53 ::close(pipe_fds[1]); 54 55 struct pollfd poll_fd { 56 pipe_fds[0], 0, 0 57 }; 58 // No events requested so this call will only return after the timeout or if 59 // the pipes peer was closed, signaling the process exited. 60 if (::poll(&poll_fd, 1, timeout_ms) == -1) 61 return ProcessStatus::error("poll(2) failed"); 62 // If the pipe wasn't closed by the child yet then timeout has expired. 63 if (!(poll_fd.revents & POLLHUP)) { 64 ::kill(pid, SIGKILL); 65 return ProcessStatus::timed_out_ps(); 66 } 67 68 int wstatus = 0; 69 // Wait on the pid of the subprocess here so it gets collected by the system 70 // and doesn't turn into a zombie. 71 pid_t status = ::waitpid(pid, &wstatus, 0); 72 if (status == -1) 73 return ProcessStatus::error("waitpid(2) failed"); 74 assert(status == pid); 75 return {wstatus}; 76 } 77 78 const char *signal_as_string(int signum) { return ::strsignal(signum); } 79 80 } // namespace testutils 81 } // namespace __llvm_libc 82