git.m6w6.name Git - awesomized/libmemcached/blob - testing/lib/ForkAndExec.cpp

   1 #include "ForkAndExec.hpp"
   2
   3 #include <cerrno>
   4 #include <cstdio>
   5
   6 #include <fcntl.h>
   7 #include <sys/poll.h>
   8 #include <unistd.h>
   9
  10 ForkAndExec::ForkAndExec(const char *binary_, char **argv_)
  11 : binary{binary_}
  12 , argv{argv_}
  13 {
  14   if (pipe2(pipes, O_CLOEXEC|O_NONBLOCK)) {
  15     int error = errno;
  16     perror("Server::start pipe2()");
  17     throw system_error(error, system_category());
  18   }
  19 }
  20
  21 ForkAndExec::~ForkAndExec() {
  22   if (pipes[0] != -1) {
  23     close(pipes[0]);
  24   }
  25   if (pipes[1] != -1) {
  26     close(pipes[1]);
  27   }
  28 }
  29
  30 optional<pid_t> ForkAndExec::operator()()  {
  31   if (pipes[0] == -1) {
  32     return {};
  33   }
  34   if (pipes[1] != -1) {
  35     close(pipes[1]);
  36     pipes[1] = -1;
  37   }
  38
  39   switch (pid_t pid = fork()) {
  40     case 0:
  41       execvp(binary, argv);
  42       [[fallthrough]];
  43     case -1:
  44       perror("fork() && exec()");
  45       return {};
  46
  47     default:
  48       pollfd fd{pipes[0], 0, 0};
  49       if (1 > poll(&fd, 1, 5000)) {
  50         cerr << "exec() timed out" << endl;
  51       }
  52       return pid;
  53   }
  54 }