FEX-Emu--FEX/Source/Tools/FEXServer/PipeScanner.cpp

// SPDX-License-Identifier: MIT
#include <cstdlib>
#include <dirent.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <vector>

namespace PipeScanner {
  std::vector<int> IncomingPipes{};

  // Scan and store any pipe files.
  // This will capture all pipe files so needs to be executed early.
  // This ensures we find any pipe files from execve for waiting FEXInterpreters.
  void ScanForPipes() {
    DIR *fd = opendir("/proc/self/fd");
    if (fd) {
      struct dirent *dir{};
      do {
        dir = readdir(fd);
        if (dir) {
          char *end{};
          int open_fd = std::strtol(dir->d_name, &end, 8);
          if (end != dir->d_name) {
            struct stat stat{};
            int result = fstat(open_fd, &stat);
            if (result == -1) {
              continue;
            }
            if (stat.st_mode & S_IFIFO) {
              // Close any incoming pipes
              IncomingPipes.emplace_back(open_fd);
            }
          }
        }
      } while (dir);

      closedir(fd);
    }
  }

  void ClosePipes() {
    for (auto pipe : IncomingPipes) {
      int Null{0};
      write(pipe, &Null, sizeof(Null));
      close(pipe);
    }
    IncomingPipes.clear();
  }
}