test/core/test_poll.c

/*
 * Copyright 2016 The Emscripten Authors.  All rights reserved.
 * Emscripten is available under two separate licenses, the MIT license and the
 * University of Illinois/NCSA Open Source License.  Both these licenses can be
 * found in the LICENSE file.
 */

#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <emscripten.h>

int main() {
  EM_ASM(
    var dummy_device = FS.makedev(64, 0);
    FS.registerDevice(dummy_device, {});

    FS.createDataFile('/', 'file', 'abcdef', true, true, false);
    FS.mkdev('/device', dummy_device);
  );
  
  struct pollfd multi[5];
  multi[0].fd = open("/file", O_RDWR, 0777);
  multi[1].fd = open("/device", O_RDWR, 0777);
  multi[2].fd = 123;
  multi[3].fd = open("/file", O_RDWR, 0777);
  multi[4].fd = open("/file", O_RDWR, 0777);
  multi[0].events = POLLIN | POLLOUT | POLLNVAL | POLLERR;
  multi[1].events = POLLIN | POLLOUT | POLLNVAL | POLLERR;
  multi[2].events = POLLIN | POLLOUT | POLLNVAL | POLLERR;
  multi[3].events = 0x00;
  multi[4].events = POLLOUT | POLLNVAL | POLLERR;

  printf("ret: %d\n", poll(multi, 5, 123));
  printf("errno: %d\n", errno);
  printf("multi[0].revents: %d\n", multi[0].revents == (POLLIN | POLLOUT));
#if WASMFS
  // TODO: Add support for POLLIN. The size of the device is 0 in WasmFS, so 
  // devices cannot POLLIN.
  printf("multi[1].revents: %d\n", multi[1].revents == POLLOUT);
#else
  printf("multi[1].revents: %d\n", multi[1].revents == (POLLIN | POLLOUT));
#endif
  printf("multi[2].revents: %d\n", multi[2].revents == POLLNVAL);
  printf("multi[3].revents: %d\n", multi[3].revents == 0);
  printf("multi[4].revents: %d\n", multi[4].revents == POLLOUT);

  return 0;
}