cosmopolitan/test/posix/pipe_write_eagain_test.c
Justine Tunney 126a44dc49
Write more tests attempting to break windows
This time I haven't succeeded in breaking anything which is a good sign.
2024-09-22 01:21:10 -07:00

107 lines
2.6 KiB
C

// Copyright 2024 Justine Alexandra Roberts Tunney
//
// Permission to use, copy, modify, and/or distribute this software for
// any purpose with or without fee is hereby granted, provided that the
// above copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
// WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
// AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
// DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
// PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
// TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.
#include <errno.h>
#include <poll.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
/**
* @fileoverview Tests that EAGAIN won't corrupt pipe.
*
* This is a real bug when using CancelIoEx() on winsock writes, so we
* need to make sure it doesn't happen on pipes too.
*/
#define ITERATIONS 100000
#define ASYMMETRY 3
int fds[2];
int got_read_eagains;
int got_write_eagains;
void *worker(void *arg) {
for (int expect = 0; expect < ITERATIONS;) {
int number;
ssize_t rc = read(fds[0], &number, sizeof(number));
if (rc == -1) {
if (errno == EAGAIN) {
++got_read_eagains;
if (poll(&(struct pollfd){fds[0], POLLIN}, 1, -1) == -1)
exit(11);
continue;
}
perror("read");
exit(8);
}
size_t got = rc;
if (got != sizeof(int))
exit(9);
if (expect != number)
exit(10);
++expect;
}
return 0;
}
int main(int argc, char *argv[]) {
if (pipe2(fds, O_NONBLOCK))
return 1;
pthread_t th;
if (pthread_create(&th, 0, worker, 0))
return 2;
int number = 0;
for (;;) {
int chunk = 0;
int numbers[ASYMMETRY];
for (;;) {
numbers[chunk] = number + chunk;
if (++chunk == ASYMMETRY)
break;
if (number + chunk == ITERATIONS)
break;
}
for (;;) {
ssize_t rc = write(fds[1], numbers, chunk * sizeof(int));
if (rc == -1) {
if (errno == EAGAIN) {
++got_write_eagains;
if (poll(&(struct pollfd){fds[1], POLLOUT}, 1, -1) == -1)
return 10;
continue;
}
return 3;
}
if (rc % sizeof(int))
return 4;
chunk = rc / sizeof(int);
number += chunk;
break;
}
if (number == ITERATIONS)
break;
}
if (pthread_join(th, 0))
return 5;
if (!got_read_eagains && !got_write_eagains)
return 7;
}