/*

* Copyright 2017 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 <unistd.h>

#include <sys/types.h>

#include <fcntl.h>

#include <poll.h>

#include <errno.h>

#include <assert.h>

#include <string.h>

#include <stdio.h>

unsigned char buf[1 << 16];

#define FALSE 0

#define TRUE 1

// This test program relies on the simplest read/write behavior when

// all the data can be read/written in one call.

void test_write(int fd1, unsigned char *ch, int size)

{

memset(buf, 0, sizeof buf);

for(int i = 0; i < size; ++i)

buf[i] = (*ch)++;

assert(write(fd1, buf, size) == size);

}

void test_read(int fd0, unsigned char *ch, int size)

{

memset(buf, 0, sizeof buf);

assert(read(fd0, buf, size) == size);

for(int i = 0; i < sizeof buf; ++i)

{

unsigned char correct_ch = (i < size) ? (*ch)++ : 0;

assert(buf[i] == correct_ch);

}

}

void test_poll(int *fd, int data_available)

{

struct pollfd pfds[2];

memset(pfds, 0, sizeof pfds);

pfds[0].fd = fd[0];

pfds[0].events = POLLIN | POLLOUT;

pfds[1].fd = fd[1];

pfds[1].events = POLLIN | POLLOUT;

int ret = poll(pfds, 2, 0);

if(data_available)

{

assert(ret == 2);

assert(pfds[0].revents == POLLIN);

}

else

{

assert(ret == 1);

assert(pfds[0].revents == 0);

}

assert(pfds[1].revents == POLLOUT);

}

int main()

{

int fd[2];

unsigned char wchar = 0;

unsigned char rchar = 0;

assert(pipe(fd) == 0);

// Test that pipe is not seekable

memset(buf, 0, sizeof buf);

assert(write(fd[1], buf, 128) == 128);

assert(lseek(fd[0], 0, SEEK_CUR) == -1);

assert(errno == ESPIPE);

assert(lseek(fd[1], 0, SEEK_CUR) == -1);

assert(errno == ESPIPE);

assert(read(fd[0], buf, sizeof buf) == 128);

// Now pipe is empty

// Test interleaved writing and reading of different buffer sizes

for(int i = 1; i < 200; ++i) // write about 40 Kb of data

{

test_write(fd[1], &wchar, i + 2);

test_poll(fd, TRUE);

test_read (fd[0], &rchar, i);

test_poll(fd, TRUE);

test_write(fd[1], &wchar, i + 1);

test_poll(fd, TRUE);

test_read (fd[0], &rchar, i + 3);

test_poll(fd, FALSE);

}

// Test reading when there is less data available than the read buffer size

assert(write(fd[1], buf, 10) == 10);

assert(read(fd[0], buf, sizeof buf) == 10);

// Write total of 1 Mb of data in small chunks

// The pipe should not overflow

int bytes_to_write = 1 << 20;

while(bytes_to_write > 0)

{

test_write(fd[1], &wchar, sizeof buf);

test_read (fd[0], &rchar, sizeof buf);

bytes_to_write -= sizeof buf;

}

// Write large chunks of data (supposed to be larger than one internal buffer)

test_write(fd[1], &wchar, 123);

test_write(fd[1], &wchar, (1 << 15) + 321);

test_write(fd[1], &wchar, 456);

test_read(fd[0], &rchar, 456);

test_read(fd[0], &rchar, (1 << 15) + 123);

test_read(fd[0], &rchar, 321);

// Test non-blocking read from empty pipe

assert(fcntl(fd[0], F_SETFL, O_NONBLOCK) == 0);

assert(read(fd[0], buf, sizeof buf) == -1);

assert(errno == EAGAIN);

// Normal operations still work in non-blocking mode

test_poll(fd, FALSE);

test_write(fd[1], &wchar, 10);

test_poll(fd, TRUE);

test_read (fd[0], &rchar, 10);

test_poll(fd, FALSE);

puts("success");

return 0;

}