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#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/select.h>
#include <string.h>
#include <errno.h>
#define BIG_PIPE_SIZE 64*1024 /* From sys/pipe.h */
/*
* Test for the non-blocking big pipe bug (write(2) returning
* EAGAIN while select(2) returns the descriptor as ready for write).
*
* $FreeBSD$
*/
void write_frame(int fd, char *buf, unsigned long buflen)
{
fd_set wfd;
int i;
while (buflen) {
FD_ZERO(&wfd);
FD_SET(fd, &wfd);
i = select(fd+1, NULL, &wfd, NULL, NULL);
if (i < 0) {
perror("select");
exit(1);
}
if (i != 1) {
fprintf(stderr, "select returned unexpected value %d\n", i);
exit(1);
}
i = write(fd, buf, buflen);
if (i < 0) {
if (errno != EAGAIN)
perror("write");
exit(1);
}
buf += i;
buflen -= i;
}
}
int main()
{
char buf[BIG_PIPE_SIZE]; /* any value over PIPE_SIZE should do */
int i, flags, fd[2];
printf("1..1\n");
if (pipe(fd) < 0) { perror("pipe"); exit(1); }
flags = fcntl(fd[1], F_GETFL);
if (flags == -1 || fcntl(fd[1], F_SETFL, flags|O_NONBLOCK) == -1) {
perror("fcntl");
exit(1);
}
switch (fork()) {
case -1:
perror("fork");
exit(1);
case 0:
close(fd[1]);
for (;;) {
i = read(fd[0], buf, 256); /* any small size should do */
if (i == 0) break;
if (i < 0) { perror("read"); exit(1); }
}
exit(0);
default:
break;
}
close(fd[0]);
memset(buf, 0, sizeof buf);
for (i = 0; i < 1000; i++) write_frame(fd[1], buf, sizeof buf);
printf("ok 1\n");
exit(0);
}
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