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go/misc/cgo/testcshared/main2.c
Russ Cox b5e2ec8bbe misc/cgo/testcshared: use fd 100 instead of fd 10 for back-channel communication
There is a report that fd 10 is already in use when run on some OS X machines.
I don't see how, and I can't reproduce the problem on my own OS X machine,
but it's easy enough to fix.

Fixes #12161.

Change-Id: I73511bdd91258ecda181d60d2829add746d1198b
Reviewed-on: https://go-review.googlesource.com/17451
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-12-05 03:56:23 +00:00

57 lines
1.2 KiB
C

// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#define fd (100)
// Tests libgo2.so, which does not export any functions.
// Read a string from the file descriptor and print it.
int main(void) {
int i;
ssize_t n;
char buf[20];
struct timespec ts;
// The descriptor will be initialized in a thread, so we have to
// give a chance to get opened.
for (i = 0; i < 100; i++) {
n = read(fd, buf, sizeof buf);
if (n >= 0)
break;
if (errno != EBADF && errno != EINVAL) {
fprintf(stderr, "BUG: read: %s\n", strerror(errno));
return 2;
}
// An EBADF error means that the shared library has not opened the
// descriptor yet.
ts.tv_sec = 0;
ts.tv_nsec = 1000000;
nanosleep(&ts, NULL);
}
if (n < 0) {
fprintf(stderr, "BUG: failed to read any data from pipe\n");
return 2;
}
if (n == 0) {
fprintf(stderr, "BUG: unexpected EOF\n");
return 2;
}
if (n == sizeof buf) {
n--;
}
buf[n] = '\0';
printf("%s\n", buf);
return 0;
}