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// 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.
// Test a C thread that calls sigaltstack and then calls Go code.
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sched.h>
#include <pthread.h>
#include "libgo4.h"
#ifdef _AIX
// On AIX, CSIGSTKSZ is too small to handle Go sighandler.
#define CSIGSTKSZ 0x4000
#else
#define CSIGSTKSZ SIGSTKSZ
#endif
static void die(const char* msg) {
perror(msg);
exit(EXIT_FAILURE);
}
static int ok = 1;
static void ioHandler(int signo, siginfo_t* info, void* ctxt) {
}
// Set up the SIGIO signal handler in a high priority constructor, so
// that it is installed before the Go code starts.
static void init(void) __attribute__ ((constructor (200)));
static void init() {
struct sigaction sa;
memset(&sa, 0, sizeof sa);
sa.sa_sigaction = ioHandler;
if (sigemptyset(&sa.sa_mask) < 0) {
die("sigemptyset");
}
sa.sa_flags = SA_SIGINFO | SA_ONSTACK;
if (sigaction(SIGIO, &sa, NULL) < 0) {
die("sigaction");
}
}
// Test raising SIGIO on a C thread with an alternate signal stack
// when there is a Go signal handler for SIGIO.
static void* thread1(void* arg __attribute__ ((unused))) {
stack_t ss;
int i;
stack_t nss;
struct timespec ts;
// Set up an alternate signal stack for this thread.
memset(&ss, 0, sizeof ss);
ss.ss_sp = malloc(CSIGSTKSZ);
if (ss.ss_sp == NULL) {
die("malloc");
}
ss.ss_flags = 0;
ss.ss_size = CSIGSTKSZ;
if (sigaltstack(&ss, NULL) < 0) {
die("sigaltstack");
}
// Send ourselves a SIGIO. This will be caught by the Go
// signal handler which should forward to the C signal
// handler.
i = pthread_kill(pthread_self(), SIGIO);
if (i != 0) {
fprintf(stderr, "pthread_kill: %s\n", strerror(i));
exit(EXIT_FAILURE);
}
// Wait until the signal has been delivered.
i = 0;
while (SIGIOCount() == 0) {
ts.tv_sec = 0;
ts.tv_nsec = 1000000;
nanosleep(&ts, NULL);
i++;
if (i > 5000) {
fprintf(stderr, "looping too long waiting for signal\n");
exit(EXIT_FAILURE);
}
}
// We should still be on the same signal stack.
if (sigaltstack(NULL, &nss) < 0) {
die("sigaltstack check");
}
if ((nss.ss_flags & SS_DISABLE) != 0) {
fprintf(stderr, "sigaltstack disabled on return from Go\n");
ok = 0;
} else if (nss.ss_sp != ss.ss_sp) {
fprintf(stderr, "sigaltstack changed on return from Go\n");
ok = 0;
}
return NULL;
}
// Test calling a Go function to raise SIGIO on a C thread with an
// alternate signal stack when there is a Go signal handler for SIGIO.
static void* thread2(void* arg __attribute__ ((unused))) {
stack_t ss;
int i;
int oldcount;
pthread_t tid;
struct timespec ts;
stack_t nss;
// Set up an alternate signal stack for this thread.
memset(&ss, 0, sizeof ss);
ss.ss_sp = malloc(CSIGSTKSZ);
if (ss.ss_sp == NULL) {
die("malloc");
}
ss.ss_flags = 0;
ss.ss_size = CSIGSTKSZ;
if (sigaltstack(&ss, NULL) < 0) {
die("sigaltstack");
}
oldcount = SIGIOCount();
// Call a Go function that will call a C function to send us a
// SIGIO.
tid = pthread_self();
GoRaiseSIGIO(&tid);
// Wait until the signal has been delivered.
i = 0;
while (SIGIOCount() == oldcount) {
ts.tv_sec = 0;
ts.tv_nsec = 1000000;
nanosleep(&ts, NULL);
i++;
if (i > 5000) {
fprintf(stderr, "looping too long waiting for signal\n");
exit(EXIT_FAILURE);
}
}
// We should still be on the same signal stack.
if (sigaltstack(NULL, &nss) < 0) {
die("sigaltstack check");
}
if ((nss.ss_flags & SS_DISABLE) != 0) {
fprintf(stderr, "sigaltstack disabled on return from Go\n");
ok = 0;
} else if (nss.ss_sp != ss.ss_sp) {
fprintf(stderr, "sigaltstack changed on return from Go\n");
ok = 0;
}
return NULL;
}
int main(int argc, char **argv) {
pthread_t tid;
int i;
// Tell the Go library to start looking for SIGIO.
GoCatchSIGIO();
i = pthread_create(&tid, NULL, thread1, NULL);
if (i != 0) {
fprintf(stderr, "pthread_create: %s\n", strerror(i));
exit(EXIT_FAILURE);
}
i = pthread_join(tid, NULL);
if (i != 0) {
fprintf(stderr, "pthread_join: %s\n", strerror(i));
exit(EXIT_FAILURE);
}
i = pthread_create(&tid, NULL, thread2, NULL);
if (i != 0) {
fprintf(stderr, "pthread_create: %s\n", strerror(i));
exit(EXIT_FAILURE);
}
i = pthread_join(tid, NULL);
if (i != 0) {
fprintf(stderr, "pthread_join: %s\n", strerror(i));
exit(EXIT_FAILURE);
}
if (!ok) {
exit(EXIT_FAILURE);
}
printf("PASS\n");
return 0;
}
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