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// RUN: %clang_tsan -O1 %s -o %t && %deflake %run %t > %t.out
// RUN: FileCheck %s --check-prefixes=CHECK,PARENT --input-file %t.out
// RUN: FileCheck %s --check-prefixes=CHECK,CHILD --input-file %t.out
// Regression test for
// https://groups.google.com/g/thread-sanitizer/c/TQrr4-9PRYo/m/HFR4FMi6AQAJ
#include "test.h"
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
long glob = 0;
void *worker(void *main) {
glob++;
// synchronize with main
barrier_wait(&barrier);
// synchronize with atfork
barrier_wait(&barrier);
pthread_kill((pthread_t)main, SIGPROF);
barrier_wait(&barrier);
// synchronize with afterfork
barrier_wait(&barrier);
pthread_kill((pthread_t)main, SIGPROF);
barrier_wait(&barrier);
return NULL;
}
void atfork() {
barrier_wait(&barrier);
barrier_wait(&barrier);
write(2, "in atfork\n", strlen("in atfork\n"));
static volatile long a;
__atomic_fetch_add(&a, 1, __ATOMIC_RELEASE);
}
void afterfork() {
barrier_wait(&barrier);
barrier_wait(&barrier);
write(2, "in afterfork\n", strlen("in afterfork\n"));
static volatile long a;
__atomic_fetch_add(&a, 1, __ATOMIC_RELEASE);
}
void afterfork_child() {
write(2, "in afterfork_child\n", strlen("in afterfork_child\n"));
glob++;
}
void handler(int sig) {
write(2, "in handler\n", strlen("in handler\n"));
glob++;
}
int main() {
barrier_init(&barrier, 2);
struct sigaction act = {};
act.sa_handler = &handler;
if (sigaction(SIGPROF, &act, 0)) {
perror("sigaction");
exit(1);
}
pthread_atfork(atfork, afterfork, afterfork_child);
pthread_t t;
pthread_create(&t, NULL, worker, (void *)pthread_self());
barrier_wait(&barrier);
pid_t pid = fork();
if (pid < 0) {
fprintf(stderr, "fork failed: %d\n", errno);
return 1;
}
if (pid == 0) {
fprintf(stderr, "CHILD\n");
return 0;
}
if (pid != waitpid(pid, NULL, 0)) {
fprintf(stderr, "waitpid failed: %d\n", errno);
return 1;
}
pthread_join(t, NULL);
fprintf(stderr, "PARENT\n");
return 0;
}
// CHECK: in atfork
// CHECK: in handler
// CHECK: ThreadSanitizer: data race
// CHECK: Write of size 8
// CHECK: #0 handler
// CHECK: Previous write of size 8
// CHECK: #0 worker
// PARENT: afterfork
// PARENT: in handler
// CHILD: afterfork_child
// CHILD: CHILD
// CHECK: PARENT
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