From a12923e265bd0f3ff9f445f620e173fe6595bacb Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Thu, 27 Feb 2014 14:36:16 +0000
Subject: tsan: intercept vfork this fixes obscure false positives see the
 comments and the test for details

llvm-svn: 202400
---
 compiler-rt/test/tsan/vfork.cc | 51 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 compiler-rt/test/tsan/vfork.cc

(limited to 'compiler-rt/test/tsan/vfork.cc')

diff --git a/compiler-rt/test/tsan/vfork.cc b/compiler-rt/test/tsan/vfork.cc
new file mode 100644
index 00000000000..b9d50a37e39
--- /dev/null
+++ b/compiler-rt/test/tsan/vfork.cc
@@ -0,0 +1,51 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %t 2>&1 | FileCheck %s
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+
+int fds[2];
+int X;
+
+void *Thread1(void *x) {
+  X = 42;
+  write(fds[1], "a", 1);
+  return NULL;
+}
+
+void *Thread2(void *x) {
+  char buf;
+  while (read(fds[0], &buf, 1) != 1) {
+  }
+  X = 43;
+  return NULL;
+}
+
+int main() {
+  pipe(fds);
+  int pid = vfork();
+  if (pid < 0) {
+    printf("FAIL to vfork\n");
+    exit(1);
+  }
+  if (pid == 0) {  // child
+    // Closing of fds must not affect parent process.
+    // Strictly saying this is undefined behavior, because vfork child is not
+    // allowed to call any functions other than exec/exit. But this is what
+    // openjdk does.
+    close(fds[0]);
+    close(fds[1]);
+    _exit(0);
+  }
+  pthread_t t[2];
+  pthread_create(&t[0], NULL, Thread1, NULL);
+  pthread_create(&t[1], NULL, Thread2, NULL);
+  pthread_join(t[0], NULL);
+  pthread_join(t[1], NULL);
+  printf("DONE\n");
+}
+
+// CHECK-NOT: WARNING: ThreadSanitizer: data race
+// CHECK-NOT: FAIL to vfork
+// CHECK: DONE
-- 
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