llvm-capstone/libcxxabi/test/test_guard.pass.cpp
Chandler Carruth 57b08b0944 Update more file headers across all of the LLVM projects in the monorepo
to reflect the new license. These used slightly different spellings that
defeated my regular expressions.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351648
2019-01-19 10:56:40 +00:00

147 lines
3.1 KiB
C++

//===----------------------------- test_guard.cpp -------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "cxxabi.h"
#include <cassert>
#ifndef _LIBCXXABI_HAS_NO_THREADS
#include <thread>
#endif
// Ensure that we initialize each variable once and only once.
namespace test1 {
static int run_count = 0;
int increment() {
++run_count;
return 0;
}
void helper() {
static int a = increment();
((void)a);
}
void test() {
static int a = increment(); ((void)a);
assert(run_count == 1);
static int b = increment(); ((void)b);
assert(run_count == 2);
helper();
assert(run_count == 3);
helper();
assert(run_count == 3);
}
}
// When initialization fails, ensure that we try to initialize it again next
// time.
namespace test2 {
#ifndef LIBCXXABI_HAS_NO_EXCEPTIONS
static int run_count = 0;
int increment() {
++run_count;
throw 0;
}
void helper() {
try {
static int a = increment();
assert(false);
((void)a);
} catch (...) {}
}
void test() {
helper();
assert(run_count == 1);
helper();
assert(run_count == 2);
}
#else
void test() {}
#endif
}
// Check that we can initialize a second value while initializing a first.
namespace test3 {
int zero() {
return 0;
}
int one() {
static int b = zero(); ((void)b);
return 0;
}
void test() {
static int a = one(); ((void)a);
}
}
#ifndef _LIBCXXABI_HAS_NO_THREADS
// A simple thread test of two threads racing to initialize a variable. This
// isn't guaranteed to catch any particular threading problems.
namespace test4 {
static int run_count = 0;
int increment() {
++run_count;
return 0;
}
void helper() {
static int a = increment(); ((void)a);
}
void test() {
std::thread t1(helper), t2(helper);
t1.join();
t2.join();
assert(run_count == 1);
}
}
// Check that we don't re-initialize a static variable even when it's
// encountered from two different threads.
namespace test5 {
static int run_count = 0;
int zero() {
++run_count;
return 0;
}
int one() {
static int b = zero(); ((void)b);
return 0;
}
void another_helper() {
static int a = one(); ((void)a);
}
void helper() {
static int a = one(); ((void)a);
std::thread t(another_helper);
t.join();
}
void test() {
std::thread t(helper);
t.join();
assert(run_count == 1);
}
}
#endif /* _LIBCXXABI_HAS_NO_THREADS */
int main()
{
test1::test();
test2::test();
test3::test();
#ifndef _LIBCXXABI_HAS_NO_THREADS
test4::test();
test5::test();
#endif
}