File: async_race.38682.pass.cpp

package info (click to toggle)
llvm-toolchain-20 1%3A20.1.6-1~exp1
  • links: PTS, VCS
  • area: main
  • in suites: experimental
  • size: 2,111,304 kB
  • sloc: cpp: 7,438,677; ansic: 1,393,822; asm: 1,012,926; python: 241,650; f90: 86,635; objc: 75,479; lisp: 42,144; pascal: 17,286; sh: 10,027; ml: 5,082; perl: 4,730; awk: 3,523; makefile: 3,349; javascript: 2,251; xml: 892; fortran: 672
file content (65 lines) | stat: -rw-r--r-- 1,757 bytes parent folder | download | duplicates (9)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// UNSUPPORTED: no-threads
// UNSUPPORTED: c++03

// This test requires the fix for http://llvm.org/PR38682 (616ef1863fae). We mark the
// test as UNSUPPORTED instead of XFAIL because the test doesn't fail consistently.
// UNSUPPORTED: using-built-library-before-llvm-10

// This test is designed to cause and allow TSAN to detect a race condition
// in std::async, as reported in https://llvm.org/PR38682.

#include <cassert>
#include <functional>
#include <future>
#include <numeric>
#include <vector>

#include "test_macros.h"


static int worker(std::vector<int> const& data) {
  return std::accumulate(data.begin(), data.end(), 0);
}

static int& worker_ref(int& i) { return i; }

static void worker_void() { }

int main(int, char**) {
  // future<T>
  {
    std::vector<int> const v{1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
    for (int i = 0; i != 20; ++i) {
      std::future<int> fut = std::async(std::launch::async, worker, v);
      int answer = fut.get();
      assert(answer == 55);
    }
  }

  // future<T&>
  {
    for (int i = 0; i != 20; ++i) {
      std::future<int&> fut = std::async(std::launch::async, worker_ref, std::ref(i));
      int& answer = fut.get();
      assert(answer == i);
    }
  }

  // future<void>
  {
    for (int i = 0; i != 20; ++i) {
      std::future<void> fut = std::async(std::launch::async, worker_void);
      fut.get();
    }
  }

  return 0;
}