xref: /llvm-project/llvm/unittests/Support/Threading.cpp (revision 40668abca4d307e02b33345cfdb7271549ff48d0)
1 //===- unittests/Threading.cpp - Thread tests -----------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "llvm/Support/Threading.h"
10 #include "llvm/Support/thread.h"
11 #include "gtest/gtest.h"
12 
13 #include <atomic>
14 #include <condition_variable>
15 
16 using namespace llvm;
17 
18 namespace {
19 
20 TEST(Threading, PhysicalConcurrency) {
21   auto Num = heavyweight_hardware_concurrency();
22   // Since Num is unsigned this will also catch us trying to
23   // return -1.
24   ASSERT_LE(Num, thread::hardware_concurrency());
25 }
26 
27 #if LLVM_ENABLE_THREADS
28 
29 class Notification {
30 public:
31   void notify() {
32     {
33       std::lock_guard<std::mutex> Lock(M);
34       Notified = true;
35     }
36     CV.notify_all();
37   }
38 
39   bool wait() {
40     std::unique_lock<std::mutex> Lock(M);
41     using steady_clock = std::chrono::steady_clock;
42     auto Deadline = steady_clock::now() +
43                     std::chrono::duration_cast<steady_clock::duration>(
44                         std::chrono::duration<double>(5));
45     return CV.wait_until(Lock, Deadline, [this] { return Notified; });
46   }
47 
48 private:
49   bool Notified = false;
50   mutable std::condition_variable CV;
51   mutable std::mutex M;
52 };
53 
54 TEST(Threading, RunOnThreadSyncAsync) {
55   Notification ThreadStarted, ThreadAdvanced, ThreadFinished;
56 
57   auto ThreadFunc = [&] {
58     ThreadStarted.notify();
59     ASSERT_TRUE(ThreadAdvanced.wait());
60     ThreadFinished.notify();
61   };
62 
63   llvm::llvm_execute_on_thread_async(ThreadFunc);
64   ASSERT_TRUE(ThreadStarted.wait());
65   ThreadAdvanced.notify();
66   ASSERT_TRUE(ThreadFinished.wait());
67 }
68 
69 TEST(Threading, RunOnThreadSync) {
70   std::atomic_bool Executed(false);
71   llvm::llvm_execute_on_thread(
72       [](void *Arg) { *static_cast<std::atomic_bool *>(Arg) = true; },
73       &Executed);
74   ASSERT_EQ(Executed, true);
75 }
76 #endif
77 
78 } // end anon namespace
79