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       // Broadcast with the lock held, so it's safe to destroy the Notification
36       // after wait() returns.
37       CV.notify_all();
38     }
39   }
40 
41   bool wait() {
42     std::unique_lock<std::mutex> Lock(M);
43     using steady_clock = std::chrono::steady_clock;
44     auto Deadline = steady_clock::now() +
45                     std::chrono::duration_cast<steady_clock::duration>(
46                         std::chrono::duration<double>(5));
47     return CV.wait_until(Lock, Deadline, [this] { return Notified; });
48   }
49 
50 private:
51   bool Notified = false;
52   mutable std::condition_variable CV;
53   mutable std::mutex M;
54 };
55 
56 TEST(Threading, RunOnThreadSyncAsync) {
57   Notification ThreadStarted, ThreadAdvanced, ThreadFinished;
58 
59   auto ThreadFunc = [&] {
60     ThreadStarted.notify();
61     ASSERT_TRUE(ThreadAdvanced.wait());
62     ThreadFinished.notify();
63   };
64 
65   llvm::llvm_execute_on_thread_async(ThreadFunc);
66   ASSERT_TRUE(ThreadStarted.wait());
67   ThreadAdvanced.notify();
68   ASSERT_TRUE(ThreadFinished.wait());
69 }
70 
71 TEST(Threading, RunOnThreadSync) {
72   std::atomic_bool Executed(false);
73   llvm::llvm_execute_on_thread(
74       [](void *Arg) { *static_cast<std::atomic_bool *>(Arg) = true; },
75       &Executed);
76   ASSERT_EQ(Executed, true);
77 }
78 #endif
79 
80 } // end anon namespace
81