[libcxx-commits] [libcxx] [libc++] fix condition_variable_any hangs on stop_request (PR #77127)

[via libcxx-commits]

https://github.com/huixie90 created https://github.com/llvm/llvm-project/pull/77127

None

>From a497c77e9afd5883fda69d1e48bd4dd329e53d11 Mon Sep 17 00:00:00 2001
From: Hui <hui.xie0621 at gmail.com>
Date: Fri, 5 Jan 2024 18:59:09 +0000
Subject: [PATCH] [libc++] fix condition_variable_any hangs on stop_request

---
 libcxx/include/condition_variable             |  3 +++
 .../wait_for_token_pred.pass.cpp              | 22 +++++++++++++++++++
 .../wait_token_pred.pass.cpp                  | 22 +++++++++++++++++++
 .../wait_until_token_pred.pass.cpp            | 22 +++++++++++++++++++
 4 files changed, 69 insertions(+)

diff --git a/libcxx/include/condition_variable b/libcxx/include/condition_variable
index cf7a570b6cb635..c512901cfb19ca 100644
--- a/libcxx/include/condition_variable
+++ b/libcxx/include/condition_variable
@@ -131,6 +131,7 @@ public:
 #include <__mutex/mutex.h>
 #include <__mutex/tag_types.h>
 #include <__mutex/unique_lock.h>
+#include <__stop_token/stop_callback.h>
 #include <__stop_token/stop_token.h>
 #include <__utility/move.h>
 #include <version>
@@ -257,6 +258,7 @@ condition_variable_any::wait_for(_Lock& __lock, const chrono::duration<_Rep, _Pe
 
 template <class _Lock, class _Predicate>
 bool condition_variable_any::wait(_Lock& __lock, stop_token __stoken, _Predicate __pred) {
+  stop_callback __cb(__stoken, [this] { notify_all(); });
   while (!__stoken.stop_requested()) {
     if (__pred())
       return true;
@@ -268,6 +270,7 @@ bool condition_variable_any::wait(_Lock& __lock, stop_token __stoken, _Predicate
 template <class _Lock, class _Clock, class _Duration, class _Predicate>
 bool condition_variable_any::wait_until(
     _Lock& __lock, stop_token __stoken, const chrono::time_point<_Clock, _Duration>& __abs_time, _Predicate __pred) {
+  stop_callback __cb(__stoken, [this] { notify_all(); });
   while (!__stoken.stop_requested()) {
     if (__pred())
       return true;
diff --git a/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_for_token_pred.pass.cpp b/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_for_token_pred.pass.cpp
index fb3f0287726eea..4bb089f3d2858f 100644
--- a/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_for_token_pred.pass.cpp
+++ b/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_for_token_pred.pass.cpp
@@ -155,6 +155,28 @@ void test() {
     assert(lock.owns_lock());
   }
 
+  // #76807 Hangs in std::condition_variable_any when used with std::stop_token
+  {
+    class MyThread {
+    public:
+      MyThread() {
+        thread_ = support::make_test_jthread([this](std::stop_token st) {
+          while (!st.stop_requested()) {
+            std::unique_lock lock{m_};
+            cv_.wait_for(lock, st, 1h, [] { return false; });
+          }
+        });
+      }
+
+    private:
+      std::mutex m_;
+      std::condition_variable_any cv_;
+      std::jthread thread_;
+    };
+
+    [[maybe_unused]] MyThread my_thread;
+  }
+
 #if !defined(TEST_HAS_NO_EXCEPTIONS)
   // Throws: Any exception thrown by pred.
   {
diff --git a/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_token_pred.pass.cpp b/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_token_pred.pass.cpp
index 451df9ab7ee287..15a64a141c6d0d 100644
--- a/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_token_pred.pass.cpp
+++ b/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_token_pred.pass.cpp
@@ -107,6 +107,28 @@ void test() {
     assert(lock.owns_lock());
   }
 
+  // #76807 Hangs in std::condition_variable_any when used with std::stop_token
+  {
+    class MyThread {
+    public:
+      MyThread() {
+        thread_ = support::make_test_jthread([this](std::stop_token st) {
+          while (!st.stop_requested()) {
+            std::unique_lock lock{m_};
+            cv_.wait(lock, st, [] { return false; });
+          }
+        });
+      }
+
+    private:
+      std::mutex m_;
+      std::condition_variable_any cv_;
+      std::jthread thread_;
+    };
+
+    [[maybe_unused]] MyThread my_thread;
+  }
+
 #if !defined(TEST_HAS_NO_EXCEPTIONS)
   // Throws: Any exception thrown by pred.
   {
diff --git a/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_until_token_pred.pass.cpp b/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_until_token_pred.pass.cpp
index 6cdcbe36d98598..3d6f0d3eae25a6 100644
--- a/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_until_token_pred.pass.cpp
+++ b/libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_until_token_pred.pass.cpp
@@ -157,6 +157,28 @@ void test() {
     assert(lock.owns_lock());
   }
 
+  // #76807 Hangs in std::condition_variable_any when used with std::stop_token
+  {
+    class MyThread {
+    public:
+      MyThread() {
+        thread_ = support::make_test_jthread([this](std::stop_token st) {
+          while (!st.stop_requested()) {
+            std::unique_lock lock{m_};
+            cv_.wait_until(lock, st, std::chrono::steady_clock::now() + std::chrono::hours(1), [] { return false; });
+          }
+        });
+      }
+
+    private:
+      std::mutex m_;
+      std::condition_variable_any cv_;
+      std::jthread thread_;
+    };
+
+    [[maybe_unused]] MyThread my_thread;
+  }
+
 #if !defined(TEST_HAS_NO_EXCEPTIONS)
   // Throws: Any exception thrown by pred.
   {