[libc++] Make std::jthread supported in non-experimental mode #107900

ldionne · 2024-09-09T18:32:11Z

We waited before supporting std::jthread fully because we wanted to investigate other implementation strategies (in particular one involving std::mutex). Since then, we did some benchmarking and decided that we wouldn't be moving forward with std::mutex. Hence, there is no real reason to punt on making std::jthread & friends non-experimental.

llvmbot · 2024-09-09T18:32:45Z

@llvm/pr-subscribers-libcxx

Author: Louis Dionne (ldionne)

Changes

We waited before supporting std::jthread fully because we wanted to investigate other implementation strategies (in particular one involving std::mutex). Since then, we did some benchmarking and decided that we wouldn't be moving forward with std::mutex. Hence, there is no real reason to punt on making std::jthread & friends non-experimental.

Patch is 24.82 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/107900.diff

19 Files Affected:

(modified) libcxx/docs/ReleaseNotes/20.rst (+1)
(modified) libcxx/docs/Status/Cxx20Papers.csv (+1-1)
(modified) libcxx/docs/UserDocumentation.rst (+1-2)
(modified) libcxx/include/__config (-1)
(modified) libcxx/include/__stop_token/atomic_unique_lock.h (+4-4)
(modified) libcxx/include/__stop_token/stop_callback.h (+3-3)
(modified) libcxx/include/__stop_token/stop_source.h (+3-3)
(modified) libcxx/include/__stop_token/stop_token.h (+2-2)
(modified) libcxx/include/__thread/jthread.h (+2-2)
(modified) libcxx/include/condition_variable (+4-4)
(modified) libcxx/include/version (+1-1)
(modified) libcxx/modules/std/thread.inc (-2)
(modified) libcxx/test/libcxx/experimental/fexperimental-library.compile.pass.cpp (-4)
(modified) libcxx/test/std/language.support/support.limits/support.limits.general/stop_token.version.compile.pass.cpp (+6-6)
(modified) libcxx/test/std/language.support/support.limits/support.limits.general/thread.version.compile.pass.cpp (+6-6)
(modified) libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp (+6-6)
(modified) libcxx/test/std/thread/thread.condition/thread.condition.condvarany/wait_terminates.sh.cpp (+2-2)
(modified) libcxx/test/support/make_test_thread.h (+4-4)
(modified) libcxx/utils/generate_feature_test_macro_components.py (+2-2)

diff --git a/libcxx/docs/ReleaseNotes/20.rst b/libcxx/docs/ReleaseNotes/20.rst
index 93d6027291ad95..a52b074fe43670 100644
--- a/libcxx/docs/ReleaseNotes/20.rst
+++ b/libcxx/docs/ReleaseNotes/20.rst
@@ -41,6 +41,7 @@ Implemented Papers
 - P2747R2: ``constexpr`` placement new (`Github <https://github.com/llvm/llvm-project/issues/105427>`__)
 - P2609R3: Relaxing Ranges Just A Smidge (`Github <https://github.com/llvm/llvm-project/issues/105253>`__)
 - P2985R0: A type trait for detecting virtual base classes (`Github <https://github.com/llvm/llvm-project/issues/105432>`__)
+- ``std::jthread`` and ``<stop_token>`` are not guarded behind ``-fexperimental-library`` anymore
 
 
 Improvements and New Features
diff --git a/libcxx/docs/Status/Cxx20Papers.csv b/libcxx/docs/Status/Cxx20Papers.csv
index ad788d7416fdad..b3c26933a9c2aa 100644
--- a/libcxx/docs/Status/Cxx20Papers.csv
+++ b/libcxx/docs/Status/Cxx20Papers.csv
@@ -105,7 +105,7 @@
 "`P0553R4 <https://wg21.link/P0553R4>`__","Bit operations","2019-07 (Cologne)","|Complete|","9.0",""
 "`P0631R8 <https://wg21.link/P0631R8>`__","Math Constants","2019-07 (Cologne)","|Complete|","11.0",""
 "`P0645R10 <https://wg21.link/P0645R10>`__","Text Formatting","2019-07 (Cologne)","|Complete|","14.0","The implementation was complete since LLVM 14, but the feature-test macro was not set until LLVM 19"
-"`P0660R10 <https://wg21.link/P0660R10>`__","Stop Token and Joining Thread, Rev 10.","2019-07 (Cologne)","|Complete|","18.0","The paper is implemented but the features are experimental and can be enabled via ``-fexperimental-library``."
+"`P0660R10 <https://wg21.link/P0660R10>`__","Stop Token and Joining Thread, Rev 10.","2019-07 (Cologne)","|Complete|","20.0","The feature was implemented since LLVM 18 but was guarded behind ``-fexperimental-library``."
 "`P0784R7 <https://wg21.link/P0784R7>`__","More constexpr containers","2019-07 (Cologne)","|Complete|","12.0",""
 "`P0980R1 <https://wg21.link/P0980R1>`__","Making std::string constexpr","2019-07 (Cologne)","|Complete|","15.0",""
 "`P1004R2 <https://wg21.link/P1004R2>`__","Making std::vector constexpr","2019-07 (Cologne)","|Complete|","15.0",""
diff --git a/libcxx/docs/UserDocumentation.rst b/libcxx/docs/UserDocumentation.rst
index 273ca8c09a93ee..3651e52ed77a75 100644
--- a/libcxx/docs/UserDocumentation.rst
+++ b/libcxx/docs/UserDocumentation.rst
@@ -69,9 +69,8 @@ The following features are currently considered experimental and are only provid
 when ``-fexperimental-library`` is passed:
 
 * The parallel algorithms library (``<execution>`` and the associated algorithms)
-* ``std::stop_token``, ``std::stop_source`` and ``std::stop_callback``
-* ``std::jthread``
 * ``std::chrono::tzdb`` and related time zone functionality
+* ``<syncstream>``
 
 .. note::
   Experimental libraries are experimental.
diff --git a/libcxx/include/__config b/libcxx/include/__config
index bccf90d1dbacd2..b57a775ad6a4e1 100644
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -224,7 +224,6 @@ _LIBCPP_HARDENING_MODE_DEBUG
 // easier to grep for target specific flags once the feature is complete.
 #  if !defined(_LIBCPP_ENABLE_EXPERIMENTAL) && !defined(_LIBCPP_BUILDING_LIBRARY)
 #    define _LIBCPP_HAS_NO_INCOMPLETE_PSTL
-#    define _LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN
 #    define _LIBCPP_HAS_NO_EXPERIMENTAL_TZDB
 #    define _LIBCPP_HAS_NO_EXPERIMENTAL_SYNCSTREAM
 #  endif
diff --git a/libcxx/include/__stop_token/atomic_unique_lock.h b/libcxx/include/__stop_token/atomic_unique_lock.h
index 13e59f9f0dce00..8fb70a4bfb510e 100644
--- a/libcxx/include/__stop_token/atomic_unique_lock.h
+++ b/libcxx/include/__stop_token/atomic_unique_lock.h
@@ -7,8 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef _LIBCPP___STOP_TOKEN_ATOMIC_UNIQUE_GUARD_H
-#define _LIBCPP___STOP_TOKEN_ATOMIC_UNIQUE_GUARD_H
+#ifndef _LIBCPP___STOP_TOKEN_ATOMIC_UNIQUE_LOCK_H
+#define _LIBCPP___STOP_TOKEN_ATOMIC_UNIQUE_LOCK_H
 
 #include <__bit/popcount.h>
 #include <__config>
@@ -133,8 +133,8 @@ class _LIBCPP_AVAILABILITY_SYNC __atomic_unique_lock {
   _LIBCPP_HIDE_FROM_ABI static constexpr auto __set_locked_bit = [](_State __state) { return __state | _LockedBit; };
 };
 
-#endif // _LIBCPP_STD_VER >= 20
+#endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_THREADS)
 
 _LIBCPP_END_NAMESPACE_STD
 
-#endif // _LIBCPP___STOP_TOKEN_ATOMIC_UNIQUE_GUARD_H
+#endif // _LIBCPP___STOP_TOKEN_ATOMIC_UNIQUE_LOCK_H
diff --git a/libcxx/include/__stop_token/stop_callback.h b/libcxx/include/__stop_token/stop_callback.h
index 760cf2bb55b0ce..8d7167a5f03467 100644
--- a/libcxx/include/__stop_token/stop_callback.h
+++ b/libcxx/include/__stop_token/stop_callback.h
@@ -31,7 +31,7 @@ _LIBCPP_PUSH_MACROS
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && !defined(_LIBCPP_HAS_NO_THREADS)
+#if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_THREADS)
 
 template <class _Callback>
 class _LIBCPP_AVAILABILITY_SYNC stop_callback : private __stop_callback_base {
@@ -93,10 +93,10 @@ class _LIBCPP_AVAILABILITY_SYNC stop_callback : private __stop_callback_base {
 template <class _Callback>
 _LIBCPP_AVAILABILITY_SYNC stop_callback(stop_token, _Callback) -> stop_callback<_Callback>;
 
-#endif // _LIBCPP_STD_VER >= 20
+#endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_THREADS)
 
 _LIBCPP_END_NAMESPACE_STD
 
 _LIBCPP_POP_MACROS
 
-#endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && !defined(_LIBCPP_HAS_NO_THREADS)
+#endif // _LIBCPP___STOP_TOKEN_STOP_CALLBACK_H
diff --git a/libcxx/include/__stop_token/stop_source.h b/libcxx/include/__stop_token/stop_source.h
index 70697462784ab4..7243856ecdd08b 100644
--- a/libcxx/include/__stop_token/stop_source.h
+++ b/libcxx/include/__stop_token/stop_source.h
@@ -22,7 +22,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && !defined(_LIBCPP_HAS_NO_THREADS)
+#if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_THREADS)
 
 struct nostopstate_t {
   explicit nostopstate_t() = default;
@@ -84,8 +84,8 @@ class _LIBCPP_AVAILABILITY_SYNC stop_source {
   __intrusive_shared_ptr<__stop_state> __state_;
 };
 
-#endif // _LIBCPP_STD_VER >= 20
+#endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_THREADS)
 
 _LIBCPP_END_NAMESPACE_STD
 
-#endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && !defined(_LIBCPP_HAS_NO_THREADS)
+#endif // _LIBCPP___STOP_TOKEN_STOP_SOURCE_H
diff --git a/libcxx/include/__stop_token/stop_token.h b/libcxx/include/__stop_token/stop_token.h
index 1bd75cbbf6f8d8..b2569738896a66 100644
--- a/libcxx/include/__stop_token/stop_token.h
+++ b/libcxx/include/__stop_token/stop_token.h
@@ -20,7 +20,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && !defined(_LIBCPP_HAS_NO_THREADS)
+#if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_THREADS)
 
 class _LIBCPP_AVAILABILITY_SYNC stop_token {
 public:
@@ -56,7 +56,7 @@ class _LIBCPP_AVAILABILITY_SYNC stop_token {
   _LIBCPP_HIDE_FROM_ABI explicit stop_token(const __intrusive_shared_ptr<__stop_state>& __state) : __state_(__state) {}
 };
 
-#endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && !defined(_LIBCPP_HAS_NO_THREADS)
+#endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_THREADS)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__thread/jthread.h b/libcxx/include/__thread/jthread.h
index b3d5c25fb71c77..d85ad3b9061b82 100644
--- a/libcxx/include/__thread/jthread.h
+++ b/libcxx/include/__thread/jthread.h
@@ -30,7 +30,7 @@
 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
 
-#if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
+#if _LIBCPP_STD_VER >= 20
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
@@ -127,7 +127,7 @@ class _LIBCPP_AVAILABILITY_SYNC jthread {
 
 _LIBCPP_END_NAMESPACE_STD
 
-#endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
+#endif // _LIBCPP_STD_VER >= 20
 
 _LIBCPP_POP_MACROS
 
diff --git a/libcxx/include/condition_variable b/libcxx/include/condition_variable
index 5195cd6057dd33..229a2ce103b5ed 100644
--- a/libcxx/include/condition_variable
+++ b/libcxx/include/condition_variable
@@ -173,7 +173,7 @@ public:
   template <class _Lock, class _Rep, class _Period, class _Predicate>
   bool _LIBCPP_HIDE_FROM_ABI wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __d, _Predicate __pred);
 
-#  if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
+#  if _LIBCPP_STD_VER >= 20
 
   template <class _Lock, class _Predicate>
   _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI bool wait(_Lock& __lock, stop_token __stoken, _Predicate __pred);
@@ -186,7 +186,7 @@ public:
   _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI bool
   wait_for(_Lock& __lock, stop_token __stoken, const chrono::duration<_Rep, _Period>& __rel_time, _Predicate __pred);
 
-#  endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
+#  endif // _LIBCPP_STD_VER >= 20
 };
 
 inline condition_variable_any::condition_variable_any() : __mut_(make_shared<mutex>()) {}
@@ -260,7 +260,7 @@ condition_variable_any::wait_for(_Lock& __lock, const chrono::duration<_Rep, _Pe
   return wait_until(__lock, chrono::steady_clock::now() + __d, std::move(__pred));
 }
 
-#  if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
+#  if _LIBCPP_STD_VER >= 20
 
 template <class _Lock, class _Predicate>
 bool condition_variable_any::wait(_Lock& __user_lock, stop_token __stoken, _Predicate __pred) {
@@ -341,7 +341,7 @@ bool condition_variable_any::wait_for(
   return wait_until(__lock, std::move(__stoken), chrono::steady_clock::now() + __rel_time, std::move(__pred));
 }
 
-#  endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
+#  endif // _LIBCPP_STD_VER >= 20
 
 _LIBCPP_EXPORTED_FROM_ABI void notify_all_at_thread_exit(condition_variable&, unique_lock<mutex>);
 
diff --git a/libcxx/include/version b/libcxx/include/version
index dc1d3fd268ce83..5d679caac0b3b7 100644
--- a/libcxx/include/version
+++ b/libcxx/include/version
@@ -417,7 +417,7 @@ __cpp_lib_void_t                                        201411L <type_traits>
 // # define __cpp_lib_is_layout_compatible                 201907L
 # define __cpp_lib_is_nothrow_convertible               201806L
 // # define __cpp_lib_is_pointer_interconvertible          201907L
-# if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && _LIBCPP_AVAILABILITY_HAS_SYNC
+# if !defined(_LIBCPP_HAS_NO_THREADS) && _LIBCPP_AVAILABILITY_HAS_SYNC
 #   define __cpp_lib_jthread                            201911L
 # endif
 # if !defined(_LIBCPP_HAS_NO_THREADS) && _LIBCPP_AVAILABILITY_HAS_SYNC
diff --git a/libcxx/modules/std/thread.inc b/libcxx/modules/std/thread.inc
index 6504a39a7aeaee..61e3191f3197b8 100644
--- a/libcxx/modules/std/thread.inc
+++ b/libcxx/modules/std/thread.inc
@@ -15,9 +15,7 @@ export namespace std {
   using std::swap;
 
   // [thread.jthread.class], class jthread
-#  if !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
   using std::jthread;
-#  endif
 
   // [thread.thread.this], namespace this_thread
   namespace this_thread {
diff --git a/libcxx/test/libcxx/experimental/fexperimental-library.compile.pass.cpp b/libcxx/test/libcxx/experimental/fexperimental-library.compile.pass.cpp
index 3d50d2347d6bb8..fd06886bf2e532 100644
--- a/libcxx/test/libcxx/experimental/fexperimental-library.compile.pass.cpp
+++ b/libcxx/test/libcxx/experimental/fexperimental-library.compile.pass.cpp
@@ -20,10 +20,6 @@
 #  error "-fexperimental-library should enable the PSTL"
 #endif
 
-#ifdef _LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN
-#  error "-fexperimental-library should enable the stop_token"
-#endif
-
 #ifdef _LIBCPP_HAS_NO_EXPERIMENTAL_TZDB
 #  error "-fexperimental-library should enable the chrono TZDB"
 #endif
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/stop_token.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/stop_token.version.compile.pass.cpp
index 0d7811eff907ed..49233cda2bd9e1 100644
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/stop_token.version.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/stop_token.version.compile.pass.cpp
@@ -44,7 +44,7 @@
 
 #elif TEST_STD_VER == 20
 
-# if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
+# if !defined(_LIBCPP_HAS_NO_THREADS) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
 #   ifndef __cpp_lib_jthread
 #     error "__cpp_lib_jthread should be defined in c++20"
 #   endif
@@ -53,13 +53,13 @@
 #   endif
 # else
 #   ifdef __cpp_lib_jthread
-#     error "__cpp_lib_jthread should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)' is not met!"
+#     error "__cpp_lib_jthread should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER == 23
 
-# if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
+# if !defined(_LIBCPP_HAS_NO_THREADS) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
 #   ifndef __cpp_lib_jthread
 #     error "__cpp_lib_jthread should be defined in c++23"
 #   endif
@@ -68,13 +68,13 @@
 #   endif
 # else
 #   ifdef __cpp_lib_jthread
-#     error "__cpp_lib_jthread should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)' is not met!"
+#     error "__cpp_lib_jthread should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)' is not met!"
 #   endif
 # endif
 
 #elif TEST_STD_VER > 23
 
-# if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
+# if !defined(_LIBCPP_HAS_NO_THREADS) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
 #   ifndef __cpp_lib_jthread
 #     error "__cpp_lib_jthread should be defined in c++26"
 #   endif
@@ -83,7 +83,7 @@
 #   endif
 # else
 #   ifdef __cpp_lib_jthread
-#     error "__cpp_lib_jthread should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)' is not met!"
+#     error "__cpp_lib_jthread should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)' is not met!"
 #   endif
 # endif
 
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/thread.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/thread.version.compile.pass.cpp
index 1735abb9bdb653..97700235ca21ad 100644
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/thread.version.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/thread.version.compile.pass.cpp
@@ -61,7 +61,7 @@
 #   error "__cpp_lib_formatters should not be defined before c++23"
 # endif
 
-# if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
+# if !defined(_LIBCPP_HAS_NO_THREADS) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
 #   ifndef __cpp_lib_jthread
 #     error "__cpp_lib_jthread should be defined in c++20"
 #   endif
@@ -70,7 +70,7 @@
 #   endif
 # else
 #   ifdef __cpp_lib_jthread
-#     error "__cpp_lib_jthread should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)' is not met!"
+#     error "__cpp_lib_jthread should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)' is not met!"
 #   endif
 # endif
 
@@ -89,7 +89,7 @@
 #   endif
 # endif
 
-# if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
+# if !defined(_LIBCPP_HAS_NO_THREADS) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
 #   ifndef __cpp_lib_jthread
 #     error "__cpp_lib_jthread should be defined in c++23"
 #   endif
@@ -98,7 +98,7 @@
 #   endif
 # else
 #   ifdef __cpp_lib_jthread
-#     error "__cpp_lib_jthread should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)' is not met!"
+#     error "__cpp_lib_jthread should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)' is not met!"
 #   endif
 # endif
 
@@ -117,7 +117,7 @@
 #   endif
 # endif
 
-# if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
+# if !defined(_LIBCPP_HAS_NO_THREADS) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
 #   ifndef __cpp_lib_jthread
 #     error "__cpp_lib_jthread should be defined in c++26"
 #   endif
@@ -126,7 +126,7 @@
 #   endif
 # else
 #   ifdef __cpp_lib_jthread
-#     error "__cpp_lib_jthread should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)' is not met!"
+#     error "__cpp_lib_jthread should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)' is not met!"
 #   endif
 # endif
 
diff --git a/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp b/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
index a022c90e166c8d..985ffeffab96db 100644
--- a/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
+++ b/libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp
@@ -3908,7 +3908,7 @@
 #   error "__cpp_lib_is_within_lifetime should not be defined before c++26"
 # endif
 
-# if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
+# if !defined(_LIBCPP_HAS_NO_THREADS) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
 #   ifndef __cpp_lib_jthread
 #     error "__cpp_lib_jthread should be defined in c++20"
 #   endif
@@ -3917,7 +3917,7 @@
 #   endif
 # else
 #   ifdef __cpp_lib_jthread
-#     error "__cpp_lib_jthread should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)' is not met!"
+#     error "__cpp_lib_jthread should not be defined when the requirement '!defined(_LIBCPP_HAS_NO_THREADS) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)' is not met!"
 #   endif
 # endif
 
@@ -5375,7 +5375,7 @@
 #   error "__cpp_lib_is_within_lifetime should not be defined before c++26"
 # endif
 
-# if !defined(_LIBCPP_HAS_NO_THREADS) && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
+# if !defined(_LIBCPP_HAS_NO_THREADS) && (!defined(_LIBCPP_VERSION) || _LIBCPP_AVAILABILITY_HAS_SYNC)
 #   ifndef __cpp_lib_jthread
 #     error "__cpp_lib_jthrea...
[truncated]

philnik777

Makes sense to me.

We waited before supporting std::jthread fully because we wanted to investigate other implementation strategies (in particular one involving std::mutex). Since then, we did some benchmarking and decided that we wouldn't be moving forward with std::mutex. Hence, there is no real reason to punt on making std::jthread & friends non-experimental.

https://wg21.link/p1869r1: Rename `condition_variable_any` interruptible wait methods The paper was implemented as experimental feature in Clang 18 in: 4fa812b Experimental status removed in: #107900 Closes #100031 --------- Co-authored-by: Hristo Hristov <zingam@outlook.com>

ldionne requested a review from huixie90 September 9, 2024 18:32

ldionne requested a review from a team as a code owner September 9, 2024 18:32

llvmbot added the libc++ libc++ C++ Standard Library. Not GNU libstdc++. Not libc++abi. label Sep 9, 2024

ldionne mentioned this pull request Sep 9, 2024

[libc++][NFC] Mark P1869R1 as implemented #107746

Merged

philnik777 approved these changes Sep 10, 2024

View reviewed changes

ldionne added 2 commits September 10, 2024 09:20

Fix C++20 modules include

b3022d8

ldionne force-pushed the review/jthread-not-experimental branch from 45a9243 to b3022d8 Compare September 10, 2024 13:21

ldionne merged commit 9917484 into llvm:main Sep 12, 2024
62 checks passed

ldionne deleted the review/jthread-not-experimental branch September 12, 2024 13:49

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[libc++] Make std::jthread supported in non-experimental mode #107900

[libc++] Make std::jthread supported in non-experimental mode #107900

ldionne commented Sep 9, 2024

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[libc++] Make std::jthread supported in non-experimental mode #107900

[libc++] Make std::jthread supported in non-experimental mode #107900

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