From febc58e0365f683df0eee973e7fa183d8cfaddbc Mon Sep 17 00:00:00 2001 From: metagn Date: Mon, 30 Sep 2024 18:34:09 +0300 Subject: [PATCH] allow C atomics on C++ with -d:nimUseCAtomics (#24207) refs https://github.com/nim-lang/Nim/pull/24200#issuecomment-2382501282 Workaround for C++ Atomic[T] issues that doesn't require a compiler change. Not tested or documented in case it's not meant to be officially supported, locally tested `tatomics` and #24159 to work with it though, can add these as tests if required. --- lib/pure/concurrency/atomics.nim | 65 ++++++++++++++++++++------------ 1 file changed, 40 insertions(+), 25 deletions(-) diff --git a/lib/pure/concurrency/atomics.nim b/lib/pure/concurrency/atomics.nim index c7b881bc55c1..a3ef2f5f70c7 100644 --- a/lib/pure/concurrency/atomics.nim +++ b/lib/pure/concurrency/atomics.nim @@ -50,8 +50,7 @@ runnableExamples: flag.clear(moRelaxed) assert not flag.testAndSet - -when defined(cpp) or defined(nimdoc): +when (defined(cpp) and not defined(nimUseCAtomics)) or defined(nimdoc): # For the C++ backend, types and operations map directly to C++11 atomics. {.push, header: "".} @@ -274,10 +273,17 @@ else: cast[T](interlockedXor(addr(location.value), cast[nonAtomicType(T)](value))) else: - {.push, header: "".} + when defined(cpp): + {.push, header: "".} + template maybeWrapStd(x: string): string = + "std::" & x + else: + {.push, header: "".} + template maybeWrapStd(x: string): string = + x type - MemoryOrder* {.importc: "memory_order".} = enum + MemoryOrder* {.importc: "memory_order".maybeWrapStd.} = enum moRelaxed moConsume moAcquire @@ -285,16 +291,25 @@ else: moAcquireRelease moSequentiallyConsistent - type - # Atomic*[T] {.importcpp: "_Atomic('0)".} = object + when defined(cpp): + type + # Atomic*[T] {.importcpp: "_Atomic('0)".} = object + + AtomicInt8 {.importc: "std::atomic".} = int8 + AtomicInt16 {.importc: "std::atomic".} = int16 + AtomicInt32 {.importc: "std::atomic".} = int32 + AtomicInt64 {.importc: "std::atomic".} = int64 + else: + type + # Atomic*[T] {.importcpp: "_Atomic('0)".} = object - AtomicInt8 {.importc: "_Atomic NI8".} = int8 - AtomicInt16 {.importc: "_Atomic NI16".} = int16 - AtomicInt32 {.importc: "_Atomic NI32".} = int32 - AtomicInt64 {.importc: "_Atomic NI64".} = int64 + AtomicInt8 {.importc: "_Atomic NI8".} = int8 + AtomicInt16 {.importc: "_Atomic NI16".} = int16 + AtomicInt32 {.importc: "_Atomic NI32".} = int32 + AtomicInt64 {.importc: "_Atomic NI64".} = int64 type - AtomicFlag* {.importc: "atomic_flag", size: 1.} = object + AtomicFlag* {.importc: "atomic_flag".maybeWrapStd, size: 1.} = object Atomic*[T] = object when T is Trivial: @@ -308,27 +323,27 @@ else: guard: AtomicFlag #proc init*[T](location: var Atomic[T]; value: T): T {.importcpp: "atomic_init(@)".} - proc atomic_load_explicit[T, A](location: ptr A; order: MemoryOrder): T {.importc.} - proc atomic_store_explicit[T, A](location: ptr A; desired: T; order: MemoryOrder = moSequentiallyConsistent) {.importc.} - proc atomic_exchange_explicit[T, A](location: ptr A; desired: T; order: MemoryOrder = moSequentiallyConsistent): T {.importc.} - proc atomic_compare_exchange_strong_explicit[T, A](location: ptr A; expected: ptr T; desired: T; success, failure: MemoryOrder): bool {.importc.} - proc atomic_compare_exchange_weak_explicit[T, A](location: ptr A; expected: ptr T; desired: T; success, failure: MemoryOrder): bool {.importc.} + proc atomic_load_explicit[T, A](location: ptr A; order: MemoryOrder): T {.importc: "atomic_load_explicit".maybeWrapStd.} + proc atomic_store_explicit[T, A](location: ptr A; desired: T; order: MemoryOrder = moSequentiallyConsistent) {.importc: "atomic_store_explicit".maybeWrapStd.} + proc atomic_exchange_explicit[T, A](location: ptr A; desired: T; order: MemoryOrder = moSequentiallyConsistent): T {.importc: "atomic_exchange_explicit".maybeWrapStd.} + proc atomic_compare_exchange_strong_explicit[T, A](location: ptr A; expected: ptr T; desired: T; success, failure: MemoryOrder): bool {.importc: "atomic_compare_exchange_strong_explicit".maybeWrapStd.} + proc atomic_compare_exchange_weak_explicit[T, A](location: ptr A; expected: ptr T; desired: T; success, failure: MemoryOrder): bool {.importc: "atomic_compare_exchange_weak_explicit".maybeWrapStd.} # Numerical operations - proc atomic_fetch_add_explicit[T, A](location: ptr A; value: T; order: MemoryOrder = moSequentiallyConsistent): T {.importc.} - proc atomic_fetch_sub_explicit[T, A](location: ptr A; value: T; order: MemoryOrder = moSequentiallyConsistent): T {.importc.} - proc atomic_fetch_and_explicit[T, A](location: ptr A; value: T; order: MemoryOrder = moSequentiallyConsistent): T {.importc.} - proc atomic_fetch_or_explicit[T, A](location: ptr A; value: T; order: MemoryOrder = moSequentiallyConsistent): T {.importc.} - proc atomic_fetch_xor_explicit[T, A](location: ptr A; value: T; order: MemoryOrder = moSequentiallyConsistent): T {.importc.} + proc atomic_fetch_add_explicit[T, A](location: ptr A; value: T; order: MemoryOrder = moSequentiallyConsistent): T {.importc: "atomic_fetch_add_explicit".maybeWrapStd.} + proc atomic_fetch_sub_explicit[T, A](location: ptr A; value: T; order: MemoryOrder = moSequentiallyConsistent): T {.importc: "atomic_fetch_sub_explicit".maybeWrapStd.} + proc atomic_fetch_and_explicit[T, A](location: ptr A; value: T; order: MemoryOrder = moSequentiallyConsistent): T {.importc: "atomic_fetch_and_explicit".maybeWrapStd.} + proc atomic_fetch_or_explicit[T, A](location: ptr A; value: T; order: MemoryOrder = moSequentiallyConsistent): T {.importc: "atomic_fetch_or_explicit".maybeWrapStd.} + proc atomic_fetch_xor_explicit[T, A](location: ptr A; value: T; order: MemoryOrder = moSequentiallyConsistent): T {.importc: "atomic_fetch_xor_explicit".maybeWrapStd.} # Flag operations # var ATOMIC_FLAG_INIT {.importc, nodecl.}: AtomicFlag # proc init*(location: var AtomicFlag) {.inline.} = location = ATOMIC_FLAG_INIT - proc testAndSet*(location: var AtomicFlag; order: MemoryOrder = moSequentiallyConsistent): bool {.importc: "atomic_flag_test_and_set_explicit".} - proc clear*(location: var AtomicFlag; order: MemoryOrder = moSequentiallyConsistent) {.importc: "atomic_flag_clear_explicit".} + proc testAndSet*(location: var AtomicFlag; order: MemoryOrder = moSequentiallyConsistent): bool {.importc: "atomic_flag_test_and_set_explicit".maybeWrapStd.} + proc clear*(location: var AtomicFlag; order: MemoryOrder = moSequentiallyConsistent) {.importc: "atomic_flag_clear_explicit".maybeWrapStd.} - proc fence*(order: MemoryOrder) {.importc: "atomic_thread_fence".} - proc signalFence*(order: MemoryOrder) {.importc: "atomic_signal_fence".} + proc fence*(order: MemoryOrder) {.importc: "atomic_thread_fence".maybeWrapStd.} + proc signalFence*(order: MemoryOrder) {.importc: "atomic_signal_fence".maybeWrapStd.} {.pop.}