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f5bdb858e0
Moved all the threading code to one place. Added explicit support for Darwin, Linux, Pthreads, C11 threads and Win32 threads, including new implementations of Once for Linux, Pthreads, C11 and Win32. rdar://90776105
104 lines
2.7 KiB
C++
104 lines
2.7 KiB
C++
//==--- C11.cpp - Threading abstraction implementation --------- -*-C++ -*-===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2022 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See https://swift.org/LICENSE.txt for license information
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// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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//
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// Implements threading support for C11 threads
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//
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//===----------------------------------------------------------------------===//
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#if SWIFT_THREADING_C11
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#include "swift/Threading/Errors.h"
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#include "swift/Threading/Impl/C11.h"
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namespace {
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#pragma clang diagnostic push
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#pragma GCC diagnostic ignored "-Wglobal-constructors"
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class C11ThreadingHelper {
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private:
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thrd_t mainThread_;
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mut_t onceMutex_;
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cnd_t onceCond_;
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public:
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C11ThreadingHelper() {
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mainThread_ = thrd_current();
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SWIFT_C11THREADS_CHECK(::mtx_init(&onceMutex_, ::mtx_plain));
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SWIFT_C11THREADS_CHECK(::cnd_init(&onceCond_));
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}
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thrd_t main_thread() const { return mainThread_; }
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void once_lock() {
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SWIFT_C11THREADS_CHECK(mtx_lock(&onceMutex_));
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}
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void once_unlock() {
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SWIFT_C11THREADS_CHECK(mtx_unlock(&onceMutex_));
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}
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void once_broadcast() {
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SWIFT_C11THREADS_CHECK(cnd_broadcast(&onceCond_));
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}
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void once_wait() {
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SWIFT_C11THREADS_CHECK(mtx_lock(&onceMutex_));
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SWIFT_C11THREADS_CHECK(cnd_wait(&onceCond_, &onceMutex_));
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SWIFT_C11THREADS_CHECK(mtx_unlock(&onceMutex_));
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}
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};
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C11ThreadingHelper helper;
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#pragma clang diagnostic pop
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}
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using namespace swift;
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using namespace threading_impl;
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thread_id
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swift::threading_impl::thread_get_main() {
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return helper.main_thread();
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}
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bool
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swift::threading_impl::thread_is_main() {
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return thrd_equal(thrd_current(), thread_get_main());
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}
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void
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swift::threading_impl::once_slow(once_t &predicate,
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void (*fn)(void *),
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void *context) {
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if (::atomic_compare_exchange_strong_explicit(&predicate,
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&(int){ 0 },
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1,
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::memory_order_relaxed,
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::memory_order_relaxed)) {
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fn(context);
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::atomic_store_explicit(&predicate, -1, ::memory_order_release);
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helper.once_lock();
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helper.once_unlock();
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helper.once_broadcast();
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return;
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}
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helper.once_lock();
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while (::atomic_load_explicit(&predicate, memory_order_acquire) >= 0) {
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helper.once_wait();
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}
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helper.once_unlock();
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}
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#endif // SWIFT_THREADING_C11
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