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f3a412dd53
Removing thread_get_main() means we don't need a static initializer on Darwin, which means we can delete Darwin.cpp as well. We can also delete Nothreads.cpp while we're about it, because there's nothing in that file. rdar://90776105
99 lines
2.6 KiB
C++
99 lines
2.6 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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bool
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swift::threading_impl::thread_is_main() {
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return thrd_equal(thrd_current(), helper.main_thread());
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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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