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fc4f941185
Fetching the current stack bounds is done using threading functions, so should be in the threading library. rdar://90776105
119 lines
3.1 KiB
C++
119 lines
3.1 KiB
C++
//==--- Pthreads.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 plain pthreads
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//
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//===----------------------------------------------------------------------===//
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#if SWIFT_THREADING_PTHREADS
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#if defined(__FreeBSD__) || defined(__OpenBSD__)
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#include <pthread_np.h>
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#endif
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#include "swift/Threading/Impl/Pthreads.h"
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#include "swift/Threading/Errors.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 MainThreadRememberer {
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private:
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pthread_t mainThread_;
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public:
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MainThreadRememberer() { mainThread_ = pthread_self(); }
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pthread_t main_thread() const { return mainThread_; }
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};
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MainThreadRememberer rememberer;
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pthread_mutex_t onceMutex = PTHREAD_MUTEX_INITIALIZER;
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pthread_cond_t onceCond = PTHREAD_COND_INITIALIZER;
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#pragma clang diagnostic pop
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} // namespace
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using namespace swift;
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using namespace threading_impl;
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bool swift::threading_impl::thread_is_main() {
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return pthread_equal(pthread_self(), rememberer.main_thread());
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}
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void swift::threading_impl::once_slow(once_t &predicate, void (*fn)(void *),
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void *context) {
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std::int64_t zero = 0;
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if (predicate.compare_exchange_strong(zero, (std::int64_t)1,
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std::memory_order_relaxed,
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std::memory_order_relaxed)) {
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fn(context);
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predicate.store((std::int64_t)-1, std::memory_order_release);
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pthread_mutex_lock(&onceMutex);
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pthread_mutex_unlock(&onceMutex);
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pthread_cond_broadcast(&onceCond);
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return;
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}
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pthread_mutex_lock(&onceMutex);
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while (predicate.load(std::memory_order_acquire) >= (std::int64_t)0) {
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pthread_cond_wait(&onceCond);
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}
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pthread_mutex_unlock(&onceMutex);
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}
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#if defined(__OpenBSD__)
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swift::threading_impl::stack_bounds
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swift::threading_impl::thread_get_current_stack_bounds() {
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stack_bounds result = { nullptr, nullptr };
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stack_t sinfo;
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if (!pthread_stackseg_np(pthread_self(), &sinfo)) {
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result.low = (char *)sinfo.ss_sp - sinfo.ss_size;
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result.high = sinfo.ss_sp;
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}
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return result;
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}
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#else
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swift::threading_impl::stack_bounds
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swift::threading_impl::thread_get_current_stack_bounds() {
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stack_bounds result = { nullptr, nullptr };
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pthread_attr_t attr;
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size_t size = 0;
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void *begin = nullptr;
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#if defined(__FreeBSD__)
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if (pthread_attr_init(&attr))
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return result;
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#endif
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if (!pthread_getattr_np(pthread_self(), &attr)) {
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if (!pthread_attr_getstack(&attr, &begin, &size)) {
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result.low = begin;
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result.high = (char *)begin + size;
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}
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pthread_attr_destroy(&attr);
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}
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return result;
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}
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#endif
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#endif // SWIFT_THREADING_PTHREADS
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