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d42f2049f7
For key paths without generic or subscript parameterization, we can turn the compiler-generated key path pattern into a global object in-place.
51 lines
1.4 KiB
C++
51 lines
1.4 KiB
C++
//===--- Once.h - Runtime support for lazy initialization -------*- 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) 2014 - 2017 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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// Swift runtime functions in support of lazy initialization.
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//
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//===----------------------------------------------------------------------===//
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#ifndef SWIFT_RUNTIME_ONCE_H
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#define SWIFT_RUNTIME_ONCE_H
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#include "swift/Runtime/HeapObject.h"
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#include <mutex>
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namespace swift {
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#ifdef __APPLE__
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// On OS X and iOS, swift_once_t matches dispatch_once_t.
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typedef long swift_once_t;
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#elif defined(__CYGWIN__)
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// On Cygwin, std::once_flag can not be used because it is larger than the
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// platform word.
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typedef uintptr_t swift_once_t;
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#else
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// On other platforms swift_once_t is std::once_flag
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typedef std::once_flag swift_once_t;
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#endif
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/// Runs the given function with the given context argument exactly once.
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/// The predicate argument must point to a global or static variable of static
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/// extent of type swift_once_t.
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SWIFT_RUNTIME_EXPORT
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void swift_once(swift_once_t *predicate, void (*fn)(void *), void *context);
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}
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#endif
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