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Using single-threaded concurrency was a temporary solution, now that the task-to-thread model actually supports multiple threads, let's switch off of it. Instead, let's introduce a "global executor none" option (implicitly set under the task-to-thread model) to denote that the concurrency model is not using a global executor. rdar://99448771
108 lines
3.6 KiB
C++
108 lines
3.6 KiB
C++
//===--- VoucherShims.h - Shims for OS vouchers --------------------*- 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 - 2021 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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// Shims for interfacing with OS voucher calls.
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//
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//===----------------------------------------------------------------------===//
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#ifndef SWIFT_CONCURRENCY_VOUCHERSHIMS_H
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#define SWIFT_CONCURRENCY_VOUCHERSHIMS_H
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#include "Config.h"
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// swift-corelibs-libdispatch has os/voucher_private.h but it doesn't work for
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// us yet, so only look for it on Apple platforms. We also don't need vouchers
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// in the single threaded concurrency runtime.
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#if __APPLE__ && !SWIFT_THREADING_NONE && __has_include(<os/voucher_private.h>)
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#define SWIFT_HAS_VOUCHER_HEADER 1
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#include <os/voucher_private.h>
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#endif
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// A "dead" voucher pointer, indicating that a voucher has been removed from
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// a Job, distinct from a NULL voucher that could just mean no voucher was
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// present. This allows us to catch problems like adopting a voucher from the
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// same Job twice without restoring it.
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#define SWIFT_DEAD_VOUCHER ((voucher_t)-1)
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// The OS has voucher support if it has the header or if it has ObjC interop.
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#if (SWIFT_HAS_VOUCHER_HEADER || SWIFT_OBJC_INTEROP) && !SWIFT_THREADING_NONE
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#define SWIFT_HAS_VOUCHERS 1
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#endif
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#if SWIFT_HAS_VOUCHERS
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#if SWIFT_CONCURRENCY_TASK_TO_THREAD_MODEL
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#error Cannot use task-to-thread model with vouchers
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#endif
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#if SWIFT_HAS_VOUCHER_HEADER
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#else
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// If the header isn't available, declare the necessary calls here.
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#include <os/object.h>
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#pragma clang diagnostic push
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#pragma clang diagnostic ignored "-Wgnu-zero-variadic-macro-arguments"
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OS_OBJECT_DECL_CLASS(voucher);
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#pragma clang diagnostic pop
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extern "C" voucher_t _Nullable voucher_copy(void);
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// Consumes argument, returns retained value.
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extern "C" voucher_t _Nullable voucher_adopt(voucher_t _Nullable voucher);
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#endif // __has_include(<os/voucher_private.h>)
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static inline void swift_voucher_release(voucher_t _Nullable voucher) {
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// This NULL check isn't necessary, but NULL vouchers will be common, so
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// optimize for that.
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if (!voucher)
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return;
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if (voucher == SWIFT_DEAD_VOUCHER)
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return;
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os_release(voucher);
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}
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#else // __APPLE__
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// Declare some do-nothing stubs for OSes without voucher support.
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typedef void *voucher_t;
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static inline voucher_t _Nullable voucher_copy(void) { return nullptr; }
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static inline voucher_t _Nullable voucher_adopt(voucher_t _Nullable voucher) {
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return nullptr;
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}
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static inline void swift_voucher_release(voucher_t _Nullable voucher) {}
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#endif // __APPLE__
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// Declare our own voucher_needs_adopt for when we don't get it from the SDK.
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// This declaration deliberately takes `void *` instead of `voucher_t`. When the
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// SDK provides one that takes `voucher_t`, then C++ overload resolution will
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// favor that one. When the SDK does not provide a declaration, then the call
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// site will invoke this stub instead.
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static inline bool voucher_needs_adopt(void * _Nullable voucher) {
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return true;
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}
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static inline bool swift_voucher_needs_adopt(voucher_t _Nullable voucher) {
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#if __APPLE__
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if (__builtin_available(macOS 12.0, iOS 15.0, tvOS 15.0, watchOS 8.0, *))
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return voucher_needs_adopt(voucher);
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return true;
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#else
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return voucher_needs_adopt(voucher);
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#endif
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}
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#endif // SWIFT_CONCURRENCY_VOUCHERSHIMS_H
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