Files
swift-mirror/stdlib/public/runtime/SwiftTLSContext.cpp
Alastair Houghton 69f0b03a73 [Threading] Don't use TLS keys as template arguments.
There's no guarantee that e.g. pthread_key_t is an integral type.  It could
be some kind of struct, or some other thing that isn't valid as a template
argument.

rdar://90776105
2022-05-24 14:57:42 +01:00

68 lines
1.9 KiB
C++

//===--- SwiftTLSContext.cpp ----------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2021 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
#include "SwiftTLSContext.h"
#include "swift/Threading/Once.h"
#include "swift/Threading/ThreadLocalStorage.h"
using namespace swift;
using namespace swift::runtime;
SwiftTLSContext &SwiftTLSContext::get() {
#if SWIFT_THREADING_USE_RESERVED_TLS_KEYS
// If we have reserved keys, use those
SwiftTLSContext *ctx =
static_cast<SwiftTLSContext *>(swift::tls_get(swift::tls_key::runtime));
if (ctx)
return *ctx;
static swift::once_t token;
swift::tls_init_once(token, swift::tls_key::runtime, [](void *pointer) {
delete static_cast<SwiftTLSContext *>(pointer);
});
ctx = new SwiftTLSContext();
swift::tls_set(swift::tls_key::runtime, ctx);
return *ctx;
#elif defined(SWIFT_THREAD_LOCAL)
// If we have the thread local attribute, use that
// (note that this happens for the no-threads case too)
static SWIFT_THREAD_LOCAL SwiftTLSContext TLSContext;
return TLSContext;
#else
// Otherwise, allocate ourselves a key and use that
static swift::tls_key_t runtimeKey;
static swift::once_t token;
swift::tls_alloc_once(token, runtimeKey, [](void *pointer) {
delete static_cast<SwiftTLSContext *>(pointer);
});
SwiftTLSContext *ctx =
static_cast<SwiftTLSContext *>(swift::tls_get(runtimeKey));
if (ctx)
return *ctx;
ctx = new SwiftTLSContext();
swift::tls_set(runtimeKey, ctx);
return *ctx;
#endif
}