LLVM 20.0.0git
ManagedStatic.cpp
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1//===-- ManagedStatic.cpp - Static Global wrapper -------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the ManagedStatic class and llvm_shutdown().
10//
11//===----------------------------------------------------------------------===//
12
14#include "llvm/Config/config.h"
16#include <cassert>
17#include <mutex>
18using namespace llvm;
19
20static const ManagedStaticBase *StaticList = nullptr;
21
22static std::recursive_mutex *getManagedStaticMutex() {
23 static std::recursive_mutex m;
24 return &m;
25}
26
28 void (*Deleter)(void*)) const {
29 assert(Creator);
31 std::lock_guard<std::recursive_mutex> Lock(*getManagedStaticMutex());
32
33 if (!Ptr.load(std::memory_order_relaxed)) {
34 void *Tmp = Creator();
35
36 Ptr.store(Tmp, std::memory_order_release);
37 DeleterFn = Deleter;
38
39 // Add to list of managed statics.
41 StaticList = this;
42 }
43 } else {
44 assert(!Ptr && !DeleterFn && !Next &&
45 "Partially initialized ManagedStatic!?");
46 Ptr = Creator();
47 DeleterFn = Deleter;
48
49 // Add to list of managed statics.
51 StaticList = this;
52 }
53}
54
56 assert(DeleterFn && "ManagedStatic not initialized correctly!");
57 assert(StaticList == this &&
58 "Not destroyed in reverse order of construction?");
59 // Unlink from list.
61 Next = nullptr;
62
63 // Destroy memory.
65
66 // Cleanup.
67 Ptr = nullptr;
68 DeleterFn = nullptr;
69}
70
71/// llvm_shutdown - Deallocate and destroy all ManagedStatic variables.
72/// IMPORTANT: it's only safe to call llvm_shutdown() in single thread,
73/// without any other threads executing LLVM APIs.
74/// llvm_shutdown() should be the last use of LLVM APIs.
76 while (StaticList)
78}
static std::recursive_mutex * getManagedStaticMutex()
static const ManagedStaticBase * StaticList
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
ManagedStaticBase - Common base class for ManagedStatic instances.
Definition: ManagedStatic.h:49
void RegisterManagedStatic(void *(*creator)(), void(*deleter)(void *)) const
void(* DeleterFn)(void *)
Definition: ManagedStatic.h:53
const ManagedStaticBase * Next
Definition: ManagedStatic.h:54
std::atomic< void * > Ptr
Definition: ManagedStatic.h:52
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
constexpr bool llvm_is_multithreaded()
Returns true if LLVM is compiled with support for multi-threading, and false otherwise.
Definition: Threading.h:53
void llvm_shutdown()
llvm_shutdown - Deallocate and destroy all ManagedStatic variables.