1 //===-- ManagedStatic.cpp - Static Global wrapper -------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the ManagedStatic class and llvm_shutdown().
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/Support/ManagedStatic.h"
15 #include "llvm/Config/config.h"
16 #include "llvm/Support/Atomic.h"
17 #include <cassert>
18 using namespace llvm;
19 
20 static const ManagedStaticBase *StaticList = 0;
21 
22 void ManagedStaticBase::RegisterManagedStatic(void *(*Creator)(),
23                                               void (*Deleter)(void*)) const {
24   if (llvm_is_multithreaded()) {
25     llvm_acquire_global_lock();
26 
27     if (Ptr == 0) {
28       void* tmp = Creator ? Creator() : 0;
29 
30       sys::MemoryFence();
31       Ptr = tmp;
32       DeleterFn = Deleter;
33 
34       // Add to list of managed statics.
35       Next = StaticList;
36       StaticList = this;
37     }
38 
39     llvm_release_global_lock();
40   } else {
41     assert(Ptr == 0 && DeleterFn == 0 && Next == 0 &&
42            "Partially initialized ManagedStatic!?");
43     Ptr = Creator ? Creator() : 0;
44     DeleterFn = Deleter;
45 
46     // Add to list of managed statics.
47     Next = StaticList;
48     StaticList = this;
49   }
50 }
51 
52 void ManagedStaticBase::destroy() const {
53   assert(DeleterFn && "ManagedStatic not initialized correctly!");
54   assert(StaticList == this &&
55          "Not destroyed in reverse order of construction?");
56   // Unlink from list.
57   StaticList = Next;
58   Next = 0;
59 
60   // Destroy memory.
61   DeleterFn(Ptr);
62 
63   // Cleanup.
64   Ptr = 0;
65   DeleterFn = 0;
66 }
67 
68 /// llvm_shutdown - Deallocate and destroy all ManagedStatic variables.
69 void llvm::llvm_shutdown() {
70   while (StaticList)
71     StaticList->destroy();
72 
73   if (llvm_is_multithreaded()) llvm_stop_multithreaded();
74 }
75 
76