Line data    Source code

       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/Mutex.h"
      17             : #include "llvm/Support/MutexGuard.h"
      18             : #include "llvm/Support/Threading.h"
      19             : #include <cassert>
      20             : using namespace llvm;
      21             : 
      22             : static const ManagedStaticBase *StaticList = nullptr;
      23             : static sys::Mutex *ManagedStaticMutex = nullptr;
      24             : static llvm::once_flag mutex_init_flag;
      25             : 
      26      181221 : static void initializeMutex() {
      27      181221 :   ManagedStaticMutex = new sys::Mutex();
      28      181221 : }
      29             : 
      30             : static sys::Mutex* getManagedStaticMutex() {
      31             :   llvm::call_once(mutex_init_flag, initializeMutex);
      32     1514565 :   return ManagedStaticMutex;
      33             : }
      34             : 
      35     1349297 : void ManagedStaticBase::RegisterManagedStatic(void *(*Creator)(),
      36             :                                               void (*Deleter)(void*)) const {
      37             :   assert(Creator);
      38     1349297 :   if (llvm_is_multithreaded()) {
      39             :     MutexGuard Lock(*getManagedStaticMutex());
      40             : 
      41     1349297 :     if (!Ptr.load(std::memory_order_relaxed)) {
      42     1349297 :       void *Tmp = Creator();
      43             : 
      44             :       Ptr.store(Tmp, std::memory_order_release);
      45     1349297 :       DeleterFn = Deleter;
      46             : 
      47             :       // Add to list of managed statics.
      48     1349297 :       Next = StaticList;
      49     1349297 :       StaticList = this;
      50             :     }
      51             :   } else {
      52             :     assert(!Ptr && !DeleterFn && !Next &&
      53             :            "Partially initialized ManagedStatic!?");
      54           0 :     Ptr = Creator();
      55           0 :     DeleterFn = Deleter;
      56             : 
      57             :     // Add to list of managed statics.
      58           0 :     Next = StaticList;
      59           0 :     StaticList = this;
      60             :   }
      61     1349297 : }
      62             : 
      63     1251686 : void ManagedStaticBase::destroy() const {
      64             :   assert(DeleterFn && "ManagedStatic not initialized correctly!");
      65             :   assert(StaticList == this &&
      66             :          "Not destroyed in reverse order of construction?");
      67             :   // Unlink from list.
      68     1251686 :   StaticList = Next;
      69     1251686 :   Next = nullptr;
      70             : 
      71             :   // Destroy memory.
      72     2503372 :   DeleterFn(Ptr);
      73             : 
      74             :   // Cleanup.
      75             :   Ptr = nullptr;
      76     1251686 :   DeleterFn = nullptr;
      77     1251686 : }
      78             : 
      79             : /// llvm_shutdown - Deallocate and destroy all ManagedStatic variables.
      80      165268 : void llvm::llvm_shutdown() {
      81             :   MutexGuard Lock(*getManagedStaticMutex());
      82             : 
      83     1416954 :   while (StaticList)
      84     1251686 :     StaticList->destroy();
      85      165268 : }