xref: /llvm-project-15.0.7/llvm/lib/Support/ThreadLocal.cpp (revision cf01800b)

//===- ThreadLocal.cpp - Thread Local Data ----------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the llvm::sys::ThreadLocal class.
//
//===----------------------------------------------------------------------===//

#include "llvm/Config/config.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ThreadLocal.h"

//===----------------------------------------------------------------------===//
//=== WARNING: Implementation here must contain only TRULY operating system
//===          independent code.
//===----------------------------------------------------------------------===//

#if !defined(LLVM_ENABLE_THREADS) || LLVM_ENABLE_THREADS == 0
// Define all methods as no-ops if threading is explicitly disabled
namespace llvm {
using namespace sys;
ThreadLocalImpl::ThreadLocalImpl() : data() { }
ThreadLocalImpl::~ThreadLocalImpl() { }
void ThreadLocalImpl::setInstance(const void* d) {
  static_assert(sizeof(d) <= sizeof(data), "size too big");
  void **pd = reinterpret_cast<void**>(&data);
  *pd = const_cast<void*>(d);
}
const void* ThreadLocalImpl::getInstance() {
  void **pd = reinterpret_cast<void**>(&data);
  return *pd;
}
void ThreadLocalImpl::removeInstance() {
  setInstance(0);
}
}
#else

#if defined(HAVE_PTHREAD_H) && defined(HAVE_PTHREAD_GETSPECIFIC)

#include <cassert>
#include <pthread.h>
#include <stdlib.h>

namespace llvm {
using namespace sys;

ThreadLocalImpl::ThreadLocalImpl() : data() {
  static_assert(sizeof(pthread_key_t) <= sizeof(data), "size too big");
  pthread_key_t* key = reinterpret_cast<pthread_key_t*>(&data);
  int errorcode = pthread_key_create(key, NULL);
  assert(errorcode == 0);
  (void) errorcode;
}

ThreadLocalImpl::~ThreadLocalImpl() {
  pthread_key_t* key = reinterpret_cast<pthread_key_t*>(&data);
  int errorcode = pthread_key_delete(*key);
  assert(errorcode == 0);
  (void) errorcode;
}

void ThreadLocalImpl::setInstance(const void* d) {
  pthread_key_t* key = reinterpret_cast<pthread_key_t*>(&data);
  int errorcode = pthread_setspecific(*key, d);
  assert(errorcode == 0);
  (void) errorcode;
}

const void* ThreadLocalImpl::getInstance() {
  pthread_key_t* key = reinterpret_cast<pthread_key_t*>(&data);
  return pthread_getspecific(*key);
}

void ThreadLocalImpl::removeInstance() {
  setInstance(0);
}

}

#elif defined(LLVM_ON_UNIX)
#include "Unix/ThreadLocal.inc"
#elif defined( LLVM_ON_WIN32)
#include "Windows/ThreadLocal.inc"
#else
#warning Neither LLVM_ON_UNIX nor LLVM_ON_WIN32 set in Support/ThreadLocal.cpp
#endif
#endif