//===-- llvm/Support/Threading.cpp- Control multithreading mode --*- C++ -*-==//

//

//                     The LLVM Compiler Infrastructure

//

// This file is distributed under the University of Illinois Open Source

// License. See LICENSE.TXT for details.

//

//===----------------------------------------------------------------------===//

//

// This file defines helper functions for running LLVM in a multi-threaded

// environment.

//

//===----------------------------------------------------------------------===//

#include "llvh/Support/Threading.h"

#include "llvh/Config/config.h"

#include "llvh/Support/Host.h"

#include <cassert>

#include <errno.h>

#include <stdlib.h>

#include <string.h>

using namespace llvh;

//===----------------------------------------------------------------------===//

//=== WARNING: Implementation here must contain only TRULY operating system

//===          independent code.

//===----------------------------------------------------------------------===//

bool llvh::llvm_is_multithreaded() {

#if LLVM_ENABLE_THREADS != 0

  return true;

#else

  return false;

#endif

}

#if LLVM_ENABLE_THREADS == 0 ||                                                \

    (!defined(_WIN32) && !defined(HAVE_PTHREAD_H))

// Support for non-Win32, non-pthread implementation.

void llvh::llvm_execute_on_thread(void (*Fn)(void *), void *UserData,

                                  unsigned RequestedStackSize) {

  (void)RequestedStackSize;

  Fn(UserData);

}

unsigned llvh::heavyweight_hardware_concurrency() { return 1; }

unsigned llvh::hardware_concurrency() { return 1; }

uint64_t llvh::get_threadid() { return 0; }

uint32_t llvh::get_max_thread_name_length() { return 0; }

void llvh::set_thread_name(const Twine &Name) {}

void llvh::get_thread_name(SmallVectorImpl<char> &Name) { Name.clear(); }

#else

#include <thread>

unsigned llvh::heavyweight_hardware_concurrency() {

  // Since we can't get here unless LLVM_ENABLE_THREADS == 1, it is safe to use

  // `std::thread` directly instead of `llvh::thread` (and indeed, doing so

  // allows us to not define `thread` in the llvm namespace, which conflicts

  // with some platforms such as FreeBSD whose headers also define a struct

  // called `thread` in the global namespace which can cause ambiguity due to

  // ADL.

  int NumPhysical = sys::getHostNumPhysicalCores();

  if (NumPhysical == -1)

    return std::thread::hardware_concurrency();

  return NumPhysical;

}

unsigned llvh::hardware_concurrency() {

#if defined(HAVE_SCHED_GETAFFINITY) && defined(HAVE_CPU_COUNT)

  cpu_set_t Set;

  if (sched_getaffinity(0, sizeof(Set), &Set))

    return CPU_COUNT(&Set);

#endif

  // Guard against std::thread::hardware_concurrency() returning 0.

  if (unsigned Val = std::thread::hardware_concurrency())

    return Val;

  return 1;

}

// Include the platform-specific parts of this class.

#ifdef LLVM_ON_UNIX

#include "Unix/Threading.inc"

#endif

#ifdef _WIN32

#include "Windows/Threading.inc"

#endif

#endif