1 //===-- llvm/Support/Threading.cpp- Control multithreading mode --*- C++ -*-==//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines helper functions for running LLVM in a multi-threaded
13 //===----------------------------------------------------------------------===//
15 #include "llvm/Support/Threading.h"
16 #include "llvm/Config/config.h"
17 #include "llvm/Support/Host.h"
26 //===----------------------------------------------------------------------===//
27 //=== WARNING: Implementation here must contain only TRULY operating system
28 //=== independent code.
29 //===----------------------------------------------------------------------===//
31 bool llvm::llvm_is_multithreaded() {
32 #if LLVM_ENABLE_THREADS != 0
39 #if LLVM_ENABLE_THREADS == 0 || \
40 (!defined(LLVM_ON_WIN32) && !defined(HAVE_PTHREAD_H))
41 // Support for non-Win32, non-pthread implementation.
42 void llvm::llvm_execute_on_thread(void (*Fn)(void *), void *UserData,
43 unsigned RequestedStackSize) {
44 (void)RequestedStackSize;
48 unsigned llvm::heavyweight_hardware_concurrency() { return 1; }
50 uint64_t llvm::get_threadid() { return 0; }
52 uint32_t llvm::get_max_thread_name_length() { return 0; }
54 void llvm::set_thread_name(const Twine &Name) {}
56 void llvm::get_thread_name(SmallVectorImpl<char> &Name) { Name.clear(); }
61 unsigned llvm::heavyweight_hardware_concurrency() {
62 // Since we can't get here unless LLVM_ENABLE_THREADS == 1, it is safe to use
63 // `std::thread` directly instead of `llvm::thread` (and indeed, doing so
64 // allows us to not define `thread` in the llvm namespace, which conflicts
65 // with some platforms such as FreeBSD whose headers also define a struct
66 // called `thread` in the global namespace which can cause ambiguity due to
68 int NumPhysical = sys::getHostNumPhysicalCores();
69 if (NumPhysical == -1)
70 return std::thread::hardware_concurrency();
74 // Include the platform-specific parts of this class.
76 #include "Unix/Threading.inc"
79 #include "Windows/Threading.inc"