| //===-- llvm/Support/Threading.cpp- Control multithreading mode --*- C++ -*-==// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines helper functions for running LLVM in a multi-threaded |
| // environment. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Support/Threading.h" |
| #include "llvm/ADT/Optional.h" |
| #include "llvm/Config/config.h" |
| #include "llvm/Support/Host.h" |
| |
| #include <cassert> |
| #include <errno.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| using namespace llvm; |
| |
| //===----------------------------------------------------------------------===// |
| //=== WARNING: Implementation here must contain only TRULY operating system |
| //=== independent code. |
| //===----------------------------------------------------------------------===// |
| |
| bool llvm::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 llvm::llvm_execute_on_thread(void (*Fn)(void *), void *UserData, |
| llvm::Optional<unsigned> StackSizeInBytes) { |
| (void)StackSizeInBytes; |
| Fn(UserData); |
| } |
| |
| uint64_t llvm::get_threadid() { return 0; } |
| |
| uint32_t llvm::get_max_thread_name_length() { return 0; } |
| |
| void llvm::set_thread_name(const Twine &Name) {} |
| |
| void llvm::get_thread_name(SmallVectorImpl<char> &Name) { Name.clear(); } |
| |
| llvm::BitVector llvm::get_thread_affinity_mask() { return {}; } |
| |
| unsigned llvm::ThreadPoolStrategy::compute_thread_count() const { |
| // When threads are disabled, ensure clients will loop at least once. |
| return 1; |
| } |
| |
| #if LLVM_ENABLE_THREADS == 0 |
| void llvm::llvm_execute_on_thread_async( |
| llvm::unique_function<void()> Func, |
| llvm::Optional<unsigned> StackSizeInBytes) { |
| (void)Func; |
| (void)StackSizeInBytes; |
| report_fatal_error("Spawning a detached thread doesn't make sense with no " |
| "threading support"); |
| } |
| #else |
| // Support for non-Win32, non-pthread implementation. |
| void llvm::llvm_execute_on_thread_async( |
| llvm::unique_function<void()> Func, |
| llvm::Optional<unsigned> StackSizeInBytes) { |
| (void)StackSizeInBytes; |
| std::thread(std::move(Func)).detach(); |
| } |
| #endif |
| |
| #else |
| |
| int computeHostNumHardwareThreads(); |
| |
| unsigned llvm::ThreadPoolStrategy::compute_thread_count() const { |
| int MaxThreadCount = UseHyperThreads ? computeHostNumHardwareThreads() |
| : sys::getHostNumPhysicalCores(); |
| if (MaxThreadCount <= 0) |
| MaxThreadCount = 1; |
| if (ThreadsRequested == 0) |
| return MaxThreadCount; |
| if (!Limit) |
| return ThreadsRequested; |
| return std::min((unsigned)MaxThreadCount, ThreadsRequested); |
| } |
| |
| namespace { |
| struct SyncThreadInfo { |
| void (*UserFn)(void *); |
| void *UserData; |
| }; |
| |
| using AsyncThreadInfo = llvm::unique_function<void()>; |
| |
| enum class JoiningPolicy { Join, Detach }; |
| } // namespace |
| |
| // Include the platform-specific parts of this class. |
| #ifdef LLVM_ON_UNIX |
| #include "Unix/Threading.inc" |
| #endif |
| #ifdef _WIN32 |
| #include "Windows/Threading.inc" |
| #endif |
| |
| void llvm::llvm_execute_on_thread(void (*Fn)(void *), void *UserData, |
| llvm::Optional<unsigned> StackSizeInBytes) { |
| |
| SyncThreadInfo Info = {Fn, UserData}; |
| llvm_execute_on_thread_impl(threadFuncSync, &Info, StackSizeInBytes, |
| JoiningPolicy::Join); |
| } |
| |
| void llvm::llvm_execute_on_thread_async( |
| llvm::unique_function<void()> Func, |
| llvm::Optional<unsigned> StackSizeInBytes) { |
| llvm_execute_on_thread_impl(&threadFuncAsync, |
| new AsyncThreadInfo(std::move(Func)), |
| StackSizeInBytes, JoiningPolicy::Detach); |
| } |
| |
| #endif |
| |
| Optional<ThreadPoolStrategy> |
| llvm::get_threadpool_strategy(StringRef Num, ThreadPoolStrategy Default) { |
| if (Num == "all") |
| return llvm::hardware_concurrency(); |
| if (Num.empty()) |
| return Default; |
| unsigned V; |
| if (Num.getAsInteger(10, V)) |
| return None; // malformed 'Num' value |
| if (V == 0) |
| return Default; |
| |
| // Do not take the Default into account. This effectively disables |
| // heavyweight_hardware_concurrency() if the user asks for any number of |
| // threads on the cmd-line. |
| ThreadPoolStrategy S = llvm::hardware_concurrency(); |
| S.ThreadsRequested = V; |
| return S; |
| } |