| // Copyright (c) 2013 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "tools/gn/scheduler.h" |
| |
| #include <algorithm> |
| |
| #include "base/bind.h" |
| #include "base/command_line.h" |
| #include "base/single_thread_task_runner.h" |
| #include "base/strings/string_number_conversions.h" |
| #include "build/build_config.h" |
| #include "tools/gn/standard_out.h" |
| #include "tools/gn/switches.h" |
| #include "tools/gn/target.h" |
| |
| #if defined(OS_WIN) |
| #include <windows.h> |
| #else |
| #include <unistd.h> |
| #endif |
| |
| Scheduler* g_scheduler = nullptr; |
| |
| namespace { |
| |
| #if defined(OS_WIN) |
| int GetCPUCount() { |
| SYSTEM_INFO sysinfo; |
| ::GetSystemInfo(&sysinfo); |
| return sysinfo.dwNumberOfProcessors; |
| } |
| #else |
| int GetCPUCount() { |
| return static_cast<int>(sysconf(_SC_NPROCESSORS_ONLN)); |
| } |
| #endif |
| |
| int GetThreadCount() { |
| std::string thread_count = |
| base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII( |
| switches::kThreads); |
| |
| // See if an override was specified on the command line. |
| int result; |
| if (!thread_count.empty() && base::StringToInt(thread_count, &result)) |
| return result; |
| |
| // Base the default number of worker threads on number of cores in the |
| // system. When building large projects, the speed can be limited by how fast |
| // the main thread can dispatch work and connect the dependency graph. If |
| // there are too many worker threads, the main thread can be starved and it |
| // will run slower overall. |
| // |
| // One less worker thread than the number of physical CPUs seems to be a |
| // good value, both theoretically and experimentally. But always use at |
| // least some workers to prevent us from being too sensitive to I/O latency |
| // on low-end systems. |
| // |
| // The minimum thread count is based on measuring the optimal threads for the |
| // Chrome build on a several-year-old 4-core MacBook. |
| int num_cores = GetCPUCount() / 2; // Almost all CPUs now are hyperthreaded. |
| return std::max(num_cores - 1, 8); |
| } |
| |
| } // namespace |
| |
| Scheduler::Scheduler() |
| : pool_(new base::SequencedWorkerPool(GetThreadCount(), |
| "worker_", |
| base::TaskPriority::USER_VISIBLE)), |
| input_file_manager_(new InputFileManager), |
| verbose_logging_(false), |
| work_count_(0), |
| is_failed_(false), |
| has_been_shutdown_(false) { |
| g_scheduler = this; |
| } |
| |
| Scheduler::~Scheduler() { |
| if (!has_been_shutdown_) |
| pool_->Shutdown(); |
| g_scheduler = nullptr; |
| } |
| |
| bool Scheduler::Run() { |
| runner_.Run(); |
| bool local_is_failed; |
| { |
| base::AutoLock lock(lock_); |
| local_is_failed = is_failed(); |
| has_been_shutdown_ = true; |
| } |
| // Don't do this inside the lock since it will block on the workers, which |
| // may be in turn waiting on the lock. |
| pool_->Shutdown(); |
| return !local_is_failed; |
| } |
| |
| void Scheduler::Log(const std::string& verb, const std::string& msg) { |
| if (task_runner()->BelongsToCurrentThread()) { |
| LogOnMainThread(verb, msg); |
| } else { |
| // The run loop always joins on the sub threads, so the lifetime of this |
| // object outlives the invocations of this function, hence "unretained". |
| task_runner()->PostTask(FROM_HERE, |
| base::Bind(&Scheduler::LogOnMainThread, |
| base::Unretained(this), verb, msg)); |
| } |
| } |
| |
| void Scheduler::FailWithError(const Err& err) { |
| DCHECK(err.has_error()); |
| { |
| base::AutoLock lock(lock_); |
| |
| if (is_failed_ || has_been_shutdown_) |
| return; // Ignore errors once we see one. |
| is_failed_ = true; |
| } |
| |
| if (task_runner()->BelongsToCurrentThread()) { |
| FailWithErrorOnMainThread(err); |
| } else { |
| // The run loop always joins on the sub threads, so the lifetime of this |
| // object outlives the invocations of this function, hence "unretained". |
| task_runner()->PostTask(FROM_HERE, |
| base::Bind(&Scheduler::FailWithErrorOnMainThread, |
| base::Unretained(this), err)); |
| } |
| } |
| |
| void Scheduler::ScheduleWork(const base::Closure& work) { |
| IncrementWorkCount(); |
| pool_->PostWorkerTaskWithShutdownBehavior( |
| FROM_HERE, base::Bind(&Scheduler::DoWork, |
| base::Unretained(this), work), |
| base::SequencedWorkerPool::BLOCK_SHUTDOWN); |
| } |
| |
| void Scheduler::AddGenDependency(const base::FilePath& file) { |
| base::AutoLock lock(lock_); |
| gen_dependencies_.push_back(file); |
| } |
| |
| std::vector<base::FilePath> Scheduler::GetGenDependencies() const { |
| base::AutoLock lock(lock_); |
| return gen_dependencies_; |
| } |
| |
| void Scheduler::AddWrittenFile(const SourceFile& file) { |
| base::AutoLock lock(lock_); |
| written_files_.push_back(file); |
| } |
| |
| void Scheduler::AddUnknownGeneratedInput(const Target* target, |
| const SourceFile& file) { |
| base::AutoLock lock(lock_); |
| unknown_generated_inputs_.insert(std::make_pair(file, target)); |
| } |
| |
| void Scheduler::AddWriteRuntimeDepsTarget(const Target* target) { |
| base::AutoLock lock(lock_); |
| write_runtime_deps_targets_.push_back(target); |
| } |
| |
| std::vector<const Target*> Scheduler::GetWriteRuntimeDepsTargets() const { |
| base::AutoLock lock(lock_); |
| return write_runtime_deps_targets_; |
| } |
| |
| bool Scheduler::IsFileGeneratedByWriteRuntimeDeps( |
| const OutputFile& file) const { |
| base::AutoLock lock(lock_); |
| // Number of targets should be quite small, so brute-force search is fine. |
| for (const Target* target : write_runtime_deps_targets_) { |
| if (file == target->write_runtime_deps_output()) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| std::multimap<SourceFile, const Target*> |
| Scheduler::GetUnknownGeneratedInputs() const { |
| base::AutoLock lock(lock_); |
| |
| // Remove all unknown inputs that were written files. These are OK as inputs |
| // to build steps since they were written as a side-effect of running GN. |
| // |
| // It's assumed that this function is called once during cleanup to check for |
| // errors, so performing this work in the lock doesn't matter. |
| std::multimap<SourceFile, const Target*> filtered = unknown_generated_inputs_; |
| for (const SourceFile& file : written_files_) |
| filtered.erase(file); |
| |
| return filtered; |
| } |
| |
| void Scheduler::ClearUnknownGeneratedInputsAndWrittenFiles() { |
| base::AutoLock lock(lock_); |
| unknown_generated_inputs_.clear(); |
| written_files_.clear(); |
| } |
| |
| void Scheduler::IncrementWorkCount() { |
| work_count_.Increment(); |
| } |
| |
| void Scheduler::DecrementWorkCount() { |
| if (!work_count_.Decrement()) { |
| if (task_runner()->BelongsToCurrentThread()) { |
| OnComplete(); |
| } else { |
| task_runner()->PostTask(FROM_HERE, base::Bind(&Scheduler::OnComplete, |
| base::Unretained(this))); |
| } |
| } |
| } |
| |
| void Scheduler::LogOnMainThread(const std::string& verb, |
| const std::string& msg) { |
| OutputString(verb, DECORATION_YELLOW); |
| OutputString(" " + msg + "\n"); |
| } |
| |
| void Scheduler::FailWithErrorOnMainThread(const Err& err) { |
| err.PrintToStdout(); |
| runner_.Quit(); |
| } |
| |
| void Scheduler::DoWork(const base::Closure& closure) { |
| closure.Run(); |
| DecrementWorkCount(); |
| } |
| |
| void Scheduler::OnComplete() { |
| // Should be called on the main thread. |
| DCHECK(task_runner()->BelongsToCurrentThread()); |
| runner_.Quit(); |
| } |