src/tools/gn/scheduler.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "tools/gn/scheduler.h"
   6
   7 #include "base/bind.h"
   8 #include "base/command_line.h"
   9 #include "base/strings/string_number_conversions.h"
  10 #include "tools/gn/ninja_target_writer.h"
  11 #include "tools/gn/standard_out.h"
  12
  13 Scheduler* g_scheduler = NULL;
  14
  15 namespace {
  16
  17 int GetThreadCount() {
  18   std::string thread_count =
  19       CommandLine::ForCurrentProcess()->GetSwitchValueASCII("threads");
  20
  21   int result;
  22   if (thread_count.empty() || !base::StringToInt(thread_count, &result))
  23     return 32;
  24   return result;
  25 }
  26
  27 }  // namespace
  28
  29 Scheduler::Scheduler()
  30     : pool_(new base::SequencedWorkerPool(GetThreadCount(), "worker_")),
  31       input_file_manager_(new InputFileManager),
  32       verbose_logging_(false),
  33       work_count_(0),
  34       is_failed_(false) {
  35   g_scheduler = this;
  36 }
  37
  38 Scheduler::~Scheduler() {
  39   g_scheduler = NULL;
  40 }
  41
  42 bool Scheduler::Run() {
  43   runner_.Run();
  44   pool_->Shutdown();
  45   return !is_failed();
  46 }
  47
  48 void Scheduler::Log(const std::string& verb, const std::string& msg) {
  49   if (base::MessageLoop::current() == &main_loop_) {
  50     LogOnMainThread(verb, msg);
  51   } else {
  52     // The run loop always joins on the sub threads, so the lifetime of this
  53     // object outlives the invocations of this function, hence "unretained".
  54     main_loop_.PostTask(FROM_HERE,
  55                         base::Bind(&Scheduler::LogOnMainThread,
  56                                    base::Unretained(this), verb, msg));
  57   }
  58 }
  59
  60 void Scheduler::FailWithError(const Err& err) {
  61   DCHECK(err.has_error());
  62   {
  63     base::AutoLock lock(lock_);
  64
  65     if (is_failed_)
  66       return;  // Ignore errors once we see one.
  67     is_failed_ = true;
  68   }
  69
  70   if (base::MessageLoop::current() == &main_loop_) {
  71     FailWithErrorOnMainThread(err);
  72   } else {
  73     // The run loop always joins on the sub threads, so the lifetime of this
  74     // object outlives the invocations of this function, hence "unretained".
  75     main_loop_.PostTask(FROM_HERE,
  76                         base::Bind(&Scheduler::FailWithErrorOnMainThread,
  77                                    base::Unretained(this), err));
  78   }
  79 }
  80
  81 void Scheduler::ScheduleWork(const base::Closure& work) {
  82   IncrementWorkCount();
  83   pool_->PostWorkerTaskWithShutdownBehavior(
  84       FROM_HERE, base::Bind(&Scheduler::DoWork,
  85                             base::Unretained(this), work),
  86       base::SequencedWorkerPool::BLOCK_SHUTDOWN);
  87 }
  88
  89 void Scheduler::ScheduleTargetFileWrite(const Target* target) {
  90   pool_->PostWorkerTaskWithShutdownBehavior(
  91       FROM_HERE, base::Bind(&Scheduler::DoTargetFileWrite,
  92                             base::Unretained(this), target),
  93       base::SequencedWorkerPool::BLOCK_SHUTDOWN);
  94 }
  95
  96 void Scheduler::AddGenDependency(const base::FilePath& file) {
  97   base::AutoLock lock(lock_);
  98   gen_dependencies_.push_back(file);
  99 }
 100
 101 std::vector<base::FilePath> Scheduler::GetGenDependencies() const {
 102   base::AutoLock lock(lock_);
 103   return gen_dependencies_;
 104 }
 105
 106 void Scheduler::IncrementWorkCount() {
 107   base::AtomicRefCountInc(&work_count_);
 108 }
 109
 110 void Scheduler::DecrementWorkCount() {
 111   if (!base::AtomicRefCountDec(&work_count_)) {
 112     if (base::MessageLoop::current() == &main_loop_) {
 113       OnComplete();
 114     } else {
 115       main_loop_.PostTask(FROM_HERE,
 116                           base::Bind(&Scheduler::OnComplete,
 117                                      base::Unretained(this)));
 118     }
 119   }
 120 }
 121
 122 void Scheduler::LogOnMainThread(const std::string& verb,
 123                                 const std::string& msg) {
 124   OutputString(verb, DECORATION_YELLOW);
 125   OutputString(" " + msg + "\n");
 126 }
 127
 128 void Scheduler::FailWithErrorOnMainThread(const Err& err) {
 129   err.PrintToStdout();
 130   runner_.Quit();
 131 }
 132
 133 void Scheduler::DoTargetFileWrite(const Target* target) {
 134   NinjaTargetWriter::RunAndWriteFile(target);
 135 }
 136
 137 void Scheduler::DoWork(const base::Closure& closure) {
 138   closure.Run();
 139   DecrementWorkCount();
 140 }
 141
 142 void Scheduler::OnComplete() {
 143   // Should be called on the main thread.
 144   DCHECK(base::MessageLoop::current() == main_loop());
 145   runner_.Quit();
 146 }