tools/gn/scheduler.h

   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 #ifndef TOOLS_GN_SCHEDULER_H_
   6 #define TOOLS_GN_SCHEDULER_H_
   7
   8 #include "base/atomic_ref_count.h"
   9 #include "base/basictypes.h"
  10 #include "base/files/file_path.h"
  11 #include "base/message_loop/message_loop.h"
  12 #include "base/run_loop.h"
  13 #include "base/synchronization/lock.h"
  14 #include "base/threading/sequenced_worker_pool.h"
  15 #include "tools/gn/input_file_manager.h"
  16
  17 class Target;
  18
  19 // Maintains the thread pool and error state.
  20 class Scheduler {
  21  public:
  22   Scheduler();
  23   ~Scheduler();
  24
  25   bool Run();
  26
  27   base::MessageLoop* main_loop() { return &main_loop_; }
  28   base::SequencedWorkerPool* pool() { return pool_; }
  29
  30   InputFileManager* input_file_manager() { return input_file_manager_; }
  31
  32   bool verbose_logging() const { return verbose_logging_; }
  33   void set_verbose_logging(bool v) { verbose_logging_ = v; }
  34
  35   // TODO(brettw) data race on this access (benign?).
  36   bool is_failed() const { return is_failed_; }
  37
  38   void Log(const std::string& verb, const std::string& msg);
  39   void FailWithError(const Err& err);
  40
  41   void ScheduleWork(const base::Closure& work);
  42
  43   void Shutdown();
  44
  45   // Declares that the given file was read and affected the build output.
  46   //
  47   // TODO(brettw) this is global rather than per-BuildSettings. If we
  48   // start using >1 build settings, then we probably want this to take a
  49   // BuildSettings object so we know the depdency on a per-build basis.
  50   void AddGenDependency(const base::FilePath& file);
  51   std::vector<base::FilePath> GetGenDependencies() const;
  52
  53   // We maintain a count of the things we need to do that works like a
  54   // refcount. When this reaches 0, the program exits.
  55   void IncrementWorkCount();
  56   void DecrementWorkCount();
  57
  58  private:
  59   void LogOnMainThread(const std::string& verb, const std::string& msg);
  60   void FailWithErrorOnMainThread(const Err& err);
  61
  62   void DoTargetFileWrite(const Target* target);
  63
  64   void DoWork(const base::Closure& closure);
  65
  66   void OnComplete();
  67
  68   base::MessageLoop main_loop_;
  69   scoped_refptr<base::SequencedWorkerPool> pool_;
  70
  71   scoped_refptr<InputFileManager> input_file_manager_;
  72
  73   base::RunLoop runner_;
  74
  75   bool verbose_logging_;
  76
  77   base::AtomicRefCount work_count_;
  78
  79   mutable base::Lock lock_;
  80   bool is_failed_;
  81
  82   // Used to track whether the worker pool has been shutdown. This is necessary
  83   // to clean up after tests that make a scheduler but don't run the message
  84   // loop.
  85   bool has_been_shutdown_;
  86
  87   // Additional input dependencies. Protected by the lock.
  88   std::vector<base::FilePath> gen_dependencies_;
  89
  90   DISALLOW_COPY_AND_ASSIGN(Scheduler);
  91 };
  92
  93 extern Scheduler* g_scheduler;
  94
  95 #endif  // TOOLS_GN_SCHEDULER_H_
  96