Use idle time to make progress on scheduled compilation jobs

src/compiler-dispatcher/compiler-dispatcher.h

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_DISPATCHER_COMPILER_DISPATCHER_H_
 #define V8_COMPILER_DISPATCHER_COMPILER_DISPATCHER_H_
 
+#include <functional>
 #include <map>
 #include <memory>
+#include <unordered_set>
 #include <utility>
 
+#include "src/base/functional.h"
 #include "src/base/macros.h"
 #include "src/globals.h"
+#include "testing/gtest/include/gtest/gtest_prod.h"
 
 namespace v8 {
+
+class Platform;
+
 namespace internal {
 
 class CompilerDispatcherJob;
 class CompilerDispatcherTracer;
 class Isolate;
 class SharedFunctionInfo;
 
 template <typename T>
 class Handle;
 
 class V8_EXPORT_PRIVATE CompilerDispatcher {
  public:
   enum class BlockingBehavior { kBlock, kDontBlock };
 
-  CompilerDispatcher(Isolate* isolate, size_t max_stack_size);
+  CompilerDispatcher(Isolate* isolate, Platform* platform,
+                     size_t max_stack_size);
   ~CompilerDispatcher();
 
   // Returns true if a job was enqueued.
   bool Enqueue(Handle<SharedFunctionInfo> function);
 
   // Returns true if there is a pending job for the given function.
   bool IsEnqueued(Handle<SharedFunctionInfo> function) const;
 
   // Blocks until the given function is compiled (and does so as fast as
   // possible). Returns true if the compile job was succesful.
   bool FinishNow(Handle<SharedFunctionInfo> function);
 
   // Aborts a given job. Blocks if requested.
   void Abort(Handle<SharedFunctionInfo> function, BlockingBehavior blocking);
 
   // Aborts all jobs. Blocks if requested.
   void AbortAll(BlockingBehavior blocking);
 
  private:
+  FRIEND_TEST(CompilerDispatcherTest, IdleTaskSmallIdleTime);
+
   typedef std::multimap<std::pair<int, int>,
                         std::unique_ptr<CompilerDispatcherJob>>

[vogelheim, 2016/12/15 15:24:12]

nitpick: Maybe typedef std::unordered_set<JobMap::const_iterator,
JobIteratorHash> to something? You're using it a number of times in this header.

[jochen (gone - plz use gerrit), 2016/12/15 15:37:59]

done

       JobMap;
+  class IdleTask;
+  struct JobIteratorHash {
+   public:
+    size_t operator()(const JobMap::const_iterator& it) const {
+      std::hash<int> hasher;

[vogelheim, 2016/12/15 15:24:12]

Why std::hash<int>, and not v8::base::hash<int>?

(Or are those the same? It doesn't look like they are...)

[jochen (gone - plz use gerrit), 2016/12/15 15:37:59]

no reason, fixed

+      return base::hash_combine(hasher(it->first.first),
+                                hasher(it->first.second));
+    }
+  };
+
   JobMap::const_iterator GetJobFor(Handle<SharedFunctionInfo> shared) const;
+  void ScheduleIdleTaskIfNeeded();
+  void DoIdleWork(double deadline_in_seconds);
+  void DoIdleWorkForJobSet(
+      double deadline_in_seconds,
+      std::unordered_set<JobMap::const_iterator, JobIteratorHash>* job_set);
+  void ClassifyJob(JobMap::const_iterator it);
 
   Isolate* isolate_;
+  Platform* platform_;
   size_t max_stack_size_;
   std::unique_ptr<CompilerDispatcherTracer> tracer_;
 
+  bool idle_task_scheduled_;
+
   // Mapping from (script id, function literal id) to job. We use a multimap,
   // as script id is not necessarily unique.
   JobMap jobs_;
 
+  std::unordered_set<JobMap::const_iterator, JobIteratorHash>
+      jobs_for_main_thread_;
+  std::unordered_set<JobMap::const_iterator, JobIteratorHash>
+      jobs_for_background_thread_;
+
   DISALLOW_COPY_AND_ASSIGN(CompilerDispatcher);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_DISPATCHER_COMPILER_DISPATCHER_H_