Add more safe points in compiler

runtime/vm/pages.h

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_VM_PAGES_H_
 #define RUNTIME_VM_PAGES_H_
 
 #include "vm/freelist.h"
 #include "vm/globals.h"
 #include "vm/lockers.h"
@@ skipping 306 matching lines @@
   uword* EndAddress() { return &bump_end_; }
   static intptr_t top_offset() { return OFFSET_OF(PageSpace, bump_top_); }
   static intptr_t end_offset() { return OFFSET_OF(PageSpace, bump_end_); }
 
   void SetupImagePage(void* pointer, uword size, bool is_executable);
 
  private:
   // Ids for time and data records in Heap::GCStats.
   enum {
     // Time
-    kMarkObjects = 0,
-    kResetFreeLists = 1,
-    kSweepPages = 2,
-    kSweepLargePages = 3,
+    kSafePoint = 0,
+    kMarkObjects = 1,
+    kResetFreeLists = 2,
+    kSweepPages = 3,
+    kSweepLargePages = 4,

[siva, 2017/03/23 18:05:01]

Might be a better to add the new time slot as the last entry of the times
section.

People who have been staring at verbose GC logs could have gotten used to the
first four entries being marking/resetting/sweeping etc.

[erikcorry, 2017/03/27 10:23:28]

I think it makes most sense to have them in the order they actually happen, and
safe-point waiting happens first.

But it's true that the output is hard to read. I propose padding better so that
the columns more or less line up with the header.  See new version at
https://screenshot.googleplex.com/GrM71QDzLFp vs old version at
https://screenshot.googleplex.com/CExFc3619EC

     // Data
     kGarbageRatio = 0,
     kGCTimeFraction = 1,
     kPageGrowth = 2,
     kAllowedGrowth = 3
   };
 
   static const intptr_t kAllocatablePageSize = 64 * KB;
 
   uword TryAllocateInternal(intptr_t size,
@@ skipping 84 matching lines @@
   friend class HeapIterationScope;
   friend class PageSpaceController;
   friend class SweeperTask;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(PageSpace);
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_PAGES_H_