Add OS::GetCurrentProcessId and prepend output from trace-gc with the current pid

src/incremental-marking.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 874 matching lines @@
 
   allocated_ = 0;
 
   steps_count_++;
   steps_count_since_last_gc_++;
 
   bool speed_up = false;
 
   if ((steps_count_ % kAllocationMarkingFactorSpeedupInterval) == 0) {
     if (FLAG_trace_gc) {
-      PrintF("Speed up marking after %d steps\n",
-             static_cast<int>(kAllocationMarkingFactorSpeedupInterval));
+      PrintPID("Speed up marking after %d steps\n",
+               static_cast<int>(kAllocationMarkingFactorSpeedupInterval));
     }
     speed_up = true;
   }
 
   bool space_left_is_very_small =
       (old_generation_space_available_at_start_of_incremental_ < 10 * MB);
 
   bool only_1_nth_of_space_that_was_available_still_left =
       (SpaceLeftInOldSpace() * (allocation_marking_factor_ + 1) <
           old_generation_space_available_at_start_of_incremental_);
 
   if (space_left_is_very_small ||
       only_1_nth_of_space_that_was_available_still_left) {
-    if (FLAG_trace_gc) PrintF("Speed up marking because of low space left\n");
+    if (FLAG_trace_gc) PrintPID("Speed up marking because of low space left\n");
     speed_up = true;
   }
 
   bool size_of_old_space_multiplied_by_n_during_marking =
       (heap_->PromotedTotalSize() >
        (allocation_marking_factor_ + 1) *
            old_generation_space_used_at_start_of_incremental_);
   if (size_of_old_space_multiplied_by_n_during_marking) {
     speed_up = true;
     if (FLAG_trace_gc) {
-      PrintF("Speed up marking because of heap size increase\n");
+      PrintPID("Speed up marking because of heap size increase\n");
     }
   }
 
   int64_t promoted_during_marking = heap_->PromotedTotalSize()
       - old_generation_space_used_at_start_of_incremental_;
   intptr_t delay = allocation_marking_factor_ * MB;
   intptr_t scavenge_slack = heap_->MaxSemiSpaceSize();
 
   // We try to scan at at least twice the speed that we are allocating.
   if (promoted_during_marking > bytes_scanned_ / 2 + scavenge_slack + delay) {
     if (FLAG_trace_gc) {
-      PrintF("Speed up marking because marker was not keeping up\n");
+      PrintPID("Speed up marking because marker was not keeping up\n");
     }
     speed_up = true;
   }
 
   if (speed_up) {
     if (state_ != MARKING) {
       if (FLAG_trace_gc) {
-        PrintF("Postponing speeding up marking until marking starts\n");
+        PrintPID("Postponing speeding up marking until marking starts\n");
       }
     } else {
       allocation_marking_factor_ += kAllocationMarkingFactorSpeedup;
       allocation_marking_factor_ = static_cast<int>(
           Min(kMaxAllocationMarkingFactor,
               static_cast<intptr_t>(allocation_marking_factor_ * 1.3)));
       if (FLAG_trace_gc) {
-        PrintF("Marking speed increased to %d\n", allocation_marking_factor_);
+        PrintPID("Marking speed increased to %d\n", allocation_marking_factor_);
       }
     }
   }
 
   if (FLAG_trace_incremental_marking || FLAG_trace_gc) {
     double end = OS::TimeCurrentMillis();
     double delta = (end - start);
     longest_step_ = Max(longest_step_, delta);
     steps_took_ += delta;
     steps_took_since_last_gc_ += delta;
@@ skipping 15 matching lines @@
   allocation_marking_factor_ = kInitialAllocationMarkingFactor;
   bytes_scanned_ = 0;
 }
 
 
 int64_t IncrementalMarking::SpaceLeftInOldSpace() {
   return heap_->MaxOldGenerationSize() - heap_->PromotedSpaceSizeOfObjects();
 }
 
 } }  // namespace v8::internal