Extend tick-processor utility to generate an execution timeline based on the reported VM states

tools/tickprocessor.js

 // 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 167 matching lines @@
       'profiler': null,
       'function-creation': null,
       'function-move': null,
       'function-delete': null,
       'heap-sample-item': null,
       // Obsolete row types.
       'code-allocate': null,
       'begin-code-region': null,
       'end-code-region': null });
 
+  this.timeline_ = "";
   this.cppEntriesProvider_ = cppEntriesProvider;
   this.callGraphSize_ = callGraphSize;
   this.ignoreUnknown_ = ignoreUnknown;
   this.stateFilter_ = stateFilter;
   this.snapshotLogProcessor_ = snapshotLogProcessor;
   this.deserializedEntriesNames_ = [];
   var ticks = this.ticks_ =
     { total: 0, unaccounted: 0, excluded: 0, gc: 0 };
 
   V8Profile.prototype.handleUnknownCode = function(
@@ skipping 142 matching lines @@
     this.deserializedEntriesNames_[addr] =
       this.snapshotLogProcessor_.getSerializedEntryName(pos);
   }
 };
 
 
 TickProcessor.prototype.includeTick = function(vmState) {
   return this.stateFilter_ == null || this.stateFilter_ == vmState;
 };
 
+TickProcessor.prototype.recordTickTimeline = function(vmState) {
+  if (vmState == TickProcessor.VmStates.JS) this.timeline_ += "J";
+  else if (vmState == TickProcessor.VmStates.GC) this.timeline_ += "G";
+  else if (vmState == TickProcessor.VmStates.COMPILER) this.timeline_ += "C";
+  else if (vmState == TickProcessor.VmStates.PARALLEL_COMPILER_PROLOGUE) this.timeline_ += "|";
+  else if (vmState == TickProcessor.VmStates.OTHER) this.timeline_ += "O";
+  else if (vmState == TickProcessor.VmStates.EXTERNAL) this.timeline_ += ".";
+  else this.timeline_ += "U";
+}
+
 TickProcessor.prototype.processTick = function(pc,
                                                sp,
                                                is_external_callback,
                                                tos_or_external_callback,
                                                vmState,
                                                stack) {
   this.ticks_.total++;
+  this.recordTickTimeline(vmState);
   if (vmState == TickProcessor.VmStates.GC) this.ticks_.gc++;
   if (!this.includeTick(vmState)) {
     this.ticks_.excluded++;
     return;
   }
   if (is_external_callback) {
     // Don't use PC when in external callback code, as it can point
     // inside callback's code, and we will erroneously report
     // that a callback calls itself. Instead we use tos_or_external_callback,
     // as simply resetting PC will produce unaccounted ticks.
@@ skipping 91 matching lines @@
   this.printHeavyProfHeader();
   var heavyProfile = this.profile_.getBottomUpProfile();
   var heavyView = this.viewBuilder_.buildView(heavyProfile);
   // To show the same percentages as in the flat profile.
   heavyView.head.totalTime = totalTicks;
   // Sort by total time, desc, then by name, desc.
   heavyView.sort(function(rec1, rec2) {
       return rec2.totalTime - rec1.totalTime ||
           (rec2.internalFuncName < rec1.internalFuncName ? -1 : 1); });
   this.printHeavyProfile(heavyView.head.children);
+
+  print('Visual Execution Timeline: ');
+  var sliceLength = 80;
+  var sliceStart = 0;
+  while (sliceStart < this.timeline_.length) {
+    print(this.timeline_.slice(sliceStart, sliceStart + sliceLength));
+    sliceStart += sliceLength;
+  }
 };
 
 
 function padLeft(s, len) {
   s = s.toString();
   if (s.length < len) {
     var padLength = len - s.length;
     if (!(padLength in padLeft)) {
       padLeft[padLength] = new Array(padLength + 1).join(' ');
     }
@@ skipping 392 matching lines @@
       if (arg !== synArg && dispatch === this.argsDispatch_[synArg]) {
         synonims.push(synArg);
         delete this.argsDispatch_[synArg];
       }
     }
     print('  ' + padRight(synonims.join(', '), 20) + dispatch[2]);
   }
   quit(2);
 };