[coverage] Report timestamp on coverage updates

This CL adds timestamps to coverage updates. This is useful for clients,
because between requesting a coverage update and collecting coverage data
significant time may pass. This change allows precise attribution at what
time a coverage update was taken.

Change-Id: I65a9cccb0171e892b7dbe35d105d3ca246ba08d0
Bug: chromium:1022031
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1992435Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Simon Zünd <szuend@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65696}

include/js_protocol.pdl

@@ -824,6 +824,9 @@ domain Profiler
       optional boolean callCount
       # Collect block-based coverage.
       optional boolean detailed
+    returns
+      # The timestamp (in milliseconds) the coverage update was taken in the backend.
+      number timestamp
 
   # Enable type profile.
   experimental command startTypeProfile
@@ -846,6 +849,8 @@ domain Profiler
     returns
       # Coverage data for the current isolate.
       array of ScriptCoverage result
+      # The timestamp (in milliseconds) the coverage update was taken in the backend.
+      number timestamp
 
   # Collect type profile.
   experimental command takeTypeProfile

src/inspector/DEPS

@@ -7,8 +7,9 @@ include_rules = [
   "+src/base/macros.h",
   "+src/base/memory.h",
   "+src/base/optional.h",
-  "+src/base/platform/platform.h",
   "+src/base/platform/mutex.h",
+  "+src/base/platform/platform.h",
+  "+src/base/platform/time.h",
   "+src/base/safe_conversions.h",
   "+src/base/template-utils.h",
   "+src/base/v8-fallthrough.h",

src/inspector/v8-profiler-agent-impl.cc

@@ -7,6 +7,7 @@
 #include <vector>
 
 #include "src/base/atomicops.h"
+#include "src/base/platform/time.h"
 #include "src/debug/debug-interface.h"
 #include "src/inspector/protocol/Protocol.h"
 #include "src/inspector/string-util.h"
@@ -260,7 +261,9 @@ void V8ProfilerAgentImpl::restore() {
         ProfilerAgentState::preciseCoverageCallCount, false);
     bool detailed = m_state->booleanProperty(
         ProfilerAgentState::preciseCoverageDetailed, false);
-    startPreciseCoverage(Maybe<bool>(callCount), Maybe<bool>(detailed));
+    double timestamp;
+    startPreciseCoverage(Maybe<bool>(callCount), Maybe<bool>(detailed),
+                         &timestamp);
   }
 }
 
@@ -292,8 +295,12 @@ Response V8ProfilerAgentImpl::stop(
 }
 
 Response V8ProfilerAgentImpl::startPreciseCoverage(Maybe<bool> callCount,
-                                                   Maybe<bool> detailed) {
+                                                   Maybe<bool> detailed,
+                                                   double* out_timestamp) {
   if (!m_enabled) return Response::Error("Profiler is not enabled");
+  *out_timestamp =
+      (v8::base::TimeTicks::HighResolutionNow() - v8::base::TimeTicks())
+          .InMilliseconds();
   bool callCountValue = callCount.fromMaybe(false);
   bool detailedValue = detailed.fromMaybe(false);
   m_state->setBoolean(ProfilerAgentState::preciseCoverageStarted, true);
@@ -395,13 +402,17 @@ Response coverageToProtocol(
 
 Response V8ProfilerAgentImpl::takePreciseCoverage(
     std::unique_ptr<protocol::Array<protocol::Profiler::ScriptCoverage>>*
-        out_result) {
+        out_result,
+    double* out_timestamp) {
   if (!m_state->booleanProperty(ProfilerAgentState::preciseCoverageStarted,
                                 false)) {
     return Response::Error("Precise coverage has not been started.");
   }
   v8::HandleScope handle_scope(m_isolate);
   v8::debug::Coverage coverage = v8::debug::Coverage::CollectPrecise(m_isolate);
+  *out_timestamp =
+      (v8::base::TimeTicks::HighResolutionNow() - v8::base::TimeTicks())
+          .InMilliseconds();
   return coverageToProtocol(m_session->inspector(), coverage, out_result);
 }
 

src/inspector/v8-profiler-agent-impl.h

@@ -39,12 +39,13 @@ class V8ProfilerAgentImpl : public protocol::Profiler::Backend {
   Response start() override;
   Response stop(std::unique_ptr<protocol::Profiler::Profile>*) override;
 
-  Response startPreciseCoverage(Maybe<bool> binary,
-                                Maybe<bool> detailed) override;
+  Response startPreciseCoverage(Maybe<bool> binary, Maybe<bool> detailed,
+                                double* out_timestamp) override;
   Response stopPreciseCoverage() override;
   Response takePreciseCoverage(
       std::unique_ptr<protocol::Array<protocol::Profiler::ScriptCoverage>>*
-          out_result) override;
+          out_result,
+      double* out_timestamp) override;
   Response getBestEffortCoverage(
       std::unique_ptr<protocol::Array<protocol::Profiler::ScriptCoverage>>*
           out_result) override;

test/inspector/cpu-profiler/coverage-block-expected.txt

@@ -6,6 +6,7 @@ Running test: testPreciseCountBaseline
     result : {
         result : [
         ]
+        timestamp : <timestamp>
     }
 }
 {
@@ -13,6 +14,7 @@ Running test: testPreciseCountBaseline
     result : {
         result : [
         ]
+        timestamp : <timestamp>
     }
 }
 
@@ -109,6 +111,7 @@ Running test: testPreciseCountCoverage
                 url : 
             }
         ]
+        timestamp : <timestamp>
     }
 }
 {
@@ -116,6 +119,7 @@ Running test: testPreciseCountCoverage
     result : {
         result : [
         ]
+        timestamp : <timestamp>
     }
 }
 
@@ -195,6 +199,7 @@ Running test: testPreciseCountCoverageIncremental
                 url : testPreciseCountCoverageIncremental
             }
         ]
+        timestamp : <timestamp>
     }
 }
 {
@@ -312,6 +317,7 @@ Running test: testPreciseCountCoverageIncremental
                 url : 
             }
         ]
+        timestamp : <timestamp>
     }
 }
 
@@ -711,6 +717,7 @@ Running test: testEnablePreciseCountCoverageAtPause
                 url : 
             }
         ]
+        timestamp : <timestamp>
     }
 }
 
@@ -780,6 +787,7 @@ Running test: testPreciseBinaryCoverage
                 url : testPreciseBinaryCoverage
             }
         ]
+        timestamp : <timestamp>
     }
 }
 {
@@ -866,6 +874,7 @@ Running test: testPreciseBinaryCoverage
                 url : 
             }
         ]
+        timestamp : <timestamp>
     }
 }
 
@@ -875,6 +884,7 @@ Running test: testPreciseEmptyScriptCoverageEntries
     result : {
         result : [
         ]
+        timestamp : <timestamp>
     }
 }
 
@@ -975,6 +985,7 @@ Running test: testPreciseCountCoveragePartial
                 url : testPreciseCountCoveragePartial
             }
         ]
+        timestamp : <timestamp>
     }
 }
 {
@@ -1027,5 +1038,6 @@ Running test: testPreciseCountCoveragePartial
                 url : 
             }
         ]
+        timestamp : <timestamp>
     }
 }

test/inspector/cpu-profiler/coverage-expected.txt

@@ -6,6 +6,7 @@ Running test: testPreciseCountBaseline
     result : {
         result : [
         ]
+        timestamp : <timestamp>
     }
 }
 {
@@ -13,6 +14,7 @@ Running test: testPreciseCountBaseline
     result : {
         result : [
         ]
+        timestamp : <timestamp>
     }
 }
 
@@ -99,6 +101,7 @@ Running test: testPreciseCountCoverage
                 url : 
             }
         ]
+        timestamp : <timestamp>
     }
 }
 {
@@ -106,6 +109,7 @@ Running test: testPreciseCountCoverage
     result : {
         result : [
         ]
+        timestamp : <timestamp>
     }
 }
 
@@ -505,6 +509,7 @@ Running test: testEnablePreciseCountCoverageAtPause
                 url : 
             }
         ]
+        timestamp : <timestamp>
     }
 }
 
@@ -574,6 +579,7 @@ Running test: testPreciseBinaryCoverage
                 url : testPreciseBinaryCoverage
             }
         ]
+        timestamp : <timestamp>
     }
 }
 {
@@ -660,6 +666,7 @@ Running test: testPreciseBinaryCoverage
                 url : 
             }
         ]
+        timestamp : <timestamp>
     }
 }
 
@@ -669,6 +676,7 @@ Running test: testPreciseEmptyScriptCoverageEntries
     result : {
         result : [
         ]
+        timestamp : <timestamp>
     }
 }
 
@@ -769,6 +777,7 @@ Running test: testPreciseCountCoveragePartial
                 url : testPreciseCountCoveragePartial
             }
         ]
+        timestamp : <timestamp>
     }
 }
 {
@@ -821,5 +830,6 @@ Running test: testPreciseCountCoveragePartial
                 url : 
             }
         ]
+        timestamp : <timestamp>
     }
 }