src: nullcheck on trace controller

gireeshpunathil · addaleax · commit e0af205c982c · 2019-02-09T00:45:06.000+01:00
Insert a NULLCHECK prior to return. Ideally we do this in the caller, but the TraceController object is somewhat special as: 1. It is accessed by most threads 2. It's life cycle is managed by Agent::Agent 3. It's getter is invoked through Base Methods (upstream) Refs: #25814 PR-URL: #25943 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Masashi Hirano <shisama07@gmail.com> Reviewed-By: Richard Lau <riclau@uk.ibm.com> Reviewed-By: Anna Henningsen <anna@addaleax.net>
diff --git a/src/env.cc b/src/env.cc
@@ -201,8 +201,7 @@ Environment::Environment(IsolateData* isolate_data,
   if (tracing::AgentWriterHandle* writer = GetTracingAgentWriter()) {
     trace_state_observer_ = std::make_unique<TrackingTraceStateObserver>(this);
     TracingController* tracing_controller = writer->GetTracingController();
-    if (tracing_controller != nullptr)
-      tracing_controller->AddTraceStateObserver(trace_state_observer_.get());
+    tracing_controller->AddTraceStateObserver(trace_state_observer_.get());
   }
 
   destroy_async_id_list_.reserve(512);
@@ -265,8 +264,7 @@ Environment::~Environment() {
     tracing::AgentWriterHandle* writer = GetTracingAgentWriter();
     CHECK_NOT_NULL(writer);
     TracingController* tracing_controller = writer->GetTracingController();
-    if (tracing_controller != nullptr)
-      tracing_controller->RemoveTraceStateObserver(trace_state_observer_.get());
+    tracing_controller->RemoveTraceStateObserver(trace_state_observer_.get());
   }
 
   delete[] heap_statistics_buffer_;
diff --git a/src/node_platform.cc b/src/node_platform.cc
@@ -459,6 +459,7 @@ double NodePlatform::CurrentClockTimeMillis() {
 }
 
 TracingController* NodePlatform::GetTracingController() {
+  CHECK_NOT_NULL(tracing_controller_);
   return tracing_controller_;
 }
 
diff --git a/src/tracing/agent.h b/src/tracing/agent.h
@@ -81,7 +81,9 @@ class Agent {
   ~Agent();
 
   TracingController* GetTracingController() {
-    return tracing_controller_.get();
+    TracingController* controller = tracing_controller_.get();
+    CHECK_NOT_NULL(controller);
+    return controller;
   }
 
   enum UseDefaultCategoryMode {

Original file line number	Diff line number	Diff line change
`@@ -459,6 +459,7 @@ double NodePlatform::CurrentClockTimeMillis() {`
`459`	`459`	`}`
`460`	`460`
`461`	`461`	`TracingController* NodePlatform::GetTracingController() {`
	`462`	`+ CHECK_NOT_NULL(tracing_controller_);`
`462`	`463`	`return tracing_controller_;`
`463`	`464`	`}`
`464`	`465`
Original file line number	Diff line number	Diff line change
`@@ -81,7 +81,9 @@ class Agent {`
`81`	`81`	`~Agent();`
`82`	`82`
`83`	`83`	`TracingController* GetTracingController() {`
`84`		`- return tracing_controller_.get();`
	`84`	`+ TracingController* controller = tracing_controller_.get();`
	`85`	`+ CHECK_NOT_NULL(controller);`
	`86`	`+ return controller;`
`85`	`87`	`}`
`86`	`88`
`87`	`89`	`enum UseDefaultCategoryMode {`