Perform CPU sampling by CPU sampling thread only iff processing thread is not running.

src/platform-openbsd.cc

Index: src/platform-openbsd.cc
diff --git a/src/platform-openbsd.cc b/src/platform-openbsd.cc
index f96d9e3031a503c6f81282cc7b8d6bc09232d5c7..fef0b0c528e3c7e8e8931fff93a6cccd91155e6a 100644
--- a/src/platform-openbsd.cc
+++ b/src/platform-openbsd.cc
@@ -731,8 +731,9 @@ static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
   Sampler* sampler = isolate->logger()->sampler();
   if (sampler == NULL || !sampler->IsActive()) return;
 
+  TickSample sample_obj;
   TickSample* sample = CpuProfiler::StartTickSampleEvent(isolate);
-  if (sample == NULL) return;
+  if (sample == NULL) sample = &sample_obj;
 
   // Extracting the sample from the context is extremely machine dependent.
   sample->state = isolate->current_vm_state();
@@ -983,4 +984,12 @@ void Sampler::Stop() {
 }
 
 
+void Sampler::StartSampling() {
+}
+
+
+void Sampler::StopSampling() {
+}
+
+
 } }  // namespace v8::internal