Simplify timeline backend

Now that we have a central list of all threads that are interacting with the VM we can stop relying on the Isolate's thread registry to cache timeline blocks.

- Move from caching blocks in the Isolate's thread registry and caching them in the Thread directly.
- This allows cached blocks to have events from multiple isolates, increasing usage density and reducing the number of blocks being cached at any given time.
- We no longer need a distinct global block, this allows me to remove a bunch of dead code.

R=turnidge@google.com

Review URL: https://codereview.chromium.org/1402383003 .

runtime/vm/dart_api_impl.cc

@@ -5887,8 +5887,7 @@ DART_EXPORT bool Dart_TimelineGetTrace(Dart_StreamConsumer consumer,
   }
   Thread* T = Thread::Current();
   StackZone zone(T);
-  // Reclaim all blocks cached by isolate.
-  Timeline::ReclaimIsolateBlocks();
+  Timeline::ReclaimCachedBlocksFromThreads();
   JSONStream js;
   IsolateTimelineEventFilter filter(isolate);
   timeline_recorder->PrintTraceEvent(&js, &filter);
@@ -5912,8 +5911,7 @@ DART_EXPORT bool Dart_GlobalTimelineGetTrace(Dart_StreamConsumer consumer,
   }
   Thread* T = Thread::Current();
   StackZone zone(T);
-  // Reclaim all blocks cached in the system.
-  Timeline::ReclaimAllBlocks();
+  Timeline::ReclaimCachedBlocksFromThreads();
   JSONStream js;
   TimelineEventFilter filter;
   timeline_recorder->PrintTraceEvent(&js, &filter);

runtime/vm/dart_api_impl_test.cc

@@ -9426,7 +9426,7 @@ TEST_CASE(Timeline_Dart_TimelineDuration) {
   Dart_TimelineDuration("testDurationEvent", 0, 1);
   // Check that it is in the output.
   TimelineEventRecorder* recorder = Timeline::recorder();
-  Timeline::ReclaimIsolateBlocks();
+  Timeline::ReclaimCachedBlocksFromThreads();
   JSONStream js;
   IsolateTimelineEventFilter filter(isolate);
   recorder->PrintJSON(&js, &filter);
@@ -9443,7 +9443,7 @@ TEST_CASE(Timeline_Dart_TimelineInstant) {
   Dart_TimelineInstant("testInstantEvent");
   // Check that it is in the output.
   TimelineEventRecorder* recorder = Timeline::recorder();
-  Timeline::ReclaimIsolateBlocks();
+  Timeline::ReclaimCachedBlocksFromThreads();
   JSONStream js;
   IsolateTimelineEventFilter filter(isolate);
   recorder->PrintJSON(&js, &filter);
@@ -9465,7 +9465,7 @@ TEST_CASE(Timeline_Dart_TimelineAsyncDisabled) {
   Dart_TimelineAsyncEnd("testAsyncEvent", async_id);
   // Check that testAsync is not in the output.
   TimelineEventRecorder* recorder = Timeline::recorder();
-  Timeline::ReclaimIsolateBlocks();
+  Timeline::ReclaimCachedBlocksFromThreads();
   JSONStream js;
   TimelineEventFilter filter;
   recorder->PrintJSON(&js, &filter);
@@ -9488,7 +9488,7 @@ TEST_CASE(Timeline_Dart_TimelineAsync) {
 
   // Check that it is in the output.
   TimelineEventRecorder* recorder = Timeline::recorder();
-  Timeline::ReclaimIsolateBlocks();
+  Timeline::ReclaimCachedBlocksFromThreads();
   JSONStream js;
   IsolateTimelineEventFilter filter(isolate);
   recorder->PrintJSON(&js, &filter);

runtime/vm/isolate.cc

@@ -1616,7 +1616,7 @@ void Isolate::LowLevelShutdown() {
   set_message_handler(NULL);
 
   // Before analyzing the isolate's timeline blocks- reclaim all cached blocks.
-  ReclaimTimelineBlocks();
+  Timeline::ReclaimCachedBlocksFromThreads();
 
   // Dump all timing data for the isolate.
   if (FLAG_timing) {
@@ -1718,15 +1718,6 @@ void Isolate::Shutdown() {
 }
 
 
-void Isolate::ReclaimTimelineBlocks() {
-  TimelineEventRecorder* recorder = Timeline::recorder();
-  if (recorder == NULL) {
-    return;
-  }
-  thread_registry_->ReclaimTimelineBlocks();
-}
-
-
 Dart_IsolateCreateCallback Isolate::create_callback_ = NULL;
 Dart_IsolateInterruptCallback Isolate::interrupt_callback_ = NULL;
 Dart_IsolateUnhandledExceptionCallback

runtime/vm/isolate.h

@@ -710,7 +710,6 @@ class Isolate : public BaseIsolate {
 
   void LowLevelShutdown();
   void Shutdown();
-  void ReclaimTimelineBlocks();
 
   void BuildName(const char* name_prefix);
   void PrintInvokedFunctions();

runtime/vm/thread.cc

@@ -182,6 +182,7 @@ Thread::Thread(bool init_vm_constants)
       thread_interrupt_data_(NULL),
       isolate_(NULL),
       heap_(NULL),
+      timeline_block_(NULL),
       store_buffer_block_(NULL),
       log_(new class Log()),
       deopt_id_(0),

runtime/vm/thread.h

@@ -272,7 +272,6 @@ class Thread {
     Zone* zone;
     uword top_exit_frame_info;
     StackResource* top_resource;
-    TimelineEventBlock* timeline_block;
     LongJumpScope* long_jump_base;
 #if defined(DEBUG)
     HandleScope* top_handle_scope;
@@ -312,12 +311,12 @@ LEAF_RUNTIME_ENTRY_LIST(DEFINE_OFFSET_METHOD)
 
   // Only safe to access when holding |timeline_block_lock_|.
   TimelineEventBlock* timeline_block() const {
-    return state_.timeline_block;
+    return timeline_block_;
   }
 
   // Only safe to access when holding |timeline_block_lock_|.
   void set_timeline_block(TimelineEventBlock* block) {
-    state_.timeline_block = block;
+    timeline_block_ = block;
   }
 
   class Log* log() const;
@@ -419,6 +418,7 @@ LEAF_RUNTIME_ENTRY_LIST(DEFINE_OFFSET_METHOD)
   Heap* heap_;
   State state_;
   Mutex timeline_block_lock_;
+  TimelineEventBlock* timeline_block_;
   StoreBufferBlock* store_buffer_block_;
   class Log* log_;
   intptr_t deopt_id_;  // Compilation specific counter.

runtime/vm/thread_registry.cc

@@ -10,7 +10,6 @@
 namespace dart {
 
 ThreadRegistry::~ThreadRegistry() {
-  ReclaimTimelineBlocks();
   // Delete monitor.
   delete monitor_;
 }
@@ -67,54 +66,7 @@ void ThreadRegistry::PruneThread(Thread* thread) {
   if (found_index < 0) {
     return;
   }
-  {
-    TimelineEventRecorder* recorder = Timeline::recorder();
-    if (recorder != NULL) {
-      // Cleanup entry.
-      Entry& entry_to_remove = entries_[found_index];
-      ReclaimTimelineBlockLocked(&entry_to_remove);
-    }
-  }
-  if (found_index != (length - 1)) {
-    // Swap with last entry.
-    entries_.Swap(found_index, length - 1);
-  }
-  entries_.RemoveLast();
-}
-
-
-void ThreadRegistry::ReclaimTimelineBlocks() {
-  // Each thread that is scheduled in this isolate may have a cached timeline
-  // block. Mark these timeline blocks as finished.
-  MonitorLocker ml(monitor_);
-  TimelineEventRecorder* recorder = Timeline::recorder();
-  if (recorder != NULL) {
-    for (intptr_t i = 0; i < entries_.length(); i++) {
-      // NOTE: It is only safe to access |entry.state| here.
-      Entry& entry = entries_[i];
-      ReclaimTimelineBlockLocked(&entry);
-    }
-  }
-}
-
-
-void ThreadRegistry::ReclaimTimelineBlockLocked(Entry* entry) {
-  if (entry == NULL) {
-    return;
-  }
-  TimelineEventRecorder* recorder = Timeline::recorder();
-  if (!entry->scheduled && (entry->state.timeline_block != NULL)) {
-    // Currently unscheduled thread.
-    recorder->FinishBlock(entry->state.timeline_block);
-    entry->state.timeline_block = NULL;
-  } else if (entry->scheduled) {
-    // Currently scheduled thread.
-    Thread* thread = entry->thread;
-    // Take |Thread| lock.
-    MutexLocker thread_lock(thread->timeline_block_lock());
-    recorder->FinishBlock(thread->timeline_block());
-    thread->set_timeline_block(NULL);
-  }
+  entries_.RemoveAt(found_index);
 }
 
 

runtime/vm/thread_registry.h

@@ -188,9 +188,6 @@ class ThreadRegistry {
     return NULL;
   }
 
-  // NOTE: Lock should be taken before this function is called.
-  void ReclaimTimelineBlockLocked(Entry* entry);
-
   // Note: Lock should be taken before this function is called.
   void CheckSafepointLocked();