Adding blink gc memory dump infrastructure for thread specific dumps.

Source/platform/heap/Heap.cpp

Index: Source/platform/heap/Heap.cpp
diff --git a/Source/platform/heap/Heap.cpp b/Source/platform/heap/Heap.cpp
index 3fef547f1660fe8dc9a2fddf735d751d6e8f191d..b8a8b7ff5a3ef792467aa30caa04b0dc3ee98f67 100644
--- a/Source/platform/heap/Heap.cpp
+++ b/Source/platform/heap/Heap.cpp
@@ -34,6 +34,7 @@
 #include "platform/ScriptForbiddenScope.h"
 #include "platform/Task.h"
 #include "platform/TraceEvent.h"
+#include "platform/heap/BlinkGCMemoryDumpProvider.h"
 #include "platform/heap/CallbackStack.h"
 #include "platform/heap/MarkingVisitor.h"
 #include "platform/heap/PageMemory.h"
@@ -41,6 +42,8 @@
 #include "platform/heap/SafePoint.h"
 #include "platform/heap/ThreadState.h"
 #include "public/platform/Platform.h"
+#include "public/platform/WebMemoryAllocatorDump.h"
+#include "public/platform/WebProcessMemoryDump.h"

[Primiano Tucci (use gerrit), 2015/05/22 19:45:57]

I think you don't need this anymore

[ssid, 2015/05/26 11:08:43]

Done.

 #include "wtf/Assertions.h"
 #include "wtf/ContainerAnnotations.h"
 #include "wtf/LeakAnnotations.h"
@@ -213,6 +216,16 @@ void BaseHeap::cleanupPages()
     m_firstPage = nullptr;
 }
 
+void BaseHeap::dumpMemory(const String& dumpBaseName)
+{
+    size_t pageCount = 0;
+    for (BasePage* page = m_firstPage; page; page = page->next()) {
+        pageCount++;
+    }
+    WebMemoryAllocatorDump* allocatorDump = BlinkGCMemoryDumpProvider::instance()->createMemoryAllocatorDumpForLastGC(dumpBaseName);
+    allocatorDump->AddScalar("blink_page_count", "objects", pageCount);
+}
+
 #if ENABLE(ASSERT) || ENABLE(GC_PROFILING)
 BasePage* BaseHeap::findPageFromAddress(Address address)
 {
@@ -1625,10 +1638,16 @@ void Heap::init()
     s_estimatedMarkingTimePerByte = 0.0;
 
     GCInfoTable::init();
+
+    if (Platform::current()->mainThread())

[Primiano Tucci (use gerrit), 2015/05/22 19:45:57]

Question for haraken@: for production (i.e. non tests) is the global Heap::
always initialized and torn down on the main thread?

[ssid, 2015/05/26 11:08:43]

changed it.

+        Platform::current()->registerMemoryDumpProvider(BlinkGCMemoryDumpProvider::instance());
 }
 
 void Heap::shutdown()
 {
+    if (Platform::current()->mainThread())
+        Platform::current()->unregisterMemoryDumpProvider(BlinkGCMemoryDumpProvider::instance());
+
     s_shutdownCalled = true;
     ThreadState::shutdownHeapIfNecessary();
 }
@@ -1863,9 +1882,24 @@ void Heap::preGC()
 
 void Heap::postGC(ThreadState::GCType gcType)
 {
+    // TODO(ssid): Change this to use api from memory-infra to check tracing
+    // memory_tracing_enabled (crbug.com/490087).
+    bool enabled;

[Primiano Tucci (use gerrit), 2015/05/22 19:45:57]

Can you encapsulate this into a "static inline bool" method of
BlinkGCMemoryDumpProvider, so we hide this dust under our class, and in future
just fix ours?
P.S. I know that BlinkGCMemoryDumpProvider is a singleton, but just for this one
use a "static inline bool" as we want this to be a fastpath.

[ssid, 2015/05/26 11:08:43]

Done.

+    TRACE_EVENT_CATEGORY_GROUP_ENABLED(TRACE_DISABLED_BY_DEFAULT("memory-infra"), &enabled);
+    if (enabled)
+        BlinkGCMemoryDumpProvider::instance()->clearLastProcessMemoryDump();
+
     ASSERT(ThreadState::current()->isInGC());
-    for (ThreadState* state : ThreadState::attachedThreads())
+    for (ThreadState* state : ThreadState::attachedThreads()) {
+        if (enabled)
+            state->dumpMemory();
+
         state->postGC(gcType);
+    }
+
+    // TODO(ssid): Request global dump from blink when support is available
+    // (crbug.com/490087). For the moment the dump is periodically invoked by
+    // the MemoryDumpManager every X secs.
 }
 
 const char* Heap::gcReasonString(GCReason reason)