commit 00f7d0eaa6bd93d33bf0c1429bf4ba0b3f28abac
author Ian Rogers <irogers@google.com> Thu Jul 19 15:28:27 2012 -0700
committer Ian Rogers <irogers@google.com> Tue Aug 14 10:45:52 2012 -0700
tree 6a2172ece15c4699e6c2a67ce76f019db0a9a21d
parent 634ea28f78c4a138e6a1de54eae8696095422415

Global lock levels.

Introduce the notion of the mutators/GC being a shared-exclusive (aka
reader-writer) lock. Introduce globally ordered locks, analysable by
annotalysis, statically at compile time. Add locking attributes to
methods.

More subtly, remove the heap_lock_ and split between various locks that
are held for smaller periods (where work doesn't get blocked). Remove
buggy Dalvik style thread transitions. Make GC use CMS in all cases when
concurrent is enabled. Fix bug where suspend counts rather than debug
suspend counts were sent to JDWP. Move the PathClassLoader to
WellKnownClasses. In debugger refactor calls to send request and
possibly suspend. Break apart different VmWait thread states. Move
identity hash code to a shared method.

Change-Id: Icdbfc3ce3fcccd14341860ac7305d8e97b51f5c6

src/hprof/hprof.cc

diff --git a/src/hprof/hprof.cc b/src/hprof/hprof.cc
index d806d71..d0c87be 100644
--- a/src/hprof/hprof.cc
+++ b/src/hprof/hprof.cc
@@ -47,7 +47,7 @@
 #include "object_utils.h"
 #include "os.h"
 #include "safe_map.h"
-#include "scoped_heap_lock.h"
+#include "scoped_thread_state_change.h"
 #include "space.h"
 #include "stringprintf.h"
 #include "thread_list.h"
@@ -165,8 +165,8 @@
 typedef HprofId HprofStringId;
 typedef HprofId HprofObjectId;
 typedef HprofId HprofClassObjectId;
-typedef std::set<const Class*> ClassSet;
-typedef std::set<const Class*>::iterator ClassSetIterator;
+typedef std::set<Class*> ClassSet;
+typedef std::set<Class*>::iterator ClassSetIterator;
 typedef SafeMap<std::string, size_t> StringMap;
 typedef SafeMap<std::string, size_t>::iterator StringMapIterator;
 
@@ -401,11 +401,16 @@
     free(body_data_ptr_);
   }
 
-  void Dump() {
+  void Dump()
+      EXCLUSIVE_LOCKS_REQUIRED(GlobalSynchronization::mutator_lock_)
+      LOCKS_EXCLUDED(GlobalSynchronization::heap_bitmap_lock_) {
     // Walk the roots and the heap.
     current_record_.StartNewRecord(body_fp_, HPROF_TAG_HEAP_DUMP_SEGMENT, HPROF_TIME);
     Runtime::Current()->VisitRoots(RootVisitor, this);
-    Runtime::Current()->GetHeap()->GetLiveBitmap()->Walk(HeapBitmapCallback, this);
+    {
+      ReaderMutexLock mu(*GlobalSynchronization::heap_bitmap_lock_);
+      Runtime::Current()->GetHeap()->GetLiveBitmap()->Walk(HeapBitmapCallback, this);
+    }
     current_record_.StartNewRecord(body_fp_, HPROF_TAG_HEAP_DUMP_END, HPROF_TIME);
     current_record_.Flush();
     fflush(body_fp_);
@@ -464,27 +469,29 @@
   }
 
  private:
-  static void RootVisitor(const Object* obj, void* arg) {
+  static void RootVisitor(const Object* obj, void* arg)
+      SHARED_LOCKS_REQUIRED(GlobalSynchronization::mutator_lock_) {
     CHECK(arg != NULL);
     Hprof* hprof = reinterpret_cast<Hprof*>(arg);
     hprof->VisitRoot(obj);
   }
 
-  static void HeapBitmapCallback(Object* obj, void* arg) {
+  static void HeapBitmapCallback(Object* obj, void* arg)
+      SHARED_LOCKS_REQUIRED(GlobalSynchronization::mutator_lock_) {
     CHECK(obj != NULL);
     CHECK(arg != NULL);
     Hprof* hprof = reinterpret_cast<Hprof*>(arg);
     hprof->DumpHeapObject(obj);
   }
 
-  void VisitRoot(const Object* obj);
+  void VisitRoot(const Object* obj) SHARED_LOCKS_REQUIRED(GlobalSynchronization::mutator_lock_);
 
-  int DumpHeapObject(const Object* obj);
+  int DumpHeapObject(Object* obj) SHARED_LOCKS_REQUIRED(GlobalSynchronization::mutator_lock_);
 
   void Finish() {
   }
 
-  int WriteClassTable() {
+  int WriteClassTable() SHARED_LOCKS_REQUIRED(GlobalSynchronization::mutator_lock_) {
     HprofRecord* rec = &current_record_;
     uint32_t nextSerialNumber = 1;
 
@@ -551,7 +558,8 @@
 
   int MarkRootObject(const Object* obj, jobject jniObj);
 
-  HprofClassObjectId LookupClassId(const Class* c) {
+  HprofClassObjectId LookupClassId(Class* c)
+      SHARED_LOCKS_REQUIRED(GlobalSynchronization::mutator_lock_) {
     if (c == NULL) {
       // c is the superclass of java.lang.Object or a primitive
       return (HprofClassObjectId)0;
@@ -585,7 +593,8 @@
     return id;
   }
 
-  HprofStringId LookupClassNameId(const Class* c) {
+  HprofStringId LookupClassNameId(const Class* c)
+      SHARED_LOCKS_REQUIRED(GlobalSynchronization::mutator_lock_) {
     return LookupStringId(PrettyDescriptor(c));
   }
 
@@ -807,7 +816,7 @@
   return HPROF_NULL_STACK_TRACE;
 }
 
-int Hprof::DumpHeapObject(const Object* obj) {
+int Hprof::DumpHeapObject(Object* obj) {
   HprofRecord* rec = &current_record_;
   HprofHeapId desiredHeap = false ? HPROF_HEAP_ZYGOTE : HPROF_HEAP_APP; // TODO: zygote objects?
 
@@ -847,7 +856,7 @@
     // allocated which hasn't been initialized yet.
   } else {
     if (obj->IsClass()) {
-      const Class* thisClass = obj->AsClass();
+      Class* thisClass = obj->AsClass();
       // obj is a ClassObject.
       size_t sFieldCount = thisClass->NumStaticFields();
       if (sFieldCount != 0) {
@@ -1053,15 +1062,11 @@
 // Otherwise, "filename" is used to create an output file.
 void DumpHeap(const char* filename, int fd, bool direct_to_ddms) {
   CHECK(filename != NULL);
-  ScopedHeapLock heap_lock;
-  ScopedThreadStateChange tsc(Thread::Current(), kRunnable);
 
-  ThreadList* thread_list = Runtime::Current()->GetThreadList();
-  thread_list->SuspendAll();
-
+  Runtime::Current()->GetThreadList()->SuspendAll();
   Hprof hprof(filename, fd, direct_to_ddms);
   hprof.Dump();
-  thread_list->ResumeAll();
+  Runtime::Current()->GetThreadList()->ResumeAll();
 }
 
 }  // namespace hprof