snapshot (broken)

classpath/TestExceptions.java

@@ -5,9 +5,7 @@ public class TestExceptions {
   }
 
   private static void moreDangerous() {
-    //    synchronized (TestExceptions.class) {
+    evenMoreDangerous();
-      evenMoreDangerous();
-      //    }
   }
 
   private static void dangerous() {

src/heap.cpp

@@ -483,12 +483,6 @@ class Segment {
     return p;
   }
 
-  void* add(void* p, unsigned size) {
-    void* target = allocate(size);
-    memcpy(target, p, size * BytesPerWord);
-    return target;
-  }
-
   void ensure(unsigned minimum) {
     if (remaining() < minimum) {
       assert(context, rear->position);
@@ -713,40 +707,48 @@ bitset(Context* c, object o)
 }
 
 inline object
-copyTo(Context* c, Segment* s, object o, unsigned size)
+copyTo(Context* c, Segment* s, object o)
 {
-  if (s->remaining() < size) {
+  class Allocator: public Heap::Allocator {
-    s->ensure(size);
+   public:
+    Allocator(Segment* s): s(s) { }
 
-    if (Verbose) {
+    virtual void* allocate(unsigned size) {
-      if (s == &(c->gen2)) {
+      if (s->remaining() < size) {
-        fprintf(stderr, "grow gen2 to %d bytes\n",
+        s->ensure(size);
-                c->gen2.capacity() * BytesPerWord);
+
-      } else if (s == &(c->nextGen1)) {
+        if (Verbose) {
-        fprintf(stderr, "grow nextGen1 to %d bytes\n",
+          if (s == &(c->gen2)) {
-                c->nextGen1.capacity() * BytesPerWord);
+            fprintf(stderr, "grow gen2 to %d bytes\n",
-      } else if (s == &(c->nextGen2)) {
+                    c->gen2.capacity() * BytesPerWord);
-        fprintf(stderr, "grow nextGen2 to %d bytes\n",
+          } else if (s == &(c->nextGen1)) {
-                c->nextGen2.capacity() * BytesPerWord);
+            fprintf(stderr, "grow nextGen1 to %d bytes\n",
-      } else {
+                    c->nextGen1.capacity() * BytesPerWord);
-        abort(c);
+          } else if (s == &(c->nextGen2)) {
+            fprintf(stderr, "grow nextGen2 to %d bytes\n",
+                    c->nextGen2.capacity() * BytesPerWord);
+          } else {
+            abort(c);
+          }
+        }
       }
-    }
-  }
 
-  return static_cast<object>(s->add(o, size));
+      return s->allocate(size);
+    }
+  } allocator(s);
+
+  c->client->copy(o, &allocator);
+  return p;
 }
 
 object
 copy2(Context* c, object o)
 {
-  unsigned size = c->client->sizeInWords(o);
-
   if (c->gen2.contains(o)) {
     assert(c, c->mode == MajorCollection
            or c->mode == Gen2Collection);
 
-    return copyTo(c, &(c->nextGen2), o, size);
+    return copyTo(c, &(c->nextGen2), o);
   } else if (c->gen1.contains(o)) {
     unsigned age = c->ageMap.get(o);
     if (age == TenureThreshold) {
@@ -758,7 +760,7 @@ copy2(Context* c, object o)
             c->gen2Base = c->gen2.position();
           }
 
-          return copyTo(c, &(c->gen2), o, size);
+          return copyTo(c, &(c->gen2), o);
         } else {
           if (Verbose) {
             fprintf(stderr, "overflow collection\n");
@@ -766,13 +768,13 @@ copy2(Context* c, object o)
 
           c->mode = OverflowCollection;
           initNextGen2(c);
-          return copyTo(c, &(c->nextGen2), o, size);          
+          return copyTo(c, &(c->nextGen2), o);          
         }
       } else {
-        return copyTo(c, &(c->nextGen2), o, size);
+        return copyTo(c, &(c->nextGen2), o);
       }
     } else {
-      o = copyTo(c, &(c->nextGen1), o, size);
+      o = copyTo(c, &(c->nextGen1), o);
       c->nextAgeMap.setOnly(o, age + 1);
       return o;
     }
@@ -780,7 +782,7 @@ copy2(Context* c, object o)
     assert(c, not c->nextGen1.contains(o));
     assert(c, not c->nextGen2.contains(o));
 
-    o = copyTo(c, &(c->nextGen1), o, size);
+    o = copyTo(c, &(c->nextGen1), o);
 
     c->nextAgeMap.clear(o);
 

src/heap.h

@@ -24,11 +24,18 @@ class Heap {
     virtual bool visit(unsigned) = 0;
   };
 
+  class Allocator {
+   public:
+    virtual ~Allocator() { }
+    virtual void* allocate(unsigned sizeInWords) = 0;
+  };
+
   class Client {
    public:
     virtual ~Client() { }
     virtual void visitRoots(Visitor*) = 0;
     virtual unsigned sizeInWords(void*) = 0;
+    virtual void copy(void*, Allocator*) = 0;
     virtual void walk(void*, Walker*) = 0;
   };
 

src/system.h

@@ -18,15 +18,101 @@ class System {
   class Monitor {
    public:
     virtual ~Monitor() { }
-    virtual bool tryAcquire(void* id) = 0;
+    virtual bool tryAcquire(void* context) = 0;
-    virtual void acquire(void* id) = 0;
+    virtual void acquire(void* context) = 0;
-    virtual void release(void* id) = 0;
+    virtual void release(void* context) = 0;
-    virtual void wait(void* id, int64_t time) = 0;
+    virtual void wait(void* context, int64_t time) = 0;
-    virtual void notify(void* id) = 0;
+    virtual void notify(void* context) = 0;
-    virtual void notifyAll(void* id) = 0;
+    virtual void notifyAll(void* context) = 0;
     virtual void dispose() = 0;
   };
 
+  class ReadWriteLock {
+   public:
+    ReadWriteLock(System* s): s(s), m(0), readers(0), writer(0) {
+      if (not s->success(s->make(&m))) {
+        s->abort();
+      }
+    }
+
+    ~ReadWriteLock() {
+      if (readers or writer) {
+        s->abort();
+      }
+
+      m->dispose();
+    }
+
+    bool tryAcquireRead(void* context) {
+      bool result;
+      m->acquire(context);
+      if (writer) {
+        result = false;
+      } else {
+        result = true;
+        ++ readers;
+      }
+      m->release(context);
+      return result;
+    }
+
+    void acquireRead(void* context) {
+      m->acquire(context);
+      while (writer) {
+        m->wait(context, 0);
+      }
+      ++ readers;
+      m->release(context);
+    }
+
+    void releaseRead(void* context) {
+      m->acquire(context);
+      if (-- readers == 0) {
+        m->notify(context);
+      }
+      m->release(context);
+    }
+
+    bool tryAcquireWrite(void* context) {
+      bool result;
+      m->acquire(context);
+      if (readers or writer) {
+        result = false;
+      } else {
+        result = true;
+        writer = context;
+      }
+      m->release(context);
+      return result;
+    }
+
+    void acquireWrite(void* context) {
+      m->acquire(context);
+      while (readers or writer) {
+        m->wait(context, 0);
+      }
+      writer = context;
+      m->release(context);
+    }
+
+    void releaseWrite(void* context) {
+      if (writer != context) {
+        s->abort();
+      }
+
+      m->acquire(context);
+      writer = 0;
+      m->notifyAll(context);
+      m->release(context);
+    }
+
+   private:
+    System* s;
+    Monitor* m;
+    unsigned readers;
+    void* writer;
+  };
+
   class Library {
    public:
     virtual ~Library() { }

src/vm.cpp

@@ -11,14 +11,26 @@
   Thread::Protector MAKE_NAME(protector_) (thread, &name);
 
 #define ACQUIRE(t, x) MonitorResource MAKE_NAME(monitorResource_) (t, x)
+
 #define ACQUIRE_RAW(t, x) RawMonitorResource MAKE_NAME(monitorResource_) (t, x)
 
+#define ACQUIRE_READ(t, x) ReadResource MAKE_NAME(readResource_) (t, x)
+
+#define ACQUIRE_WRITE(t, x) WriteResource MAKE_NAME(writeResource_) (t, x)
+
+#define ENTER(t, state) StateResource MAKE_NAME(stateResource_) (t, state)
+
 using namespace vm;
 
 namespace {
 
-static const bool Verbose = false;
+const bool Verbose = false;
-static const bool Debug = false;
+const bool Debug = false;
+
+const uintptr_t HashTakenMark = 1;
+const uintptr_t ExtendedMark = 2;
+const uintptr_t MonitorFlag
+= static_cast<uintptr_t>(1) << ((BytesPerWord * 8) - 1);
 
 class Thread;
 
@@ -73,10 +85,12 @@ class Machine {
   System::Monitor* stateLock;
   System::Monitor* heapLock;
   System::Monitor* classLock;
+  System::ReadWriteLock monitorMapLock;
   System::Library* libraries;
   object classMap;
   object bootstrapClassMap;
   object builtinMap;
+  object monitorMap;
   object types;
   bool unsafe;
   JNIEnvVTable jniEnvVTable;
@@ -168,13 +182,57 @@ objectClass(Thread*, object o)
 
 void enter(Thread* t, Thread::State state);
 
+class StateResource {
+ public:
+  StateResource(Thread* t, Thread::State state): t(t), oldState(t->state) {
+    enter(t, state);
+  }
+
+  ~StateResource() { enter(t, oldState); }
+
+ private:
+  Thread* t;
+  Thread::State oldState;
+};
+
+class ReadResource {
+ public:
+  ReadResource(Thread* t, System::ReadWriteLock& lock): t(t), lock(lock) {
+    if (not lock.tryAcquireRead(t)) {
+      ENTER(t, Thread::IdleState);
+      lock.acquireRead(t);
+    }
+  }
+
+  ~ReadResource() { lock.releaseRead(t); }
+
+ private:
+  Thread* t;
+  System::ReadWriteLock& lock;
+};
+
+class WriteResource {
+ public:
+  WriteResource(Thread* t, System::ReadWriteLock& lock): t(t), lock(lock) {
+    if (not lock.tryAcquireWrite(t)) {
+      ENTER(t, Thread::IdleState);
+      lock.acquireWrite(t);
+    }
+  }
+
+  ~WriteResource() { lock.releaseWrite(t); }
+
+ private:
+  Thread* t;
+  System::ReadWriteLock& lock;
+};
+
 class MonitorResource {
  public:
   MonitorResource(Thread* t, System::Monitor* m): t(t), m(m) {
     if (not m->tryAcquire(t)) {
-      enter(t, Thread::IdleState);
+      ENTER(t, Thread::IdleState);
       m->acquire(t);
-      enter(t, Thread::ActiveState);
     }
   }
 
@@ -224,6 +282,105 @@ hash(const int8_t* s, unsigned length)
   return h;  
 }
 
+inline bool
+objectExtended(Thread*, object o)
+{
+  return (cast<uintptr_t>(o, 0) & (~PointerMask)) == ExtendedMark;
+}
+
+inline uintptr_t&
+extendedWord(Thread* t, object o, unsigned baseSize)
+{
+  assert(t, objectExtended(t, o));
+  return cast<uintptr_t>(o, baseSize * BytesPerWord);
+}
+
+unsigned
+baseSize(Thread* t, object o, object class_)
+{
+  return divide(classFixedSize(t, class_), BytesPerWord)
+    + divide(classArrayElementSize(t, class_)
+             * cast<uint32_t>(o, classFixedSize(t, class_) - 4),
+             BytesPerWord);
+}
+
+inline unsigned
+baseSize(Thread* t, object o)
+{
+  return baseSize(t, o, objectClass(t, o));
+}
+
+unsigned
+extendedSize(Thread* t, object o, unsigned baseSize)
+{
+  unsigned n = baseSize;
+
+  if (objectExtended(t, o)) {
+    if (extendedWord(t, o, n) & MonitorFlag) {
+      n += BytesPerWord;
+    }
+    n += BytesPerWord;
+  }
+
+  return n;
+}
+
+inline unsigned
+extendedSize(Thread* t, object o)
+{
+  return extendedSize(t, o, baseSize(t, o));
+}
+
+inline bool
+monitorAttached(Thread* t, object o, unsigned baseSize)
+{
+  return objectExtended(t, o)
+    and (extendedWord(t, o, baseSize) & MonitorFlag);
+}
+
+inline System::Monitor*&
+attachedMonitor(Thread* t, object o, unsigned baseSize)
+{
+  assert(t, monitorAttached(t, o, baseSize));
+  return cast<System::Monitor*>(o, (baseSize + 1) * BytesPerWord);
+}
+
+inline bool
+hashTaken(Thread*, object o)
+{
+  return (cast<uintptr_t>(o, 0) & (~PointerMask)) == HashTakenMark;
+}
+
+inline void
+markHashTaken(Thread* t, object o)
+{
+  assert(t, not objectExtended(t, o));
+  cast<uintptr_t>(o, 0) |= HashTakenMark;
+}
+
+inline uint32_t
+takeHash(Thread*, object o)
+{
+  return reinterpret_cast<uintptr_t>(o) / BytesPerWord;
+}
+
+inline uint32_t
+objectHash(Thread* t, object o)
+{
+  if (objectExtended(t, o)) {
+    return extendedWord(t, o, baseSize(t, o)) & PointerMask;
+  } else {
+    markHashTaken(t, o);
+    return takeHash(t, o);
+  }
+}
+
+inline bool
+objectEqual(Thread*, object a, object b)
+{
+  return a == b;
+}
+
 inline uint32_t
 byteArrayHash(Thread* t, object array)
 {
@@ -479,6 +636,7 @@ collect(Machine* m, Heap::CollectionType type)
       v->visit(&(m->classMap));
       v->visit(&(m->bootstrapClassMap));
       v->visit(&(m->builtinMap));
+      v->visit(&(m->monitorMap));
       v->visit(&(m->types));
 
       for (Thread* t = m->rootThread; t; t = t->next) {
@@ -486,16 +644,64 @@ collect(Machine* m, Heap::CollectionType type)
       }
     }
 
-    virtual unsigned sizeInWords(void* p) {
+    virtual unsigned sizeInWords(object o) {
       Thread* t = m->rootThread;
 
-      p = m->heap->follow(mask(p));
+      o = m->heap->follow(mask(o));
-      object class_ = m->heap->follow(objectClass(t, p));
 
-      return divide(classFixedSize(t, class_), BytesPerWord)
+      return extendedSize
-        + divide(classArrayElementSize(t, class_)
+        (t, o, baseSize(t, o, m->heap->follow(objectClass(t, o))));
-                 * cast<uint32_t>(p, classFixedSize(t, class_) - 4),
+    }
-                 BytesPerWord);
+
+    virtual void copy(object o, Heap::Allocator* allocator) {
+      Thread* t = m->rootThread;
+
+      o = m->heap->follow(mask(o));
+
+      unsigned base = baseSize(t, o, m->heap->follow(objectClass(t, o)));
+      unsigned copyCount = base;
+      unsigned allocateCount = base;
+
+      System::Monitor* monitor = 0;
+
+      if (objectExtended(t, o)) {
+        copyCount += BytesPerWord;
+        allocateCount += BytesPerWord;
+
+        if (extendedWord(t, o, base) & MonitorFlag) {
+          copyCount += BytesPerWord;
+          allocateCount += BytesPerWord;
+        } else {
+          monitor = gcHashMapRemove
+            (t, m->monitorMap, o, gcObjectHash, gcObjectEqual);
+
+          if (monitor) {
+            allocateCount += BytesPerWord;
+          }
+        }
+      } else if (hashTaken(t, o)) {
+        allocateCount += BytesPerWord;
+
+        monitor = gcHashMapRemove
+          (t, m->monitorMap, o, gcObjectHash, gcObjectEqual);
+
+        if (monitor) {
+          allocateCount += BytesPerWord;
+        }
+      }
+
+      object dst = allocator->allocate(allocateCount);
+      memcpy(o, dst, copyCount * BytesPerWord);
+
+      if (hashTaken(t, o)) {
+        extendedWord(t, dst, base) = takeHash(t, o);
+        cast<uintptr_t>(dst, 0) &= PointerMask;
+        cast<uintptr_t>(dst, 0) |= ExtendedMark;
+      }
+
+      if (monitor) {
+        attachedMonitor(t, dst, base) = monitor;
+      }
     }
 
     virtual void walk(void* p, Heap::Walker* w) {
@@ -755,15 +961,41 @@ make(Thread* t, object class_)
   return instance;
 }
 
-unsigned
+System::Monitor*
-objectSize(Thread* t, object o)
+mappedMonitor(Thread* t, object o)
 {
-  object class_ = objectClass(t, o);
+  PROTECT(t, o);
 
-  return divide(classFixedSize(t, class_), BytesPerWord)
+  System::Monitor* m = 0;
-    + divide(classArrayElementSize(t, class_)
+  { ACQUIRE_READ(t, t->vm->monitorMapLock);
-             * cast<uint32_t>(o, classFixedSize(t, class_) - 4),
+    object p = hashMapFind(t, t->vm->monitorMap, o, objectHash, objectEqual);
-             BytesPerWord);
+    if (p) {
+      m = static_cast<System::Monitor*>(pointerValue(t, p));
+    }
+  }
+
+  if (m == 0) {
+    System::Status s = t->vm->system->make(&m);
+    expect(t, t->vm->system->success(s));
+
+    object pointer = makePointer(t, m);
+    PROTECT(t, pointer);
+
+    ACQUIRE_WRITE(t, t->vm->monitorMapLock);
+
+    hashMapInsert(t, t->vm->monitorMap, o, pointer, objectHash);
+  }
+}
+
+inline System::Monitor*
+objectMonitor(Thread* t, object o)
+{
+  unsigned base = baseSize(t, o);
+  if (monitorAttached(t, o, base)) {
+    return attachedMonitor(t, o, base);
+  } else {
+    return mappedMonitor(t, o);
+  }
 }
 
 object
@@ -1985,9 +2217,9 @@ updateBootstrapClass(Thread* t, object bootstrapClass, object class_)
   PROTECT(t, bootstrapClass);
   PROTECT(t, class_);
 
-  enter(t, Thread::ExclusiveState);
+  ENTER(t, Thread::ExclusiveState);
 
-  memcpy(bootstrapClass, class_, objectSize(t, class_) * BytesPerWord);
+  memcpy(bootstrapClass, class_, extendedSize(t, class_) * BytesPerWord);
 
   object fieldTable = classFieldTable(t, class_);
   if (fieldTable) {
@@ -2002,8 +2234,6 @@ updateBootstrapClass(Thread* t, object bootstrapClass, object class_)
       set(t, methodClass(t, arrayBody(t, methodTable, i)), bootstrapClass);
     }
   }
-
-  enter(t, Thread::ActiveState);
 }
 
 object
@@ -2369,7 +2599,7 @@ GetStringUTFLength(JNIEnv* e, jstring s)
 {
   Thread* t = static_cast<Thread*>(e);
 
-  enter(t, Thread::ActiveState);
+  ENTER(t, Thread::ActiveState);
 
   jsize length = 0;
   if (LIKELY(s)) {
@@ -2378,8 +2608,6 @@ GetStringUTFLength(JNIEnv* e, jstring s)
     t->exception = makeNullPointerException(t);
   }
 
-  enter(t, Thread::IdleState);
-
   return length;
 }
 
@@ -2388,7 +2616,7 @@ GetStringUTFChars(JNIEnv* e, jstring s, jboolean* isCopy)
 {
   Thread* t = static_cast<Thread*>(e);
 
-  enter(t, Thread::ActiveState);
+  ENTER(t, Thread::ActiveState);
 
   char* chars = 0;
   if (LIKELY(s)) {
@@ -2403,8 +2631,6 @@ GetStringUTFChars(JNIEnv* e, jstring s, jboolean* isCopy)
     t->exception = makeNullPointerException(t);
   }
 
-  enter(t, Thread::IdleState);
-
   if (isCopy) *isCopy = true;
   return chars;
 }
@@ -2428,10 +2654,12 @@ Machine::Machine(System* system, Heap* heap, ClassFinder* classFinder):
   stateLock(0),
   heapLock(0),
   classLock(0),
+  monitorMapLock(system),
   libraries(0),
   classMap(0),
   bootstrapClassMap(0),
   builtinMap(0),
+  monitorMap(0),
   types(0),
   unsafe(false)
 {
@@ -2505,6 +2733,7 @@ Thread::Thread(Machine* m):
 
     m->classMap = makeHashMap(this, 0, 0);
     m->builtinMap = makeHashMap(this, 0, 0);
+    m->monitorMap = makeHashMap(this, 0, 0);
 
     struct {
       const char* key;
@@ -3635,25 +3864,25 @@ run(Thread* t)
     push(t, makeLong(t, longValue(t, a) ^ longValue(t, b)));
   } goto loop;
 
-//   case monitorenter: {
+  case monitorenter: {
-//     object o = pop(t);
+    object o = pop(t);
-//     if (LIKELY(o)) {
+    if (LIKELY(o)) {
-//       objectMonitor(t, o)->acquire(t);
+      objectMonitor(t, o)->acquire(t);
-//     } else {
+    } else {
-//       exception = makeNullPointerException(t);
+      exception = makeNullPointerException(t);
-//       goto throw_;
+      goto throw_;
-//     }
+    }
-//   } goto loop;
+  } goto loop;
 
-//   case monitorexit: {
+  case monitorexit: {
-//     object o = pop(t);
+    object o = pop(t);
-//     if (LIKELY(o)) {
+    if (LIKELY(o)) {
-//       objectMonitor(t, o)->release(t);
+      objectMonitor(t, o)->release(t);
-//     } else {
+    } else {
-//       exception = makeNullPointerException(t);
+      exception = makeNullPointerException(t);
-//       goto throw_;
+      goto throw_;
-//     }
+    }
-//   } goto loop;
+  } goto loop;
 
   case new_: {
     uint8_t index1 = codeBody(t, code, ip++);