6873116: Modify reexecute implementation to use pcDesc to record the reexecute bit

Summary: use PcDesc to keep record of the reexecute bit instead of using DebugInfoStreams
Reviewed-by: kvn, never, twisti

agent/src/share/classes/sun/jvm/hotspot/code/DebugInfoReadStream.java

@@ -81,4 +81,8 @@ public class DebugInfoReadStream extends CompressedReadStream {
     Assert.that(false, "should not reach here");
     return null;
   }
+
+  public int readBCI() {
+    return readInt() + InvocationEntryBCI;
+  }
 }

agent/src/share/classes/sun/jvm/hotspot/code/NMethod.java

 /*
- * Copyright 2000-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2000-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -259,7 +259,7 @@ public class NMethod extends CodeBlob {
     if (Assert.ASSERTS_ENABLED) {
       Assert.that(pd != null, "scope must be present");
     }
-    return new ScopeDesc(this, pd.getScopeDecodeOffset());
+    return new ScopeDesc(this, pd.getScopeDecodeOffset(), pd.getReexecute());
   }
 
   /** This is only for use by the debugging system, and is only
@@ -291,7 +291,7 @@ public class NMethod extends CodeBlob {
   public ScopeDesc getScopeDescNearDbg(Address pc) {
     PCDesc pd = getPCDescNearDbg(pc);
     if (pd == null) return null;
-    return new ScopeDesc(this, pd.getScopeDecodeOffset());
+    return new ScopeDesc(this, pd.getScopeDecodeOffset(), pd.getReexecute());
   }
 
   public Map/*<Address, PcDesc>*/ getSafepoints() {

agent/src/share/classes/sun/jvm/hotspot/code/PCDesc.java

 /*
- * Copyright 2000-2004 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2000-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -36,6 +36,7 @@ import sun.jvm.hotspot.types.*;
 public class PCDesc extends VMObject {
   private static CIntegerField pcOffsetField;
   private static CIntegerField scopeDecodeOffsetField;
+  private static CIntegerField pcFlagsField;
 
   static {
     VM.registerVMInitializedObserver(new Observer() {
@@ -50,6 +51,7 @@ public class PCDesc extends VMObject {
 
     pcOffsetField          = type.getCIntegerField("_pc_offset");
     scopeDecodeOffsetField = type.getCIntegerField("_scope_decode_offset");
+    pcFlagsField           = type.getCIntegerField("_flags");
   }
 
   public PCDesc(Address addr) {
@@ -70,6 +72,12 @@ public class PCDesc extends VMObject {
     return code.instructionsBegin().addOffsetTo(getPCOffset());
   }
 
+
+  public boolean getReexecute() {
+    int flags = (int)pcFlagsField.getValue(addr);
+    return ((flags & 0x1)== 1); //first is the reexecute bit
+  }
+
   public void print(NMethod code) {
     printOn(System.out, code);
   }

agent/src/share/classes/sun/jvm/hotspot/code/ScopeDesc.java

@@ -52,44 +52,46 @@ public class ScopeDesc {
   private List    objects; // ArrayList<ScopeValue>
 
 
-  public ScopeDesc(NMethod code, int decodeOffset) {
+  public ScopeDesc(NMethod code, int decodeOffset, boolean reexecute) {
     this.code = code;
     this.decodeOffset = decodeOffset;
     this.objects      = decodeObjectValues(DebugInformationRecorder.SERIALIZED_NULL);
+    this.reexecute    = reexecute;
 
     // Decode header
     DebugInfoReadStream stream  = streamAt(decodeOffset);
 
     senderDecodeOffset = stream.readInt();
     method = (Method) VM.getVM().getObjectHeap().newOop(stream.readOopHandle());
-    setBCIAndReexecute(stream.readInt());
+    bci    = stream.readBCI();
     // Decode offsets for body and sender
     localsDecodeOffset      = stream.readInt();
     expressionsDecodeOffset = stream.readInt();
     monitorsDecodeOffset    = stream.readInt();
   }
 
-  public ScopeDesc(NMethod code, int decodeOffset, int objectDecodeOffset) {
+  public ScopeDesc(NMethod code, int decodeOffset, int objectDecodeOffset, boolean reexecute) {
     this.code = code;
     this.decodeOffset = decodeOffset;
     this.objects      = decodeObjectValues(objectDecodeOffset);
+    this.reexecute    = reexecute;
 
     // Decode header
     DebugInfoReadStream stream  = streamAt(decodeOffset);
 
     senderDecodeOffset = stream.readInt();
     method = (Method) VM.getVM().getObjectHeap().newOop(stream.readOopHandle());
-    setBCIAndReexecute(stream.readInt());
+    bci    = stream.readBCI();
     // Decode offsets for body and sender
     localsDecodeOffset      = stream.readInt();
     expressionsDecodeOffset = stream.readInt();
     monitorsDecodeOffset    = stream.readInt();
   }
 
-  public NMethod getNMethod() { return code; }
-  public Method getMethod() { return method; }
-  public int    getBCI()    { return bci;    }
-  public boolean getReexecute() {return reexecute;}
+  public NMethod getNMethod()   { return code; }
+  public Method getMethod()     { return method; }
+  public int    getBCI()        { return bci;    }
+  public boolean getReexecute() { return reexecute;}
 
   /** Returns a List&lt;ScopeValue&gt; */
   public List getLocals() {
@@ -117,7 +119,7 @@ public class ScopeDesc {
       return null;
     }
 
-    return new ScopeDesc(code, senderDecodeOffset);
+    return new ScopeDesc(code, senderDecodeOffset, false);
   }
 
   /** Returns where the scope was decoded */
@@ -151,8 +153,8 @@ public class ScopeDesc {
   public void printValueOn(PrintStream tty) {
     tty.print("ScopeDesc for ");
     method.printValueOn(tty);
-    tty.println(" @bci " + bci);
-    tty.println(" reexecute: " + reexecute);
+    tty.print(" @bci " + bci);
+    tty.println(" reexecute=" + reexecute);
   }
 
   // FIXME: add more accessors
@@ -160,12 +162,6 @@ public class ScopeDesc {
   //--------------------------------------------------------------------------------
   // Internals only below this point
   //
-  private void setBCIAndReexecute(int combination) {
-    int InvocationEntryBci = VM.getVM().getInvocationEntryBCI();
-    bci = (combination >> 1) + InvocationEntryBci;
-    reexecute = (combination & 1)==1 ? true : false;
-  }
-
   private DebugInfoReadStream streamAt(int decodeOffset) {
     return new DebugInfoReadStream(code, decodeOffset, objects);
   }

src/share/vm/classfile/javaClasses.cpp

@@ -1229,13 +1229,10 @@ void java_lang_Throwable::fill_in_stack_trace(Handle throwable, TRAPS) {
 
     // Compiled java method case.
     if (decode_offset != 0) {
-      bool dummy_reexecute = false;
       DebugInfoReadStream stream(nm, decode_offset);
       decode_offset = stream.read_int();
       method = (methodOop)nm->oop_at(stream.read_int());
-      //fill_in_stack_trace does not need the reexecute information which is designed
-      //for the deopt to reexecute
-      bci = stream.read_bci_and_reexecute(dummy_reexecute);
+      bci = stream.read_bci();
     } else {
       if (fr.is_first_frame()) break;
       address pc = fr.pc();

src/share/vm/code/debugInfo.hpp

 /*
- * Copyright 1997-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -255,8 +255,7 @@ class DebugInfoReadStream : public CompressedReadStream {
   ScopeValue* read_object_value();
   ScopeValue* get_cached_object();
   // BCI encoding is mostly unsigned, but -1 is a distinguished value
-  // Decoding based on encoding: bci = InvocationEntryBci + read_int()/2; reexecute = read_int()%2 == 1 ? true : false;
-  int read_bci_and_reexecute(bool& reexecute) { int i = read_int(); reexecute = (i & 1) ? true : false; return (i >> 1) + InvocationEntryBci; }
+  int read_bci() { return read_int() + InvocationEntryBci; }
 };
 
 // DebugInfoWriteStream specializes CompressedWriteStream for
@@ -269,6 +268,5 @@ class DebugInfoWriteStream : public CompressedWriteStream {
  public:
   DebugInfoWriteStream(DebugInformationRecorder* recorder, int initial_size);
   void write_handle(jobject h);
-  //Encoding bci and reexecute into one word as (bci - InvocationEntryBci)*2 + reexecute
-  void write_bci_and_reexecute(int bci, bool reexecute) { write_int(((bci - InvocationEntryBci) << 1) + (reexecute ? 1 : 0)); }
+  void write_bci(int bci) { write_int(bci - InvocationEntryBci); }
 };

src/share/vm/code/debugInfoRec.cpp

 /*
- * Copyright 1998-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1998-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -292,13 +292,16 @@ void DebugInformationRecorder::describe_scope(int         pc_offset,
   int stream_offset = stream()->position();
   last_pd->set_scope_decode_offset(stream_offset);
 
+  // Record reexecute bit into pcDesc
+  last_pd->set_should_reexecute(reexecute);
+
   // serialize sender stream offest
   stream()->write_int(sender_stream_offset);
 
   // serialize scope
   jobject method_enc = (method == NULL)? NULL: method->encoding();
   stream()->write_int(oop_recorder()->find_index(method_enc));
-  stream()->write_bci_and_reexecute(bci, reexecute);
+  stream()->write_bci(bci);
   assert(method == NULL ||
          (method->is_native() && bci == 0) ||
          (!method->is_native() && 0 <= bci && bci < method->code_size()) ||

src/share/vm/code/nmethod.cpp

 /*
- * Copyright 1997-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -966,7 +966,7 @@ ScopeDesc* nmethod::scope_desc_at(address pc) {
   PcDesc* pd = pc_desc_at(pc);
   guarantee(pd != NULL, "scope must be present");
   return new ScopeDesc(this, pd->scope_decode_offset(),
-                       pd->obj_decode_offset());
+                       pd->obj_decode_offset(), pd->should_reexecute());
 }
 
 
@@ -1932,7 +1932,7 @@ void nmethod::verify_interrupt_point(address call_site) {
   PcDesc* pd = pc_desc_at(ic->end_of_call());
   assert(pd != NULL, "PcDesc must exist");
   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
-                                     pd->obj_decode_offset());
+                                     pd->obj_decode_offset(), pd->should_reexecute());
        !sd->is_top(); sd = sd->sender()) {
     sd->verify();
   }
@@ -2181,7 +2181,7 @@ ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
   PcDesc* p = pc_desc_near(begin+1);
   if (p != NULL && p->real_pc(this) <= end) {
     return new ScopeDesc(this, p->scope_decode_offset(),
-                         p->obj_decode_offset());
+                         p->obj_decode_offset(), p->should_reexecute());
   }
   return NULL;
 }

src/share/vm/code/pcDesc.cpp

 /*
- * Copyright 1997-2005 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,9 +26,11 @@
 # include "incls/_pcDesc.cpp.incl"
 
 PcDesc::PcDesc(int pc_offset, int scope_decode_offset, int obj_decode_offset) {
+  assert(sizeof(PcDescFlags) <= 4, "occupies more than a word");
   _pc_offset           = pc_offset;
   _scope_decode_offset = scope_decode_offset;
   _obj_decode_offset   = obj_decode_offset;
+  _flags.word          = 0;
 }
 
 address PcDesc::real_pc(const nmethod* code) const {
@@ -50,6 +52,7 @@ void PcDesc::print(nmethod* code) {
     tty->print("  ");
     sd->method()->print_short_name(tty);
     tty->print("  @%d", sd->bci());
+    tty->print("  reexecute=%s", sd->should_reexecute()?"true":"false");
     tty->cr();
   }
 #endif

src/share/vm/code/pcDesc.hpp

 /*
- * Copyright 1997-2005 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -34,6 +34,13 @@ class PcDesc VALUE_OBJ_CLASS_SPEC {
   int _scope_decode_offset; // offset for scope in nmethod
   int _obj_decode_offset;
 
+  union PcDescFlags {
+    int word;
+    struct {
+      unsigned int reexecute: 1;
+    } bits;
+  } _flags;
+
  public:
   int pc_offset() const           { return _pc_offset;   }
   int scope_decode_offset() const { return _scope_decode_offset; }
@@ -53,6 +60,10 @@ class PcDesc VALUE_OBJ_CLASS_SPEC {
     upper_offset_limit = (unsigned int)-1 >> 1
   };
 
+  // Flags
+  bool     should_reexecute()              const { return _flags.bits.reexecute; }
+  void set_should_reexecute(bool z)              { _flags.bits.reexecute = z;    }
+
   // Returns the real pc
   address real_pc(const nmethod* code) const;
 

src/share/vm/code/scopeDesc.cpp

 /*
- * Copyright 1997-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,17 +26,19 @@
 # include "incls/_scopeDesc.cpp.incl"
 
 
-ScopeDesc::ScopeDesc(const nmethod* code, int decode_offset, int obj_decode_offset) {
+ScopeDesc::ScopeDesc(const nmethod* code, int decode_offset, int obj_decode_offset, bool reexecute) {
   _code          = code;
   _decode_offset = decode_offset;
   _objects       = decode_object_values(obj_decode_offset);
+  _reexecute     = reexecute;
   decode_body();
 }
 
-ScopeDesc::ScopeDesc(const nmethod* code, int decode_offset) {
+ScopeDesc::ScopeDesc(const nmethod* code, int decode_offset, bool reexecute) {
   _code          = code;
   _decode_offset = decode_offset;
   _objects       = decode_object_values(DebugInformationRecorder::serialized_null);
+  _reexecute     = reexecute;
   decode_body();
 }
 
@@ -45,8 +47,8 @@ ScopeDesc::ScopeDesc(const ScopeDesc* parent) {
   _code          = parent->_code;
   _decode_offset = parent->_sender_decode_offset;
   _objects       = parent->_objects;
+  _reexecute     = false; //reexecute only applies to the first scope
   decode_body();
-  assert(_reexecute == false, "reexecute not allowed");
 }
 
 
@@ -57,7 +59,6 @@ void ScopeDesc::decode_body() {
     _sender_decode_offset = DebugInformationRecorder::serialized_null;
     _method = methodHandle(_code->method());
     _bci = InvocationEntryBci;
-    _reexecute = false;
     _locals_decode_offset = DebugInformationRecorder::serialized_null;
     _expressions_decode_offset = DebugInformationRecorder::serialized_null;
     _monitors_decode_offset = DebugInformationRecorder::serialized_null;
@@ -67,7 +68,7 @@ void ScopeDesc::decode_body() {
 
     _sender_decode_offset = stream->read_int();
     _method = methodHandle((methodOop) stream->read_oop());
-    _bci    = stream->read_bci_and_reexecute(_reexecute);
+    _bci    = stream->read_bci();
 
     // decode offsets for body and sender
     _locals_decode_offset      = stream->read_int();

src/share/vm/code/scopeDesc.hpp

 /*
- * Copyright 1997-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 1997-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -39,8 +39,7 @@ class SimpleScopeDesc : public StackObj {
     DebugInfoReadStream buffer(code, pc_desc->scope_decode_offset());
     int ignore_sender = buffer.read_int();
     _method           = methodOop(buffer.read_oop());
-    bool dummy_reexecute; //only methodOop and bci are needed!
-    _bci              = buffer.read_bci_and_reexecute(dummy_reexecute);
+    _bci              = buffer.read_bci();
   }
 
   methodOop method() { return _method; }
@@ -53,12 +52,12 @@ class SimpleScopeDesc : public StackObj {
 class ScopeDesc : public ResourceObj {
  public:
   // Constructor
-  ScopeDesc(const nmethod* code, int decode_offset, int obj_decode_offset);
+  ScopeDesc(const nmethod* code, int decode_offset, int obj_decode_offset, bool reexecute);
 
   // Calls above, giving default value of "serialized_null" to the
   // "obj_decode_offset" argument.  (We don't use a default argument to
   // avoid a .hpp-.hpp dependency.)
-  ScopeDesc(const nmethod* code, int decode_offset);
+  ScopeDesc(const nmethod* code, int decode_offset, bool reexecute);
 
   // JVM state
   methodHandle method()   const { return _method; }

src/share/vm/opto/callnode.cpp

@@ -493,7 +493,8 @@ void JVMState::dump_spec(outputStream *st) const {
     if (!printed)
       _method->print_short_name(st);
     st->print(" @ bci:%d",_bci);
-    st->print(" reexecute:%s", _reexecute==Reexecute_True?"true":"false");
+    if(_reexecute == Reexecute_True)
+      st->print(" reexecute");
   } else {
     st->print(" runtime stub");
   }

src/share/vm/prims/jvmtiCodeBlobEvents.cpp

 /*
- * Copyright 2003-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2003-2009 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -402,7 +402,7 @@ void JvmtiCodeBlobEvents::build_jvmti_addr_location_map(nmethod *nm,
 
     address scopes_data = nm->scopes_data_begin();
     for( pcd = nm->scopes_pcs_begin(); pcd < nm->scopes_pcs_end(); ++pcd ) {
-      ScopeDesc sc0(nm, pcd->scope_decode_offset());
+      ScopeDesc sc0(nm, pcd->scope_decode_offset(), pcd->should_reexecute());
       ScopeDesc *sd  = &sc0;
       while( !sd->is_top() ) { sd = sd->sender(); }
       int bci = sd->bci();

src/share/vm/runtime/vframe.hpp

@@ -402,12 +402,7 @@ inline void vframeStreamCommon::fill_from_compiled_frame(int decode_offset) {
   DebugInfoReadStream buffer(nm(), decode_offset);
   _sender_decode_offset = buffer.read_int();
   _method               = methodOop(buffer.read_oop());
-  // Deoptimization needs reexecute bit to determine whether to reexecute the bytecode
-  // only at the time when it "unpack_frames", and the reexecute bit info could always
-  // be obtained from the scopeDesc in the compiledVFrame. As a result, we don't keep
-  // the reexecute bit here.
-  bool dummy_reexecute;
-  _bci                  = buffer.read_bci_and_reexecute(dummy_reexecute);
+  _bci                  = buffer.read_bci();
 
   assert(_method->is_method(), "checking type of decoded method");
 }

src/share/vm/runtime/vmStructs.cpp

@@ -593,6 +593,7 @@ static inline uint64_t cast_uint64_t(size_t x)
                                                                                                                                      \
   nonstatic_field(PcDesc,                      _pc_offset,                                    int)                                   \
   nonstatic_field(PcDesc,                      _scope_decode_offset,                          int)                                   \
+  nonstatic_field(PcDesc,                      _flags,                        PcDesc::PcDescFlags)                                   \
                                                                                                                                      \
   /***************************************************/                                                                              \
   /* CodeBlobs (NOTE: incomplete, but only a little) */                                                                              \
@@ -1158,6 +1159,7 @@ static inline uint64_t cast_uint64_t(size_t x)
   /***************************************/                               \
                                                                           \
   declare_toplevel_type(PcDesc)                                           \
+  declare_integer_type(PcDesc::PcDescFlags)                               \
                                                                           \
   /************************/                                              \
   /* OopMap and OopMapSet */                                              \