view src/cpu/zero/vm/jniTypes_zero.hpp @ 3249:e1162778c1c8

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer. Reviewed-by: kvn, iveresov, never, tonyp, dholmes
author johnc
date Thu, 07 Apr 2011 09:53:20 -0700
parents f95d63e2154a
children
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/*
 * Copyright (c) 1998, 2010, Oracle and/or its affiliates. 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
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#ifndef CPU_ZERO_VM_JNITYPES_ZERO_HPP
#define CPU_ZERO_VM_JNITYPES_ZERO_HPP

#include "memory/allocation.hpp"
#include "oops/oop.hpp"
#include "prims/jni.h"

// This file holds platform-dependent routines used to write primitive jni
// types to the array of arguments passed into JavaCalls::call

class JNITypes : AllStatic {
  // These functions write a java primitive type (in native format)
  // to a java stack slot array to be passed as an argument to JavaCalls:calls.
  // I.e., they are functionally 'push' operations if they have a 'pos'
  // formal parameter.  Note that jlong's and jdouble's are written
  // _in reverse_ of the order in which they appear in the interpreter
  // stack.  This is because call stubs (see stubGenerator_zero.cpp)
  // reverse the argument list constructed by JavaCallArguments (see
  // javaCalls.hpp).

private:
  // Helper routines.
  static inline void    put_int2 (jint *from, jint *to)           { to[0] = from[0]; to[1] = from[1]; }
  static inline void    put_int2 (jint *from, jint *to, int& pos) { put_int2 (from, (jint *)((intptr_t *)to + pos)); pos += 2; }
  static inline void    put_int2r(jint *from, jint *to)           { to[0] = from[1]; to[1] = from[0]; }
  static inline void    put_int2r(jint *from, jint *to, int& pos) { put_int2r(from, (jint *)((intptr_t *)to + pos)); pos += 2; }

public:
  // Ints are stored in native format in one JavaCallArgument slot at *to.
  static inline void    put_int(jint  from, intptr_t *to)               { *(jint *)(to +   0  ) =  from; }
  static inline void    put_int(jint  from, intptr_t *to, int& pos)     { *(jint *)(to + pos++) =  from; }
  static inline void    put_int(jint *from, intptr_t *to, int& pos)     { *(jint *)(to + pos++) = *from; }

#ifdef _LP64
  // Longs are stored in native format in one JavaCallArgument slot at *(to+1).
  static inline void    put_long(jlong  from, intptr_t *to)             { *(jlong *)(to + 1 +   0) =  from; }
  static inline void    put_long(jlong  from, intptr_t *to, int& pos)   { *(jlong *)(to + 1 + pos) =  from; pos += 2; }
  static inline void    put_long(jlong *from, intptr_t *to, int& pos)   { *(jlong *)(to + 1 + pos) = *from; pos += 2; }
#else
  // Longs are stored in reversed native word format in two JavaCallArgument slots at *to.
  // The high half is in *(to+1) and the low half in *to.
  static inline void    put_long(jlong  from, intptr_t *to)            { put_int2r((jint *)&from, (jint *)to); }
  static inline void    put_long(jlong  from, intptr_t *to, int& pos)  { put_int2r((jint *)&from, (jint *)to, pos); }
  static inline void    put_long(jlong *from, intptr_t *to, int& pos)  { put_int2r((jint *) from, (jint *)to, pos); }
#endif

  // Oops are stored in native format in one JavaCallArgument slot at *to.
  static inline void    put_obj(oop  from, intptr_t *to)                { *(oop *)(to +   0  ) =  from; }
  static inline void    put_obj(oop  from, intptr_t *to, int& pos)      { *(oop *)(to + pos++) =  from; }
  static inline void    put_obj(oop *from, intptr_t *to, int& pos)      { *(oop *)(to + pos++) = *from; }

  // Floats are stored in native format in one JavaCallArgument slot at *to.
  static inline void    put_float(jfloat  from, intptr_t *to)           { *(jfloat *)(to +   0  ) =  from; }
  static inline void    put_float(jfloat  from, intptr_t *to, int& pos) { *(jfloat *)(to + pos++) =  from; }
  static inline void    put_float(jfloat *from, intptr_t *to, int& pos) { *(jfloat *)(to + pos++) = *from; }

#ifdef _LP64
  // Doubles are stored in native word format in one JavaCallArgument slot at *(to+1).
  static inline void    put_double(jdouble  from, intptr_t *to)           { *(jdouble *)(to + 1 +   0) =  from; }
  static inline void    put_double(jdouble  from, intptr_t *to, int& pos) { *(jdouble *)(to + 1 + pos) =  from; pos += 2; }
  static inline void    put_double(jdouble *from, intptr_t *to, int& pos) { *(jdouble *)(to + 1 + pos) = *from; pos += 2; }
#else
  // Doubles are stored in reversed native word format in two JavaCallArgument slots at *to.
  static inline void    put_double(jdouble  from, intptr_t *to)           { put_int2r((jint *)&from, (jint *)to); }
  static inline void    put_double(jdouble  from, intptr_t *to, int& pos) { put_int2r((jint *)&from, (jint *)to, pos); }
  static inline void    put_double(jdouble *from, intptr_t *to, int& pos) { put_int2r((jint *) from, (jint *)to, pos); }
#endif

  // The get_xxx routines, on the other hand, actually _do_ fetch
  // java primitive types from the interpreter stack.
  static inline jint    get_int(intptr_t *from)         { return *(jint *)from; }

#ifdef _LP64
  static inline jlong   get_long(intptr_t *from)        { return *(jlong *)from; }
#else
  static inline jlong   get_long(intptr_t *from)        { return ((jlong)(*(  signed int *)((jint *)from    )) << 32) |
                                                                 ((jlong)(*(unsigned int *)((jint *)from + 1)) <<  0); }
#endif

  static inline oop     get_obj(intptr_t *from)         { return *(oop *)from; }
  static inline jfloat  get_float(intptr_t *from)       { return *(jfloat *)from; }

#ifdef _LP64
  static inline jdouble get_double(intptr_t *from)      { return *(jdouble *)from; }
#else
  static inline jdouble get_double(intptr_t *from)      { jlong jl = ((jlong)(*(  signed int *)((jint *)from    )) << 32) |
                                                                     ((jlong)(*(unsigned int *)((jint *)from + 1)) <<  0);
                                                          return *(jdouble *)&jl; }
#endif

};

#endif // CPU_ZERO_VM_JNITYPES_ZERO_HPP