zgu@7074: /*
zgu@7074:  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
zgu@7074:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
zgu@7074:  *
zgu@7074:  * This code is free software; you can redistribute it and/or modify it
zgu@7074:  * under the terms of the GNU General Public License version 2 only, as
zgu@7074:  * published by the Free Software Foundation.
zgu@7074:  *
zgu@7074:  * This code is distributed in the hope that it will be useful, but WITHOUT
zgu@7074:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
zgu@7074:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
zgu@7074:  * version 2 for more details (a copy is included in the LICENSE file that
zgu@7074:  * accompanied this code).
zgu@7074:  *
zgu@7074:  * You should have received a copy of the GNU General Public License version
zgu@7074:  * 2 along with this work; if not, write to the Free Software Foundation,
zgu@7074:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
zgu@7074:  *
zgu@7074:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
zgu@7074:  * or visit www.oracle.com if you need additional information or have any
zgu@7074:  * questions.
zgu@7074:  *
zgu@7074:  */
zgu@7074: 
zgu@7074: #ifndef SHARE_VM_UTILITIES_NATIVE_CALL_STACK_HPP
zgu@7074: #define SHARE_VM_UTILITIES_NATIVE_CALL_STACK_HPP
zgu@7074: 
zgu@7074: #include "memory/allocation.hpp"
zgu@7074: #include "services/nmtCommon.hpp"
zgu@7074: #include "utilities/ostream.hpp"
zgu@7074: 
zgu@7074: /*
zgu@7074:  * This class represents a native call path (does not include Java frame)
zgu@7074:  *
zgu@7074:  * This class is developed in the context of native memory tracking, it can
zgu@7074:  * be an useful tool for debugging purpose.
zgu@7074:  *
zgu@7074:  * For example, following code should print out native call path:
zgu@7074:  *
zgu@7074:  *   ....
zgu@7074:  *   NativeCallStack here;
zgu@7074:  *   here.print_on(tty);
zgu@7074:  *   ....
zgu@7074:  *
zgu@7074:  * However, there are a couple of restrictions on this class. If the restrictions are
zgu@7074:  * not strictly followed, it may break native memory tracking badly.
zgu@7074:  *
zgu@7074:  * 1. Number of stack frames to capture, is defined by native memory tracking.
zgu@7074:  *    This number has impacts on how much memory to be used by native
zgu@7074:  *    memory tracking.
zgu@7074:  * 2. The class is strict stack object, no heap or virtual memory can be allocated
zgu@7074:  *    from it.
zgu@7074:  */
zgu@7074: class NativeCallStack : public StackObj {
zgu@7078:  public:
zgu@7078:   static const NativeCallStack EMPTY_STACK;
zgu@7078: 
zgu@7074:  private:
zgu@7074:   address   _stack[NMT_TrackingStackDepth];
zgu@7074:   int       _hash_value;
zgu@7074: 
zgu@7074:  public:
zgu@7074:   NativeCallStack(int toSkip = 0, bool fillStack = false);
zgu@7074:   NativeCallStack(address* pc, int frameCount);
zgu@7074: 
zgu@7074: 
zgu@7074:   // if it is an empty stack
zgu@7074:   inline bool is_empty() const {
zgu@7074:     return _stack[0] == NULL;
zgu@7074:   }
zgu@7074: 
zgu@7074:   // number of stack frames captured
zgu@7074:   int frames() const;
zgu@7074: 
zgu@7074:   inline int compare(const NativeCallStack& other) const {
zgu@7074:     return memcmp(_stack, other._stack, sizeof(_stack));
zgu@7074:   }
zgu@7074: 
zgu@7074:   inline bool equals(const NativeCallStack& other) const {
zgu@7074:     // compare hash values
zgu@7074:     if (hash() != other.hash()) return false;
zgu@7074:     // compare each frame
zgu@7074:     return compare(other) == 0;
zgu@7074:   }
zgu@7074: 
zgu@7074:   inline address get_frame(int index) const {
zgu@7074:     assert(index >= 0 && index < NMT_TrackingStackDepth, "Index out of bound");
zgu@7074:     return _stack[index];
zgu@7074:   }
zgu@7074: 
zgu@7074:   // Hash code. Any better algorithm?
zgu@7074:   int hash() const;
zgu@7074: 
zgu@7074:   void print_on(outputStream* out) const;
zgu@7074:   void print_on(outputStream* out, int indent) const;
zgu@7074: };
zgu@7074: 
zgu@7074: #endif