6619271: The -Xprintflags causes the VM to segv
Summary: add null checks
Reviewed-by: jrose, kvn
/*
* Copyright 1997-2003 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
* 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
// A simple allocation profiler for Java. The profiler collects and prints
// the number and total size of instances allocated per class, including
// array classes.
//
// The profiler is currently global for all threads. It can be changed to a
// per threads profiler by keeping a more elaborate data structure and calling
// iterate_since_last_scavenge at thread switches.
class AllocationProfiler: AllStatic {
friend class GenCollectedHeap;
friend class MarkSweep;
private:
static bool _active; // tells whether profiler is active
static GrowableArray<klassOop>* _print_array; // temporary array for printing
// Utility printing functions
static void add_class_to_array(klassOop k);
static void add_classes_to_array(klassOop k);
static int compare_classes(klassOop* k1, klassOop* k2);
static int average(size_t alloc_size, int alloc_count);
static void sort_and_print_array(size_t cutoff);
// Call for collecting allocation information. Called at scavenge, mark-sweep and disengage.
static void iterate_since_last_gc();
public:
// Start profiler
static void engage();
// Stop profiler
static void disengage();
// Tells whether profiler is active
static bool is_active() { return _active; }
// Print profile
static void print(size_t cutoff); // Cutoff in total allocation size (in words)
};