duke@435: /*
coleenp@4037:  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #ifndef SHARE_VM_RUNTIME_SWEEPER_HPP
stefank@2314: #define SHARE_VM_RUNTIME_SWEEPER_HPP
stefank@2314: 
duke@435: // An NmethodSweeper is an incremental cleaner for:
duke@435: //    - cleanup inline caches
duke@435: //    - reclamation of unreferences zombie nmethods
duke@435: //
duke@435: 
duke@435: class NMethodSweeper : public AllStatic {
duke@435:   static long      _traversals;   // Stack traversal count
never@1970:   static nmethod*  _current;      // Current nmethod
duke@435:   static int       _seen;         // Nof. nmethod we have currently processed in current pass of CodeCache
never@1999: 
neliasso@5038:   static volatile int  _invocations;   // No. of invocations left until we are completed with this pass
neliasso@5038:   static volatile int  _sweep_started; // Flag to control conc sweeper
duke@435: 
neliasso@5038:   //The following are reset in scan_stacks and synchronized by the safepoint
neliasso@5038:   static bool      _resweep;           // Indicates that a change has happend and we want another sweep,
neliasso@5038:                                        // always checked and reset at a safepoint so memory will be in sync.
neliasso@5038:   static int       _locked_seen;       // Number of locked nmethods encountered during the scan
duke@435:   static int       _not_entrant_seen_on_stack; // Number of not entrant nmethod were are still on stack
neliasso@5038:   static jint      _flush_token;       // token that guards method flushing, making sure it is executed only once.
duke@435: 
neliasso@5038:   // These are set during a flush, a VM-operation
neliasso@5038:   static long      _last_flush_traversal_id; // trav number at last flush unloading
neliasso@5038:   static jlong     _last_full_flush_time;    // timestamp of last emergency unloading
neliasso@5038: 
neliasso@5038:   // These are synchronized by the _sweep_started token
neliasso@5038:   static int       _highest_marked;   // highest compile id dumped at last emergency unloading
neliasso@5038:   static int       _dead_compile_ids; // number of compile ids that where not in the cache last flush
duke@435: 
duke@435:   static void process_nmethod(nmethod *nm);
coleenp@4037:   static void release_nmethod(nmethod* nm);
coleenp@4037: 
never@1999:   static void log_sweep(const char* msg, const char* format = NULL, ...);
neliasso@5038:   static bool sweep_in_progress();
never@1999: 
duke@435:  public:
duke@435:   static long traversal_count() { return _traversals; }
duke@435: 
never@2916: #ifdef ASSERT
never@2916:   // Keep track of sweeper activity in the ring buffer
never@2916:   static void record_sweep(nmethod* nm, int line);
never@2916:   static void report_events(int id, address entry);
never@2916:   static void report_events();
never@2916: #endif
never@2916: 
never@1893:   static void scan_stacks();      // Invoked at the end of each safepoint
never@1893:   static void sweep_code_cache(); // Concurrent part of sweep job
never@1893:   static void possibly_sweep();   // Compiler threads call this to sweep
duke@435: 
duke@435:   static void notify(nmethod* nm) {
neliasso@5038:     // Request a new sweep of the code cache from the beginning. No
duke@435:     // need to synchronize the setting of this flag since it only
duke@435:     // changes to false at safepoint so we can never overwrite it with false.
neliasso@5038:      _resweep = true;
duke@435:   }
kvn@1637: 
kvn@1637:   static void handle_full_code_cache(bool is_full); // Called by compilers who fail to allocate
kvn@1637:   static void speculative_disconnect_nmethods(bool was_full);   // Called by vm op to deal with alloc failure
duke@435: };
stefank@2314: 
stefank@2314: #endif // SHARE_VM_RUNTIME_SWEEPER_HPP