Mercurial > hg > graal-compiler
view src/share/vm/memory/sharedHeap.hpp @ 549:fe3d7c11b4b7
6700941: G1: allocation spec missing for some G1 classes
Reviewed-by: tonyp
author | apetrusenko |
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date | Tue, 10 Feb 2009 18:39:09 +0300 |
parents | 7d7a7c599c17 |
children | 0fbdb4381b99 |
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/* * Copyright 2000-2006 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 "SharedHeap" is an implementation of a java heap for HotSpot. This // is an abstract class: there may be many different kinds of heaps. This // class defines the functions that a heap must implement, and contains // infrastructure common to all heaps. class PermGen; class Generation; class BarrierSet; class GenRemSet; class Space; class SpaceClosure; class OopClosure; class OopsInGenClosure; class ObjectClosure; class SubTasksDone; class WorkGang; class CollectorPolicy; class KlassHandle; class SharedHeap : public CollectedHeap { friend class VMStructs; friend class VM_GC_Operation; friend class VM_CGC_Operation; private: // For claiming strong_roots tasks. SubTasksDone* _process_strong_tasks; protected: // There should be only a single instance of "SharedHeap" in a program. // This is enforced with the protected constructor below, which will also // set the static pointer "_sh" to that instance. static SharedHeap* _sh; // All heaps contain a "permanent generation." This is some ways // similar to a generation in a generational system, in other ways not. // See the "PermGen" class. PermGen* _perm_gen; // and the Gen Remembered Set, at least one good enough to scan the perm // gen. GenRemSet* _rem_set; // A gc policy, controls global gc resource issues CollectorPolicy *_collector_policy; // See the discussion below, in the specification of the reader function // for this variable. int _strong_roots_parity; // If we're doing parallel GC, use this gang of threads. WorkGang* _workers; // Number of parallel threads currently working on GC tasks. // O indicates use sequential code; 1 means use parallel code even with // only one thread, for performance testing purposes. int _n_par_threads; // Full initialization is done in a concrete subtype's "initialize" // function. SharedHeap(CollectorPolicy* policy_); // Returns true if the calling thread holds the heap lock, // or the calling thread is a par gc thread and the heap_lock is held // by the vm thread doing a gc operation. bool heap_lock_held_for_gc(); // True if the heap_lock is held by the a non-gc thread invoking a gc // operation. bool _thread_holds_heap_lock_for_gc; public: static SharedHeap* heap() { return _sh; } CollectorPolicy *collector_policy() const { return _collector_policy; } void set_barrier_set(BarrierSet* bs); // Does operations required after initialization has been done. virtual void post_initialize(); // Initialization of ("weak") reference processing support virtual void ref_processing_init(); void set_perm(PermGen* perm_gen) { _perm_gen = perm_gen; } // This function returns the "GenRemSet" object that allows us to scan // generations; at least the perm gen, possibly more in a fully // generational heap. GenRemSet* rem_set() { return _rem_set; } // These function return the "permanent" generation, in which // reflective objects are allocated and stored. Two versions, the second // of which returns the view of the perm gen as a generation. PermGen* perm() const { return _perm_gen; } Generation* perm_gen() const { return _perm_gen->as_gen(); } // Iteration functions. void oop_iterate(OopClosure* cl) = 0; // Same as above, restricted to a memory region. virtual void oop_iterate(MemRegion mr, OopClosure* cl) = 0; // Iterate over all objects allocated since the last collection, calling // "cl->do_object" on each. The heap must have been initialized properly // to support this function, or else this call will fail. virtual void object_iterate_since_last_GC(ObjectClosure* cl) = 0; // Iterate over all spaces in use in the heap, in an undefined order. virtual void space_iterate(SpaceClosure* cl) = 0; // A SharedHeap will contain some number of spaces. This finds the // space whose reserved area contains the given address, or else returns // NULL. virtual Space* space_containing(const void* addr) const = 0; bool no_gc_in_progress() { return !is_gc_active(); } // Some collectors will perform "process_strong_roots" in parallel. // Such a call will involve claiming some fine-grained tasks, such as // scanning of threads. To make this process simpler, we provide the // "strong_roots_parity()" method. Collectors that start parallel tasks // whose threads invoke "process_strong_roots" must // call "change_strong_roots_parity" in sequential code starting such a // task. (This also means that a parallel thread may only call // process_strong_roots once.) // // For calls to process_strong_roots by sequential code, the parity is // updated automatically. // // The idea is that objects representing fine-grained tasks, such as // threads, will contain a "parity" field. A task will is claimed in the // current "process_strong_roots" call only if its parity field is the // same as the "strong_roots_parity"; task claiming is accomplished by // updating the parity field to the strong_roots_parity with a CAS. // // If the client meats this spec, then strong_roots_parity() will have // the following properties: // a) to return a different value than was returned before the last // call to change_strong_roots_parity, and // c) to never return a distinguished value (zero) with which such // task-claiming variables may be initialized, to indicate "never // claimed". void change_strong_roots_parity(); int strong_roots_parity() { return _strong_roots_parity; } enum ScanningOption { SO_None = 0x0, SO_AllClasses = 0x1, SO_SystemClasses = 0x2, SO_Symbols = 0x4, SO_Strings = 0x8, SO_CodeCache = 0x10 }; WorkGang* workers() const { return _workers; } // Sets the number of parallel threads that will be doing tasks // (such as process strong roots) subsequently. virtual void set_par_threads(int t); // Number of threads currently working on GC tasks. int n_par_threads() { return _n_par_threads; } // Invoke the "do_oop" method the closure "roots" on all root locations. // If "collecting_perm_gen" is false, then roots that may only contain // references to permGen objects are not scanned. If true, the // "perm_gen" closure is applied to all older-to-younger refs in the // permanent generation. The "so" argument determines which of roots // the closure is applied to: // "SO_None" does none; // "SO_AllClasses" applies the closure to all entries in the SystemDictionary; // "SO_SystemClasses" to all the "system" classes and loaders; // "SO_Symbols" applies the closure to all entries in SymbolsTable; // "SO_Strings" applies the closure to all entries in StringTable; // "SO_CodeCache" applies the closure to all elements of the CodeCache. void process_strong_roots(bool collecting_perm_gen, ScanningOption so, OopClosure* roots, OopsInGenClosure* perm_blk); // Apply "blk" to all the weak roots of the system. These include // JNI weak roots, the code cache, system dictionary, symbol table, // string table. void process_weak_roots(OopClosure* root_closure, OopClosure* non_root_closure); // Like CollectedHeap::collect, but assume that the caller holds the Heap_lock. virtual void collect_locked(GCCause::Cause cause) = 0; // The functions below are helper functions that a subclass of // "SharedHeap" can use in the implementation of its virtual // functions. public: // Do anything common to GC's. virtual void gc_prologue(bool full) = 0; virtual void gc_epilogue(bool full) = 0; // // New methods from CollectedHeap // size_t permanent_capacity() const { assert(perm_gen(), "NULL perm gen"); return perm_gen()->capacity(); } size_t permanent_used() const { assert(perm_gen(), "NULL perm gen"); return perm_gen()->used(); } bool is_in_permanent(const void *p) const { assert(perm_gen(), "NULL perm gen"); return perm_gen()->is_in_reserved(p); } // Different from is_in_permanent in that is_in_permanent // only checks if p is in the reserved area of the heap // and this checks to see if it in the commited area. // This is typically used by things like the forte stackwalker // during verification of suspicious frame values. bool is_permanent(const void *p) const { assert(perm_gen(), "NULL perm gen"); return perm_gen()->is_in(p); } HeapWord* permanent_mem_allocate(size_t size) { assert(perm_gen(), "NULL perm gen"); return _perm_gen->mem_allocate(size); } void permanent_oop_iterate(OopClosure* cl) { assert(perm_gen(), "NULL perm gen"); _perm_gen->oop_iterate(cl); } void permanent_object_iterate(ObjectClosure* cl) { assert(perm_gen(), "NULL perm gen"); _perm_gen->object_iterate(cl); } // Some utilities. void print_size_transition(outputStream* out, size_t bytes_before, size_t bytes_after, size_t capacity); };