graal-compiler: src/share/vm/memory/sharedHeap.hpp comparison

comparison src/share/vm/memory/sharedHeap.hpp @ 0:a61af66fc99e jdk7-b24

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author	duke
date	Sat, 01 Dec 2007 00:00:00 +0000
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children	37f87013dfd8

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+:a61af66fc99e
+/*
+* 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;
+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_);
+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; }
+// A helper function that fills an allocated-but-not-yet-initialized
+// region with a garbage object.
+static void fill_region_with_object(MemRegion mr);
+// Minimum garbage fill object size
+static size_t min_fill_size()          { return (size_t)align_object_size(oopDesc::header_size()); }
+static size_t min_fill_size_in_bytes() { return min_fill_size() * HeapWordSize; }
+// 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.
+protected:
+// Do anything common to GC's.
+virtual void gc_prologue(bool full) = 0;
+virtual void gc_epilogue(bool full) = 0;
+public:
+//
+// 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(size_t bytes_before,
+size_t bytes_after,
+size_t capacity);
+};

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comparison src/share/vm/memory/sharedHeap.hpp @ 0:a61af66fc99e jdk7-b24