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src/share/vm/code/stubs.hpp@24128c2ffa87 (annotated)

src/share/vm/code/stubs.hpp

Fri, 29 Jan 2010 08:33:24 -0800

author

twisti

date

Fri, 29 Jan 2010 08:33:24 -0800

changeset 1636

24128c2ffa87

parent 435

a61af66fc99e

child 1907

c18cbe5936b8

permissions

-rw-r--r--

6921339: backout 6917766
Reviewed-by: mr

duke@435	1	/*
duke@435	2	* Copyright 1997-2002 Sun Microsystems, Inc. All Rights Reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
duke@435	19	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435	20	* CA 95054 USA or visit www.sun.com if you need additional information or
duke@435	21	* have any questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
duke@435	25	// The classes in this file provide a simple framework for the
duke@435	26	// management of little pieces of machine code - or stubs -
duke@435	27	// created on the fly and frequently discarded. In this frame-
duke@435	28	// work stubs are stored in a queue.
duke@435	29
duke@435	30
duke@435	31	// Stub serves as abstract base class. A concrete stub
duke@435	32	// implementation is a subclass of Stub, implementing
duke@435	33	// all (non-virtual!) functions required sketched out
duke@435	34	// in the Stub class.
duke@435	35	//
duke@435	36	// A concrete stub layout may look like this (both data
duke@435	37	// and code sections could be empty as well):
duke@435	38	//
duke@435	39	// ________
duke@435	40	// stub -->| | <--+
duke@435	41	// | data | |
duke@435	42	// |________| |
duke@435	43	// code_begin -->| | |
duke@435	44	// | | |
duke@435	45	// | code | | size
duke@435	46	// | | |
duke@435	47	// |________| |
duke@435	48	// code_end -->| | |
duke@435	49	// | data | |
duke@435	50	// |________| |
duke@435	51	// <--+
duke@435	52
duke@435	53
duke@435	54	class Stub VALUE_OBJ_CLASS_SPEC {
duke@435	55	public:
duke@435	56	// Initialization/finalization
duke@435	57	void initialize(int size) { ShouldNotCallThis(); } // called to initialize/specify the stub's size
duke@435	58	void finalize() { ShouldNotCallThis(); } // called before the stub is deallocated
duke@435	59
duke@435	60	// General info/converters
duke@435	61	int size() const { ShouldNotCallThis(); return 0; } // must return the size provided by initialize
duke@435	62	static int code_size_to_size(int code_size) { ShouldNotCallThis(); return 0; } // computes the size given the code size
duke@435	63
duke@435	64	// Code info
duke@435	65	address code_begin() const { ShouldNotCallThis(); return NULL; } // points to the first byte of the code
duke@435	66	address code_end() const { ShouldNotCallThis(); return NULL; } // points to the first byte after the code
duke@435	67
duke@435	68	// Debugging
duke@435	69	void verify() { ShouldNotCallThis(); } // verifies the Stub
duke@435	70	void print() { ShouldNotCallThis(); } // prints some information about the stub
duke@435	71	};
duke@435	72
duke@435	73
duke@435	74	// A stub interface defines the interface between a stub queue
duke@435	75	// and the stubs it queues. In order to avoid a vtable and
duke@435	76	// (and thus the extra word) in each stub, a concrete stub
duke@435	77	// interface object is created and associated with a stub
duke@435	78	// buffer which in turn uses the stub interface to interact
duke@435	79	// with its stubs.
duke@435	80	//
duke@435	81	// StubInterface serves as an abstract base class. A concrete
duke@435	82	// stub interface implementation is a subclass of StubInterface,
duke@435	83	// forwarding its virtual function calls to non-virtual calls
duke@435	84	// of the concrete stub (see also macro below). There's exactly
duke@435	85	// one stub interface instance required per stub queue.
duke@435	86
duke@435	87	class StubInterface: public CHeapObj {
duke@435	88	public:
duke@435	89	// Initialization/finalization
duke@435	90	virtual void initialize(Stub* self, int size) = 0; // called after creation (called twice if allocated via (request, commit))
duke@435	91	virtual void finalize(Stub* self) = 0; // called before deallocation
duke@435	92
duke@435	93	// General info/converters
duke@435	94	virtual int size(Stub* self) const = 0; // the total size of the stub in bytes (must be a multiple of CodeEntryAlignment)
duke@435	95	virtual int code_size_to_size(int code_size) const = 0; // computes the total stub size in bytes given the code size in bytes
duke@435	96
duke@435	97	// Code info
duke@435	98	virtual address code_begin(Stub* self) const = 0; // points to the first code byte
duke@435	99	virtual address code_end(Stub* self) const = 0; // points to the first byte after the code
duke@435	100
duke@435	101	// Debugging
duke@435	102	virtual void verify(Stub* self) = 0; // verifies the stub
duke@435	103	virtual void print(Stub* self) = 0; // prints information about the stub
duke@435	104	};
duke@435	105
duke@435	106
duke@435	107	// DEF_STUB_INTERFACE is used to create a concrete stub interface
duke@435	108	// class, forwarding stub interface calls to the corresponding
duke@435	109	// stub calls.
duke@435	110
duke@435	111	#define DEF_STUB_INTERFACE(stub) \
duke@435	112	class stub##Interface: public StubInterface { \
duke@435	113	private: \
duke@435	114	static stub* cast(Stub* self) { return (stub*)self; } \
duke@435	115	\
duke@435	116	public: \
duke@435	117	/* Initialization/finalization */ \
duke@435	118	virtual void initialize(Stub* self, int size) { cast(self)->initialize(size); } \
duke@435	119	virtual void finalize(Stub* self) { cast(self)->finalize(); } \
duke@435	120	\
duke@435	121	/* General info */ \
duke@435	122	virtual int size(Stub* self) const { return cast(self)->size(); } \
duke@435	123	virtual int code_size_to_size(int code_size) const { return stub::code_size_to_size(code_size); } \
duke@435	124	\
duke@435	125	/* Code info */ \
duke@435	126	virtual address code_begin(Stub* self) const { return cast(self)->code_begin(); } \
duke@435	127	virtual address code_end(Stub* self) const { return cast(self)->code_end(); } \
duke@435	128	\
duke@435	129	/* Debugging */ \
duke@435	130	virtual void verify(Stub* self) { cast(self)->verify(); } \
duke@435	131	virtual void print(Stub* self) { cast(self)->print(); } \
duke@435	132	};
duke@435	133
duke@435	134
duke@435	135	// A StubQueue maintains a queue of stubs.
duke@435	136	// Note: All sizes (spaces) are given in bytes.
duke@435	137
duke@435	138	class StubQueue: public CHeapObj {
duke@435	139	friend class VMStructs;
duke@435	140	private:
duke@435	141	StubInterface* _stub_interface; // the interface prototype
duke@435	142	address _stub_buffer; // where all stubs are stored
duke@435	143	int _buffer_size; // the buffer size in bytes
duke@435	144	int _buffer_limit; // the (byte) index of the actual buffer limit (_buffer_limit <= _buffer_size)
duke@435	145	int _queue_begin; // the (byte) index of the first queue entry (word-aligned)
duke@435	146	int _queue_end; // the (byte) index of the first entry after the queue (word-aligned)
duke@435	147	int _number_of_stubs; // the number of buffered stubs
duke@435	148	Mutex* const _mutex; // the lock used for a (request, commit) transaction
duke@435	149
duke@435	150	void check_index(int i) const { assert(0 <= i && i < _buffer_limit && i % CodeEntryAlignment == 0, "illegal index"); }
duke@435	151	bool is_contiguous() const { return _queue_begin <= _queue_end; }
duke@435	152	int index_of(Stub* s) const { int i = (address)s - _stub_buffer; check_index(i); return i; }
duke@435	153	Stub* stub_at(int i) const { check_index(i); return (Stub*)(_stub_buffer + i); }
duke@435	154	Stub* current_stub() const { return stub_at(_queue_end); }
duke@435	155
duke@435	156	// Stub functionality accessed via interface
duke@435	157	void stub_initialize(Stub* s, int size) { assert(size % CodeEntryAlignment == 0, "size not aligned"); _stub_interface->initialize(s, size); }
duke@435	158	void stub_finalize(Stub* s) { _stub_interface->finalize(s); }
duke@435	159	int stub_size(Stub* s) const { return _stub_interface->size(s); }
duke@435	160	bool stub_contains(Stub* s, address pc) const { return _stub_interface->code_begin(s) <= pc && pc < _stub_interface->code_end(s); }
duke@435	161	int stub_code_size_to_size(int code_size) const { return _stub_interface->code_size_to_size(code_size); }
duke@435	162	void stub_verify(Stub* s) { _stub_interface->verify(s); }
duke@435	163	void stub_print(Stub* s) { _stub_interface->print(s); }
duke@435	164
duke@435	165	static void register_queue(StubQueue*);
duke@435	166
duke@435	167	public:
duke@435	168	StubQueue(StubInterface* stub_interface, int buffer_size, Mutex* lock,
duke@435	169	const char* name);
duke@435	170	~StubQueue();
duke@435	171
duke@435	172	// General queue info
duke@435	173	bool is_empty() const { return _queue_begin == _queue_end; }
duke@435	174	int total_space() const { return _buffer_size - 1; }
duke@435	175	int available_space() const { int d = _queue_begin - _queue_end - 1; return d < 0 ? d + _buffer_size : d; }
duke@435	176	int used_space() const { return total_space() - available_space(); }
duke@435	177	int number_of_stubs() const { return _number_of_stubs; }
duke@435	178	bool contains(address pc) const { return _stub_buffer <= pc && pc < _stub_buffer + _buffer_limit; }
duke@435	179	Stub* stub_containing(address pc) const;
duke@435	180	address code_start() const { return _stub_buffer; }
duke@435	181	address code_end() const { return _stub_buffer + _buffer_limit; }
duke@435	182
duke@435	183	// Stub allocation (atomic transactions)
duke@435	184	Stub* request_committed(int code_size); // request a stub that provides exactly code_size space for code
duke@435	185	Stub* request(int requested_code_size); // request a stub with a (maximum) code space - locks the queue
duke@435	186	void commit (int committed_code_size); // commit the previously requested stub - unlocks the queue
duke@435	187
duke@435	188	// Stub deallocation
duke@435	189	void remove_first(); // remove the first stub in the queue
duke@435	190	void remove_first(int n); // remove the first n stubs in the queue
duke@435	191	void remove_all(); // remove all stubs in the queue
duke@435	192
duke@435	193	// Iteration
duke@435	194	static void queues_do(void f(StubQueue* s)); // call f with each StubQueue
duke@435	195	void stubs_do(void f(Stub* s)); // call f with all stubs
duke@435	196	Stub* first() const { return number_of_stubs() > 0 ? stub_at(_queue_begin) : NULL; }
duke@435	197	Stub* next(Stub* s) const { int i = index_of(s) + stub_size(s);
duke@435	198	if (i == _buffer_limit) i = 0;
duke@435	199	return (i == _queue_end) ? NULL : stub_at(i);
duke@435	200	}
duke@435	201
duke@435	202	address stub_code_begin(Stub* s) const { return _stub_interface->code_begin(s); }
duke@435	203	address stub_code_end(Stub* s) const { return _stub_interface->code_end(s); }
duke@435	204
duke@435	205	// Debugging/printing
duke@435	206	void verify(); // verifies the stub queue
duke@435	207	void print(); // prints information about the stub queue
duke@435	208	};