--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/code/stubs.hpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,208 @@
+/*
+ * Copyright 1997-2002 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.
+ *
+ */
+
+// The classes in this file provide a simple framework for the
+// management of little pieces of machine code - or stubs -
+// created on the fly and frequently discarded. In this frame-
+// work stubs are stored in a queue.
+
+
+// Stub serves as abstract base class. A concrete stub
+// implementation is a subclass of Stub, implementing
+// all (non-virtual!) functions required sketched out
+// in the Stub class.
+//
+// A concrete stub layout may look like this (both data
+// and code sections could be empty as well):
+//
+// ________
+// stub -->| | <--+
+// | data | |
+// |________| |
+// code_begin -->| | |
+// | | |
+// | code | | size
+// | | |
+// |________| |
+// code_end -->| | |
+// | data | |
+// |________| |
+// <--+
+
+
+class Stub VALUE_OBJ_CLASS_SPEC {
+ public:
+ // Initialization/finalization
+ void initialize(int size) { ShouldNotCallThis(); } // called to initialize/specify the stub's size
+ void finalize() { ShouldNotCallThis(); } // called before the stub is deallocated
+
+ // General info/converters
+ int size() const { ShouldNotCallThis(); return 0; } // must return the size provided by initialize
+ static int code_size_to_size(int code_size) { ShouldNotCallThis(); return 0; } // computes the size given the code size
+
+ // Code info
+ address code_begin() const { ShouldNotCallThis(); return NULL; } // points to the first byte of the code
+ address code_end() const { ShouldNotCallThis(); return NULL; } // points to the first byte after the code
+
+ // Debugging
+ void verify() { ShouldNotCallThis(); } // verifies the Stub
+ void print() { ShouldNotCallThis(); } // prints some information about the stub
+};
+
+
+// A stub interface defines the interface between a stub queue
+// and the stubs it queues. In order to avoid a vtable and
+// (and thus the extra word) in each stub, a concrete stub
+// interface object is created and associated with a stub
+// buffer which in turn uses the stub interface to interact
+// with its stubs.
+//
+// StubInterface serves as an abstract base class. A concrete
+// stub interface implementation is a subclass of StubInterface,
+// forwarding its virtual function calls to non-virtual calls
+// of the concrete stub (see also macro below). There's exactly
+// one stub interface instance required per stub queue.
+
+class StubInterface: public CHeapObj {
+ public:
+ // Initialization/finalization
+ virtual void initialize(Stub* self, int size) = 0; // called after creation (called twice if allocated via (request, commit))
+ virtual void finalize(Stub* self) = 0; // called before deallocation
+
+ // General info/converters
+ virtual int size(Stub* self) const = 0; // the total size of the stub in bytes (must be a multiple of CodeEntryAlignment)
+ virtual int code_size_to_size(int code_size) const = 0; // computes the total stub size in bytes given the code size in bytes
+
+ // Code info
+ virtual address code_begin(Stub* self) const = 0; // points to the first code byte
+ virtual address code_end(Stub* self) const = 0; // points to the first byte after the code
+
+ // Debugging
+ virtual void verify(Stub* self) = 0; // verifies the stub
+ virtual void print(Stub* self) = 0; // prints information about the stub
+};
+
+
+// DEF_STUB_INTERFACE is used to create a concrete stub interface
+// class, forwarding stub interface calls to the corresponding
+// stub calls.
+
+#define DEF_STUB_INTERFACE(stub) \
+ class stub##Interface: public StubInterface { \
+ private: \
+ static stub* cast(Stub* self) { return (stub*)self; } \
+ \
+ public: \
+ /* Initialization/finalization */ \
+ virtual void initialize(Stub* self, int size) { cast(self)->initialize(size); } \
+ virtual void finalize(Stub* self) { cast(self)->finalize(); } \
+ \
+ /* General info */ \
+ virtual int size(Stub* self) const { return cast(self)->size(); } \
+ virtual int code_size_to_size(int code_size) const { return stub::code_size_to_size(code_size); } \
+ \
+ /* Code info */ \
+ virtual address code_begin(Stub* self) const { return cast(self)->code_begin(); } \
+ virtual address code_end(Stub* self) const { return cast(self)->code_end(); } \
+ \
+ /* Debugging */ \
+ virtual void verify(Stub* self) { cast(self)->verify(); } \
+ virtual void print(Stub* self) { cast(self)->print(); } \
+ };
+
+
+// A StubQueue maintains a queue of stubs.
+// Note: All sizes (spaces) are given in bytes.
+
+class StubQueue: public CHeapObj {
+ friend class VMStructs;
+ private:
+ StubInterface* _stub_interface; // the interface prototype
+ address _stub_buffer; // where all stubs are stored
+ int _buffer_size; // the buffer size in bytes
+ int _buffer_limit; // the (byte) index of the actual buffer limit (_buffer_limit <= _buffer_size)
+ int _queue_begin; // the (byte) index of the first queue entry (word-aligned)
+ int _queue_end; // the (byte) index of the first entry after the queue (word-aligned)
+ int _number_of_stubs; // the number of buffered stubs
+ Mutex* const _mutex; // the lock used for a (request, commit) transaction
+
+ void check_index(int i) const { assert(0 <= i && i < _buffer_limit && i % CodeEntryAlignment == 0, "illegal index"); }
+ bool is_contiguous() const { return _queue_begin <= _queue_end; }
+ int index_of(Stub* s) const { int i = (address)s - _stub_buffer; check_index(i); return i; }
+ Stub* stub_at(int i) const { check_index(i); return (Stub*)(_stub_buffer + i); }
+ Stub* current_stub() const { return stub_at(_queue_end); }
+
+ // Stub functionality accessed via interface
+ void stub_initialize(Stub* s, int size) { assert(size % CodeEntryAlignment == 0, "size not aligned"); _stub_interface->initialize(s, size); }
+ void stub_finalize(Stub* s) { _stub_interface->finalize(s); }
+ int stub_size(Stub* s) const { return _stub_interface->size(s); }
+ bool stub_contains(Stub* s, address pc) const { return _stub_interface->code_begin(s) <= pc && pc < _stub_interface->code_end(s); }
+ int stub_code_size_to_size(int code_size) const { return _stub_interface->code_size_to_size(code_size); }
+ void stub_verify(Stub* s) { _stub_interface->verify(s); }
+ void stub_print(Stub* s) { _stub_interface->print(s); }
+
+ static void register_queue(StubQueue*);
+
+ public:
+ StubQueue(StubInterface* stub_interface, int buffer_size, Mutex* lock,
+ const char* name);
+ ~StubQueue();
+
+ // General queue info
+ bool is_empty() const { return _queue_begin == _queue_end; }
+ int total_space() const { return _buffer_size - 1; }
+ int available_space() const { int d = _queue_begin - _queue_end - 1; return d < 0 ? d + _buffer_size : d; }
+ int used_space() const { return total_space() - available_space(); }
+ int number_of_stubs() const { return _number_of_stubs; }
+ bool contains(address pc) const { return _stub_buffer <= pc && pc < _stub_buffer + _buffer_limit; }
+ Stub* stub_containing(address pc) const;
+ address code_start() const { return _stub_buffer; }
+ address code_end() const { return _stub_buffer + _buffer_limit; }
+
+ // Stub allocation (atomic transactions)
+ Stub* request_committed(int code_size); // request a stub that provides exactly code_size space for code
+ Stub* request(int requested_code_size); // request a stub with a (maximum) code space - locks the queue
+ void commit (int committed_code_size); // commit the previously requested stub - unlocks the queue
+
+ // Stub deallocation
+ void remove_first(); // remove the first stub in the queue
+ void remove_first(int n); // remove the first n stubs in the queue
+ void remove_all(); // remove all stubs in the queue
+
+ // Iteration
+ static void queues_do(void f(StubQueue* s)); // call f with each StubQueue
+ void stubs_do(void f(Stub* s)); // call f with all stubs
+ Stub* first() const { return number_of_stubs() > 0 ? stub_at(_queue_begin) : NULL; }
+ Stub* next(Stub* s) const { int i = index_of(s) + stub_size(s);
+ if (i == _buffer_limit) i = 0;
+ return (i == _queue_end) ? NULL : stub_at(i);
+ }
+
+ address stub_code_begin(Stub* s) const { return _stub_interface->code_begin(s); }
+ address stub_code_end(Stub* s) const { return _stub_interface->code_end(s); }
+
+ // Debugging/printing
+ void verify(); // verifies the stub queue
+ void print(); // prints information about the stub queue
+};