--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/code/nmethod.hpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,578 @@
+/*
+ * Copyright 1997-2007 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.
+ *
+ */
+
+// This class is used internally by nmethods, to cache
+// exception/pc/handler information.
+
+class ExceptionCache : public CHeapObj {
+ friend class VMStructs;
+ private:
+ static address _unwind_handler;
+ enum { cache_size = 16 };
+ klassOop _exception_type;
+ address _pc[cache_size];
+ address _handler[cache_size];
+ int _count;
+ ExceptionCache* _next;
+
+ address pc_at(int index) { assert(index >= 0 && index < count(),""); return _pc[index]; }
+ void set_pc_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _pc[index] = a; }
+ address handler_at(int index) { assert(index >= 0 && index < count(),""); return _handler[index]; }
+ void set_handler_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _handler[index] = a; }
+ int count() { return _count; }
+ void increment_count() { _count++; }
+
+ public:
+
+ ExceptionCache(Handle exception, address pc, address handler);
+
+ klassOop exception_type() { return _exception_type; }
+ klassOop* exception_type_addr() { return &_exception_type; }
+ ExceptionCache* next() { return _next; }
+ void set_next(ExceptionCache *ec) { _next = ec; }
+
+ address match(Handle exception, address pc);
+ bool match_exception_with_space(Handle exception) ;
+ address test_address(address addr);
+ bool add_address_and_handler(address addr, address handler) ;
+
+ static address unwind_handler() { return _unwind_handler; }
+};
+
+
+// cache pc descs found in earlier inquiries
+class PcDescCache VALUE_OBJ_CLASS_SPEC {
+ friend class VMStructs;
+ private:
+ enum { cache_size = 4 };
+ PcDesc* _last_pc_desc; // most recent pc_desc found
+ PcDesc* _pc_descs[cache_size]; // last cache_size pc_descs found
+ public:
+ PcDescCache() { debug_only(_last_pc_desc = NULL); }
+ void reset_to(PcDesc* initial_pc_desc);
+ PcDesc* find_pc_desc(int pc_offset, bool approximate);
+ void add_pc_desc(PcDesc* pc_desc);
+ PcDesc* last_pc_desc() { return _last_pc_desc; }
+};
+
+
+// nmethods (native methods) are the compiled code versions of Java methods.
+
+struct nmFlags {
+ friend class VMStructs;
+ unsigned int version:8; // version number (0 = first version)
+ unsigned int level:4; // optimization level
+ unsigned int age:4; // age (in # of sweep steps)
+
+ unsigned int state:2; // {alive, zombie, unloaded)
+
+ unsigned int isUncommonRecompiled:1; // recompiled because of uncommon trap?
+ unsigned int isToBeRecompiled:1; // to be recompiled as soon as it matures
+ unsigned int hasFlushedDependencies:1; // Used for maintenance of dependencies
+ unsigned int markedForReclamation:1; // Used by NMethodSweeper
+
+ unsigned int has_unsafe_access:1; // May fault due to unsafe access.
+
+ void clear();
+};
+
+
+// A nmethod contains:
+// - header (the nmethod structure)
+// [Relocation]
+// - relocation information
+// - constant part (doubles, longs and floats used in nmethod)
+// [Code]
+// - code body
+// - exception handler
+// - stub code
+// [Debugging information]
+// - oop array
+// - data array
+// - pcs
+// [Exception handler table]
+// - handler entry point array
+// [Implicit Null Pointer exception table]
+// - implicit null table array
+
+class Dependencies;
+class ExceptionHandlerTable;
+class ImplicitExceptionTable;
+class AbstractCompiler;
+class xmlStream;
+
+class nmethod : public CodeBlob {
+ friend class VMStructs;
+ friend class NMethodSweeper;
+ private:
+ // Shared fields for all nmethod's
+ static int _zombie_instruction_size;
+
+ methodOop _method;
+ int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method
+
+ nmethod* _link; // To support simple linked-list chaining of nmethods
+
+ AbstractCompiler* _compiler; // The compiler which compiled this nmethod
+
+ // Offsets for different nmethod parts
+ int _exception_offset;
+ // All deoptee's will resume execution at this location described by this offset
+ int _deoptimize_offset;
+ int _stub_offset;
+ int _consts_offset;
+ int _scopes_data_offset;
+ int _scopes_pcs_offset;
+ int _dependencies_offset;
+ int _handler_table_offset;
+ int _nul_chk_table_offset;
+ int _nmethod_end_offset;
+
+ // location in frame (offset for sp) that deopt can store the original
+ // pc during a deopt.
+ int _orig_pc_offset;
+
+ int _compile_id; // which compilation made this nmethod
+ int _comp_level; // compilation level
+
+ // offsets for entry points
+ address _entry_point; // entry point with class check
+ address _verified_entry_point; // entry point without class check
+ address _osr_entry_point; // entry point for on stack replacement
+
+ nmFlags flags; // various flags to keep track of nmethod state
+ bool _markedForDeoptimization; // Used for stack deoptimization
+ enum { alive = 0,
+ not_entrant = 1, // uncommon trap has happend but activations may still exist
+ zombie = 2,
+ unloaded = 3 };
+
+ // used by jvmti to track if an unload event has been posted for this nmethod.
+ bool _unload_reported;
+
+ NOT_PRODUCT(bool _has_debug_info; )
+
+ // Nmethod Flushing lock (if non-zero, then the nmethod is not removed)
+ jint _lock_count;
+
+ // not_entrant method removal. Each mark_sweep pass will update
+ // this mark to current sweep invocation count if it is seen on the
+ // stack. An not_entrant method can be removed when there is no
+ // more activations, i.e., when the _stack_traversal_mark is less than
+ // current sweep traversal index.
+ long _stack_traversal_mark;
+
+ ExceptionCache *_exception_cache;
+ PcDescCache _pc_desc_cache;
+
+ // These are only used for compiled synchronized native methods to
+ // locate the owner and stack slot for the BasicLock so that we can
+ // properly revoke the bias of the owner if necessary. They are
+ // needed because there is no debug information for compiled native
+ // wrappers and the oop maps are insufficient to allow
+ // frame::retrieve_receiver() to work. Currently they are expected
+ // to be byte offsets from the Java stack pointer for maximum code
+ // sharing between platforms. Note that currently biased locking
+ // will never cause Class instances to be biased but this code
+ // handles the static synchronized case as well.
+ ByteSize _compiled_synchronized_native_basic_lock_owner_sp_offset;
+ ByteSize _compiled_synchronized_native_basic_lock_sp_offset;
+
+ friend class nmethodLocker;
+
+ // For native wrappers
+ nmethod(methodOop method,
+ int nmethod_size,
+ CodeOffsets* offsets,
+ CodeBuffer *code_buffer,
+ int frame_size,
+ ByteSize basic_lock_owner_sp_offset, /* synchronized natives only */
+ ByteSize basic_lock_sp_offset, /* synchronized natives only */
+ OopMapSet* oop_maps);
+
+ // Creation support
+ nmethod(methodOop method,
+ int nmethod_size,
+ int compile_id,
+ int entry_bci,
+ CodeOffsets* offsets,
+ int orig_pc_offset,
+ DebugInformationRecorder *recorder,
+ Dependencies* dependencies,
+ CodeBuffer *code_buffer,
+ int frame_size,
+ OopMapSet* oop_maps,
+ ExceptionHandlerTable* handler_table,
+ ImplicitExceptionTable* nul_chk_table,
+ AbstractCompiler* compiler,
+ int comp_level);
+
+ // helper methods
+ void* operator new(size_t size, int nmethod_size);
+ void check_store();
+
+ const char* reloc_string_for(u_char* begin, u_char* end);
+ void make_not_entrant_or_zombie(int state);
+ void inc_decompile_count();
+
+ // used to check that writes to nmFlags are done consistently.
+ static void check_safepoint() PRODUCT_RETURN;
+
+ // Used to manipulate the exception cache
+ void add_exception_cache_entry(ExceptionCache* new_entry);
+ ExceptionCache* exception_cache_entry_for_exception(Handle exception);
+
+ // Inform external interfaces that a compiled method has been unloaded
+ inline void post_compiled_method_unload();
+
+ public:
+ // create nmethod with entry_bci
+ static nmethod* new_nmethod(methodHandle method,
+ int compile_id,
+ int entry_bci,
+ CodeOffsets* offsets,
+ int orig_pc_offset,
+ DebugInformationRecorder* recorder,
+ Dependencies* dependencies,
+ CodeBuffer *code_buffer,
+ int frame_size,
+ OopMapSet* oop_maps,
+ ExceptionHandlerTable* handler_table,
+ ImplicitExceptionTable* nul_chk_table,
+ AbstractCompiler* compiler,
+ int comp_level);
+
+ static nmethod* new_native_nmethod(methodHandle method,
+ CodeBuffer *code_buffer,
+ int vep_offset,
+ int frame_complete,
+ int frame_size,
+ ByteSize receiver_sp_offset,
+ ByteSize basic_lock_sp_offset,
+ OopMapSet* oop_maps);
+
+ // accessors
+ methodOop method() const { return _method; }
+ AbstractCompiler* compiler() const { return _compiler; }
+
+#ifndef PRODUCT
+ bool has_debug_info() const { return _has_debug_info; }
+ void set_has_debug_info(bool f) { _has_debug_info = false; }
+#endif // NOT PRODUCT
+
+ // type info
+ bool is_nmethod() const { return true; }
+ bool is_java_method() const { return !method()->is_native(); }
+ bool is_native_method() const { return method()->is_native(); }
+ bool is_osr_method() const { return _entry_bci != InvocationEntryBci; }
+ bool is_osr_only_method() const { return is_osr_method(); }
+
+ bool is_compiled_by_c1() const;
+ bool is_compiled_by_c2() const;
+
+ // boundaries for different parts
+ address code_begin () const { return _entry_point; }
+ address code_end () const { return header_begin() + _stub_offset ; }
+ address exception_begin () const { return header_begin() + _exception_offset ; }
+ address deopt_handler_begin() const { return header_begin() + _deoptimize_offset ; }
+ address stub_begin () const { return header_begin() + _stub_offset ; }
+ address stub_end () const { return header_begin() + _consts_offset ; }
+ address consts_begin () const { return header_begin() + _consts_offset ; }
+ address consts_end () const { return header_begin() + _scopes_data_offset ; }
+ address scopes_data_begin () const { return header_begin() + _scopes_data_offset ; }
+ address scopes_data_end () const { return header_begin() + _scopes_pcs_offset ; }
+ PcDesc* scopes_pcs_begin () const { return (PcDesc*)(header_begin() + _scopes_pcs_offset ); }
+ PcDesc* scopes_pcs_end () const { return (PcDesc*)(header_begin() + _dependencies_offset); }
+ address dependencies_begin () const { return header_begin() + _dependencies_offset ; }
+ address dependencies_end () const { return header_begin() + _handler_table_offset ; }
+ address handler_table_begin() const { return header_begin() + _handler_table_offset ; }
+ address handler_table_end () const { return header_begin() + _nul_chk_table_offset ; }
+ address nul_chk_table_begin() const { return header_begin() + _nul_chk_table_offset ; }
+ address nul_chk_table_end () const { return header_begin() + _nmethod_end_offset ; }
+
+ int code_size () const { return code_end () - code_begin (); }
+ int stub_size () const { return stub_end () - stub_begin (); }
+ int consts_size () const { return consts_end () - consts_begin (); }
+ int scopes_data_size () const { return scopes_data_end () - scopes_data_begin (); }
+ int scopes_pcs_size () const { return (intptr_t)scopes_pcs_end () - (intptr_t)scopes_pcs_begin (); }
+ int dependencies_size () const { return dependencies_end () - dependencies_begin (); }
+ int handler_table_size() const { return handler_table_end() - handler_table_begin(); }
+ int nul_chk_table_size() const { return nul_chk_table_end() - nul_chk_table_begin(); }
+
+ int total_size () const;
+
+ bool code_contains (address addr) const { return code_begin () <= addr && addr < code_end (); }
+ bool stub_contains (address addr) const { return stub_begin () <= addr && addr < stub_end (); }
+ bool consts_contains (address addr) const { return consts_begin () <= addr && addr < consts_end (); }
+ bool scopes_data_contains (address addr) const { return scopes_data_begin () <= addr && addr < scopes_data_end (); }
+ bool scopes_pcs_contains (PcDesc* addr) const { return scopes_pcs_begin () <= addr && addr < scopes_pcs_end (); }
+ bool handler_table_contains(address addr) const { return handler_table_begin() <= addr && addr < handler_table_end(); }
+ bool nul_chk_table_contains(address addr) const { return nul_chk_table_begin() <= addr && addr < nul_chk_table_end(); }
+
+ // entry points
+ address entry_point() const { return _entry_point; } // normal entry point
+ address verified_entry_point() const { return _verified_entry_point; } // if klass is correct
+
+ // flag accessing and manipulation
+ bool is_in_use() const { return flags.state == alive; }
+ bool is_alive() const { return flags.state == alive || flags.state == not_entrant; }
+ bool is_not_entrant() const { return flags.state == not_entrant; }
+ bool is_zombie() const { return flags.state == zombie; }
+ bool is_unloaded() const { return flags.state == unloaded; }
+
+ // Make the nmethod non entrant. The nmethod will continue to be alive.
+ // It is used when an uncommon trap happens.
+ void make_not_entrant() { make_not_entrant_or_zombie(not_entrant); }
+ void make_zombie() { make_not_entrant_or_zombie(zombie); }
+
+ // used by jvmti to track if the unload event has been reported
+ bool unload_reported() { return _unload_reported; }
+ void set_unload_reported() { _unload_reported = true; }
+
+ bool is_marked_for_deoptimization() const { return _markedForDeoptimization; }
+ void mark_for_deoptimization() { _markedForDeoptimization = true; }
+
+ void make_unloaded(BoolObjectClosure* is_alive, oop cause);
+
+ bool has_dependencies() { return dependencies_size() != 0; }
+ void flush_dependencies(BoolObjectClosure* is_alive);
+ bool has_flushed_dependencies() { return flags.hasFlushedDependencies; }
+ void set_has_flushed_dependencies() {
+ check_safepoint();
+ assert(!has_flushed_dependencies(), "should only happen once");
+ flags.hasFlushedDependencies = 1;
+ }
+
+ bool is_marked_for_reclamation() const { return flags.markedForReclamation; }
+ void mark_for_reclamation() { check_safepoint(); flags.markedForReclamation = 1; }
+ void unmark_for_reclamation() { check_safepoint(); flags.markedForReclamation = 0; }
+
+ bool has_unsafe_access() const { return flags.has_unsafe_access; }
+ void set_has_unsafe_access(bool z) { flags.has_unsafe_access = z; }
+
+ int level() const { return flags.level; }
+ void set_level(int newLevel) { check_safepoint(); flags.level = newLevel; }
+
+ int comp_level() const { return _comp_level; }
+
+ int version() const { return flags.version; }
+ void set_version(int v);
+
+ // Sweeper support
+ long stack_traversal_mark() { return _stack_traversal_mark; }
+ void set_stack_traversal_mark(long l) { _stack_traversal_mark = l; }
+
+ // Exception cache support
+ ExceptionCache* exception_cache() const { return _exception_cache; }
+ void set_exception_cache(ExceptionCache *ec) { _exception_cache = ec; }
+ address handler_for_exception_and_pc(Handle exception, address pc);
+ void add_handler_for_exception_and_pc(Handle exception, address pc, address handler);
+ void remove_from_exception_cache(ExceptionCache* ec);
+
+ // implicit exceptions support
+ address continuation_for_implicit_exception(address pc);
+
+ // On-stack replacement support
+ int osr_entry_bci() const { assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod"); return _entry_bci; }
+ address osr_entry() const { assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod"); return _osr_entry_point; }
+ void invalidate_osr_method();
+ nmethod* link() const { return _link; }
+ void set_link(nmethod *n) { _link = n; }
+
+ // tells whether frames described by this nmethod can be deoptimized
+ // note: native wrappers cannot be deoptimized.
+ bool can_be_deoptimized() const { return is_java_method(); }
+
+ // Inline cache support
+ void clear_inline_caches();
+ void cleanup_inline_caches();
+ bool inlinecache_check_contains(address addr) const {
+ return (addr >= instructions_begin() && addr < verified_entry_point());
+ }
+
+ // unlink and deallocate this nmethod
+ // Only NMethodSweeper class is expected to use this. NMethodSweeper is not
+ // expected to use any other private methods/data in this class.
+
+ protected:
+ void flush();
+
+ public:
+ // If returning true, it is unsafe to remove this nmethod even though it is a zombie
+ // nmethod, since the VM might have a reference to it. Should only be called from a safepoint.
+ bool is_locked_by_vm() const { return _lock_count >0; }
+
+ // See comment at definition of _last_seen_on_stack
+ void mark_as_seen_on_stack();
+ bool can_not_entrant_be_converted();
+
+ // Evolution support. We make old (discarded) compiled methods point to new methodOops.
+ void set_method(methodOop method) { _method = method; }
+
+ // GC support
+ void do_unloading(BoolObjectClosure* is_alive, OopClosure* keep_alive,
+ bool unloading_occurred);
+ bool can_unload(BoolObjectClosure* is_alive, OopClosure* keep_alive,
+ oop* root, bool unloading_occurred);
+
+ void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map,
+ OopClosure* f);
+ void oops_do(OopClosure* f);
+
+ // ScopeDesc for an instruction
+ ScopeDesc* scope_desc_at(address pc);
+
+ private:
+ ScopeDesc* scope_desc_in(address begin, address end);
+
+ address* orig_pc_addr(const frame* fr ) { return (address*) ((address)fr->unextended_sp() + _orig_pc_offset); }
+
+ PcDesc* find_pc_desc_internal(address pc, bool approximate);
+
+ PcDesc* find_pc_desc(address pc, bool approximate) {
+ PcDesc* desc = _pc_desc_cache.last_pc_desc();
+ if (desc != NULL && desc->pc_offset() == pc - instructions_begin()) {
+ return desc;
+ }
+ return find_pc_desc_internal(pc, approximate);
+ }
+
+ public:
+ // ScopeDesc retrieval operation
+ PcDesc* pc_desc_at(address pc) { return find_pc_desc(pc, false); }
+ // pc_desc_near returns the first PcDesc at or after the givne pc.
+ PcDesc* pc_desc_near(address pc) { return find_pc_desc(pc, true); }
+
+ public:
+ // copying of debugging information
+ void copy_scopes_pcs(PcDesc* pcs, int count);
+ void copy_scopes_data(address buffer, int size);
+
+ // deopt
+ // return true is the pc is one would expect if the frame is being deopted.
+ bool is_deopt_pc(address pc);
+ // Accessor/mutator for the original pc of a frame before a frame was deopted.
+ address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
+ void set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
+
+ // jvmti support:
+ void post_compiled_method_load_event();
+
+ // verify operations
+ void verify();
+ void verify_scopes();
+ void verify_interrupt_point(address interrupt_point);
+
+ // printing support
+ void print() const PRODUCT_RETURN;
+ void print_code() PRODUCT_RETURN;
+ void print_relocations() PRODUCT_RETURN;
+ void print_pcs() PRODUCT_RETURN;
+ void print_scopes() PRODUCT_RETURN;
+ void print_dependencies() PRODUCT_RETURN;
+ void print_value_on(outputStream* st) const PRODUCT_RETURN;
+ void print_calls(outputStream* st) PRODUCT_RETURN;
+ void print_handler_table() PRODUCT_RETURN;
+ void print_nul_chk_table() PRODUCT_RETURN;
+ void print_nmethod(bool print_code) PRODUCT_RETURN;
+
+ void print_on(outputStream* st, const char* title) const;
+
+ // Logging
+ void log_identity(xmlStream* log) const;
+ void log_new_nmethod() const;
+ void log_state_change(int state) const;
+
+ // Prints a comment for one native instruction (reloc info, pc desc)
+ void print_code_comment_on(outputStream* st, int column, address begin, address end) PRODUCT_RETURN;
+ static void print_statistics() PRODUCT_RETURN;
+
+ // Compiler task identification. Note that all OSR methods
+ // are numbered in an independent sequence if CICountOSR is true,
+ // and native method wrappers are also numbered independently if
+ // CICountNative is true.
+ int compile_id() const { return _compile_id; }
+ const char* compile_kind() const;
+
+ // For debugging
+ // CompiledIC* IC_at(char* p) const;
+ // PrimitiveIC* primitiveIC_at(char* p) const;
+ oop embeddedOop_at(address p);
+
+ // tells if any of this method's dependencies have been invalidated
+ // (this is expensive!)
+ bool check_all_dependencies();
+
+ // tells if this compiled method is dependent on the given changes,
+ // and the changes have invalidated it
+ bool check_dependency_on(DepChange& changes);
+
+ // Evolution support. Tells if this compiled method is dependent on any of
+ // methods m() of class dependee, such that if m() in dependee is replaced,
+ // this compiled method will have to be deoptimized.
+ bool is_evol_dependent_on(klassOop dependee);
+
+ // Fast breakpoint support. Tells if this compiled method is
+ // dependent on the given method. Returns true if this nmethod
+ // corresponds to the given method as well.
+ bool is_dependent_on_method(methodOop dependee);
+
+ // is it ok to patch at address?
+ bool is_patchable_at(address instr_address);
+
+ // UseBiasedLocking support
+ ByteSize compiled_synchronized_native_basic_lock_owner_sp_offset() {
+ return _compiled_synchronized_native_basic_lock_owner_sp_offset;
+ }
+ ByteSize compiled_synchronized_native_basic_lock_sp_offset() {
+ return _compiled_synchronized_native_basic_lock_sp_offset;
+ }
+
+ // support for code generation
+ static int verified_entry_point_offset() { return offset_of(nmethod, _verified_entry_point); }
+ static int osr_entry_point_offset() { return offset_of(nmethod, _osr_entry_point); }
+ static int entry_bci_offset() { return offset_of(nmethod, _entry_bci); }
+
+};
+
+// Locks an nmethod so its code will not get removed, even if it is a zombie/not_entrant method
+class nmethodLocker : public StackObj {
+ nmethod* _nm;
+
+ static void lock_nmethod(nmethod* nm); // note: nm can be NULL
+ static void unlock_nmethod(nmethod* nm); // (ditto)
+
+ public:
+ nmethodLocker(address pc); // derive nm from pc
+ nmethodLocker(nmethod *nm) { _nm = nm; lock_nmethod(_nm); }
+ nmethodLocker() { _nm = NULL; }
+ ~nmethodLocker() { unlock_nmethod(_nm); }
+
+ nmethod* code() { return _nm; }
+ void set_code(nmethod* new_nm) {
+ unlock_nmethod(_nm); // note: This works even if _nm==new_nm.
+ _nm = new_nm;
+ lock_nmethod(_nm);
+ }
+};