--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/runtime/deoptimization.hpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,348 @@
+/*
+ * 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.
+ *
+ */
+
+class ProfileData;
+class vframeArray;
+class MonitorValue;
+class ObjectValue;
+
+class Deoptimization : AllStatic {
+ public:
+ // What condition caused the deoptimization?
+ enum DeoptReason {
+ Reason_many = -1, // indicates presence of several reasons
+ Reason_none = 0, // indicates absence of a relevant deopt.
+ Reason_null_check, // saw unexpected null or zero divisor (@bci)
+ Reason_null_assert, // saw unexpected non-null or non-zero (@bci)
+ Reason_range_check, // saw unexpected array index (@bci)
+ Reason_class_check, // saw unexpected object class (@bci)
+ Reason_array_check, // saw unexpected array class (aastore @bci)
+ Reason_intrinsic, // saw unexpected operand to intrinsic (@bci)
+ Reason_unloaded, // unloaded class or constant pool entry
+ Reason_uninitialized, // bad class state (uninitialized)
+ Reason_unreached, // code is not reached, compiler
+ Reason_unhandled, // arbitrary compiler limitation
+ Reason_constraint, // arbitrary runtime constraint violated
+ Reason_div0_check, // a null_check due to division by zero
+ Reason_age, // nmethod too old; tier threshold reached
+ Reason_LIMIT,
+ // Note: Keep this enum in sync. with _trap_reason_name.
+ Reason_RECORDED_LIMIT = Reason_unloaded // some are not recorded per bc
+ // Note: Reason_RECORDED_LIMIT should be < 8 to fit into 3 bits of
+ // DataLayout::trap_bits. This dependency is enforced indirectly
+ // via asserts, to avoid excessive direct header-to-header dependencies.
+ // See Deoptimization::trap_state_reason and class DataLayout.
+ };
+
+ // What action must be taken by the runtime?
+ enum DeoptAction {
+ Action_none, // just interpret, do not invalidate nmethod
+ Action_maybe_recompile, // recompile the nmethod; need not invalidate
+ Action_reinterpret, // invalidate the nmethod, reset IC, maybe recompile
+ Action_make_not_entrant, // invalidate the nmethod, recompile (probably)
+ Action_make_not_compilable, // invalidate the nmethod and do not compile
+ Action_LIMIT
+ // Note: Keep this enum in sync. with _trap_action_name.
+ };
+
+ enum {
+ _action_bits = 3,
+ _reason_bits = 4,
+ _action_shift = 0,
+ _reason_shift = _action_shift+_action_bits,
+ BC_CASE_LIMIT = PRODUCT_ONLY(1) NOT_PRODUCT(4) // for _deoptimization_hist
+ };
+
+ enum UnpackType {
+ Unpack_deopt = 0, // normal deoptimization, use pc computed in unpack_vframe_on_stack
+ Unpack_exception = 1, // exception is pending
+ Unpack_uncommon_trap = 2, // redo last byte code (C2 only)
+ Unpack_reexecute = 3 // reexecute bytecode (C1 only)
+ };
+
+ // Checks all compiled methods. Invalid methods are deleted and
+ // corresponding activations are deoptimized.
+ static int deoptimize_dependents();
+
+ // Deoptimizes a frame lazily. nmethod gets patched deopt happens on return to the frame
+ static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map);
+
+ private:
+ // Does the actual work for deoptimizing a single frame
+ static void deoptimize_single_frame(JavaThread* thread, frame fr);
+
+ // Helper function to revoke biases of all monitors in frame if UseBiasedLocking
+ // is enabled
+ static void revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map);
+ // Helper function to revoke biases of all monitors in frames
+ // executing in a particular CodeBlob if UseBiasedLocking is enabled
+ static void revoke_biases_of_monitors(CodeBlob* cb);
+
+#ifdef COMPILER2
+ // Support for restoring non-escaping objects
+ static bool realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS);
+ static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type);
+ static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj);
+ static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects);
+ static void relock_objects(frame* fr, RegisterMap* reg_map, GrowableArray<MonitorValue*>* monitors);
+ NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects);)
+#endif // COMPILER2
+
+ public:
+ static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk);
+
+ // Interface used for unpacking deoptimized frames
+
+ // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob).
+ // This is only a CheapObj to ease debugging after a deopt failure
+ class UnrollBlock : public CHeapObj {
+ private:
+ int _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame
+ int _caller_adjustment; // Adjustment, in bytes, to caller's SP by initial interpreted frame
+ int _number_of_frames; // Number frames to unroll
+ int _total_frame_sizes; // Total of number*sizes frames
+ intptr_t* _frame_sizes; // Array of frame sizes, in bytes, for unrolling the stack
+ address* _frame_pcs; // Array of frame pc's, in bytes, for unrolling the stack
+ intptr_t* _register_block; // Block for storing callee-saved registers.
+ BasicType _return_type; // Tells if we have to restore double or long return value
+ // The following fields are used as temps during the unpacking phase
+ // (which is tight on registers, especially on x86). They really ought
+ // to be PD variables but that involves moving this class into its own
+ // file to use the pd include mechanism. Maybe in a later cleanup ...
+ intptr_t _counter_temp; // SHOULD BE PD VARIABLE (x86 frame count temp)
+ intptr_t _initial_fp; // SHOULD BE PD VARIABLE (x86/c2 initial ebp)
+ intptr_t _unpack_kind; // SHOULD BE PD VARIABLE (x86 unpack kind)
+ intptr_t _sender_sp_temp; // SHOULD BE PD VARIABLE (x86 sender_sp)
+ public:
+ // Constructor
+ UnrollBlock(int size_of_deoptimized_frame,
+ int caller_adjustment,
+ int number_of_frames,
+ intptr_t* frame_sizes,
+ address* frames_pcs,
+ BasicType return_type);
+ ~UnrollBlock();
+
+ // Returns where a register is located.
+ intptr_t* value_addr_at(int register_number) const;
+
+ // Accessors
+ intptr_t* frame_sizes() const { return _frame_sizes; }
+ int number_of_frames() const { return _number_of_frames; }
+ address* frame_pcs() const { return _frame_pcs ; }
+
+ // Returns the total size of frames
+ int size_of_frames() const;
+
+ // Accessors used by the code generator for the unpack stub.
+ static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); }
+ static int caller_adjustment_offset_in_bytes() { return offset_of(UnrollBlock, _caller_adjustment); }
+ static int number_of_frames_offset_in_bytes() { return offset_of(UnrollBlock, _number_of_frames); }
+ static int frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _frame_sizes); }
+ static int total_frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _total_frame_sizes); }
+ static int frame_pcs_offset_in_bytes() { return offset_of(UnrollBlock, _frame_pcs); }
+ static int register_block_offset_in_bytes() { return offset_of(UnrollBlock, _register_block); }
+ static int return_type_offset_in_bytes() { return offset_of(UnrollBlock, _return_type); }
+ static int counter_temp_offset_in_bytes() { return offset_of(UnrollBlock, _counter_temp); }
+ static int initial_fp_offset_in_bytes() { return offset_of(UnrollBlock, _initial_fp); }
+ static int unpack_kind_offset_in_bytes() { return offset_of(UnrollBlock, _unpack_kind); }
+ static int sender_sp_temp_offset_in_bytes() { return offset_of(UnrollBlock, _sender_sp_temp); }
+
+ BasicType return_type() const { return _return_type; }
+ void print();
+ };
+
+ //** Returns an UnrollBlock continuing information
+ // how to make room for the resulting interpreter frames.
+ // Called by assembly stub after execution has returned to
+ // deoptimized frame.
+ // @argument thread. Thread where stub_frame resides.
+ // @see OptoRuntime::deoptimization_fetch_unroll_info_C
+ static UnrollBlock* fetch_unroll_info(JavaThread* thread);
+
+ //** Unpacks vframeArray onto execution stack
+ // Called by assembly stub after execution has returned to
+ // deoptimized frame and after the stack unrolling.
+ // @argument thread. Thread where stub_frame resides.
+ // @argument exec_mode. Determines how execution should be continuted in top frame.
+ // 0 means continue after current byte code
+ // 1 means exception has happened, handle exception
+ // 2 means reexecute current bytecode (for uncommon traps).
+ // @see OptoRuntime::deoptimization_unpack_frames_C
+ // Return BasicType of call return type, if any
+ static BasicType unpack_frames(JavaThread* thread, int exec_mode);
+
+ // Cleans up deoptimization bits on thread after unpacking or in the
+ // case of an exception.
+ static void cleanup_deopt_info(JavaThread *thread,
+ vframeArray * array);
+
+ // Restores callee saved values from deoptimized frame into oldest interpreter frame
+ // so caller of the deoptimized frame will get back the values it expects.
+ static void unwind_callee_save_values(frame* f, vframeArray* vframe_array);
+
+ //** Performs an uncommon trap for compiled code.
+ // The top most compiler frame is converted into interpreter frames
+ static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index);
+ // Helper routine that enters the VM and may block
+ static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index);
+
+ //** Deoptimizes the frame identified by id.
+ // Only called from VMDeoptimizeFrame
+ // @argument thread. Thread where stub_frame resides.
+ // @argument id. id of frame that should be deoptimized.
+ static void deoptimize_frame(JavaThread* thread, intptr_t* id);
+
+ // Statistics
+ static void gather_statistics(DeoptReason reason, DeoptAction action,
+ Bytecodes::Code bc = Bytecodes::_illegal);
+ static void print_statistics();
+
+ // How much room to adjust the last frame's SP by, to make space for
+ // the callee's interpreter frame (which expects locals to be next to
+ // incoming arguments)
+ static int last_frame_adjust(int callee_parameters, int callee_locals);
+
+ // trap_request codes
+ static DeoptReason trap_request_reason(int trap_request) {
+ if (trap_request < 0)
+ return (DeoptReason)
+ ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits));
+ else
+ // standard reason for unloaded CP entry
+ return Reason_unloaded;
+ }
+ static DeoptAction trap_request_action(int trap_request) {
+ if (trap_request < 0)
+ return (DeoptAction)
+ ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits));
+ else
+ // standard action for unloaded CP entry
+ return _unloaded_action;
+ }
+ static int trap_request_index(int trap_request) {
+ if (trap_request < 0)
+ return -1;
+ else
+ return trap_request;
+ }
+ static int make_trap_request(DeoptReason reason, DeoptAction action,
+ int index = -1) {
+ assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits");
+ assert((1 << _action_bits) >= Action_LIMIT, "enough bits");
+ int trap_request;
+ if (index != -1)
+ trap_request = index;
+ else
+ trap_request = (~(((reason) << _reason_shift)
+ + ((action) << _action_shift)));
+ assert(reason == trap_request_reason(trap_request), "valid reason");
+ assert(action == trap_request_action(trap_request), "valid action");
+ assert(index == trap_request_index(trap_request), "valid index");
+ return trap_request;
+ }
+
+ // The trap_state stored in a MDO is decoded here.
+ // It records two items of information.
+ // reason: If a deoptimization happened here, what its reason was,
+ // or if there were multiple deopts with differing reasons.
+ // recompiled: If a deoptimization here triggered a recompilation.
+ // Note that not all reasons are recorded per-bci.
+ static DeoptReason trap_state_reason(int trap_state);
+ static int trap_state_has_reason(int trap_state, int reason);
+ static int trap_state_add_reason(int trap_state, int reason);
+ static bool trap_state_is_recompiled(int trap_state);
+ static int trap_state_set_recompiled(int trap_state, bool z);
+ static const char* format_trap_state(char* buf, size_t buflen,
+ int trap_state);
+
+ static bool reason_is_recorded_per_bytecode(DeoptReason reason) {
+ return reason > Reason_none && reason < Reason_RECORDED_LIMIT;
+ }
+
+ static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) {
+ if (reason_is_recorded_per_bytecode(reason))
+ return reason;
+ else if (reason == Reason_div0_check) // null check due to divide-by-zero?
+ return Reason_null_check; // recorded per BCI as a null check
+ else
+ return Reason_none;
+ }
+
+ static const char* trap_reason_name(int reason);
+ static const char* trap_action_name(int action);
+ // Format like reason='foo' action='bar' index='123'.
+ // This is suitable both for XML and for tty output.
+ static const char* format_trap_request(char* buf, size_t buflen,
+ int trap_request);
+
+ static jint total_deoptimization_count();
+ static jint deoptimization_count(DeoptReason reason);
+
+ // JVMTI PopFrame support
+
+ // Preserves incoming arguments to the popped frame when it is
+ // returning to a deoptimized caller
+ static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address);
+
+ private:
+ enum {
+ _no_count = -1
+ };
+
+ static void reset_invocation_counter(ScopeDesc* trap_scope, jint count = _no_count);
+
+ static methodDataOop get_method_data(JavaThread* thread, methodHandle m, bool create_if_missing);
+ // Update the mdo's count and per-BCI reason bits, returning previous state:
+ static ProfileData* query_update_method_data(methodDataHandle trap_mdo,
+ int trap_bci,
+ DeoptReason reason,
+ //outputs:
+ uint& ret_this_trap_count,
+ bool& ret_maybe_prior_trap,
+ bool& ret_maybe_prior_recompile);
+ // class loading support for uncommon trap
+ static void load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS);
+ static void load_class_by_index(constantPoolHandle constant_pool, int index);
+
+ static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread);
+
+ static DeoptAction _unloaded_action; // == Action_reinterpret;
+ static const char* _trap_reason_name[Reason_LIMIT];
+ static const char* _trap_action_name[Action_LIMIT];
+
+ static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT];
+ // Note: Histogram array size is 1-2 Kb.
+
+ public:
+ static void update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason);
+};
+
+class DeoptimizationMarker : StackObj { // for profiling
+ static bool _is_active;
+public:
+ DeoptimizationMarker() { _is_active = true; }
+ ~DeoptimizationMarker() { _is_active = false; }
+ static bool is_active() { return _is_active; }
+};