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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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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.
// Next 7 reasons are recorded per bytecode in DataLayout::trap_bits
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_bimorphic, // saw unexpected object class in bimorphic inlining (@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_predicate, // compiler generated predicate failed
Reason_LIMIT,
// Note: Keep this enum in sync. with _trap_reason_name.
Reason_RECORDED_LIMIT = Reason_bimorphic // 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(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread);
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; }
};