959 }
960
961 // lock object
962 //
963 // Registers alive
964 // monitor - Address of the BasicObjectLock to be used for locking,
965 // which must be initialized with the object to lock.
966 // object - Address of the object to be locked.
967 void InterpreterMacroAssembler::lock_object(Register monitor, Register object) {
968
969 if (UseHeavyMonitors) {
970 call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorenter),
971 monitor, /*check_for_exceptions=*/false);
972 return;
973 }
974
975 // template code:
976 //
977 // markWord displaced_header = obj->mark().set_unlocked();
978 // monitor->lock()->set_displaced_header(displaced_header);
979 // if (Atomic::cmpxchg(/*ex=*/monitor, /*addr*/obj->mark_addr(), /*cmp*/displaced_header) == displaced_header) {
980 // // We stored the monitor address into the object's mark word.
981 // } else if (THREAD->is_lock_owned((address)displaced_header))
982 // // Simple recursive case.
983 // monitor->lock()->set_displaced_header(NULL);
984 // } else {
985 // // Slow path.
986 // InterpreterRuntime::monitorenter(THREAD, monitor);
987 // }
988
989 const Register displaced_header = Z_ARG5;
990 const Register object_mark_addr = Z_ARG4;
991 const Register current_header = Z_ARG5;
992
993 NearLabel done;
994 NearLabel slow_case;
995
996 // markWord displaced_header = obj->mark().set_unlocked();
997
998 // Load markWord from object into displaced_header.
999 z_lg(displaced_header, oopDesc::mark_offset_in_bytes(), object);
1000
1001 if (UseBiasedLocking) {
1002 biased_locking_enter(object, displaced_header, Z_R1, Z_R0, done, &slow_case);
1003 }
1004
1005 // Set displaced_header to be (markWord of object | UNLOCK_VALUE).
1006 z_oill(displaced_header, markWord::unlocked_value);
1007
1008 // monitor->lock()->set_displaced_header(displaced_header);
1009
1010 // Initialize the box (Must happen before we update the object mark!).
1011 z_stg(displaced_header, BasicObjectLock::lock_offset_in_bytes() +
1012 BasicLock::displaced_header_offset_in_bytes(), monitor);
1013
1014 // if (Atomic::cmpxchg(/*ex=*/monitor, /*addr*/obj->mark_addr(), /*cmp*/displaced_header) == displaced_header) {
1015
1016 // Store stack address of the BasicObjectLock (this is monitor) into object.
1017 add2reg(object_mark_addr, oopDesc::mark_offset_in_bytes(), object);
1018
1019 z_csg(displaced_header, monitor, 0, object_mark_addr);
1020 assert(current_header==displaced_header, "must be same register"); // Identified two registers from z/Architecture.
1021
1022 z_bre(done);
1023
1024 // } else if (THREAD->is_lock_owned((address)displaced_header))
1025 // // Simple recursive case.
1026 // monitor->lock()->set_displaced_header(NULL);
1027
1028 // We did not see an unlocked object so try the fast recursive case.
1029
1030 // Check if owner is self by comparing the value in the markWord of object
1031 // (current_header) with the stack pointer.
1032 z_sgr(current_header, Z_SP);
1033
1034 assert(os::vm_page_size() > 0xfff, "page size too small - change the constant");
1065 // Unlocks an object. Used in monitorexit bytecode and remove_activation.
1066 //
1067 // Registers alive
1068 // monitor - address of the BasicObjectLock to be used for locking,
1069 // which must be initialized with the object to lock.
1070 //
1071 // Throw IllegalMonitorException if object is not locked by current thread.
1072 void InterpreterMacroAssembler::unlock_object(Register monitor, Register object) {
1073
1074 if (UseHeavyMonitors) {
1075 call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorexit), monitor);
1076 return;
1077 }
1078
1079 // else {
1080 // template code:
1081 //
1082 // if ((displaced_header = monitor->displaced_header()) == NULL) {
1083 // // Recursive unlock. Mark the monitor unlocked by setting the object field to NULL.
1084 // monitor->set_obj(NULL);
1085 // } else if (Atomic::cmpxchg(displaced_header, obj->mark_addr(), monitor) == monitor) {
1086 // // We swapped the unlocked mark in displaced_header into the object's mark word.
1087 // monitor->set_obj(NULL);
1088 // } else {
1089 // // Slow path.
1090 // InterpreterRuntime::monitorexit(THREAD, monitor);
1091 // }
1092
1093 const Register displaced_header = Z_ARG4;
1094 const Register current_header = Z_R1;
1095 Address obj_entry(monitor, BasicObjectLock::obj_offset_in_bytes());
1096 Label done;
1097
1098 if (object == noreg) {
1099 // In the template interpreter, we must assure that the object
1100 // entry in the monitor is cleared on all paths. Thus we move
1101 // loading up to here, and clear the entry afterwards.
1102 object = Z_ARG3; // Use Z_ARG3 if caller didn't pass object.
1103 z_lg(object, obj_entry);
1104 }
1105
1106 assert_different_registers(monitor, object, displaced_header, current_header);
1107
1108 // if ((displaced_header = monitor->displaced_header()) == NULL) {
1109 // // Recursive unlock. Mark the monitor unlocked by setting the object field to NULL.
1110 // monitor->set_obj(NULL);
1111
1112 clear_mem(obj_entry, sizeof(oop));
1113
1114 if (UseBiasedLocking) {
1115 // The object address from the monitor is in object.
1116 assert(oopDesc::mark_offset_in_bytes() == 0, "offset of _mark is not 0");
1117 biased_locking_exit(object, displaced_header, done);
1118 }
1119
1120 // Test first if we are in the fast recursive case.
1121 MacroAssembler::load_and_test_long(displaced_header,
1122 Address(monitor, BasicObjectLock::lock_offset_in_bytes() +
1123 BasicLock::displaced_header_offset_in_bytes()));
1124 z_bre(done); // displaced_header == 0 -> goto done
1125
1126 // } else if (Atomic::cmpxchg(displaced_header, obj->mark_addr(), monitor) == monitor) {
1127 // // We swapped the unlocked mark in displaced_header into the object's mark word.
1128 // monitor->set_obj(NULL);
1129
1130 // If we still have a lightweight lock, unlock the object and be done.
1131
1132 // The markword is expected to be at offset 0.
1133 assert(oopDesc::mark_offset_in_bytes() == 0, "unlock_object: review code below");
1134
1135 // We have the displaced header in displaced_header. If the lock is still
1136 // lightweight, it will contain the monitor address and we'll store the
1137 // displaced header back into the object's mark word.
1138 z_lgr(current_header, monitor);
1139 z_csg(current_header, displaced_header, 0, object);
1140 z_bre(done);
1141
1142 // } else {
1143 // // Slow path.
1144 // InterpreterRuntime::monitorexit(THREAD, monitor);
1145
1146 // The lock has been converted into a heavy lock and hence
|
959 }
960
961 // lock object
962 //
963 // Registers alive
964 // monitor - Address of the BasicObjectLock to be used for locking,
965 // which must be initialized with the object to lock.
966 // object - Address of the object to be locked.
967 void InterpreterMacroAssembler::lock_object(Register monitor, Register object) {
968
969 if (UseHeavyMonitors) {
970 call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorenter),
971 monitor, /*check_for_exceptions=*/false);
972 return;
973 }
974
975 // template code:
976 //
977 // markWord displaced_header = obj->mark().set_unlocked();
978 // monitor->lock()->set_displaced_header(displaced_header);
979 // if (Atomic::cmpxchg(/*addr*/obj->mark_addr(), /*cmp*/displaced_header, /*ex=*/monitor) == displaced_header) {
980 // // We stored the monitor address into the object's mark word.
981 // } else if (THREAD->is_lock_owned((address)displaced_header))
982 // // Simple recursive case.
983 // monitor->lock()->set_displaced_header(NULL);
984 // } else {
985 // // Slow path.
986 // InterpreterRuntime::monitorenter(THREAD, monitor);
987 // }
988
989 const Register displaced_header = Z_ARG5;
990 const Register object_mark_addr = Z_ARG4;
991 const Register current_header = Z_ARG5;
992
993 NearLabel done;
994 NearLabel slow_case;
995
996 // markWord displaced_header = obj->mark().set_unlocked();
997
998 // Load markWord from object into displaced_header.
999 z_lg(displaced_header, oopDesc::mark_offset_in_bytes(), object);
1000
1001 if (UseBiasedLocking) {
1002 biased_locking_enter(object, displaced_header, Z_R1, Z_R0, done, &slow_case);
1003 }
1004
1005 // Set displaced_header to be (markWord of object | UNLOCK_VALUE).
1006 z_oill(displaced_header, markWord::unlocked_value);
1007
1008 // monitor->lock()->set_displaced_header(displaced_header);
1009
1010 // Initialize the box (Must happen before we update the object mark!).
1011 z_stg(displaced_header, BasicObjectLock::lock_offset_in_bytes() +
1012 BasicLock::displaced_header_offset_in_bytes(), monitor);
1013
1014 // if (Atomic::cmpxchg(/*addr*/obj->mark_addr(), /*cmp*/displaced_header, /*ex=*/monitor) == displaced_header) {
1015
1016 // Store stack address of the BasicObjectLock (this is monitor) into object.
1017 add2reg(object_mark_addr, oopDesc::mark_offset_in_bytes(), object);
1018
1019 z_csg(displaced_header, monitor, 0, object_mark_addr);
1020 assert(current_header==displaced_header, "must be same register"); // Identified two registers from z/Architecture.
1021
1022 z_bre(done);
1023
1024 // } else if (THREAD->is_lock_owned((address)displaced_header))
1025 // // Simple recursive case.
1026 // monitor->lock()->set_displaced_header(NULL);
1027
1028 // We did not see an unlocked object so try the fast recursive case.
1029
1030 // Check if owner is self by comparing the value in the markWord of object
1031 // (current_header) with the stack pointer.
1032 z_sgr(current_header, Z_SP);
1033
1034 assert(os::vm_page_size() > 0xfff, "page size too small - change the constant");
1065 // Unlocks an object. Used in monitorexit bytecode and remove_activation.
1066 //
1067 // Registers alive
1068 // monitor - address of the BasicObjectLock to be used for locking,
1069 // which must be initialized with the object to lock.
1070 //
1071 // Throw IllegalMonitorException if object is not locked by current thread.
1072 void InterpreterMacroAssembler::unlock_object(Register monitor, Register object) {
1073
1074 if (UseHeavyMonitors) {
1075 call_VM(noreg, CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorexit), monitor);
1076 return;
1077 }
1078
1079 // else {
1080 // template code:
1081 //
1082 // if ((displaced_header = monitor->displaced_header()) == NULL) {
1083 // // Recursive unlock. Mark the monitor unlocked by setting the object field to NULL.
1084 // monitor->set_obj(NULL);
1085 // } else if (Atomic::cmpxchg(obj->mark_addr(), monitor, displaced_header) == monitor) {
1086 // // We swapped the unlocked mark in displaced_header into the object's mark word.
1087 // monitor->set_obj(NULL);
1088 // } else {
1089 // // Slow path.
1090 // InterpreterRuntime::monitorexit(THREAD, monitor);
1091 // }
1092
1093 const Register displaced_header = Z_ARG4;
1094 const Register current_header = Z_R1;
1095 Address obj_entry(monitor, BasicObjectLock::obj_offset_in_bytes());
1096 Label done;
1097
1098 if (object == noreg) {
1099 // In the template interpreter, we must assure that the object
1100 // entry in the monitor is cleared on all paths. Thus we move
1101 // loading up to here, and clear the entry afterwards.
1102 object = Z_ARG3; // Use Z_ARG3 if caller didn't pass object.
1103 z_lg(object, obj_entry);
1104 }
1105
1106 assert_different_registers(monitor, object, displaced_header, current_header);
1107
1108 // if ((displaced_header = monitor->displaced_header()) == NULL) {
1109 // // Recursive unlock. Mark the monitor unlocked by setting the object field to NULL.
1110 // monitor->set_obj(NULL);
1111
1112 clear_mem(obj_entry, sizeof(oop));
1113
1114 if (UseBiasedLocking) {
1115 // The object address from the monitor is in object.
1116 assert(oopDesc::mark_offset_in_bytes() == 0, "offset of _mark is not 0");
1117 biased_locking_exit(object, displaced_header, done);
1118 }
1119
1120 // Test first if we are in the fast recursive case.
1121 MacroAssembler::load_and_test_long(displaced_header,
1122 Address(monitor, BasicObjectLock::lock_offset_in_bytes() +
1123 BasicLock::displaced_header_offset_in_bytes()));
1124 z_bre(done); // displaced_header == 0 -> goto done
1125
1126 // } else if (Atomic::cmpxchg(obj->mark_addr(), monitor, displaced_header) == monitor) {
1127 // // We swapped the unlocked mark in displaced_header into the object's mark word.
1128 // monitor->set_obj(NULL);
1129
1130 // If we still have a lightweight lock, unlock the object and be done.
1131
1132 // The markword is expected to be at offset 0.
1133 assert(oopDesc::mark_offset_in_bytes() == 0, "unlock_object: review code below");
1134
1135 // We have the displaced header in displaced_header. If the lock is still
1136 // lightweight, it will contain the monitor address and we'll store the
1137 // displaced header back into the object's mark word.
1138 z_lgr(current_header, monitor);
1139 z_csg(current_header, displaced_header, 0, object);
1140 z_bre(done);
1141
1142 // } else {
1143 // // Slow path.
1144 // InterpreterRuntime::monitorexit(THREAD, monitor);
1145
1146 // The lock has been converted into a heavy lock and hence
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