< prev index next > src/hotspot/cpu/aarch64/interp_masm_aarch64.cpp
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ldrw(tmp, Address(tmp, Klass::access_flags_offset()));
tstw(tmp, JVM_ACC_IS_VALUE_BASED_CLASS);
br(Assembler::NE, slow_case);
}
! // Load (object->mark() | 1) into swap_reg
! ldr(rscratch1, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
! orr(swap_reg, rscratch1, 1);
!
! // Save (object->mark() | 1) into BasicLock's displaced header
! str(swap_reg, Address(lock_reg, mark_offset));
!
! assert(lock_offset == 0,
! "displached header must be first word in BasicObjectLock");
!
! Label fail;
! cmpxchg_obj_header(swap_reg, lock_reg, obj_reg, rscratch1, count, /*fallthrough*/NULL);
!
! // Fast check for recursive lock.
! //
! // Can apply the optimization only if this is a stack lock
! // allocated in this thread. For efficiency, we can focus on
! // recently allocated stack locks (instead of reading the stack
! // base and checking whether 'mark' points inside the current
! // thread stack):
! // 1) (mark & 7) == 0, and
! // 2) sp <= mark < mark + os::pagesize()
! //
! // Warning: sp + os::pagesize can overflow the stack base. We must
! // neither apply the optimization for an inflated lock allocated
! // just above the thread stack (this is why condition 1 matters)
! // nor apply the optimization if the stack lock is inside the stack
! // of another thread. The latter is avoided even in case of overflow
! // because we have guard pages at the end of all stacks. Hence, if
! // we go over the stack base and hit the stack of another thread,
! // this should not be in a writeable area that could contain a
! // stack lock allocated by that thread. As a consequence, a stack
! // lock less than page size away from sp is guaranteed to be
! // owned by the current thread.
! //
! // These 3 tests can be done by evaluating the following
! // expression: ((mark - sp) & (7 - os::vm_page_size())),
! // assuming both stack pointer and pagesize have their
! // least significant 3 bits clear.
! // NOTE: the mark is in swap_reg %r0 as the result of cmpxchg
! // NOTE2: aarch64 does not like to subtract sp from rn so take a
! // copy
! mov(rscratch1, sp);
! sub(swap_reg, swap_reg, rscratch1);
! ands(swap_reg, swap_reg, (uint64_t)(7 - (int)os::vm_page_size()));
!
! // Save the test result, for recursive case, the result is zero
! str(swap_reg, Address(lock_reg, mark_offset));
! br(Assembler::EQ, count);
!
bind(slow_case);
// Call the runtime routine for slow case
call_VM(noreg,
CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorenter),
! lock_reg);
b(done);
bind(count);
increment(Address(rthread, JavaThread::held_monitor_count_offset()));
ldrw(tmp, Address(tmp, Klass::access_flags_offset()));
tstw(tmp, JVM_ACC_IS_VALUE_BASED_CLASS);
br(Assembler::NE, slow_case);
}
! if (UseFastLocking) {
! ldr(tmp, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
! fast_lock(obj_reg, tmp, rscratch1, rscratch2, slow_case);
! b(count);
! } else {
! // Load (object->mark() | 1) into swap_reg
! ldr(rscratch1, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
! orr(swap_reg, rscratch1, 1);
!
! // Save (object->mark() | 1) into BasicLock's displaced header
! str(swap_reg, Address(lock_reg, mark_offset));
!
! assert(lock_offset == 0,
! "displached header must be first word in BasicObjectLock");
!
! Label fail;
! cmpxchg_obj_header(swap_reg, lock_reg, obj_reg, rscratch1, count, /*fallthrough*/NULL);
!
! // Fast check for recursive lock.
! //
! // Can apply the optimization only if this is a stack lock
! // allocated in this thread. For efficiency, we can focus on
! // recently allocated stack locks (instead of reading the stack
! // base and checking whether 'mark' points inside the current
! // thread stack):
! // 1) (mark & 7) == 0, and
! // 2) sp <= mark < mark + os::pagesize()
! //
! // Warning: sp + os::pagesize can overflow the stack base. We must
! // neither apply the optimization for an inflated lock allocated
! // just above the thread stack (this is why condition 1 matters)
! // nor apply the optimization if the stack lock is inside the stack
! // of another thread. The latter is avoided even in case of overflow
! // because we have guard pages at the end of all stacks. Hence, if
! // we go over the stack base and hit the stack of another thread,
! // this should not be in a writeable area that could contain a
! // stack lock allocated by that thread. As a consequence, a stack
! // lock less than page size away from sp is guaranteed to be
! // owned by the current thread.
! //
! // These 3 tests can be done by evaluating the following
! // expression: ((mark - sp) & (7 - os::vm_page_size())),
! // assuming both stack pointer and pagesize have their
! // least significant 3 bits clear.
! // NOTE: the mark is in swap_reg %r0 as the result of cmpxchg
! // NOTE2: aarch64 does not like to subtract sp from rn so take a
! // copy
! mov(rscratch1, sp);
! sub(swap_reg, swap_reg, rscratch1);
! ands(swap_reg, swap_reg, (uint64_t)(7 - (int)os::vm_page_size()));
+
+ // Save the test result, for recursive case, the result is zero
+ str(swap_reg, Address(lock_reg, mark_offset));
+ br(Assembler::EQ, count);
+ }
bind(slow_case);
// Call the runtime routine for slow case
call_VM(noreg,
CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorenter),
! UseFastLocking ? obj_reg : lock_reg);
b(done);
bind(count);
increment(Address(rthread, JavaThread::held_monitor_count_offset()));
const Register header_reg = c_rarg2; // Will contain the old oopMark
const Register obj_reg = c_rarg3; // Will contain the oop
save_bcp(); // Save in case of exception
! // Convert from BasicObjectLock structure to object and BasicLock
! // structure Store the BasicLock address into %r0
! lea(swap_reg, Address(lock_reg, BasicObjectLock::lock_offset_in_bytes()));
// Load oop into obj_reg(%c_rarg3)
ldr(obj_reg, Address(lock_reg, BasicObjectLock::obj_offset_in_bytes()));
// Free entry
str(zr, Address(lock_reg, BasicObjectLock::obj_offset_in_bytes()));
! // Load the old header from BasicLock structure
! ldr(header_reg, Address(swap_reg,
- BasicLock::displaced_header_offset_in_bytes()));
! // Test for recursion
! cbz(header_reg, count);
! // Atomic swap back the old header
! cmpxchg_obj_header(swap_reg, header_reg, obj_reg, rscratch1, count, /*fallthrough*/NULL);
// Call the runtime routine for slow case.
str(obj_reg, Address(lock_reg, BasicObjectLock::obj_offset_in_bytes())); // restore obj
call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorexit), lock_reg);
b(done);
const Register header_reg = c_rarg2; // Will contain the old oopMark
const Register obj_reg = c_rarg3; // Will contain the oop
save_bcp(); // Save in case of exception
! if (!UseFastLocking) {
! // Convert from BasicObjectLock structure to object and BasicLock
! // structure Store the BasicLock address into %r0
+ lea(swap_reg, Address(lock_reg, BasicObjectLock::lock_offset_in_bytes()));
+ }
// Load oop into obj_reg(%c_rarg3)
ldr(obj_reg, Address(lock_reg, BasicObjectLock::obj_offset_in_bytes()));
// Free entry
str(zr, Address(lock_reg, BasicObjectLock::obj_offset_in_bytes()));
! if (UseFastLocking) {
! Label slow_case;
! // Check for non-symmetric locking. This is allowed by the spec and the interpreter
! // must handle it.
+ Register tmp = header_reg;
+ ldr(tmp, Address(rthread, JavaThread::lock_stack_current_offset()));
+ ldr(tmp, Address(tmp, -oopSize));
+ cmpoop(tmp, obj_reg);
+ br(Assembler::NE, slow_case);
+
+ ldr(header_reg, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
+ fast_unlock(obj_reg, header_reg, swap_reg, rscratch1, slow_case);
+ b(count);
+ bind(slow_case);
+ } else {
+ // Load the old header from BasicLock structure
+ ldr(header_reg, Address(swap_reg,
+ BasicLock::displaced_header_offset_in_bytes()));
! // Test for recursion
! cbz(header_reg, count);
+ // Atomic swap back the old header
+ cmpxchg_obj_header(swap_reg, header_reg, obj_reg, rscratch1, count, /*fallthrough*/NULL);
+ }
// Call the runtime routine for slow case.
str(obj_reg, Address(lock_reg, BasicObjectLock::obj_offset_in_bytes())); // restore obj
call_VM_leaf(CAST_FROM_FN_PTR(address, InterpreterRuntime::monitorexit), lock_reg);
b(done);
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