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AlanBatemanAlanBateman
committedNov 1, 2024
Merge commit 'e5a9ce2af0536b04f3faf1d44fca215b020b5444' into fibers
2 parents 178008a + e5a9ce2 commit 32e4704

21 files changed

+63
-50
lines changed
 

‎src/hotspot/cpu/aarch64/c1_MacroAssembler_aarch64.cpp

+2-2
Original file line numberDiff line numberDiff line change
@@ -119,7 +119,7 @@ int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr
119119
cbnz(hdr, slow_case);
120120
// done
121121
bind(done);
122-
inc_held_monitor_count();
122+
inc_held_monitor_count(rscratch1);
123123
}
124124
return null_check_offset;
125125
}
@@ -159,7 +159,7 @@ void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_
159159
}
160160
// done
161161
bind(done);
162-
dec_held_monitor_count();
162+
dec_held_monitor_count(rscratch1);
163163
}
164164
}
165165

‎src/hotspot/cpu/aarch64/c2_MacroAssembler_aarch64.cpp

+2-2
Original file line numberDiff line numberDiff line change
@@ -139,7 +139,7 @@ void C2_MacroAssembler::fast_lock(Register objectReg, Register boxReg, Register
139139

140140
bind(count);
141141
if (LockingMode == LM_LEGACY) {
142-
inc_held_monitor_count();
142+
inc_held_monitor_count(rscratch1);
143143
}
144144

145145
bind(no_count);
@@ -248,7 +248,7 @@ void C2_MacroAssembler::fast_unlock(Register objectReg, Register boxReg, Registe
248248

249249
bind(count);
250250
if (LockingMode == LM_LEGACY) {
251-
dec_held_monitor_count();
251+
dec_held_monitor_count(rscratch1);
252252
}
253253

254254
bind(no_count);

‎src/hotspot/cpu/aarch64/interp_masm_aarch64.cpp

+2-2
Original file line numberDiff line numberDiff line change
@@ -750,7 +750,7 @@ void InterpreterMacroAssembler::lock_object(Register lock_reg)
750750
br(Assembler::NE, slow_case);
751751

752752
bind(count);
753-
inc_held_monitor_count();
753+
inc_held_monitor_count(rscratch1);
754754
b(done);
755755
}
756756
bind(slow_case);
@@ -820,7 +820,7 @@ void InterpreterMacroAssembler::unlock_object(Register lock_reg)
820820
cmpxchg_obj_header(swap_reg, header_reg, obj_reg, rscratch1, count, &slow_case);
821821

822822
bind(count);
823-
dec_held_monitor_count();
823+
dec_held_monitor_count(rscratch1);
824824
b(done);
825825
}
826826

‎src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp

+10-12
Original file line numberDiff line numberDiff line change
@@ -5337,15 +5337,14 @@ void MacroAssembler::tlab_allocate(Register obj,
53375337
bs->tlab_allocate(this, obj, var_size_in_bytes, con_size_in_bytes, t1, t2, slow_case);
53385338
}
53395339

5340-
// Clobbers: rscratch1 and rscratch2
5341-
void MacroAssembler::inc_held_monitor_count() {
5340+
void MacroAssembler::inc_held_monitor_count(Register tmp) {
53425341
Address dst(rthread, JavaThread::held_monitor_count_offset());
53435342
#ifdef ASSERT
5344-
ldr(rscratch2, dst);
5345-
increment(rscratch2);
5346-
str(rscratch2, dst);
5343+
ldr(tmp, dst);
5344+
increment(tmp);
5345+
str(tmp, dst);
53475346
Label ok;
5348-
tbz(rscratch2, 63, ok);
5347+
tbz(tmp, 63, ok);
53495348
STOP("assert(held monitor count underflow)");
53505349
should_not_reach_here();
53515350
bind(ok);
@@ -5354,15 +5353,14 @@ void MacroAssembler::inc_held_monitor_count() {
53545353
#endif
53555354
}
53565355

5357-
// Clobbers: rscratch1 and rscratch2
5358-
void MacroAssembler::dec_held_monitor_count() {
5356+
void MacroAssembler::dec_held_monitor_count(Register tmp) {
53595357
Address dst(rthread, JavaThread::held_monitor_count_offset());
53605358
#ifdef ASSERT
5361-
ldr(rscratch2, dst);
5362-
decrement(rscratch2);
5363-
str(rscratch2, dst);
5359+
ldr(tmp, dst);
5360+
decrement(tmp);
5361+
str(tmp, dst);
53645362
Label ok;
5365-
tbz(rscratch2, 63, ok);
5363+
tbz(tmp, 63, ok);
53665364
STOP("assert(held monitor count underflow)");
53675365
should_not_reach_here();
53685366
bind(ok);

‎src/hotspot/cpu/aarch64/macroAssembler_aarch64.hpp

+2-2
Original file line numberDiff line numberDiff line change
@@ -941,8 +941,8 @@ class MacroAssembler: public Assembler {
941941
void push_cont_fastpath(Register java_thread = rthread);
942942
void pop_cont_fastpath(Register java_thread = rthread);
943943

944-
void inc_held_monitor_count();
945-
void dec_held_monitor_count();
944+
void inc_held_monitor_count(Register tmp);
945+
void dec_held_monitor_count(Register tmp);
946946

947947
// Round up to a power of two
948948
void round_to(Register reg, int modulus);

‎src/hotspot/cpu/aarch64/sharedRuntime_aarch64.cpp

+3-3
Original file line numberDiff line numberDiff line change
@@ -1833,7 +1833,7 @@ nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
18331833
__ br(Assembler::NE, slow_path_lock);
18341834

18351835
__ bind(count);
1836-
__ inc_held_monitor_count();
1836+
__ inc_held_monitor_count(rscratch1);
18371837
} else {
18381838
assert(LockingMode == LM_LIGHTWEIGHT, "must be");
18391839
__ lightweight_lock(lock_reg, obj_reg, swap_reg, tmp, lock_tmp, slow_path_lock);
@@ -1949,7 +1949,7 @@ nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
19491949
// Simple recursive lock?
19501950
__ ldr(rscratch1, Address(sp, lock_slot_offset * VMRegImpl::stack_slot_size));
19511951
__ cbnz(rscratch1, not_recursive);
1952-
__ dec_held_monitor_count();
1952+
__ dec_held_monitor_count(rscratch1);
19531953
__ b(done);
19541954
}
19551955

@@ -1972,7 +1972,7 @@ nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
19721972
Label count;
19731973
__ cmpxchg_obj_header(r0, old_hdr, obj_reg, rscratch1, count, &slow_path_unlock);
19741974
__ bind(count);
1975-
__ dec_held_monitor_count();
1975+
__ dec_held_monitor_count(rscratch1);
19761976
} else {
19771977
assert(LockingMode == LM_LIGHTWEIGHT, "");
19781978
__ lightweight_unlock(obj_reg, old_hdr, swap_reg, lock_tmp, slow_path_unlock);

‎src/hotspot/cpu/ppc/macroAssembler_ppc.cpp

+1-1
Original file line numberDiff line numberDiff line change
@@ -737,7 +737,7 @@ void MacroAssembler::clobber_volatile_gprs(Register excluded_register) {
737737

738738
void MacroAssembler::clobber_nonvolatile_registers() {
739739
BLOCK_COMMENT("clobber nonvolatile registers {");
740-
Register regs[] = {
740+
static const Register regs[] = {
741741
R14,
742742
R15,
743743
// don't zap R16_thread

‎src/hotspot/cpu/riscv/c1_MacroAssembler_riscv.cpp

+2-2
Original file line numberDiff line numberDiff line change
@@ -109,7 +109,7 @@ int C1_MacroAssembler::lock_object(Register hdr, Register obj, Register disp_hdr
109109

110110
// done
111111
bind(done);
112-
inc_held_monitor_count();
112+
inc_held_monitor_count(t0);
113113
}
114114

115115
return null_check_offset;
@@ -150,7 +150,7 @@ void C1_MacroAssembler::unlock_object(Register hdr, Register obj, Register disp_
150150

151151
// done
152152
bind(done);
153-
dec_held_monitor_count();
153+
dec_held_monitor_count(t0);
154154
}
155155
}
156156

‎src/hotspot/cpu/riscv/c2_MacroAssembler_riscv.cpp

+2-2
Original file line numberDiff line numberDiff line change
@@ -140,7 +140,7 @@ void C2_MacroAssembler::fast_lock(Register objectReg, Register boxReg,
140140
bind(locked);
141141
mv(flag, zr);
142142
if (LockingMode == LM_LEGACY) {
143-
inc_held_monitor_count();
143+
inc_held_monitor_count(t0);
144144
}
145145

146146
#ifdef ASSERT
@@ -256,7 +256,7 @@ void C2_MacroAssembler::fast_unlock(Register objectReg, Register boxReg,
256256
bind(unlocked);
257257
mv(flag, zr);
258258
if (LockingMode == LM_LEGACY) {
259-
dec_held_monitor_count();
259+
dec_held_monitor_count(t0);
260260
}
261261

262262
#ifdef ASSERT

‎src/hotspot/cpu/riscv/continuationFreezeThaw_riscv.inline.hpp

+1-1
Original file line numberDiff line numberDiff line change
@@ -269,7 +269,7 @@ template<typename FKind> frame ThawBase::new_stack_frame(const frame& hf, frame&
269269
// fp always points to the address above the pushed return pc. We need correct address.
270270
? frame_sp + fsize - frame::sender_sp_offset
271271
// we need to re-read fp because it may be an oop and we might have fixed the frame.
272-
: *(intptr_t**)(hf.sp() - 2);
272+
: *(intptr_t**)(hf.sp() - frame::sender_sp_offset);
273273
}
274274
// TODO PERF : this computes deopt state; is it necessary?
275275
return frame(frame_sp, frame_sp, fp, hf.pc(), hf.cb(), hf.oop_map(), false);

‎src/hotspot/cpu/riscv/interp_masm_riscv.cpp

+2-2
Original file line numberDiff line numberDiff line change
@@ -789,7 +789,7 @@ void InterpreterMacroAssembler::lock_object(Register lock_reg)
789789
bnez(swap_reg, slow_case);
790790

791791
bind(count);
792-
inc_held_monitor_count();
792+
inc_held_monitor_count(t0);
793793
j(done);
794794
}
795795

@@ -860,7 +860,7 @@ void InterpreterMacroAssembler::unlock_object(Register lock_reg)
860860
cmpxchg_obj_header(swap_reg, header_reg, obj_reg, tmp_reg, count, &slow_case);
861861

862862
bind(count);
863-
dec_held_monitor_count();
863+
dec_held_monitor_count(t0);
864864
j(done);
865865
}
866866

‎src/hotspot/cpu/riscv/macroAssembler_riscv.hpp

+2-2
Original file line numberDiff line numberDiff line change
@@ -789,8 +789,8 @@ class MacroAssembler: public Assembler {
789789
void push_cont_fastpath(Register java_thread = xthread);
790790
void pop_cont_fastpath(Register java_thread = xthread);
791791

792-
void inc_held_monitor_count(Register tmp = t0);
793-
void dec_held_monitor_count(Register tmp = t0);
792+
void inc_held_monitor_count(Register tmp);
793+
void dec_held_monitor_count(Register tmp);
794794

795795
// if heap base register is used - reinit it with the correct value
796796
void reinit_heapbase();

‎src/hotspot/cpu/riscv/sharedRuntime_riscv.cpp

+3-3
Original file line numberDiff line numberDiff line change
@@ -1730,7 +1730,7 @@ nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
17301730
__ bnez(swap_reg, slow_path_lock);
17311731

17321732
__ bind(count);
1733-
__ inc_held_monitor_count();
1733+
__ inc_held_monitor_count(t0);
17341734
} else {
17351735
assert(LockingMode == LM_LIGHTWEIGHT, "must be");
17361736
__ lightweight_lock(lock_reg, obj_reg, swap_reg, tmp, lock_tmp, slow_path_lock);
@@ -1839,7 +1839,7 @@ nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
18391839
// Simple recursive lock?
18401840
__ ld(t0, Address(sp, lock_slot_offset * VMRegImpl::stack_slot_size));
18411841
__ bnez(t0, not_recursive);
1842-
__ dec_held_monitor_count();
1842+
__ dec_held_monitor_count(t0);
18431843
__ j(done);
18441844
}
18451845

@@ -1862,7 +1862,7 @@ nmethod* SharedRuntime::generate_native_wrapper(MacroAssembler* masm,
18621862
Label count;
18631863
__ cmpxchg_obj_header(x10, old_hdr, obj_reg, lock_tmp, count, &slow_path_unlock);
18641864
__ bind(count);
1865-
__ dec_held_monitor_count();
1865+
__ dec_held_monitor_count(t0);
18661866
} else {
18671867
assert(LockingMode == LM_LIGHTWEIGHT, "");
18681868
__ lightweight_unlock(obj_reg, old_hdr, swap_reg, lock_tmp, slow_path_unlock);

‎src/hotspot/share/runtime/continuation.cpp

+4-4
Original file line numberDiff line numberDiff line change
@@ -124,7 +124,7 @@ class JvmtiUnmountBeginMark : public StackObj {
124124
bool failed() { return _failed; }
125125
};
126126

127-
static bool is_safe_vthread_to_preempt_for_jvmti(JavaThread* target, oop vthread) {
127+
static bool is_vthread_safe_to_preempt_for_jvmti(JavaThread* target, oop vthread) {
128128
if (target->is_in_any_VTMS_transition()) {
129129
// We caught target at the end of a mount transition (is_in_VTMS_transition()) or at the
130130
// beginning or end of a temporary switch to carrier thread (is_in_tmp_VTMS_transition()).
@@ -134,12 +134,12 @@ static bool is_safe_vthread_to_preempt_for_jvmti(JavaThread* target, oop vthread
134134
}
135135
#endif // INCLUDE_JVMTI
136136

137-
static bool is_safe_vthread_to_preempt(JavaThread* target, oop vthread) {
137+
static bool is_vthread_safe_to_preempt(JavaThread* target, oop vthread) {
138138
if (!java_lang_VirtualThread::is_instance(vthread) || // inside tmp transition
139139
java_lang_VirtualThread::state(vthread) != java_lang_VirtualThread::RUNNING) { // inside transition
140140
return false;
141141
}
142-
return JVMTI_ONLY(is_safe_vthread_to_preempt_for_jvmti(target, vthread)) NOT_JVMTI(true);
142+
return JVMTI_ONLY(is_vthread_safe_to_preempt_for_jvmti(target, vthread)) NOT_JVMTI(true);
143143
}
144144

145145
typedef int (*FreezeContFnT)(JavaThread*, intptr_t*);
@@ -161,7 +161,7 @@ int Continuation::try_preempt(JavaThread* target, oop continuation) {
161161
return freeze_unsupported;
162162
}
163163

164-
if (!is_safe_vthread_to_preempt(target, target->vthread())) {
164+
if (!is_vthread_safe_to_preempt(target, target->vthread())) {
165165
return freeze_pinned_native;
166166
}
167167

‎src/hotspot/share/runtime/continuation.hpp

+3-3
Original file line numberDiff line numberDiff line change
@@ -47,7 +47,7 @@ void continuations_init();
4747
class javaVFrame;
4848
class JavaThread;
4949

50-
// should match Continuation.PreemptStatus() in Continuation.java
50+
// should match Continuation.pinnedReason() in Continuation.java
5151
enum freeze_result {
5252
freeze_ok = 0,
5353
freeze_ok_bottom = 1,
@@ -63,8 +63,8 @@ class Continuation : AllStatic {
6363
public:
6464

6565
enum preempt_kind {
66-
freeze_on_monitorenter = 1,
67-
freeze_on_wait = 2
66+
freeze_on_monitorenter,
67+
freeze_on_wait
6868
};
6969

7070
enum thaw_kind {

‎src/hotspot/share/runtime/continuationFreezeThaw.cpp

+2
Original file line numberDiff line numberDiff line change
@@ -886,6 +886,8 @@ NOINLINE freeze_result FreezeBase::recurse_freeze(frame& f, frame& caller, int c
886886
assert(f.is_native_frame() || f.is_runtime_frame(), "");
887887
return f.is_native_frame() ? recurse_freeze_native_frame(f, caller) : recurse_freeze_stub_frame(f, caller);
888888
} else {
889+
// frame can't be freezed. Most likely the call_stub or upcall_stub
890+
// which indicates there are further natives frames up the stack.
889891
return freeze_pinned_native;
890892
}
891893
}

‎src/hotspot/share/runtime/continuationJavaClasses.inline.hpp

+1
Original file line numberDiff line numberDiff line change
@@ -185,6 +185,7 @@ inline void jdk_internal_vm_StackChunk::set_maxThawingSize(oop chunk, int value)
185185
chunk->int_field_put(_maxThawingSize_offset, value);
186186
}
187187

188+
// lockStackSize is read concurrently by GC threads so we use Atomic.
188189
inline uint8_t jdk_internal_vm_StackChunk::lockStackSize(oop chunk) {
189190
return Atomic::load(chunk->field_addr<uint8_t>(_lockStackSize_offset));
190191
}

‎src/hotspot/share/runtime/objectMonitor.cpp

+1-2
Original file line numberDiff line numberDiff line change
@@ -1187,7 +1187,6 @@ void ObjectMonitor::VThreadEpilog(JavaThread* current, ObjectWaiter* node) {
11871187
}
11881188
}
11891189

1190-
assert(node->TState == ObjectWaiter::TS_ENTER || node->TState == ObjectWaiter::TS_CXQ, "");
11911190
UnlinkAfterAcquire(current, node);
11921191
delete node;
11931192

@@ -2539,7 +2538,7 @@ void ObjectMonitor::print_debug_style_on(outputStream* st) const {
25392538
st->print_cr(" _recursions = " INTX_FORMAT, _recursions);
25402539
st->print_cr(" _EntryList = " INTPTR_FORMAT, p2i(_EntryList));
25412540
st->print_cr(" _cxq = " INTPTR_FORMAT, p2i(_cxq));
2542-
st->print_cr(" _succ = " INT64_FORMAT, _succ);
2541+
st->print_cr(" _succ = " INT64_FORMAT, successor());
25432542
st->print_cr(" _SpinDuration = %d", _SpinDuration);
25442543
st->print_cr(" _contentions = %d", contentions());
25452544
st->print_cr(" _WaitSet = " INTPTR_FORMAT, p2i(_WaitSet));

‎src/hotspot/share/runtime/objectMonitor.hpp

+3-2
Original file line numberDiff line numberDiff line change
@@ -309,11 +309,12 @@ class ObjectMonitor : public CHeapObj<mtObjectMonitor> {
309309
// from _cxq/_EntryList by the current owner when releasing the monitor,
310310
// to run again and re-try acquiring the monitor. It is used to avoid
311311
// unnecessary wake-ups if there is already a successor set.
312-
bool has_successor();
313-
bool has_successor(JavaThread* thread);
312+
bool has_successor() const;
313+
bool has_successor(JavaThread* thread) const;
314314
void set_successor(JavaThread* thread);
315315
void set_successor(oop vthread);
316316
void clear_successor();
317+
int64_t successor() const;
317318

318319
// Returns true if _owner field == tid of thread, false otherwise.
319320
bool has_owner(JavaThread* thread) const { return owner() == owner_from(thread); }

‎src/hotspot/share/runtime/objectMonitor.inline.hpp

+7-3
Original file line numberDiff line numberDiff line change
@@ -41,7 +41,7 @@
4141

4242
inline int64_t ObjectMonitor::owner_from(JavaThread* thread) {
4343
int64_t tid = thread->lock_id();
44-
assert(tid >= 3 && tid < ThreadIdentifier::current(), "must be reasonable");
44+
assert(tid >= ThreadIdentifier::initial() && tid < ThreadIdentifier::current(), "must be reasonable");
4545
return tid;
4646
}
4747

@@ -204,11 +204,11 @@ inline int64_t ObjectMonitor::try_set_owner_from(int64_t old_value, JavaThread*
204204
return try_set_owner_from_raw(old_value, owner_from(current));
205205
}
206206

207-
inline bool ObjectMonitor::has_successor() {
207+
inline bool ObjectMonitor::has_successor() const {
208208
return Atomic::load(&_succ) != NO_OWNER;
209209
}
210210

211-
inline bool ObjectMonitor::has_successor(JavaThread* thread) {
211+
inline bool ObjectMonitor::has_successor(JavaThread* thread) const {
212212
return owner_from(thread) == Atomic::load(&_succ);
213213
}
214214

@@ -224,6 +224,10 @@ inline void ObjectMonitor::clear_successor() {
224224
Atomic::store(&_succ, NO_OWNER);
225225
}
226226

227+
inline int64_t ObjectMonitor::successor() const {
228+
return Atomic::load(&_succ);
229+
}
230+
227231
// The _next_om field can be concurrently read and modified so we
228232
// use Atomic operations to disable compiler optimizations that
229233
// might try to elide loading and/or storing this field.

‎src/hotspot/share/services/threadService.cpp

+8
Original file line numberDiff line numberDiff line change
@@ -464,6 +464,14 @@ DeadlockCycle* ThreadService::find_deadlocks_at_safepoint(ThreadsList * t_list,
464464
} else if (waitingToLockMonitor != nullptr) {
465465
if (waitingToLockMonitor->has_owner()) {
466466
currentThread = Threads::owning_thread_from_monitor(t_list, waitingToLockMonitor);
467+
// If currentThread is nullptr we would like to know if the owner
468+
// is an unmounted vthread (no JavaThread*), because if it's not,
469+
// it would mean the previous currentThread is blocked permanently
470+
// and we should record this as a deadlock. Since there is currently
471+
// no fast way to determine if the owner is indeed an unmounted
472+
// vthread we never record this as a deadlock. Note: unless there
473+
// is a bug in the VM, or a thread exits without releasing monitors
474+
// acquired through JNI, nullptr should imply unmounted vthread owner.
467475
}
468476
} else {
469477
if (concurrent_locks) {

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