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/*
! * Copyright (c) 1998, 2022, Oracle and/or its affiliates. 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.
/*
! * Copyright (c) 1998, 2024, Oracle and/or its affiliates. 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.
// have busy multi-threaded access. _header and _object are set at initial
// inflation. The _object does not change, so it is a good choice to share
// its cache line with _header.
DEFINE_PAD_MINUS_SIZE(0, OM_CACHE_LINE_SIZE, sizeof(volatile markWord) +
sizeof(WeakHandle));
! // Used by async deflation as a marker in the _owner field:
! #define DEFLATER_MARKER reinterpret_cast<void*>(-1)
void* volatile _owner; // pointer to owning thread OR BasicLock
volatile jlong _previous_owner_tid; // thread id of the previous owner of the monitor
// Separate _owner and _next_om on different cache lines since
// both can have busy multi-threaded access. _previous_owner_tid is only
// changed by ObjectMonitor::exit() so it is a good choice to share the
// have busy multi-threaded access. _header and _object are set at initial
// inflation. The _object does not change, so it is a good choice to share
// its cache line with _header.
DEFINE_PAD_MINUS_SIZE(0, OM_CACHE_LINE_SIZE, sizeof(volatile markWord) +
sizeof(WeakHandle));
! // Used by async deflation as a marker in the _owner field.
! // Note that the choice of the two markers is peculiar:
+ // - They need to represent values that cannot be pointers. In particular,
+ // we achieve this by using the lowest two bits.
+ // - ANONYMOUS_OWNER should be a small value, it is used in generated code
+ // and small values encode much better.
+ // - We test for anonymous owner by testing for the lowest bit, therefore
+ // DEFLATER_MARKER must *not* have that bit set.
+ #define DEFLATER_MARKER reinterpret_cast<void*>(2)
+ public:
+ // NOTE: Typed as uintptr_t so that we can pick it up in SA, via vmStructs.
+ static const uintptr_t ANONYMOUS_OWNER = 1;
+
+ private:
+ static void* anon_owner_ptr() { return reinterpret_cast<void*>(ANONYMOUS_OWNER); }
+
void* volatile _owner; // pointer to owning thread OR BasicLock
volatile jlong _previous_owner_tid; // thread id of the previous owner of the monitor
// Separate _owner and _next_om on different cache lines since
// both can have busy multi-threaded access. _previous_owner_tid is only
// changed by ObjectMonitor::exit() so it is a good choice to share the
}
return ret_code != 0;
}
const char* is_busy_to_string(stringStream* ss);
! intptr_t is_entered(JavaThread* current) const;
void* owner() const; // Returns NULL if DEFLATER_MARKER is observed.
void* owner_raw() const;
// Returns true if owner field == DEFLATER_MARKER and false otherwise.
bool owner_is_DEFLATER_MARKER() const;
// Returns true if 'this' is being async deflated and false otherwise.
}
return ret_code != 0;
}
const char* is_busy_to_string(stringStream* ss);
! bool is_entered(JavaThread* current) const;
+ bool has_owner() const;
void* owner() const; // Returns NULL if DEFLATER_MARKER is observed.
void* owner_raw() const;
// Returns true if owner field == DEFLATER_MARKER and false otherwise.
bool owner_is_DEFLATER_MARKER() const;
// Returns true if 'this' is being async deflated and false otherwise.
// Try to set _owner field to new_value if the current value matches
// old_value, using Atomic::cmpxchg(). Otherwise, does not change the
// _owner field. Returns the prior value of the _owner field.
void* try_set_owner_from(void* old_value, void* new_value);
+ void set_owner_anonymous() {
+ set_owner_from(NULL, anon_owner_ptr());
+ }
+
+ bool is_owner_anonymous() const {
+ return owner_raw() == anon_owner_ptr();
+ }
+
+ void set_owner_from_anonymous(Thread* owner) {
+ set_owner_from(anon_owner_ptr(), owner);
+ }
+
// Simply get _next_om field.
ObjectMonitor* next_om() const;
// Get _next_om field with acquire semantics.
ObjectMonitor* next_om_acquire() const;
// Simply set _next_om field to new_value.
jint waiters() const;
jint contentions() const;
void add_to_contentions(jint value);
intx recursions() const { return _recursions; }
+ void set_recursions(size_t recursions);
// JVM/TI GetObjectMonitorUsage() needs this:
ObjectWaiter* first_waiter() { return _WaitSet; }
ObjectWaiter* next_waiter(ObjectWaiter* o) { return o->_next; }
JavaThread* thread_of_waiter(ObjectWaiter* o) { return o->_thread; }
public:
ClearSuccOnSuspend(ObjectMonitor* om) : _om(om) {}
void operator()(JavaThread* current);
};
public:
+ bool enter_for(JavaThread* locking_thread);
bool enter(JavaThread* current);
void exit(JavaThread* current, bool not_suspended = true);
void wait(jlong millis, bool interruptible, TRAPS);
void notify(TRAPS);
void notifyAll(TRAPS);
// Use the following at your own risk
intx complete_exit(JavaThread* current);
bool reenter(intx recursions, JavaThread* current);
+ static void maybe_deflate_dead(oop* p);
+
private:
void AddWaiter(ObjectWaiter* waiter);
void INotify(JavaThread* current);
ObjectWaiter* DequeueWaiter();
void DequeueSpecificWaiter(ObjectWaiter* waiter);
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