historical/toontown-classic.git/panda/include/atomicAdjustDummyImpl.I

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/**
* PANDA 3D SOFTWARE
* Copyright (c) Carnegie Mellon University. All rights reserved.
*
* All use of this software is subject to the terms of the revised BSD
* license. You should have received a copy of this license along
* with this source code in a file named "LICENSE."
*
* @file atomicAdjustDummyImpl.I
* @author drose
* @date 2002-08-09
*/
/**
* Atomically increments the indicated variable.
*/
ALWAYS_INLINE void AtomicAdjustDummyImpl::
inc(TVOLATILE AtomicAdjustDummyImpl::Integer &var) {
++var;
}
/**
* Atomically decrements the indicated variable and returns true if the new
* value is nonzero, false if it is zero.
*/
ALWAYS_INLINE bool AtomicAdjustDummyImpl::
dec(TVOLATILE AtomicAdjustDummyImpl::Integer &var) {
return (--var) != 0;
}
/**
* Atomically computes var += delta. It is legal for delta to be negative.
* Returns the result of the addition.
*/
ALWAYS_INLINE AtomicAdjustDummyImpl::Integer AtomicAdjustDummyImpl::
add(TVOLATILE AtomicAdjustDummyImpl::Integer &var, AtomicAdjustDummyImpl::Integer delta) {
Integer new_value = var + delta;
var = new_value;
return new_value;
}
/**
* Atomically changes the indicated variable and returns the original value.
*/
ALWAYS_INLINE AtomicAdjustDummyImpl::Integer AtomicAdjustDummyImpl::
set(TVOLATILE AtomicAdjustDummyImpl::Integer &var, AtomicAdjustDummyImpl::Integer new_value) {
Integer orig_value = var;
var = new_value;
return orig_value;
}
/**
* Atomically retrieves the snapshot value of the indicated variable. This is
* the only guaranteed safe way to retrieve the value that other threads might
* be asynchronously setting, incrementing, or decrementing (via other
* AtomicAjust methods).
*/
ALWAYS_INLINE AtomicAdjustDummyImpl::Integer AtomicAdjustDummyImpl::
get(const TVOLATILE AtomicAdjustDummyImpl::Integer &var) {
return var;
}
/**
* Atomically changes the indicated variable and returns the original value.
*/
ALWAYS_INLINE AtomicAdjustDummyImpl::Pointer AtomicAdjustDummyImpl::
set_ptr(TVOLATILE AtomicAdjustDummyImpl::Pointer &var,
AtomicAdjustDummyImpl::Pointer new_value) {
Pointer orig_value = var;
var = new_value;
return orig_value;
}
/**
* Atomically retrieves the snapshot value of the indicated variable. This is
* the only guaranteed safe way to retrieve the value that other threads might
* be asynchronously setting, incrementing, or decrementing (via other
* AtomicAjust methods).
*/
ALWAYS_INLINE AtomicAdjustDummyImpl::Pointer AtomicAdjustDummyImpl::
get_ptr(const TVOLATILE AtomicAdjustDummyImpl::Pointer &var) {
return var;
}
/**
* Atomic compare and exchange.
*
* If mem is equal to old_value, store new_value in mem. In either case,
* return the original value of mem. The caller can test for success by
* comparing return_value == old_value.
*/
ALWAYS_INLINE AtomicAdjustDummyImpl::Integer AtomicAdjustDummyImpl::
compare_and_exchange(TVOLATILE AtomicAdjustDummyImpl::Integer &mem,
AtomicAdjustDummyImpl::Integer old_value,
AtomicAdjustDummyImpl::Integer new_value) {
Integer orig_value = mem;
if (mem == old_value) {
mem = new_value;
}
return orig_value;
}
/**
* Atomic compare and exchange.
*
* As above, but works on pointers instead of integers.
*/
ALWAYS_INLINE AtomicAdjustDummyImpl::Pointer AtomicAdjustDummyImpl::
compare_and_exchange_ptr(TVOLATILE AtomicAdjustDummyImpl::Pointer &mem,
AtomicAdjustDummyImpl::Pointer old_value,
AtomicAdjustDummyImpl::Pointer new_value) {
Pointer orig_value = mem;
if (mem == old_value) {
mem = new_value;
}
return orig_value;
}