historical/toontown-classic.git/panda/include/atomicAdjustGccImpl.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 atomicAdjustGccImpl.I
* @author rdb
* @date 2014-07-04
*/
/**
* Atomically increments the indicated variable.
*/
INLINE void AtomicAdjustGccImpl::
inc(TVOLATILE AtomicAdjustGccImpl::Integer &var) {
__atomic_fetch_add(&var, 1, __ATOMIC_SEQ_CST);
}
/**
* Atomically decrements the indicated variable and returns true if the new
* value is nonzero, false if it is zero.
*/
INLINE bool AtomicAdjustGccImpl::
dec(TVOLATILE AtomicAdjustGccImpl::Integer &var) {
return (__atomic_sub_fetch(&var, 1, __ATOMIC_SEQ_CST) != 0);
}
/**
* Atomically computes var += delta. It is legal for delta to be negative.
* Returns the result of the addition.
*/
INLINE AtomicAdjustGccImpl::Integer AtomicAdjustGccImpl::
add(TVOLATILE AtomicAdjustGccImpl::Integer &var,
AtomicAdjustGccImpl::Integer delta) {
return __atomic_add_fetch(&var, delta, __ATOMIC_SEQ_CST);
}
/**
* Atomically changes the indicated variable and returns the original value.
*/
INLINE AtomicAdjustGccImpl::Integer AtomicAdjustGccImpl::
set(TVOLATILE AtomicAdjustGccImpl::Integer &var,
AtomicAdjustGccImpl::Integer new_value) {
return __atomic_exchange_n(&var, new_value, __ATOMIC_SEQ_CST);
}
/**
* 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).
*/
INLINE AtomicAdjustGccImpl::Integer AtomicAdjustGccImpl::
get(const TVOLATILE AtomicAdjustGccImpl::Integer &var) {
return __atomic_load_n(&var, __ATOMIC_SEQ_CST);
}
/**
* Atomically changes the indicated variable and returns the original value.
*/
INLINE AtomicAdjustGccImpl::Pointer AtomicAdjustGccImpl::
set_ptr(TVOLATILE AtomicAdjustGccImpl::Pointer &var,
AtomicAdjustGccImpl::Pointer new_value) {
return __atomic_exchange_n(&var, new_value, __ATOMIC_SEQ_CST);
}
/**
* 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).
*/
INLINE AtomicAdjustGccImpl::Pointer AtomicAdjustGccImpl::
get_ptr(const TVOLATILE AtomicAdjustGccImpl::Pointer &var) {
return __atomic_load_n(&var, __ATOMIC_SEQ_CST);
}
/**
* 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.
*
* The atomic function expressed in pseudo-code:
*
* orig_value = mem; if (mem == old_value) { mem = new_value; } return
* orig_value;
*
*/
INLINE AtomicAdjustGccImpl::Integer AtomicAdjustGccImpl::
compare_and_exchange(TVOLATILE AtomicAdjustGccImpl::Integer &mem,
AtomicAdjustGccImpl::Integer old_value,
AtomicAdjustGccImpl::Integer new_value) {
__atomic_compare_exchange_n(&mem, &old_value, new_value, false,
__ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
return old_value;
}
/**
* Atomic compare and exchange.
*
* As above, but works on pointers instead of integers.
*/
INLINE AtomicAdjustGccImpl::Pointer AtomicAdjustGccImpl::
compare_and_exchange_ptr(TVOLATILE AtomicAdjustGccImpl::Pointer &mem,
AtomicAdjustGccImpl::Pointer old_value,
AtomicAdjustGccImpl::Pointer new_value) {
__atomic_compare_exchange_n(&mem, &old_value, new_value, false,
__ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
return old_value;
}