/contrib/bind9/lib/isc/ia64/include/isc/atomic.h
https://bitbucket.org/freebsd/freebsd-head/ · C Header · 100 lines · 57 code · 12 blank · 31 comment · 3 complexity · 1c787fef15eca0cf25e3024a7a095fb4 MD5 · raw file
- /*
- * Copyright (C) 2006, 2007, 2009 Internet Systems Consortium, Inc. ("ISC")
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
- * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
- * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
- * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
- * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
- * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
- * PERFORMANCE OF THIS SOFTWARE.
- */
- /* $Id: atomic.h,v 1.7 2009/06/24 02:22:50 marka Exp $ */
- #ifndef ISC_ATOMIC_H
- #define ISC_ATOMIC_H 1
- #include <isc/platform.h>
- #include <isc/types.h>
- #ifdef ISC_PLATFORM_USEGCCASM
- /*
- * This routine atomically increments the value stored in 'p' by 'val', and
- * returns the previous value.
- *
- * Open issue: can 'fetchadd' make the code faster for some particular values
- * (e.g., 1 and -1)?
- */
- static inline isc_int32_t
- #ifdef __GNUC__
- __attribute__ ((unused))
- #endif
- isc_atomic_xadd(isc_int32_t *p, isc_int32_t val)
- {
- isc_int32_t prev, swapped;
- for (prev = *(volatile isc_int32_t *)p; ; prev = swapped) {
- swapped = prev + val;
- __asm__ volatile(
- "mov ar.ccv=%2;;"
- "cmpxchg4.acq %0=%4,%3,ar.ccv"
- : "=r" (swapped), "=m" (*p)
- : "r" (prev), "r" (swapped), "m" (*p)
- : "memory");
- if (swapped == prev)
- break;
- }
- return (prev);
- }
- /*
- * This routine atomically stores the value 'val' in 'p'.
- */
- static inline void
- #ifdef __GNUC__
- __attribute__ ((unused))
- #endif
- isc_atomic_store(isc_int32_t *p, isc_int32_t val)
- {
- __asm__ volatile(
- "st4.rel %0=%1"
- : "=m" (*p)
- : "r" (val)
- : "memory"
- );
- }
- /*
- * This routine atomically replaces the value in 'p' with 'val', if the
- * original value is equal to 'cmpval'. The original value is returned in any
- * case.
- */
- static inline isc_int32_t
- #ifdef __GNUC__
- __attribute__ ((unused))
- #endif
- isc_atomic_cmpxchg(isc_int32_t *p, isc_int32_t cmpval, isc_int32_t val)
- {
- isc_int32_t ret;
- __asm__ volatile(
- "mov ar.ccv=%2;;"
- "cmpxchg4.acq %0=%4,%3,ar.ccv"
- : "=r" (ret), "=m" (*p)
- : "r" (cmpval), "r" (val), "m" (*p)
- : "memory");
- return (ret);
- }
- #else /* !ISC_PLATFORM_USEGCCASM */
- #error "unsupported compiler. disable atomic ops by --disable-atomic"
- #endif
- #endif /* ISC_ATOMIC_H */