xrootd
XrdSysAtomics.hh
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1 #ifndef _XRDSYSATOMICS_
2 #define _XRDSYSATOMICS_
3 /******************************************************************************/
4 /* */
5 /* X r d S y s A t o m i c s . h h */
6 /* */
7 /* (c) 2011 by the Board of Trustees of the Leland Stanford, Jr., University */
8 /* All Rights Reserved */
9 /* Produced by Andrew Hanushevsky for Stanford University under contract */
10 /* DE-AC02-76-SFO0515 with the Department of Energy */
11 /* */
12 /* This file is part of the XRootD software suite. */
13 /* */
14 /* XRootD is free software: you can redistribute it and/or modify it under */
15 /* the terms of the GNU Lesser General Public License as published by the */
16 /* Free Software Foundation, either version 3 of the License, or (at your */
17 /* option) any later version. */
18 /* */
19 /* XRootD is distributed in the hope that it will be useful, but WITHOUT */
20 /* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or */
21 /* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public */
22 /* License for more details. */
23 /* */
24 /* You should have received a copy of the GNU Lesser General Public License */
25 /* along with XRootD in a file called COPYING.LESSER (LGPL license) and file */
26 /* COPYING (GPL license). If not, see <http://www.gnu.org/licenses/>. */
27 /* */
28 /* The copyright holder's institutional names and contributor's names may not */
29 /* be used to endorse or promote products derived from this software without */
30 /* specific prior written permission of the institution or contributor. */
31 /******************************************************************************/
32 
33 /* The following instruction acronyms are used:
34  AtomicCAS() -> Compare And [if equal] Set
35  AtomicFAZ() -> Fetch And Zero
36 */
37 
38 #ifdef HAVE_ATOMICS
39 #define AtomicBeg(Mtx)
40 #define AtomicEnd(Mtx)
41 #define AtomicAdd(x, y) __sync_fetch_and_add(&x, y)
42 #define AtomicCAS(x, y, z) __sync_bool_compare_and_swap(&x, y, z)
43 #define AtomicDec(x) __sync_fetch_and_sub(&x, 1)
44 #define AtomicFAZ(x) __sync_fetch_and_and(&x, 0)
45 #define AtomicGet(x) __sync_fetch_and_or(&x, 0)
46 #define AtomicInc(x) __sync_fetch_and_add(&x, 1)
47 #define AtomicSub(x, y) __sync_fetch_and_sub(&x, y)
48 #else
49 #define AtomicBeg(Mtx) Mtx.Lock()
50 #define AtomicEnd(Mtx) Mtx.UnLock()
51 #define AtomicAdd(x, y) x += y
52 #define AtomicCAS(x, y, z) if (x == y) x = z
53 #define AtomicDec(x) x--
54 #define AtomicFAZ(x) x; x = 0
55 #define AtomicGet(x) x
56 #define AtomicInc(x) x++
57 #define AtomicSub(x, y) x -= y
58 #endif
59 #endif