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Diffstat (limited to 'mcon/U/d_sync_atomic.U')
| -rw-r--r-- | mcon/U/d_sync_atomic.U | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/mcon/U/d_sync_atomic.U b/mcon/U/d_sync_atomic.U new file mode 100644 index 0000000..3e94cb7 --- /dev/null +++ b/mcon/U/d_sync_atomic.U @@ -0,0 +1,42 @@ +?RCS: $Id: d_sync_atomic.U 167 2013-05-08 17:58:00Z rmanfredi $ +?RCS: +?RCS: Copyright (c) 2011, Raphael Manfredi +?RCS: +?RCS: You may redistribute only under the terms of the Artistic License, +?RCS: as specified in the README file that comes with the distribution. +?RCS: You may reuse parts of this distribution only within the terms of +?RCS: that same Artistic License; a copy of which may be found at the root +?RCS: of the source tree for dist 4.0. +?RCS: +?MAKE:d_sync_atomic: Trylink cat +?MAKE: -pick add $@ %< +?S:d_sync_atomic: +?S: This variable conditionally defines the HAS_SYNC_ATOMIC symbol, which +?S: indicates to the C program that __sync_xxx() atomic operations are +?S: made available by the compiler. +?S:. +?C:HAS_SYNC_ATOMIC: +?C: This symbol, if defined, indicates that __sync_xxx() atomic operations +?C: are made available by the compiler, namely __sync_synchronize() to +?C: issue a memory barrieer, __sync_bool_compare_and_swap() for issuing a +?C: test-and-set and __sync_fetch_and_add() for atomic increases of values. +?C:. +?H:#$d_sync_atomic HAS_SYNC_ATOMIC /**/ +?H:. +?LINT:set d_sync_atomic +: check for __sync_synchronize and friends +$cat >try.c <<EOC +int main(void) +{ + static int ret; + int i; + __sync_synchronize(); + ret |= __sync_bool_compare_and_swap(&i, 0, 1); + ret += __sync_fetch_and_add(&i, 1); + return ret; +} +EOC +cyn="whether atomic memory operations are possible" +set d_sync_atomic +eval $trylink + |