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Diffstat (limited to 'libthreads/alpha/lock.S')
| -rw-r--r-- | libthreads/alpha/lock.S | 83 |
1 files changed, 0 insertions, 83 deletions
diff --git a/libthreads/alpha/lock.S b/libthreads/alpha/lock.S deleted file mode 100644 index e7acb039..00000000 --- a/libthreads/alpha/lock.S +++ /dev/null @@ -1,83 +0,0 @@ -/* - * Mach Operating System - * Copyright (c) 1992 Carnegie Mellon University - * All Rights Reserved. - * - * Permission to use, copy, modify and distribute this software and its - * documentation is hereby granted, provided that both the copyright - * notice and this permission notice appear in all copies of the - * software, derivative works or modified versions, and any portions - * thereof, and that both notices appear in supporting documentation. - * - * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" - * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR - * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. - * - * Carnegie Mellon requests users of this software to return to - * - * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU - * School of Computer Science - * Carnegie Mellon University - * Pittsburgh PA 15213-3890 - * - * any improvements or extensions that they make and grant Carnegie Mellon - * the rights to redistribute these changes. - */ -/* - * HISTORY - * $Log: lock.s,v $ - * Revision 2.3 93/03/09 10:59:04 danner - * Lost in previous merge: - * Added memory barriers where needed. - * Locks are longs now. - * [93/01/15 af] - * - * Revision 2.2 93/01/14 18:04:31 danner - * Mumble, "try_lock" really means "try_hard_once". - * That is, try hard until you either get it or lose it. - * [92/12/24 af] - * Created a while back. - * [92/12/10 af] - * - */ - -#include <mach/alpha/asm.h> - -/* - The C interface for this function is - - boolean_t - spin_try_lock_sw(m) - long * m; - - The function has a slightly different semantics than TAS: it will - return a boolean value that indicates whether the lock was acquired - or not. If not, we'll presume that the user will retry after some - appropriate delay. - */ - .text - .align 4 - .set noreorder - -LEAF(spin_try_lock,1) - mb - ldq_l t0,0(a0) - or zero,2,v0 /* build lock value */ - bne t0,nope /* already set, forget it */ - stq_c v0,0(a0) /* see if we still had the lock */ - beq v0,yipe /* if we just took an interrupt.. */ - RET /* if v0 != 0 then we got it */ -nope: - mov zero,v0 /* failed to acquire lock */ - RET -yipe: br zero,spin_try_lock /* I love branch predictions.. */ - - END(spin_try_lock) - -LEAF(spin_unlock,1) - mb /* but this might be needed.. */ - stq zero,0(a0) /* no need for interlocks (sec 10.5.2) */ - mb /* but this might be needed.. */ - RET - - END(spin_unlock) |