Date: Fri, 20 Oct 2000 00:00:49 -0700 (PDT) From: John Baldwin <jhb@FreeBSD.org> To: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/i386/include atomic.h src/sys/alpha/include atomic.h src/sys/ia64/include atomic.h Message-ID: <200010200700.AAA28573@freefall.freebsd.org>
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jhb 2000/10/20 00:00:49 PDT
Modified files:
sys/i386/include atomic.h
sys/alpha/include atomic.h
sys/ia64/include atomic.h
Log:
- Expand the set of atomic operations to optionally include memory barriers
in most of the atomic operations. Now for these operations, you can
use the normal atomic operation, you can use the operation with a read
barrier, or you can use the operation with a write barrier. The function
names follow the same semantics used in the ia64 instruction set. An
atomic operation with a read barrier has the extra suffix 'acq', due to
it having "acquire" semantics. An atomic operation with a write barrier
has the extra suffix 'rel'. These suffixes are inserted between the
name of the operation to perform and the typename. For example, the
atomic_add_int() function now has 3 variants:
- atomic_add_int() - this is the same as the previous function
- atomic_add_acq_int() - this function combines the add operation with a
read memory barrier
- atomic_add_rel_int() - this function combines the add operation with a
write memory barrier
- Add 'ptr' to the list of types that we can perform atomic operations
on. This allows one to do atomic operations on uintptr_t's. This is
useful in the mutex code, for example, because the actual mutex lock is
a pointer.
- Add two new operations for doing loads and stores with memory barriers.
The new load operations use a read barrier before the load, and the
new store operations use a write barrier after the load. For example,
atomic_load_acq_int() will atomically load an integer as well as
enforcing a read barrier.
Revision Changes Path
1.14 +109 -3 src/sys/i386/include/atomic.h
1.6 +170 -1 src/sys/alpha/include/atomic.h
1.3 +214 -64 src/sys/ia64/include/atomic.h
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