atomic_dec(3) - NetBSD Manual Pages

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ATOMIC_DEC(3)           NetBSD Library Functions Manual          ATOMIC_DEC(3)


NAME

     atomic_dec, atomic_dec_32, atomic_dec_uint, atomic_dec_ulong,
     atomic_dec_ptr, atomic_dec_64, atomic_dec_32_nv, atomic_dec_uint_nv,
     atomic_dec_ulong_nv, atomic_dec_ptr_nv, atomic_dec_64_nv -- atomic decre-
     ment operations


SYNOPSIS

     #include <sys/atomic.h>

     void
     atomic_dec_32(volatile uint32_t *ptr);

     void
     atomic_dec_uint(volatile unsigned int *ptr);

     void
     atomic_dec_ulong(volatile unsigned long *ptr);

     void
     atomic_dec_ptr(volatile void *ptr);

     void
     atomic_dec_64(volatile uint64_t *ptr);

     uint32_t
     atomic_dec_32_nv(volatile uint32_t *ptr);

     unsigned int
     atomic_dec_uint_nv(volatile unsigned int *ptr);

     unsigned long
     atomic_dec_ulong_nv(volatile unsigned long *ptr);

     void *
     atomic_dec_ptr_nv(volatile void *ptr);

     uint64_t
     atomic_dec_64_nv(volatile uint64_t *ptr);


DESCRIPTION

     The atomic_dec family of functions decrement (by one) the variable refer-
     enced by ptr in an atomic fashion.

     The *_nv() variants of these functions return the new value.

     The 64-bit variants of these functions are available only on platforms
     that can support atomic 64-bit memory access.  Applications can check for
     the availability of 64-bit atomic memory operations by testing if the
     pre-processor macro __HAVE_ATOMIC64_OPS is defined.


SEE ALSO

     atomic_ops(3)


HISTORY

     The atomic_dec functions first appeared in NetBSD 5.0.

NetBSD 6.0                      April 11, 2007                      NetBSD 6.0