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test_and_set_bit(9) [centos man page]

TEST_AND_SET_BIT(9)					     Basic C Library Functions					       TEST_AND_SET_BIT(9)

NAME
test_and_set_bit - Set a bit and return its old value SYNOPSIS
int test_and_set_bit(int nr, volatile unsigned long * addr); ARGUMENTS
nr Bit to set addr Address to count from DESCRIPTION
This operation is atomic and cannot be reordered. It also implies a memory barrier. COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 TEST_AND_SET_BIT(9)

Check Out this Related Man Page

ATOMIC_DEC(3)						   BSD 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 decrement 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 referenced 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. BSD
April 11, 2007 BSD

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