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ATOMIC_SUB_INT(9) FreeBSD Kernel Developer's Manual ATOMIC_SUB_INT(9) NAME atomic_sub_int, atomic_sub_int_nv, atomic_sub_long, atomic_sub_long_nv - atomic subtraction operations SYNOPSIS #include <sys/atomic.h> void atomic_sub_int(volatile unsigned int *p, unsigned int v); unsigned int atomic_sub_int_nv(volatile unsigned int *p, unsigned int v); void atomic_sub_long(volatile unsigned long *p, unsigned long v); unsigned long atomic_sub_long_nv(volatile unsigned long *p, unsigned long v); DESCRIPTION The atomic_sub set of functions provide an interface for atomically performing sub and sub-and-fetch operations with respect to interrupts and multiple processors in the system. The value referenced by the pointer p is decremented by the value v. CONTEXT atomic_sub_int(), atomic_sub_int_nv(), atomic_sub_long(), and atomic_sub_long_nv() can all be called during autoconf, from process context, or from interrupt context. RETURN VALUES atomic_sub_int and atomic_sub_long perform the subtraction without returning any knowledge of the value at p. atomic_sub_int_nv and atomic_sub_long_nv return the value at p after the subtraction was performed. SEE ALSO atomic_add_int(9), atomic_dec_int(9) HISTORY The atomic_sub functions first appeared in OpenBSD 5.5. FreeBSD 14.1-RELEASE-p8 July 23, 2014 FreeBSD 14.1-RELEASE-p8