Mastering Linux Kernel Development

Atomic integer operations

Generic atomic operation interfaces include support for integer and bitwise operations. Integer operations are implemented to operate on special kernel-defined types called atomic_t (32-bit integer) and atomic64_t (64-bit integer). Definitions for these types can be found in the generic kernel header <linux/types.h>:

typedef struct {        int counter;} atomic_t;#ifdef CONFIG_64BITtypedef struct {        long counter;} atomic64_t;#endif

The implementation provides two groups of integer operations; one set applicable on 32 bit and the other group for 64 bit atomic variables. These interface operations are implemented as a set of macros and inline functions. Following is a summarized list of operations applicable on atomic_t type ...