cmap_inc(3) Decrease already stored value in CMAP


#include <corosync/cmap.h>

cs_error_t cmap_dec (cmap_handle_t handle, const char *key_name);


The cmap_dec function is used to decrease integer value of already stored key inside cmap. The handle argument is connection to CMAP database obtained by calling cmap_initialize(3) function. key_name is name of key to increase value of.

Function is defined only on values where increase makes sense and is well defined, so it can be one of:

CMAP_VALUETYPE_INT8 - 8-bit signed integer

CMAP_VALUETYPE_UINT8 - 8-bit unsigned integer

CMAP_VALUETYPE_INT16 - 16-bit signed integer

CMAP_VALUETYPE_UINT16 - 16-bit unsigned integer

CMAP_VALUETYPE_INT32 - 32-bit signed integer

CMAP_VALUETYPE_UINT32 - 32-bit unsigned integer

CMAP_VALUETYPE_INT64 - 64-bit signed integer

CMAP_VALUETYPE_UINT64 - 64-bit unsigned integer

Overflow/underflow is not detected and it's ignored.


This call returns the CS_OK value if successful. If value or key_name are unspecified, CS_ERR_INVALID_PARAM is returned. CS_ERR_NOT_EXIST error is returned if key doesn't exist (wasn't created by calling cmap_set(3) first). Some of keys may be tagged read-only directly in corosync and seting such key will result in CS_ERR_ACCESS error.