counter_u64_add_protected

NAME

SYNOPSIS

DESCRIPTION

counter_u64_alloc(wait)

Allocate a new 64-bit unsigned counter. The wait argument is the malloc(9) wait flag, should be either M_NOWAIT or M_WAITOK. If M_NOWAIT is specified the operation may fail.

counter_u64_free(c)

Free the previously allocated counter c.

counter_u64_add(c, v)

Add v to c. The KPI does not guarantee any protection from wraparound.

counter_enter()

Enter mode that would allow the safe update of several counters via counter_u64_add_protected(). On some machines this expands to critical(9) section, while on other is a nop. See IMPLEMENTATION DETAILS.

counter_exit()

Exit mode for updating several counters.

counter_u64_add_protected(c, v)

Same as counter_u64_add(), but should be preceded by counter_enter().

counter_u64_fetch(c)

Take a snapshot of counter c. The data obtained is not guaranteed to reflect the real cumulative value for any moment.

counter_u64_zero(c)

Clear the counter c and set it to zero.

counter_ratecheck(cr, limit)

The function is a multiprocessor-friendly version of ppsratecheck() which uses counter internally. Returns non-negative value if the rate is not yet reached during the current second, and a negative value otherwise. If the limit was reached on previous second, but was just reset back to zero, then counter_ratecheck() returns number of events since previous reset.

COUNTER_U64_SYSINIT(c)

Define a SYSINIT(9) initializer for the global counter c.

COUNTER_U64_DEFINE_EARLY(c)

Define and initialize a global counter c. It is always safe to increment c, though updates prior to the SI_SUB_COUNTER SYSINIT(9) event are lost.

SYSCTL_COUNTER_U64(parent, nbr, name, access, ptr, descr)

Declare a static sysctl(9) oid that would represent a counter. The ptr argument should be a pointer to allocated counter_u64_t. A read of the oid returns value obtained through counter_u64_fetch(). Any write to the oid zeroes it.

SYSCTL_ADD_COUNTER_U64(ctx, parent, nbr, name, access, ptr, descr)

Create a sysctl(9) oid that would represent a counter. The ptr argument should be a pointer to allocated counter_u64_t. A read of the oid returns value obtained through counter_u64_fetch(). Any write to the oid zeroes it.

SYSCTL_COUNTER_U64_ARRAY(parent, nbr, name, access, ptr, len, descr)

Declare a static sysctl(9) oid that would represent an array of counter. The ptr argument should be a pointer to allocated array of counter_u64_t's. The len argument should specify number of elements in the array. A read of the oid returns len-sized array of uint64_t values obtained through counter_u64_fetch(). Any write to the oid zeroes all array elements.

SYSCTL_ADD_COUNTER_U64_ARRAY(ctx, parent, nbr, name, access, ptr, len, descr)

Create a sysctl(9) oid that would represent an array of counter. The ptr argument should be a pointer to allocated array of counter_u64_t's. The len argument should specify number of elements in the array. A read of the oid returns len-sized array of uint64_t values obtained through counter_u64_fetch(). Any write to the oid zeroes all array elements.

IMPLEMENTATION DETAILS

EXAMPLES

#define MY_SIZE 8 
static counter_u64_t array[MY_SIZE]; 
SYSCTL_COUNTER_U64_ARRAY(_debug, OID_AUTO, counter_array, CTLFLAG_RW, 
    &array[0], MY_SIZE, "Test counter array");

SEE ALSO

HISTORY

AUTHORS