rte_random.h File Reference

#include <stdint.h>

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Functions
void	rte_srand (uint64_t seedval)
uint64_t	rte_rand (void)
uint64_t	rte_rand_max (uint64_t upper_bound)
double	rte_drand (void)

Detailed Description

Pseudo-random Generators in RTE

Definition in file rte_random.h.

Function Documentation

rte_srand()

void rte_srand

(

uint64_t

seedval

)

Seed the pseudo-random generator.

The generator is automatically seeded by the EAL init with a timer value. It may need to be re-seeded by the user with a real random value.

This function is not multi-thread safe in regards to other rte_srand() calls, nor is it in relation to concurrent rte_rand(), rte_rand_max() or rte_drand() calls.

Parameters

seedval

The value of the seed.

rte_rand()

uint64_t rte_rand

(

void

)

Get a pseudo-random value.

The generator is not cryptographically secure.

rte_rand(), rte_rand_max() and rte_drand() are multi-thread safe, with the exception that they may not be called by multiple unregistered non-EAL threads in parallel.

Returns

A pseudo-random value between 0 and (1<<64)-1.

Examples:

examples/fips_validation/main.c, and examples/ipsec-secgw/sa.c.

rte_rand_max()

uint64_t rte_rand_max

(

uint64_t

upper_bound

)

Generates a pseudo-random number with an upper bound.

This function returns an uniformly distributed (unbiased) random number less than a user-specified maximum value.

rte_rand(), rte_rand_max() and rte_drand() are multi-thread safe, with the exception that they may not be called by multiple unregistered non-EAL threads in parallel.

Parameters

upper_bound

The upper bound of the generated number.

Returns

A pseudo-random value between 0 and (upper_bound-1).

Examples:

examples/l2fwd-keepalive/main.c.

rte_drand()

double rte_drand

(

void

)

Generates a pseudo-random floating point number.

This function returns a non-negative double-precision floating random number uniformly distributed over the interval [0.0, 1.0).

The generator is not cryptographically secure.

rte_rand(), rte_rand_max() and rte_drand() are multi-thread safe, with the exception that they may not be called by multiple unregistered non-EAL threads in parallel.

Returns

A pseudo-random value between 0 and 1.0.