diff --git a/sys/include/trickle.h b/sys/include/trickle.h index 89b42bdd1b8279409448d05470017cc19c447e09..e8155b6c27dfdaaa9835e818dad5a07860779198 100644 --- a/sys/include/trickle.h +++ b/sys/include/trickle.h @@ -59,6 +59,9 @@ typedef struct { /** * @brief resets the trickle timer * + * @pre `trickle->I > trickle->Imin` + * @see https://tools.ietf.org/html/rfc6206#section-4.2, number 6 + * * @param[in] trickle the trickle timer */ void trickle_reset_timer(trickle_t *trickle); @@ -66,6 +69,9 @@ void trickle_reset_timer(trickle_t *trickle); /** * @brief start the trickle timer * + * @pre `Imin > 0` + * @pre `(Imin << Imax) < (UINT32_MAX / 2)` to avoid overflow of uint32_t + * * @param[in] pid target thread * @param[in] trickle trickle timer * @param[in] msg_type msg_t.type for messages @@ -93,6 +99,8 @@ void trickle_increment_counter(trickle_t *trickle); /** * @brief is called after the interval is over and calculates the next interval * + * @pre `(trickle->I > 0)` required for trickle algorithm to work + * * @param[in] trickle trickle timer */ void trickle_interval(trickle_t *trickle); diff --git a/sys/trickle/trickle.c b/sys/trickle/trickle.c index 0437b4280ed7419f0149a17c1d07e500d1112c44..294fd490a67f8986a085d2c3995f01a70077dfcc 100644 --- a/sys/trickle/trickle.c +++ b/sys/trickle/trickle.c @@ -18,7 +18,7 @@ #include "random.h" #include "trickle.h" -#define ENABLE_DEBUG (0) +#define ENABLE_DEBUG (0) #include "debug.h" void trickle_callback(trickle_t *trickle) @@ -33,13 +33,14 @@ void trickle_callback(trickle_t *trickle) void trickle_interval(trickle_t *trickle) { + assert(trickle->I > 0); + uint32_t old_interval = trickle->I; uint32_t max_interval = trickle->Imin << trickle->Imax; uint32_t diff = old_interval - trickle->t; trickle->I *= 2; - - if ((trickle->I == 0) || (trickle->I > max_interval)) { + if (trickle->I > max_interval) { trickle->I = max_interval; old_interval = max_interval / 2; } @@ -47,24 +48,29 @@ void trickle_interval(trickle_t *trickle) DEBUG("trickle: I == %" PRIu32 ", diff == %" PRIu32 "\n", trickle->I, diff); trickle->c = 0; + /* old_interval == trickle->I / 2 */ trickle->t = random_uint32_range(old_interval, trickle->I); trickle->msg_time = (trickle->t + diff) * MS_PER_SEC; xtimer_set_msg64(&trickle->msg_timer, trickle->msg_time, &trickle->msg, trickle->pid); - } void trickle_reset_timer(trickle_t *trickle) { + assert(trickle->I > trickle->Imin); + trickle_stop(trickle); - trickle_start(trickle->pid, trickle, trickle->msg.type, trickle->Imin, - trickle->Imax, trickle->k); + trickle->I = trickle->Imin; + trickle_interval(trickle); } void trickle_start(kernel_pid_t pid, trickle_t *trickle, uint16_t msg_type, uint32_t Imin, uint8_t Imax, uint8_t k) { + assert(Imin > 0); + assert((Imin << Imax) < (UINT32_MAX / 2)); + trickle->pid = pid; trickle->c = 0;