diff options
Diffstat (limited to 'research/experiments/020-lossy-paths/sim.c')
| -rw-r--r-- | research/experiments/020-lossy-paths/sim.c | 38 |
1 files changed, 33 insertions, 5 deletions
diff --git a/research/experiments/020-lossy-paths/sim.c b/research/experiments/020-lossy-paths/sim.c index 699c9d4..361db14 100644 --- a/research/experiments/020-lossy-paths/sim.c +++ b/research/experiments/020-lossy-paths/sim.c @@ -5,10 +5,12 @@ * (a backlog), stored by the host at once. It takes in link-protocol.c * whole, to read the sender's window and RTT. * - * sim SIZE COUNT DELAY_MS LOSS_PERMIL JITTER_MS RATE_MBIT QUEUE_PACKETS SEED + * sim SIZE COUNT DELAY_MS LOSS_PERMIL JITTER_MS RATE_MBIT QUEUE_PACKETS SEED [PACE] * prints a line of JSON: virtual seconds, records a second, packets sent, * dropped (by loss, by the queue), called lost, of them late, congestion * episodes undone, sent again, and the window and RTT seen each 100 ms. + * PACE: records queued a second (else all at once), and the time each took + * from queued to handed over (p50, p99, max), and probes sent (PTO). * * cc -O2 -std=c17 -I link research/experiments/020-lossy-paths/sim.c link/crypto.c -lm -ldl -o build/sim * PURE_CRYPTO=build/pure-crypto.so build/sim 1000 30000 10 10 5 50 100 1 */ @@ -36,6 +38,7 @@ static uint64_t dropped_loss, dropped_queue, sent_count; static uint64_t heard, records, size; static PureLinkDone dones[64]; static size_t done_count; +static uint64_t *queued_at, *waited; static void put(bool to_receiver, const unsigned char *bytes, size_t n) { ++sent_count; @@ -63,6 +66,11 @@ static void put(bool to_receiver, const unsigned char *bytes, size_t n) { memcpy(p->bytes, bytes, n); } +static int by_value(const void *a, const void *b) { + uint64_t x = *(const uint64_t *)a, y = *(const uint64_t *)b; + return x < y ? -1 : x > y; +} + static bool sim_answer(void *context, const unsigned char *packet, size_t n, const unsigned char *to, size_t to_size) { (void)context, (void)to, (void)to_size; put(false, packet, n); @@ -79,7 +87,10 @@ static bool sim_deliver(void *context, const PureLinkDelivery *d) { if (done_count == 64) return false; uint64_t h = heard; for (unsigned k = 0; k < d->count; ++k) - if (d->first + k == h + 1) h = d->first + k; + if (d->first + k == h + 1) { + h = d->first + k; + if (queued_at) waited[h] = now - queued_at[h]; + } heard = h; dones[done_count++] = (PureLinkDone){d->token, heard, true, d->first > heard + 1}; return true; @@ -95,6 +106,8 @@ int main(int argc, char **argv) { rate_bps = strtoull(argv[6], NULL, 10) * 1000000u; queue_limit = strtoull(argv[7], NULL, 10); sim_seed = strtoull(argv[8], NULL, 10) * 0x9e3779b97f4a7c15u | 1; + double pace = argc > 9 ? strtod(argv[9], NULL) : 0; + if (pace > 0) queued_at = calloc(records + 1, sizeof(*queued_at)), waited = calloc(records + 1, sizeof(*waited)); char dir[] = "/tmp/pure-sim-XXXXXX", path[512], hex[65], error[256]; if (!mkdtemp(dir)) return 1; unsigned char pa[32], pb[32]; @@ -109,12 +122,18 @@ int main(int argc, char **argv) { PureLinkReceiver *r = pure_link_receiver(b, pb, &(PureLinkHost){input_of, sim_deliver, NULL}, error, sizeof(error)); pure_link_allow(r, "sim.out", pa, error, sizeof(error)); unsigned char *bytes = calloc(1, size + 1); - for (uint64_t seq = 1; seq <= records; ++seq) + uint64_t queued = 0, ptos = 0; + for (uint64_t seq = 1; !queued_at && seq <= records; ++seq) if (!pure_link_sender_queue(s, seq, bytes, size)) return 1; + if (!queued_at) queued = records; unsigned char out[PURE_LINK_DATAGRAM_MOST]; uint64_t sample_at = 0, window_sum = 0, rtt_sum = 0, samples = 0, window_least = UINT64_MAX; PureLinkDone told[64]; while (heard < records || s->stored < records) { + for (; queued < records && (uint64_t)((double)queued * 1e9 / pace) <= now; ++queued) { + queued_at[queued + 1] = now; + if (!pure_link_sender_queue(s, queued + 1, bytes, size)) return 1; + } uint64_t number; for (size_t n; (n = pure_link_sender_packet(s, out, false, now, &number));) put(true, out, n); uint64_t next = UINT64_MAX, due = pure_link_sender_due(s), turn = pure_link_receiver_due(r); @@ -123,6 +142,7 @@ int main(int argc, char **argv) { if (due && due < next) next = due; if (turn && turn < next) next = turn; if (done_count && now + 1000 < next) next = now + 1000; + if (queued < records && (uint64_t)((double)queued * 1e9 / pace) < next) next = (uint64_t)((double)queued * 1e9 / pace); if (next == UINT64_MAX || next > 3600000 * MS) { fprintf(stderr, "sim: stuck at %llu of %llu\n", (unsigned long long)heard, (unsigned long long)records); return 1; @@ -143,7 +163,9 @@ int main(int argc, char **argv) { else pure_link_sender_take(s, p->bytes, p->size, now); *p = packets[--packet_count]; } + unsigned before = s->pto_count; pure_link_sender_tick(s, now); + ptos += s->pto_count > before; size_t count = done_count; memcpy(told, dones, count * sizeof(*dones)); done_count = 0; @@ -153,13 +175,19 @@ int main(int argc, char **argv) { printf("{\"size\":%llu,\"records\":%llu,\"delay_ms\":%llu,\"loss_permil\":%llu,\"jitter_ms\":%llu,\"rate_mbit\":%llu," "\"queue\":%llu,\"seconds\":%.3f,\"per_second\":%.0f,\"mbit\":%.2f,\"sent\":%llu,\"dropped_loss\":%llu," "\"dropped_queue\":%llu,\"declared_lost\":%llu,\"late\":%llu,\"undone\":%llu,\"resent\":%llu,\"window_mean\":%.0f,\"window_least\":%llu," - "\"srtt_mean_ms\":%.2f}\n", + "\"srtt_mean_ms\":%.2f,\"probes\":%llu", (unsigned long long)size, (unsigned long long)records, (unsigned long long)(delay_ns / MS), (unsigned long long)loss_permil, (unsigned long long)(jitter / MS), (unsigned long long)(rate_bps / 1000000), (unsigned long long)queue_limit, seconds, records / seconds, records * (double)size * 8 / seconds / 1e6, (unsigned long long)s->counts.packets, (unsigned long long)dropped_loss, (unsigned long long)dropped_queue, (unsigned long long)s->counts.lost, (unsigned long long)s->counts.late, (unsigned long long)s->counts.undone, (unsigned long long)s->counts.resent, (double)window_sum / samples, - (unsigned long long)window_least, (double)rtt_sum / samples / 1e6); + (unsigned long long)window_least, (double)rtt_sum / samples / 1e6, (unsigned long long)ptos); + if (queued_at) { + qsort(waited + 1, records, sizeof(*waited), by_value); + printf(",\"waited_ms_p50\":%.3f,\"waited_ms_p99\":%.3f,\"waited_ms_max\":%.3f", waited[1 + records / 2] / 1e6, + waited[1 + records * 99 / 100] / 1e6, waited[records] / 1e6); + } + printf("}\n"); snprintf(path, sizeof(path), "rm -rf %s", dir); return system(path) ? 1 : 0; } |