From bfc29ca20406ccd69363b0f9796987534318e7ae Mon Sep 17 00:00:00 2001 From: Dimitri Staessens Date: Fri, 27 Jul 2018 00:18:20 +0200 Subject: lib: Support for rudimentary retransmission This adds rudimentary support for sending and processing acknowledgments and doing retransmission. It replaces the generic timerwheel with a specific one for retransmission. This is currently a fixed wheel allowing retransmissions to be scheduled up to about 32 seconds into the future. It currently has an 8ms resolution. This could be made configurable in the future. Failures of the flow (i.e. rtx not working) are indicated by the rxmwheel_move() function returning a fd. This is currently not yet handled (maybe just setting the state of the flow to FLOWDOWN is a better solution). The shm_rdrbuff tracks the number of users of a du_buff. One user is the full stack, each retransmission will increment the refs counter (which effectively acts as a semaphore). The refs counter is decremented when a packet is acked. The du_buff is only allowed to be removed if there is only one user left (the "stack"). When a packet is retransmitted, it is copied in the rdrbuff. This is to ensure integrity of the packet when multiple layers do retransmission and it is passed down the stack again. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders --- src/lib/tests/CMakeLists.txt | 7 --- src/lib/tests/timerwheel_test.c | 104 ---------------------------------------- 2 files changed, 111 deletions(-) delete mode 100644 src/lib/tests/timerwheel_test.c (limited to 'src/lib/tests') diff --git a/src/lib/tests/CMakeLists.txt b/src/lib/tests/CMakeLists.txt index 7d5b3651..cc51c203 100644 --- a/src/lib/tests/CMakeLists.txt +++ b/src/lib/tests/CMakeLists.txt @@ -1,12 +1,6 @@ get_filename_component(PARENT_PATH ${CMAKE_CURRENT_SOURCE_DIR} DIRECTORY) get_filename_component(PARENT_DIR ${PARENT_PATH} NAME) -if (NOT (APPLE OR GNU)) - set(TIMERWHEEL_TEST "timerwheel_test.c") -else () - set(TIMERWHEEL_TEST "") -endif () - create_test_sourcelist(${PARENT_DIR}_tests test_suite.c # Add new tests here bitmap_test.c @@ -16,7 +10,6 @@ create_test_sourcelist(${PARENT_DIR}_tests test_suite.c md5_test.c sha3_test.c time_utils_test.c - ${TIMERWHEEL_TEST} ) add_executable(${PARENT_DIR}_test EXCLUDE_FROM_ALL ${${PARENT_DIR}_tests}) diff --git a/src/lib/tests/timerwheel_test.c b/src/lib/tests/timerwheel_test.c deleted file mode 100644 index 0ec98316..00000000 --- a/src/lib/tests/timerwheel_test.c +++ /dev/null @@ -1,104 +0,0 @@ -/* - * Ouroboros - Copyright (C) 2016 - 2018 - * - * Test of the timer wheel - * - * Dimitri Staessens - * Sander Vrijders - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., http://www.fsf.org/about/contact/. - */ - -#include "timerwheel.c" - -#include -#include -#include -#include - -#define MAX_ELEMENTS 100 -#define MAX_RESOLUTION 10 /* ms */ -#define MAX_ADDITIONS 1000 - -int total; - -int add(void * o) -{ - total += *((int *) o); - return 0; -} - -int timerwheel_test(int argc, char ** argv) -{ - struct timerwheel * tw; - long resolution; - long elements; - struct timespec wait; - - int additions; - - int check_total = 0; - - int i; - int var = 5; - - struct tw_f * f; - - (void) argc; - (void) argv; - - total = 0; - - srand(time(NULL)); - - resolution = rand() % (MAX_RESOLUTION - 1) + 1; - elements = rand() % (MAX_ELEMENTS - 10) + 10; - - tw = timerwheel_create(resolution, resolution * elements); - if (tw == NULL) { - printf("Failed to create timerwheel.\n"); - return -1; - } - - wait.tv_sec = (resolution * elements) / 1000; - wait.tv_nsec = ((resolution * elements) % 1000) * MILLION; - - additions = rand() % MAX_ADDITIONS + 1000; - - for (i = 0; i < additions; ++i) { - int delay = rand() % (resolution * elements); - check_total += var; - f = timerwheel_start(tw, - (void (*)(void *)) add, - (void *) &var, - delay); - if (f == NULL) { - printf("Failed to add function."); - return -1; - } - } - - nanosleep(&wait, NULL); - - timerwheel_move(tw); - - timerwheel_destroy(tw); - - if (total != check_total) { - printf("Totals do not match: %d and %d.\n", total, check_total); - return -1; - } - - return 0; -} -- cgit v1.2.3