X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/37f24fd67e04254218bd7b43dcb7650506776868..4c4671eeabdfa4c951086939613eaccf7f2b973d:/examples/msg/bittorrent/peer.c diff --git a/examples/msg/bittorrent/peer.c b/examples/msg/bittorrent/peer.c index 026be29d45..0ef1d35574 100644 --- a/examples/msg/bittorrent/peer.c +++ b/examples/msg/bittorrent/peer.c @@ -1,33 +1,39 @@ - /* Copyright (c) 2012. The SimGrid Team. - * All rights reserved. */ +/* Copyright (c) 2012-2016. The SimGrid Team. + * All rights reserved. */ /* This program is free software; you can redistribute it and/or modify it * under the terms of the license (GNU LGPL) which comes with this package. */ + #include "peer.h" #include "tracker.h" #include "connection.h" #include "messages.h" -#include +#include #include +#include XBT_LOG_NEW_DEFAULT_CATEGORY(msg_peers, "Messages specific for the peers"); //TODO: Let users change this /* * File transfered data - * + * For the test, default values are : * File size: 10 pieces * 5 blocks/piece * 16384 bytes/block = 819200 bytes */ -static int FILE_SIZE = 10 * 5 * 16384; -static int FILE_PIECES = 10; -static int PIECES_BLOCKS = 5; -static int BLOCK_SIZE = 16384; -static int BLOCKS_REQUESTED = 2; +#define FILE_PIECES 10 +#define PIECES_BLOCKS 5 +#define BLOCK_SIZE 16384 +#define ENABLE_END_GAME_MODE 1 -/** - * Peer main function - */ +/** Number of blocks asked by each request */ +#define BLOCKS_REQUESTED 2 + +static const unsigned long int FILE_SIZE = FILE_PIECES * PIECES_BLOCKS * BLOCK_SIZE; + +#define SLEEP_DURATION 1 + +/** Peer main function */ int peer(int argc, char *argv[]) { s_peer_t peer; @@ -35,12 +41,12 @@ int peer(int argc, char *argv[]) xbt_assert(argc == 3 || argc == 4, "Wrong number of arguments"); //Build peer object if (argc == 4) { - peer_init(&peer, atoi(argv[1]), 1); + peer_init(&peer, xbt_str_parse_int(argv[1],"Invalid ID: %s"), 1); } else { - peer_init(&peer, atoi(argv[1]), 0); + peer_init(&peer, xbt_str_parse_int(argv[1],"Invalid ID: %s"), 0); } //Retrieve deadline - double deadline = atof(argv[2]); + double deadline = xbt_str_parse_double(argv[2],"Invalid deadline: %s"); xbt_assert(deadline > 0, "Wrong deadline supplied"); XBT_INFO("Hi, I'm joining the network with id %d", peer.id); //Getting peer data from the tracker. @@ -48,6 +54,7 @@ int peer(int argc, char *argv[]) XBT_DEBUG("Got %d peers from the tracker", xbt_dict_length(peer.peers)); XBT_DEBUG("Here is my current status: %s", peer.bitfield); peer.begin_receive_time = MSG_get_clock(); + MSG_mailbox_set_async(peer.mailbox); if (has_finished(peer.bitfield)) { peer.pieces = FILE_PIECES; send_handshake_all(&peer); @@ -69,10 +76,9 @@ int peer(int argc, char *argv[]) return 0; } -/** - * Peer main loop when it is leeching. - * @param peer peer data - * @param deadline time at which the peer has to leave +/** @brief Peer main loop when it is leeching. + * @param peer peer data + * @param deadline time at which the peer has to leave */ void leech_loop(peer_t peer, double deadline) { @@ -83,9 +89,8 @@ void leech_loop(peer_t peer, double deadline) * (since it couldn't have gotten more than 50 peers) */ send_handshake_all(peer); - //Wait for at least one "bitfield" message. - wait_for_pieces(peer, deadline); XBT_DEBUG("Starting main leech loop"); + while (MSG_get_clock() < deadline && peer->pieces < FILE_PIECES) { if (peer->comm_received == NULL) { peer->task_received = NULL; @@ -99,30 +104,23 @@ void leech_loop(peer_t peer, double deadline) handle_message(peer, peer->task_received); } } else { - handle_pending_sends(peer); - if (peer->current_piece != -1) { - send_interested_to_peers(peer); - } else { - //If the current interested pieces is < MAX - if (peer->pieces_requested < MAX_PIECES) { - update_current_piece(peer); - } - } //We don't execute the choke algorithm if we don't already have a piece if (MSG_get_clock() >= next_choked_update && peer->pieces > 0) { update_choked_peers(peer); next_choked_update += UPDATE_CHOKED_INTERVAL; } else { - MSG_process_sleep(1); + MSG_process_sleep(SLEEP_DURATION); } } } + if (peer->pieces == FILE_PIECES) + XBT_DEBUG("%d becomes a seeder", peer->id); + } -/** - * Peer main loop when it is seeding - * @param peer peer data - * @param deadline time when the peer will leave +/** @brief Peer main loop when it is seeding + * @param peer peer data + * @param deadline time when the peer will leave */ void seed_loop(peer_t peer, double deadline) { @@ -147,33 +145,29 @@ void seed_loop(peer_t peer, double deadline) //TODO: Change the choked peer algorithm when seeding. next_choked_update += UPDATE_CHOKED_INTERVAL; } else { - MSG_process_sleep(1); + MSG_process_sleep(SLEEP_DURATION); } } } } -/** - * Retrieves the peer list from the tracker - * @param peer current peer data +/** @brief Retrieves the peer list from the tracker + * @param peer current peer data */ int get_peers_data(peer_t peer) { int success = 0, send_success = 0; double timeout = MSG_get_clock() + GET_PEERS_TIMEOUT; //Build the task to send to the tracker - tracker_task_data_t data = - tracker_task_data_new(MSG_host_get_name(MSG_host_self()), - peer->mailbox_tracker, peer->id, 0, 0, FILE_SIZE); + tracker_task_data_t data = tracker_task_data_new(MSG_host_get_name(MSG_host_self()), peer->mailbox_tracker, + peer->id, 0, 0, FILE_SIZE); //Build the task to send. msg_task_t task_send = MSG_task_create(NULL, 0, TRACKER_COMM_SIZE, data); msg_task_t task_received = NULL; msg_comm_t comm_received; while (!send_success && MSG_get_clock() < timeout) { XBT_DEBUG("Sending a peer request to the tracker."); - msg_error_t status = - MSG_task_send_with_timeout(task_send, TRACKER_MAILBOX, - GET_PEERS_TIMEOUT); + msg_error_t status = MSG_task_send_with_timeout(task_send, TRACKER_MAILBOX, GET_PEERS_TIMEOUT); if (status == MSG_OK) { send_success = 1; } @@ -188,8 +182,7 @@ int get_peers_data(peer_t peer) //Add the peers the tracker gave us to our peer list. xbt_dynar_foreach(data->peers, i, peer_id) { if (peer_id != peer->id) - xbt_dict_set_ext(peer->peers, (char *) &peer_id, sizeof(int), - connection_new(peer_id), NULL); + xbt_dict_set_ext(peer->peers, (char *) &peer_id, sizeof(int), connection_new(peer_id), NULL); } success = 1; //free the communication and the task @@ -203,11 +196,10 @@ int get_peers_data(peer_t peer) return success; } -/** - * Initialize the peer data. - * @param peer peer data - * @param id id of the peer to take in the network - * @param seed indicates if the peer is a seed. +/** @brief Initialize the peer data. + * @param peer peer data + * @param id id of the peer to take in the network + * @param seed indicates if the peer is a seed. */ void peer_init(peer_t peer, int id, int seed) { @@ -222,34 +214,26 @@ void peer_init(peer_t peer, int id, int seed) peer->bitfield_blocks = xbt_new(char, (FILE_PIECES) * (PIECES_BLOCKS) + 1); if (seed) { memset(peer->bitfield, '1', sizeof(char) * (FILE_PIECES + 1)); - memset(peer->bitfield_blocks, '1', - sizeof(char) * FILE_PIECES * (PIECES_BLOCKS)); + memset(peer->bitfield_blocks, '1', sizeof(char) * FILE_PIECES * (PIECES_BLOCKS)); } else { memset(peer->bitfield, '0', sizeof(char) * (FILE_PIECES + 1)); - memset(peer->bitfield_blocks, '0', - sizeof(char) * FILE_PIECES * (PIECES_BLOCKS)); + memset(peer->bitfield_blocks, '0', sizeof(char) * FILE_PIECES * (PIECES_BLOCKS)); } peer->bitfield[FILE_PIECES] = '\0'; peer->pieces = 0; peer->pieces_count = xbt_new0(short, FILE_PIECES); - peer->pieces_requested = 0; peer->current_pieces = xbt_dynar_new(sizeof(int), NULL); - peer->current_piece = -1; - peer->stream = RngStream_CreateStream(""); + peer->stream = (RngStream)MSG_host_get_property_value(MSG_host_self(), "stream"); peer->comm_received = NULL; peer->round = 0; - - peer->pending_sends = xbt_dynar_new(sizeof(msg_comm_t), NULL); } -/** - * Destroys a poor peer object. - */ +/** Destroys a poor peer object. */ void peer_free(peer_t peer) { char *key; @@ -261,48 +245,50 @@ void peer_free(peer_t peer) xbt_dict_free(&peer->peers); xbt_dict_free(&peer->active_peers); xbt_dynar_free(&peer->current_pieces); - xbt_dynar_free(&peer->pending_sends); xbt_free(peer->pieces_count); xbt_free(peer->bitfield); xbt_free(peer->bitfield_blocks); - - RngStream_DeleteStream(&peer->stream); } -/** - * Returns if a peer has finished downloading the file - * @param bitfield peer bitfield +/** @brief Returns if a peer has finished downloading the file + * @param bitfield peer bitfield */ int has_finished(char *bitfield) { return ((memchr(bitfield, '0', sizeof(char) * FILE_PIECES) == NULL) ? 1 : 0); } -/** - * Handle pending sends and remove those which are done - * @param peer Peer data - */ -void handle_pending_sends(peer_t peer) +int nb_interested_peers(peer_t peer) { - int index; - - while ((index = MSG_comm_testany(peer->pending_sends)) != -1) { - msg_comm_t comm_send = xbt_dynar_get_as(peer->pending_sends, index, msg_comm_t); - int status = MSG_comm_get_status(comm_send); - xbt_dynar_remove_at(peer->pending_sends, index, &comm_send); - XBT_DEBUG("Communication %p is finished with status %d, dynar size is now %lu", comm_send, status, xbt_dynar_length(peer->pending_sends)); - - msg_task_t task = MSG_comm_get_task(comm_send); - MSG_comm_destroy(comm_send); + xbt_dict_cursor_t cursor = NULL; + char *key; + connection_t connection; + int nb = 0; + xbt_dict_foreach(peer->peers, cursor, key, connection) { + if (connection->interested) + nb++; + } + return nb; +} - if (status != MSG_OK) { - task_message_free(task); +void update_active_peers_set(peer_t peer, connection_t remote_peer) +{ + if (remote_peer->interested && !remote_peer->choked_upload) { + //add in the active peers set + xbt_dict_set_ext(peer->active_peers, (char *) &remote_peer->id, sizeof(int), remote_peer, NULL); + } else { + //remove + xbt_ex_t e; + TRY { + xbt_dict_remove_ext(peer->active_peers, (char *) &remote_peer->id, sizeof(int)); + } + CATCH(e) { + xbt_ex_free(e); } } } -/** - * Handle a received message sent by another peer +/** @brief Handle a received message sent by another peer * @param peer Peer data * @param task task received. */ @@ -310,137 +296,104 @@ void handle_message(peer_t peer, msg_task_t task) { message_t message = MSG_task_get_data(task); connection_t remote_peer; - remote_peer = - xbt_dict_get_or_null_ext(peer->peers, (char *) &message->peer_id, - sizeof(int)); + remote_peer = xbt_dict_get_or_null_ext(peer->peers, (char *) &message->peer_id, sizeof(int)); switch (message->type) { - case MESSAGE_HANDSHAKE: - XBT_DEBUG("Received a HANDSHAKE from %s (%s)", message->mailbox, - message->issuer_host_name); + XBT_DEBUG("Received a HANDSHAKE from %s (%s)", message->mailbox, message->issuer_host_name); //Check if the peer is in our connection list. if (!remote_peer) { - xbt_dict_set_ext(peer->peers, (char *) &message->peer_id, sizeof(int), - connection_new(message->peer_id), NULL); + xbt_dict_set_ext(peer->peers, (char *) &message->peer_id, sizeof(int), connection_new(message->peer_id), NULL); send_handshake(peer, message->mailbox); } //Send our bitfield to the peer send_bitfield(peer, message->mailbox); break; case MESSAGE_BITFIELD: - XBT_DEBUG("Recieved a BITFIELD message from %s (%s)", message->mailbox, - message->issuer_host_name); + XBT_DEBUG("Recieved a BITFIELD message from %s (%s)", message->mailbox, message->issuer_host_name); //Update the pieces list update_pieces_count_from_bitfield(peer, message->bitfield); //Store the bitfield remote_peer->bitfield = xbt_strdup(message->bitfield); - //Update the current piece - if (peer->current_piece == -1 && peer->pieces < FILE_PIECES) { - update_current_piece(peer); + xbt_assert(!remote_peer->am_interested, "Should not be interested at first"); + if (is_interested(peer, remote_peer)) { + remote_peer->am_interested = 1; + send_interested(peer, message->mailbox); } break; case MESSAGE_INTERESTED: - XBT_DEBUG("Recieved an INTERESTED message from %s (%s)", message->mailbox, - message->issuer_host_name); - xbt_assert((remote_peer != NULL), - "A non-in-our-list peer has sent us a message. WTH ?"); + XBT_DEBUG("Recieved an INTERESTED message from %s (%s)", message->mailbox, message->issuer_host_name); + xbt_assert((remote_peer != NULL), "A non-in-our-list peer has sent us a message. WTH ?"); //Update the interested state of the peer. remote_peer->interested = 1; + update_active_peers_set(peer, remote_peer); break; case MESSAGE_NOTINTERESTED: - XBT_DEBUG("Received a NOTINTERESTED message from %s (%s)", message->mailbox, - message->issuer_host_name); - xbt_assert((remote_peer != NULL), - "A non-in-our-list peer has sent us a message. WTH ?"); + XBT_DEBUG("Received a NOTINTERESTED message from %s (%s)", message->mailbox, message->issuer_host_name); + xbt_assert((remote_peer != NULL), "A non-in-our-list peer has sent us a message. WTH ?"); remote_peer->interested = 0; + update_active_peers_set(peer, remote_peer); break; case MESSAGE_UNCHOKE: - xbt_assert((remote_peer != NULL), - "A non-in-our-list peer has sent us a message. WTH ?"); - XBT_DEBUG("Received a UNCHOKE message from %s (%s)", message->mailbox, - message->issuer_host_name); + xbt_assert((remote_peer != NULL), "A non-in-our-list peer has sent us a message. WTH ?"); + XBT_DEBUG("Received a UNCHOKE message from %s (%s)", message->mailbox, message->issuer_host_name); + xbt_assert(remote_peer->choked_download, "WTF !!!"); remote_peer->choked_download = 0; - xbt_dict_set_ext(peer->active_peers, (char *) &message->peer_id, - sizeof(int), remote_peer, NULL); //Send requests to the peer, since it has unchoked us - send_requests_to_peer(peer, remote_peer); + if (remote_peer->am_interested) + request_new_piece_to_peer(peer, remote_peer); break; case MESSAGE_CHOKE: - xbt_assert((remote_peer != NULL), - "A non-in-our-list peer has sent us a message. WTH ?"); - XBT_DEBUG("Received a CHOKE message from %s (%s)", message->mailbox, - message->issuer_host_name); + xbt_assert((remote_peer != NULL), "A non-in-our-list peer has sent us a message. WTH ?"); + XBT_DEBUG("Received a CHOKE message from %s (%s)", message->mailbox, message->issuer_host_name); + xbt_assert(!remote_peer->choked_download, "WTF !!!"); remote_peer->choked_download = 1; - xbt_ex_t e; - TRY { - xbt_dict_remove_ext(peer->active_peers, (char *) &message->peer_id, - sizeof(int)); - } - CATCH(e) { - xbt_ex_free(e); - } + remove_current_piece(peer, remote_peer, remote_peer->current_piece); break; case MESSAGE_HAVE: - XBT_DEBUG("Received a HAVE message from %s (%s) of piece %d", - message->mailbox, message->issuer_host_name, message->index); - xbt_assert((message->index >= 0 - && message->index < FILE_PIECES), - "Wrong HAVE message received"); - if (remote_peer->bitfield == NULL) - return; + XBT_DEBUG("Received a HAVE message from %s (%s) of piece %d", message->mailbox, message->issuer_host_name, + message->index); + xbt_assert(remote_peer->bitfield, "bitfield not received"); + xbt_assert((message->index >= 0 && message->index < FILE_PIECES), "Wrong HAVE message received"); remote_peer->bitfield[message->index] = '1'; peer->pieces_count[message->index]++; //If the piece is in our pieces, we tell the peer that we are interested. - if (!remote_peer->am_interested && in_current_pieces(peer, message->index)) { + if (!remote_peer->am_interested && peer->bitfield[message->index] == '0') { remote_peer->am_interested = 1; - send_interested(peer, remote_peer->mailbox); + send_interested(peer, message->mailbox); + if (!remote_peer->choked_download) + request_new_piece_to_peer(peer, remote_peer); } break; case MESSAGE_REQUEST: - xbt_assert((message->index >= 0 - && message->index < FILE_PIECES), "Wrong request received"); + xbt_assert(remote_peer->interested, "WTF !!!"); + + xbt_assert((message->index >= 0 && message->index < FILE_PIECES), "Wrong request received"); if (!remote_peer->choked_upload) { - XBT_DEBUG("Received a REQUEST from %s (%s) for %d (%d,%d)", - message->mailbox, message->issuer_host_name, message->peer_id, - message->block_index, - message->block_index + message->block_length); + XBT_DEBUG("Received a REQUEST from %s (%s) for %d (%d,%d)", message->mailbox, message->issuer_host_name, + message->index, message->block_index, message->block_index + message->block_length); if (peer->bitfield[message->index] == '1') { - send_piece(peer, message->mailbox, message->index, 0, - message->block_index, message->block_length); + send_piece(peer, message->mailbox, message->index, message->block_index, message->block_length); } } else { - XBT_DEBUG("Received a REQUEST from %s (%s) for %d but he is choked.", - message->mailbox, message->issuer_host_name, message->peer_id); + XBT_DEBUG("Received a REQUEST from %s (%s) for %d but he is choked.", message->mailbox, + message->issuer_host_name, message->peer_id); } break; case MESSAGE_PIECE: - xbt_assert((message->index >= 0 - && message->index < FILE_PIECES), "Wrong piece received"); + XBT_DEBUG("Received piece %d (%d,%d) from %s (%s)", message->index, message->block_index, + message->block_index + message->block_length, message->mailbox, message->issuer_host_name); + xbt_assert(!remote_peer->choked_download, "WTF !!!"); + xbt_assert(remote_peer->am_interested || ENABLE_END_GAME_MODE, + "Can't received a piece if I'm not interested wihtout end-game mode!" + "piece (%d) bitfield(%s) remote bitfield(%s)", message->index, peer->bitfield, remote_peer->bitfield); + xbt_assert(remote_peer->choked_download != 1, "Can't received a piece if I'm choked !"); + xbt_assert((message->index >= 0 && message->index < FILE_PIECES), "Wrong piece received"); //TODO: Execute à computation. - if (message->stalled) { - XBT_DEBUG("The received piece %d from %s (%s) is STALLED", message->index, - message->mailbox, message->issuer_host_name); - } else { - XBT_DEBUG("Received piece %d (%d,%d) from %s (%s)", message->index, - message->block_index, - message->block_index + message->block_length, message->mailbox, - message->issuer_host_name); if (peer->bitfield[message->index] == '0') { - update_bitfield_blocks(peer, message->index, message->block_index, - message->block_length); + update_bitfield_blocks(peer, message->index, message->block_index, message->block_length); if (piece_complete(peer, message->index)) { - peer->pieces_requested--; //Removing the piece from our piece list - unsigned i; - int piece_index = -1, piece; - xbt_dynar_foreach(peer->current_pieces, i, piece) { - if (piece == message->index) { - piece_index = i; - break; - } - } - xbt_assert(piece_index != -1, "Received an incorrect piece"); - xbt_dynar_remove_at(peer->current_pieces, piece_index, NULL); + remove_current_piece(peer, remote_peer, message->index); //Setting the fact that we have the piece peer->bitfield[message->index] = '1'; peer->pieces++; @@ -449,58 +402,57 @@ void handle_message(peer_t peer, msg_task_t task) send_have(peer, message->index); //sending UNINTERSTED to peers that doesn't have what we want. update_interested_after_receive(peer); + } else { // piece not completed + send_request_to_peer(peer, remote_peer, message->index); // ask for the next block } } else { XBT_DEBUG("However, we already have it"); + xbt_assert(ENABLE_END_GAME_MODE, "Should not happen because we don't use end game mode !"); + request_new_piece_to_peer(peer, remote_peer); } - } break; case MESSAGE_CANCEL: + XBT_DEBUG("The received CANCEL from %s (%s)", message->mailbox, message->issuer_host_name); break; } //Update the peer speed. if (remote_peer) { - connection_add_speed_value(remote_peer, - 1.0 / (MSG_get_clock() - - peer->begin_receive_time)); + connection_add_speed_value(remote_peer, 1.0 / (MSG_get_clock() - peer->begin_receive_time)); } peer->begin_receive_time = MSG_get_clock(); task_message_free(task); } -/** - * Wait for the node to receive interesting bitfield messages (ie: non empty) - * to be received - * @param deadline peer deadline - * @param peer peer data - */ -void wait_for_pieces(peer_t peer, double deadline) +/** Selects the appropriate piece to download and requests it to the remote_peer */ +void request_new_piece_to_peer(peer_t peer, connection_t remote_peer) { - int finished = 0; - while (MSG_get_clock() < deadline && !finished) { - if (peer->comm_received == NULL) { - peer->task_received = NULL; - peer->comm_received = MSG_task_irecv(&peer->task_received, peer->mailbox); - } - msg_error_t status = MSG_comm_wait(peer->comm_received, TIMEOUT_MESSAGE); - //free the comm already, we don't need it anymore - MSG_comm_destroy(peer->comm_received); - peer->comm_received = NULL; - if (status == MSG_OK) { - MSG_task_get_data(peer->task_received); - handle_message(peer, peer->task_received); - if (peer->current_piece != -1) { - finished = 1; - } + int piece = select_piece_to_download(peer, remote_peer); + if (piece != -1) { + xbt_dynar_push_as(peer->current_pieces, int, piece); + send_request_to_peer(peer, remote_peer, piece); + } +} + +/** remove current_piece from the list of currently downloaded pieces. */ +void remove_current_piece(peer_t peer, connection_t remote_peer, int current_piece) +{ + int piece_index = -1, piece; + unsigned int i; + xbt_dynar_foreach(peer->current_pieces, i, piece) { + if (piece == current_piece) { + piece_index = i; + break; } } + if (piece_index != -1) + xbt_dynar_remove_at(peer->current_pieces, piece_index, NULL); + remote_peer->current_piece = -1; } -/** - * Updates the list of who has a piece from a bitfield - * @param peer peer we want to update the list - * @param bitfield bitfield +/** @brief Updates the list of who has a piece from a bitfield + * @param peer peer we want to update the list + * @param bitfield bitfield */ void update_pieces_count_from_bitfield(peer_t peer, char *bitfield) { @@ -512,88 +464,143 @@ void update_pieces_count_from_bitfield(peer_t peer, char *bitfield) } } -/** - * Update the piece the peer is currently interested in. - * There is two cases (as described in "Bittorrent Architecture Protocol", Ryan Toole : - * If the peer has less than 3 pieces, he chooses a piece at random. - * If the peer has more than pieces, he downloads the pieces that are the less - * replicated +/** @brief Return the piece to be downloaded + * There are two cases (as described in "Bittorrent Architecture Protocol", Ryan Toole : + * If a piece is partially downloaded, this piece will be selected prioritarily + * If the peer has strictly less than 4 pieces, he chooses a piece at random. + * If the peer has more than pieces, he downloads the pieces that are the less replicated (rarest policy). + * If all pieces have been downloaded or requested, we select a random requested piece (endgame mode). + * @param peer: local peer + * @param remote_peer: information about the connection + * @return the piece to download if possible. -1 otherwise */ -void update_current_piece(peer_t peer) +int select_piece_to_download(peer_t peer, connection_t remote_peer) { - if (xbt_dynar_length(peer->current_pieces) >= (FILE_PIECES - peer->pieces)) { - return; + int piece = -1; + + piece = partially_downloaded_piece(peer, remote_peer); + // strict priority policy + if (piece != -1) + return piece; + + // end game mode + if (xbt_dynar_length(peer->current_pieces) >= (FILE_PIECES - peer->pieces) && is_interested(peer, remote_peer)) { + if(!ENABLE_END_GAME_MODE) + return -1; + int i; + int nb_interesting_pieces = 0; + int random_piece_index, current_index = 0; + // compute the number of interesting pieces + for (i = 0; i < FILE_PIECES; i++) { + if (peer->bitfield[i] == '0' && remote_peer->bitfield[i] == '1') { + nb_interesting_pieces++; + } + } + xbt_assert(nb_interesting_pieces != 0, "WTF !!!"); + // get a random interesting piece + random_piece_index = RngStream_RandInt(peer->stream, 0, nb_interesting_pieces - 1); + for (i = 0; i < FILE_PIECES; i++) { + if (peer->bitfield[i] == '0' && remote_peer->bitfield[i] == '1') { + if (random_piece_index == current_index) { + piece = i; + break; + } + current_index++; + } + } + xbt_assert(piece != -1, "WTF !!!"); + return piece; } - if (1 || peer->pieces < 3) { - int i = 0; - do { - peer->current_piece = - RngStream_RandInt(peer->stream, 0, FILE_PIECES - 1);; - i++; - } while (! - (peer->bitfield[peer->current_piece] == '0' - && !in_current_pieces(peer, peer->current_piece))); - } else { - //Trivial min algorithm. - int i, min_id = -1; - short min = -1; + // Random first policy + if (peer->pieces < 4 && is_interested_and_free(peer, remote_peer)) { + int i; + int nb_interesting_pieces = 0; + int random_piece_index, current_index = 0; + // compute the number of interesting pieces for (i = 0; i < FILE_PIECES; i++) { - if (peer->bitfield[i] == '0') { - min = peer->pieces_count[i]; - min_id = i; - break; + if (peer->bitfield[i] == '0' && remote_peer->bitfield[i] == '1' && !in_current_pieces(peer, i)) { + nb_interesting_pieces++; } } - xbt_assert((min > -1), "Couldn't find a minimum"); - for (i = 1; i < FILE_PIECES; i++) { - if (peer->pieces_count[i] < min && peer->bitfield[i] == '0') { + xbt_assert(nb_interesting_pieces != 0, "WTF !!!"); + // get a random interesting piece + random_piece_index = RngStream_RandInt(peer->stream, 0, nb_interesting_pieces - 1); + for (i = 0; i < FILE_PIECES; i++) { + if (peer->bitfield[i] == '0' && remote_peer->bitfield[i] == '1' && !in_current_pieces(peer, i)) { + if (random_piece_index == current_index) { + piece = i; + break; + } + current_index++; + } + } + xbt_assert(piece != -1, "WTF !!!"); + return piece; + } else { // Rarest first policy + int i; + short min = SHRT_MAX; + int nb_min_pieces = 0; + int random_rarest_index, current_index = 0; + // compute the smallest number of copies of available pieces + for (i = 0; i < FILE_PIECES; i++) { + if (peer->pieces_count[i] < min && peer->bitfield[i] == '0' && remote_peer->bitfield[i] == '1' + && !in_current_pieces(peer, i)) min = peer->pieces_count[i]; - min_id = i; + } + xbt_assert(min != SHRT_MAX || !is_interested_and_free(peer, remote_peer), "WTF !!!"); + // compute the number of rarest pieces + for (i = 0; i < FILE_PIECES; i++) { + if (peer->pieces_count[i] == min && peer->bitfield[i] == '0' && remote_peer->bitfield[i] == '1' + && !in_current_pieces(peer, i)) + nb_min_pieces++; + } + xbt_assert(nb_min_pieces != 0 || !is_interested_and_free(peer, remote_peer), "WTF !!!"); + // get a random rarest piece + random_rarest_index = RngStream_RandInt(peer->stream, 0, nb_min_pieces - 1); + for (i = 0; i < FILE_PIECES; i++) { + if (peer->pieces_count[i] == min && peer->bitfield[i] == '0' && remote_peer->bitfield[i] == '1' + && !in_current_pieces(peer, i)) { + if (random_rarest_index == current_index) { + piece = i; + break; + } + current_index++; } } - peer->current_piece = min_id; + xbt_assert(piece != -1 || !is_interested_and_free(peer, remote_peer), "WTF !!!"); + return piece; } - xbt_dynar_push_as(peer->current_pieces, int, peer->current_piece); - XBT_DEBUG("New interested piece: %d", peer->current_piece); - xbt_assert((peer->current_piece >= 0 && peer->current_piece < FILE_PIECES), - "Peer want to retrieve a piece that doesn't exist."); } -/** - * Update the list of current choked and unchoked peers, using the - * choke algorithm - * @param peer the current peer +/** @brief Update the list of current choked and unchoked peers, using the choke algorithm + * @param peer the current peer */ void update_choked_peers(peer_t peer) { + if (nb_interested_peers(peer) == 0) + return; + XBT_DEBUG("(%d) update_choked peers %d active peers", peer->id, xbt_dict_size(peer->active_peers)); //update the current round peer->round = (peer->round + 1) % 3; - char *key; + char *key, *key_choked=NULL; connection_t peer_choosed = NULL; + connection_t peer_choked = NULL; //remove a peer from the list xbt_dict_cursor_t cursor = NULL; xbt_dict_cursor_first(peer->active_peers, &cursor); if (xbt_dict_length(peer->active_peers) > 0) { - key = xbt_dict_cursor_get_key(cursor); - connection_t peer_choked = xbt_dict_cursor_get_data(cursor); - if (peer_choked) { - send_choked(peer, peer_choked->mailbox); - peer_choked->choked_upload = 1; - } - xbt_dict_remove_ext(peer->active_peers, key, sizeof(int)); + key_choked = xbt_dict_cursor_get_key(cursor); + peer_choked = xbt_dict_cursor_get_data(cursor); } xbt_dict_cursor_free(&cursor); - /** - * If we are currently seeding, we unchoke the peer which has - * been unchoke the least time. - */ + /**If we are currently seeding, we unchoke the peer which has been unchoked the last time.*/ if (peer->pieces == FILE_PIECES) { connection_t connection; double unchoke_time = MSG_get_clock() + 1; xbt_dict_foreach(peer->peers, cursor, key, connection) { - if (connection->last_unchoke < unchoke_time && connection->interested) { + if (connection->last_unchoke < unchoke_time && connection->interested && connection->choked_upload) { unchoke_time = connection->last_unchoke; peer_choosed = connection; } @@ -604,9 +611,7 @@ void update_choked_peers(peer_t peer) int j = 0; do { //We choose a random peer to unchoke. - int id_chosen = - RngStream_RandInt(peer->stream, 0, - xbt_dict_length(peer->peers) - 1); + int id_chosen = RngStream_RandInt(peer->stream, 0, xbt_dict_length(peer->peers) - 1); int i = 0; connection_t connection; xbt_dict_foreach(peer->peers, cursor, key, connection) { @@ -617,7 +622,7 @@ void update_choked_peers(peer_t peer) i++; } xbt_dict_cursor_free(&cursor); - if (peer_choosed->interested == 0) { + if (!peer_choosed->interested || !peer_choosed->choked_upload) { peer_choosed = NULL; } j++; @@ -627,49 +632,61 @@ void update_choked_peers(peer_t peer) connection_t connection; double fastest_speed = 0.0; xbt_dict_foreach(peer->peers, cursor, key, connection) { - if (connection->peer_speed > fastest_speed && connection->choked_upload - && connection->interested) { + if (connection->peer_speed > fastest_speed && connection->choked_upload && connection->interested) { peer_choosed = connection; fastest_speed = connection->peer_speed; } } } - - } - if (peer_choosed != NULL) { - peer_choosed->choked_upload = 0; - xbt_dict_set_ext(peer->active_peers, (char *) &peer_choosed->id, - sizeof(int), peer_choosed, NULL); - peer_choosed->last_unchoke = MSG_get_clock(); - send_unchoked(peer, peer_choosed->mailbox); } + if (peer_choosed != NULL) + XBT_DEBUG("(%d) update_choked peers unchoked (%d) ; int (%d) ; choked (%d) ", + peer->id, peer_choosed->id, peer_choosed->interested, peer_choosed->choked_upload); + + if (peer_choked != peer_choosed) { + if (peer_choked != NULL) { + xbt_assert((!peer_choked->choked_upload), "Tries to choked a choked peer"); + peer_choked->choked_upload = 1; + xbt_assert((*((int *) key_choked) == peer_choked->id), "WTF !!!"); + update_active_peers_set(peer, peer_choked); + XBT_DEBUG("(%d) Sending a CHOKE to %d", peer->id, peer_choked->id); + send_choked(peer, peer_choked->mailbox); + } + if (peer_choosed != NULL) { + xbt_assert((peer_choosed->choked_upload), "Tries to unchoked an unchoked peer"); + peer_choosed->choked_upload = 0; + xbt_dict_set_ext(peer->active_peers, (char *) &peer_choosed->id, sizeof(int), peer_choosed, NULL); + peer_choosed->last_unchoke = MSG_get_clock(); + XBT_DEBUG("(%d) Sending a UNCHOKE to %d", peer->id, peer_choosed->id); + update_active_peers_set(peer, peer_choosed); + send_unchoked(peer, peer_choosed->mailbox); + } + } } -/** - * Updates our "interested" state about peers: send "not interested" to peers - * that don't have any more pieces we want. - * @param peer our peer data +/** @brief Update "interested" state of peers: send "not interested" to peers that don't have any more pieces we want. + * @param peer our peer data */ void update_interested_after_receive(peer_t peer) { char *key; xbt_dict_cursor_t cursor; connection_t connection; - unsigned cpt; - int interested, piece; + int interested; xbt_dict_foreach(peer->peers, cursor, key, connection) { interested = 0; if (connection->am_interested) { + xbt_assert(connection->bitfield, "Bitfield not received"); //Check if the peer still has a piece we want. - xbt_dynar_foreach(peer->current_pieces, cpt, piece) { - xbt_assert((piece >= 0), "Wrong piece."); - if (connection->bitfield && connection->bitfield[piece] == '1') { + int i; + for (i = 0; i < FILE_PIECES; i++) { + if (connection->bitfield[i] == '1' && peer->bitfield[i] == '0') { interested = 1; break; } } - if (!interested) { + if (!interested) { //no more piece to download from connection connection->am_interested = 0; send_notinterested(peer, connection->mailbox); } @@ -677,22 +694,17 @@ void update_interested_after_receive(peer_t peer) } } -void update_bitfield_blocks(peer_t peer, int index, int block_index, - int block_length) +void update_bitfield_blocks(peer_t peer, int index, int block_index, int block_length) { int i; xbt_assert((index >= 0 && index <= FILE_PIECES), "Wrong piece."); - xbt_assert((block_index >= 0 - && block_index <= PIECES_BLOCKS), "Wrong block : %d.", - block_index); + xbt_assert((block_index >= 0 && block_index <= PIECES_BLOCKS), "Wrong block : %d.", block_index); for (i = block_index; i < (block_index + block_length); i++) { peer->bitfield_blocks[index * PIECES_BLOCKS + i] = '1'; } } -/** - * Returns if a peer has completed the download of a piece - */ +/** Returns if a peer has completed the download of a piece */ int piece_complete(peer_t peer, int index) { int i; @@ -704,9 +716,7 @@ int piece_complete(peer_t peer, int index) return 1; } -/** - * Returns the first block that a peer doesn't have in a piece - */ +/** Returns the first block that a peer doesn't have in a piece. If the peer has all blocks of the piece, returns -1. */ int get_first_block(peer_t peer, int piece) { int i; @@ -718,88 +728,111 @@ int get_first_block(peer_t peer, int piece) return -1; } -/** - * Send request messages to a peer that have unchoked us - * @param peer peer - * @param remote_peer peer data to the peer we want to send the request - */ -void send_requests_to_peer(peer_t peer, connection_t remote_peer) +/** Indicates if the remote peer has a piece not stored by the local peer */ +int is_interested(peer_t peer, connection_t remote_peer) { - unsigned i; - int piece, block_index, block_length; - xbt_dynar_foreach(peer->current_pieces, i, piece) { - if (remote_peer->bitfield && remote_peer->bitfield[piece] == '1') { - block_index = get_first_block(peer, piece); - if (block_index != -1) { - block_length = PIECES_BLOCKS - block_index; - block_length = min(BLOCKS_REQUESTED, block_length); - send_request(peer, remote_peer->mailbox, piece, block_index, - block_length); - break; - } + xbt_assert(remote_peer->bitfield, "Bitfield not received"); + int i; + for (i = 0; i < FILE_PIECES; i++) { + if (remote_peer->bitfield[i] == '1' && peer->bitfield[i] == '0') { + return 1; } } + return 0; } -/** - * Find the peers that have the current interested piece and send them - * the "interested" message +/** Indicates if the remote peer has a piece not stored by the local peer nor requested by the local peer */ +int is_interested_and_free(peer_t peer, connection_t remote_peer) +{ + xbt_assert(remote_peer->bitfield, "Bitfield not received"); + int i; + for (i = 0; i < FILE_PIECES; i++) { + if (remote_peer->bitfield[i] == '1' && peer->bitfield[i] == '0' && !in_current_pieces(peer, i)) { + return 1; + } + } + return 0; +} + +/** Returns a piece that is partially downloaded and stored by the remote peer if any -1 otherwise. */ +int partially_downloaded_piece(peer_t peer, connection_t remote_peer) +{ + xbt_assert(remote_peer->bitfield, "Bitfield not received"); + int i; + for (i = 0; i < FILE_PIECES; i++) { + if (remote_peer->bitfield[i] == '1' && peer->bitfield[i] == '0' && !in_current_pieces(peer, i)) { + if (get_first_block(peer, i) > 0) + return i; + } + } + return -1; +} + +/** @brief Send request messages to a peer that have unchoked us + * @param peer peer + * @param remote_peer peer data to the peer we want to send the request */ -void send_interested_to_peers(peer_t peer) +void send_request_to_peer(peer_t peer, connection_t remote_peer, int piece) { - char *key; - xbt_dict_cursor_t cursor = NULL; - connection_t connection; - xbt_assert((peer->current_piece != -1), - "Tried to send a interested message wheras the current_piece is -1"); - xbt_dict_foreach(peer->peers, cursor, key, connection) { - if (connection->bitfield - && connection->bitfield[peer->current_piece] == '1') { - connection->am_interested = 1; - msg_task_t task = - task_message_new(MESSAGE_INTERESTED, peer->hostname, peer->mailbox, - peer->id, task_message_size(MESSAGE_INTERESTED)); - MSG_task_dsend(task, connection->mailbox, task_message_free); - XBT_DEBUG("Send INTERESTED to %s", connection->mailbox); + remote_peer->current_piece = piece; + int block_index, block_length; + xbt_assert(remote_peer->bitfield, "bitfield not received"); + xbt_assert(remote_peer->bitfield[piece] == '1', "WTF !!!"); + block_index = get_first_block(peer, piece); + if (block_index != -1) { + block_length = PIECES_BLOCKS - block_index; + block_length = MIN(BLOCKS_REQUESTED, block_length); + send_request(peer, remote_peer->mailbox, piece, block_index, block_length); + } +} + +/** Indicates if a piece is currently being downloaded by the peer. */ +int in_current_pieces(peer_t peer, int piece) +{ + unsigned i; + int peer_piece; + xbt_dynar_foreach(peer->current_pieces, i, peer_piece) { + if (peer_piece == piece) { + return 1; } } - peer->current_piece = -1; - peer->pieces_requested++; + return 0; } -/** - * Send a "interested" message to a peer - * @param peer peer data - * @param mailbox destination mailbox +/*********************************************************** + * + * Low level message functions + * + ***********************************************************/ + + + +/** @brief Send a "interested" message to a peer + * @param peer peer data + * @param mailbox destination mailbox */ void send_interested(peer_t peer, const char *mailbox) { - msg_task_t task = - task_message_new(MESSAGE_INTERESTED, peer->hostname, peer->mailbox, - peer->id, task_message_size(MESSAGE_INTERESTED)); + msg_task_t task = task_message_new(MESSAGE_INTERESTED, peer->hostname, peer->mailbox, peer->id, + task_message_size(MESSAGE_INTERESTED)); MSG_task_dsend(task, mailbox, task_message_free); XBT_DEBUG("Sending INTERESTED to %s", mailbox); - } -/** - * Send a "not interested" message to a peer - * @param peer peer data - * @param mailbox destination mailbox +/** @brief Send a "not interested" message to a peer + * @param peer peer data + * @param mailbox destination mailbox */ void send_notinterested(peer_t peer, const char *mailbox) { - msg_task_t task = - task_message_new(MESSAGE_NOTINTERESTED, peer->hostname, peer->mailbox, - peer->id, task_message_size(MESSAGE_NOTINTERESTED)); + msg_task_t task = task_message_new(MESSAGE_NOTINTERESTED, peer->hostname, peer->mailbox, peer->id, + task_message_size(MESSAGE_NOTINTERESTED)); MSG_task_dsend(task, mailbox, task_message_free); XBT_DEBUG("Sending NOTINTERESTED to %s", mailbox); - } -/** - * Send a handshake message to all the peers the peer has. - * @param peer peer data +/** @brief Send a handshake message to all the peers the peer has. + * @param peer peer data */ void send_handshake_all(peer_t peer) { @@ -807,55 +840,44 @@ void send_handshake_all(peer_t peer) xbt_dict_cursor_t cursor = NULL; char *key; xbt_dict_foreach(peer->peers, cursor, key, remote_peer) { - msg_task_t task = - task_message_new(MESSAGE_HANDSHAKE, peer->hostname, peer->mailbox, - peer->id, task_message_size(MESSAGE_HANDSHAKE)); + msg_task_t task = task_message_new(MESSAGE_HANDSHAKE, peer->hostname, peer->mailbox, peer->id, + task_message_size(MESSAGE_HANDSHAKE)); MSG_task_dsend(task, remote_peer->mailbox, task_message_free); XBT_DEBUG("Sending a HANDSHAKE to %s", remote_peer->mailbox); } } -/** - * Send a "handshake" message to an user - * @param peer peer data - * @param mailbox mailbox where to we send the message +/** @brief Send a "handshake" message to an user + * @param peer peer data + * @param mailbox mailbox where to we send the message */ void send_handshake(peer_t peer, const char *mailbox) { - msg_task_t task = - task_message_new(MESSAGE_HANDSHAKE, peer->hostname, peer->mailbox, - peer->id, task_message_size(MESSAGE_HANDSHAKE)); + msg_task_t task = task_message_new(MESSAGE_HANDSHAKE, peer->hostname, peer->mailbox, peer->id, + task_message_size(MESSAGE_HANDSHAKE)); MSG_task_dsend(task, mailbox, task_message_free); XBT_DEBUG("Sending a HANDSHAKE to %s", mailbox); } -/** - * Send a "choked" message to a peer. - */ +/** Send a "choked" message to a peer. */ void send_choked(peer_t peer, const char *mailbox) { XBT_DEBUG("Sending a CHOKE to %s", mailbox); - msg_task_t task = - task_message_new(MESSAGE_CHOKE, peer->hostname, peer->mailbox, - peer->id, task_message_size(MESSAGE_CHOKE)); + msg_task_t task = task_message_new(MESSAGE_CHOKE, peer->hostname, peer->mailbox, peer->id, + task_message_size(MESSAGE_CHOKE)); MSG_task_dsend(task, mailbox, task_message_free); } -/** - * Send a "unchoked" message to a peer - */ +/** Send a "unchoked" message to a peer */ void send_unchoked(peer_t peer, const char *mailbox) { XBT_DEBUG("Sending a UNCHOKE to %s", mailbox); - msg_task_t task = - task_message_new(MESSAGE_UNCHOKE, peer->hostname, peer->mailbox, - peer->id, task_message_size(MESSAGE_UNCHOKE)); + msg_task_t task = task_message_new(MESSAGE_UNCHOKE, peer->hostname, peer->mailbox, peer->id, + task_message_size(MESSAGE_UNCHOKE)); MSG_task_dsend(task, mailbox, task_message_free); } -/** - * Send a "HAVE" message to all peers we are connected to - */ +/** Send a "HAVE" message to all peers we are connected to */ void send_have(peer_t peer, int piece) { XBT_DEBUG("Sending HAVE message to all my peers"); @@ -863,68 +885,37 @@ void send_have(peer_t peer, int piece) xbt_dict_cursor_t cursor = NULL; char *key; xbt_dict_foreach(peer->peers, cursor, key, remote_peer) { - msg_task_t task = - task_message_index_new(MESSAGE_HAVE, peer->hostname, peer->mailbox, - peer->id, piece, task_message_size(MESSAGE_HAVE)); + msg_task_t task = task_message_index_new(MESSAGE_HAVE, peer->hostname, peer->mailbox, peer->id, piece, + task_message_size(MESSAGE_HAVE)); MSG_task_dsend(task, remote_peer->mailbox, task_message_free); } } -/** - * Send a bitfield message to all the peers the peer has. - * @param peer peer data +/** @brief Send a bitfield message to all the peers the peer has. + * @param peer peer data */ void send_bitfield(peer_t peer, const char *mailbox) { XBT_DEBUG("Sending a BITFIELD to %s", mailbox); - msg_task_t task = - task_message_bitfield_new(peer->hostname, peer->mailbox, peer->id, - peer->bitfield, FILE_PIECES); - //Async send and append to pending sends - msg_comm_t comm = MSG_task_isend(task, mailbox); - xbt_dynar_push(peer->pending_sends, &comm); -} - -/** - * Send a "request" message to a pair, containing a request for a piece - */ -void send_request(peer_t peer, const char *mailbox, int piece, int block_index, - int block_length) -{ - XBT_DEBUG("Sending a REQUEST to %s for piece %d (%d,%d)", mailbox, piece, - block_index, block_length); - msg_task_t task = - task_message_request_new(peer->hostname, peer->mailbox, peer->id, piece, - block_index, block_length); + msg_task_t task = task_message_bitfield_new(peer->hostname, peer->mailbox, peer->id, peer->bitfield, FILE_PIECES); MSG_task_dsend(task, mailbox, task_message_free); } -/** - * Send a "piece" message to a pair, containing a piece of the file - */ -void send_piece(peer_t peer, const char *mailbox, int piece, int stalled, - int block_index, int block_length) +/** Send a "request" message to a pair, containing a request for a piece */ +void send_request(peer_t peer, const char *mailbox, int piece, int block_index, int block_length) { - XBT_DEBUG("Sending the PIECE %d (%d,%d) to %s", piece, block_index, - block_length, mailbox); - xbt_assert(piece >= 0, "Tried to send a piece that doesn't exist."); - xbt_assert((peer->bitfield[piece] == '1'), - "Tried to send a piece that we doesn't have."); - msg_task_t task = - task_message_piece_new(peer->hostname, peer->mailbox, peer->id, piece, - stalled, block_index, block_length, BLOCK_SIZE); + XBT_DEBUG("Sending a REQUEST to %s for piece %d (%d,%d)", mailbox, piece, block_index, block_length); + msg_task_t task = task_message_request_new(peer->hostname, peer->mailbox, peer->id, piece, block_index, block_length); MSG_task_dsend(task, mailbox, task_message_free); } -int in_current_pieces(peer_t peer, int piece) +/** Send a "piece" message to a pair, containing a piece of the file */ +void send_piece(peer_t peer, const char *mailbox, int piece, int block_index, int block_length) { - unsigned i; - int is_in = 0, peer_piece; - xbt_dynar_foreach(peer->current_pieces, i, peer_piece) { - if (peer_piece == piece) { - is_in = 1; - break; - } - } - return is_in; + XBT_DEBUG("Sending the PIECE %d (%d,%d) to %s", piece, block_index, block_length, mailbox); + xbt_assert(piece >= 0, "Tried to send a piece that doesn't exist."); + xbt_assert((peer->bitfield[piece] == '1'), "Tried to send a piece that we doesn't have."); + msg_task_t task = task_message_piece_new(peer->hostname, peer->mailbox, peer->id, piece, block_index, block_length, + BLOCK_SIZE); + MSG_task_dsend(task, mailbox, task_message_free); }