typedef struct _ENetPacket
{size_t                               referenceCount;  enet_uint32                     flags;           enet_uint8 *                    data;            size_t                               dataLength;      ENetPacketFreeCallback  freeCallback;
} ENetPacket;

ENetPacketFreeCallback  freeCallback;

static int
enet_protocol_check_timeouts (ENetHost * host, ENetPeer * peer, ENetEvent * event)
{ENetOutgoingCommand * outgoingCommand;ENetListIterator currentCommand, insertPosition;currentCommand = enet_list_begin (& peer -> sentReliableCommands);insertPosition = enet_list_begin (& peer -> outgoingReliableCommands);while (currentCommand != enet_list_end (& peer -> sentReliableCommands)){outgoingCommand = (ENetOutgoingCommand *) currentCommand;currentCommand = enet_list_next (currentCommand);if (ENET_TIME_DIFFERENCE (host -> serviceTime, outgoingCommand -> sentTime) < outgoingCommand -> roundTripTimeout)continue;if (peer -> earliestTimeout == 0 ||ENET_TIME_LESS (outgoingCommand -> sentTime, peer -> earliestTimeout))peer -> earliestTimeout = outgoingCommand -> sentTime;if (peer -> earliestTimeout != 0 &&(ENET_TIME_DIFFERENCE (host -> serviceTime, peer -> earliestTimeout) >= ENET_PEER_TIMEOUT_MAXIMUM ||(outgoingCommand -> roundTripTimeout >= outgoingCommand -> roundTripTimeoutLimit &&ENET_TIME_DIFFERENCE (host -> serviceTime, peer -> earliestTimeout) >= ENET_PEER_TIMEOUT_MINIMUM))){enet_protocol_notify_disconnect (host, peer, event);return 1;}if (outgoingCommand -> packet != NULL)peer -> reliableDataInTransit -= outgoingCommand -> fragmentLength;++ peer -> packetsLost;outgoingCommand -> roundTripTimeout *= 2;enet_list_insert (insertPosition, enet_list_remove (& outgoingCommand -> outgoingCommandList));if (currentCommand == enet_list_begin (& peer -> sentReliableCommands) &&! enet_list_empty (& peer -> sentReliableCommands)){outgoingCommand = (ENetOutgoingCommand *) currentCommand;peer -> nextTimeout = outgoingCommand -> sentTime + outgoingCommand -> roundTripTimeout;}}return 0;
}

outgoingCommand -> roundTripTimeout *= 2;

./configure --prefix=安装路径
make
make install

$ gcc -o ENetDemo ENetDemo.c -I /usr/local/enetlib1.3.0/include/ -L /usr/local/enetlib1.3.0/lib/ -lenet

/*** @file ENetDemo.c* @brief A demo of ENet. Clinet just sends one file. And server just handles one file.* @author allen* @date 2010-12-9* @other For convenient I used many global variables. And I know it's not good.*/#define _LARGE_FILES
#undef  _FILE_OFFSET_BITS
#define _FILE_OFFSET_BITS   64
#include <enet/enet.h>
#include <stdio.h>
#include<string.h>
#include<stdlib.h>char * file_name;
int packet_size;
int per_wait_time;
int my_flag = 1;
/*** @brief this is a callback function. I want to use it check whether the packet was sent.*/
ENetPacketFreeCallback packetCallback(ENetPacket * pac) {my_flag = 0;
};
/*** @brief the enetServer main funtion* @param port the port enet server bind to.*/
void enetServer(int port) {ENetAddress address;ENetHost * server;/* Bind the server to the default localhost.     *//* A specific host address can be specified by   *//* enet_address_set_host (& address, "x.x.x.x"); */address.host = ENET_HOST_ANY;/* Bind the server to port 1234. */address.port = port;
#if ENET_VERSION ==  ENET_VERSION_CREATE(1,2,2)server = enet_host_create(& address /* the address to bind the server host to */,32 /* allow up to 32 clients and/or outgoing connections */,0 /* assume any amount of incoming bandwidth */,0 /* assume any amount of outgoing bandwidth */);
#elif ENET_VERSION ==  ENET_VERSION_CREATE(1,3,0)server = enet_host_create(&address/* the address to bind the server host to */,32 /* allow up to 32 clients and/or outgoing connections*/,2 /*allow up to 2 channels to be used, 0 and 1 */,0 /*assume any amount of incoming bandwidth*/,0 /* assume any amount of outgoing bandwidth */);
#endifif (server == NULL) {fprintf(stderr,"An error occurred while trying to create an ENet server host.\n");exit(EXIT_FAILURE);}ENetEvent event;char * filename = file_name;FILE *fp;puts(file_name);unsigned int sumsize = 0;/* Wait up to 5000 milliseconds for an event. */while (enet_host_service(server, & event, 5000) >= 0) {/*  printf("Type %d\n", event.type);*/switch (event.type) {case ENET_EVENT_TYPE_CONNECT:printf("A new client connected from %x:%u.\n",event.peer -> address.host,event.peer -> address.port);/* Store any relevant client information here. *//*  event.peer -> data = "Client information";*/static unsigned int num = 0;ENetAddress remote = event.peer->address; /*remote address*/char ip[256];static char peerInfo[256];enet_address_get_host_ip(&remote, ip, 256);num++;printf("ip:%s has connected. No.%u\n", ip, num);sprintf(peerInfo, "ip:%s No.%u connection.", ip, num);event.peer->data = (void*) peerInfo;break;case ENET_EVENT_TYPE_RECEIVE:printf("%s\n", (char*) (event.peer->data));if ((fp = fopen(filename, "ab")) == NULL) {fprintf(stderr, "enetServer: file open error");enet_packet_destroy(event.packet);enet_host_destroy(server);return;}size_t writeBytes = fwrite(event.packet -> data, sizeof (char), event.packet -> dataLength, fp);if (writeBytes != event.packet -> dataLength) {fprintf(stderr, "enetServer: write to file error");}sumsize += writeBytes;printf("%d\n", writeBytes);fclose(fp);/* Clean up the packet now that we're done using it. */enet_packet_destroy(event.packet);break;case ENET_EVENT_TYPE_DISCONNECT:printf("%s disconected.\n", (char*) (event.peer -> data));/* Reset the peer's client information. */event.peer -> data = NULL;printf("get%d\n", sumsize);enet_host_destroy(server);return;}}enet_host_destroy(server);
}/*** @brief this function used to send one file by enet.* @param fileName the filename* @param client the enethost* @param peer the target peer to send* @return 0 means success. 1 means failure.*/int sendFile(char * fileName, ENetHost * client, ENetPeer *peer) {const int failureCode = 1;const int successCode = 0;ENetEvent event;char * datas;int dataSize = packet_size;unsigned int sum = 0;FILE *fp;if ((fp = fopen(fileName, "rb")) == NULL) {fprintf(stderr, "sendFile: file read error");return failureCode;}datas = (char*) malloc(dataSize);if (datas == NULL) {fprintf(stderr, "sendFile: memory malloc error");fclose(fp);return failureCode;}size_t readBytes = 0;ENetPacket *packet;while (!feof(fp)) {readBytes = fread(datas, sizeof (char), dataSize, fp);packet = enet_packet_create(datas, readBytes, ENET_PACKET_FLAG_RELIABLE); /*create reliable packet*/if (packet == NULL) {fprintf(stderr, "sendFile:: packet error");fclose(fp);free(datas);return failureCode;}printf("sendFile: packet:%d\n", packet -> dataLength);int errorcode = 0;packet->freeCallback = (ENetPacketFreeCallback) packetCallback;if ((errorcode = enet_peer_send(peer, 0, packet)) != 0) {fprintf(stderr, "sendFile: enet_peer_send errorcode %d\n", errorcode);fclose(fp);free(datas);fprintf(stderr, "sendFile: sumsize%u\n", sum);return failureCode;}printf("sendFile: enet_peer_send errorcode %d\n", errorcode);do {errorcode = enet_host_service(client, &event, per_wait_time);if (errorcode > 0) {fprintf(stderr, "enetClient: eventtype:%d\n", event.type);}} while (my_flag != 0);my_flag = 1;printf(" service errorcode %d\n", errorcode);sum += readBytes;printf("sumSize%u\n", sum);}fclose(fp);free(datas);printf("total file sumsize%d\n", sum);return successCode;
}
/*** @brief the enetClient main funtion* @param hostname target IP or hostname* @param port target port*/
void enetClient(char * hostname, int port) {ENetHost * client;
#if ENET_VERSION ==  ENET_VERSION_CREATE(1,2,2)client = enet_host_create(NULL /* create a client host */,1 /* only allow 1 outgoing connection */,57600 / 8 /* 56K modem with 56 Kbps downstream bandwidth */,14400 / 8 /* 56K modem with 14 Kbps upstream bandwidth */);
#elif ENET_VERSION ==  ENET_VERSION_CREATE(1,3,0)client = enet_host_create(NULL /* create a client host */,1 /*only allow 1 outgoing connection */,2 /*allow up to 2 channels to be used, 0 and 1  */,57600 / 8 /*56K modem with 56 Kbps downstream bandwidth */,14400 / 8 /* 56K modem with 14 Kbps upstream bandwidth */);
#endifif (client == NULL) {fprintf(stderr,"enetClient: An error occurred while trying to create an ENet client host.\n");/*exit(EXIT_FAILURE);*/return;}ENetAddress address;ENetEvent event;ENetPeer *peer;/* Connect to host. */enet_address_set_host(& address, hostname);address.port = port;#if ENET_VERSION ==  ENET_VERSION_CREATE(1,2,2)/* Initiate the connection, allocating the two channels 0 and 1. */peer = enet_host_connect(client, & address, 2);
#elif ENET_VERSION ==  ENET_VERSION_CREATE(1,3,0)/* Initiate the connection, allocating the two channels 0 and 1. */peer = enet_host_connect(client, & address, 2, 0);
#endifif (peer == NULL) {fprintf(stderr,"enetClient: No available peers for initiating an ENet connection.\n");/*exit(EXIT_FAILURE);*/return;}/* Wait up to 10 seconds for the connection attempt to succeed. */if (enet_host_service(client, &event, 10000) > 0 &&event.type == ENET_EVENT_TYPE_CONNECT) {printf("enetClient: Connection %s:%d succeeded.", hostname, port);/*send a file*/int errCode = sendFile(file_name, client, peer);if (errCode != 0) {puts("send error\n");}/*send file end*/} else {/* Either the 10 seconds are up or a disconnect event was *//* received. Reset the peer in the event the 5 seconds   *//* had run out without any significant event.            */enet_peer_reset(peer);printf("enetClient: Connection %s:%d failed.", hostname, port);}enet_peer_disconnect(peer, 0);/* Allow up to 3 seconds for the disconnect to succeed and drop any packets received packets. */while (enet_host_service(client, & event, 3000) > 0) {switch (event.type) {case ENET_EVENT_TYPE_RECEIVE:enet_packet_destroy(event.packet);break;case ENET_EVENT_TYPE_DISCONNECT:puts("Disconnection succeeded.");enet_host_destroy(client);return;}}/* We've arrived here, so the disconnect attempt didn't *//* succeed yet.  Force the connection down.             */enet_peer_reset(peer);puts("Disconnection force succeeded.");enet_host_destroy(client);
}
/*** @brief as server : ENetDemo s port filename*                    port means the port server to bind.*                    filename is the file server recieved save as.*        as client : ENetDemo c IP port filename packetsize perwaittime(ms)*                    IP is the target server IP(hostname)*                    port the target server listened.*                    filename the file client send*                    packetsize the client send per time.*                    perwaittime (please see the enet_host_service() )*/
int main(int argc, char ** argv) {
#if ENET_VERSION ==  ENET_VERSION_CREATE(1,2,2)/* Initiate the connection, allocating the two channels 0 and 1. */printf("Enet Version 1.2.2\n");
#elif ENET_VERSION ==  ENET_VERSION_CREATE(1,3,0)/* Initiate the connection, allocating the two channels 0 and 1. */printf("Enet Version 1.3.0\n");
#endifif (argc < 4) {fprintf(stderr, "Wrong Format. ENetDemo [c IP port filename packetsize perwaittime(ms)] [ s port filename] \n");return EXIT_FAILURE;}int err = 0;if ((err = enet_initialize()) != 0) {fprintf(stderr, "An error occurred while initializing ENet %d.\n", err);return EXIT_FAILURE;}atexit(enet_deinitialize);if (strcmp(argv[1], "s") == 0) {puts("SERVER");file_name = argv[3];puts(file_name);enetServer(atoi(argv[2]));}if (strcmp(argv[1], "c") == 0) {puts("CLIENT");if (argc < 7) {fprintf(stderr, "Wrong Format. ENetDemo [c IP port filename packetsize perwaittime(ms)] [ s port filename] \n");return EXIT_FAILURE;}file_name = argv[4];printf("send file %s\n", file_name);packet_size = atoi(argv[5]);per_wait_time = atoi(argv[6]);enetClient(argv[2], atoi(argv[3]));}int endPause;puts("enter any key to end\n");scanf("%d", &endPause);return 0;}