cocos2d-x 基于BSD Socket网络通讯模块

1. 预备知识: 线程,互斥锁,信号量: // 创建一个线程 int pthread_create(pthread_t *restrict tidp, const pthread_attr_t *restrict attr, void *(*start_rtn)( void ), void *restrict arg); // 初始化互斥量 int pthread_mutex_init(pthread_mutex_t *mut

1. 预备知识:

线程,互斥锁,信号量: 

 <span>//</span><span>创建一个线程 </span>
 <span>int</span> pthread_create(pthread_t *restrict tidp, <span>const</span> pthread_attr_t *restrict attr, <span>void</span> *(*start_rtn)(<span>void</span>), <span>void</span> *restrict arg);
<span>//</span><span>初始化互斥量</span>
 <span>int</span> pthread_mutex_init(pthread_mutex_t *mutex, <span>const</span> pthread_mutex-attr_t *mutexattr);
<span>//</span><span>给互斥量上锁</span>
<span>int</span> pthread_mutex_lock(pthread_mutex_t *mutex);
<span>//</span><span>给互斥量解锁</span>
<span>int</span> pthread_mutex_unlock(pthread_mutex_t *mutex);
<span>//</span><span>信号量初始化</span>
<span>int</span> sem_init(sem_t *sem, <span>int</span> pshared, unsigned <span>int</span> value);
<span>//</span><span>发送信号量</span>
<span>int</span> sem_post(sem_t *sem);
<span>//</span><span>等待信号量</span>
<span>int</span> sem_wait(sem_t *sem);

注意：cocos2d-x引擎，已经内置pthread库，如下加入条件编译即可：

#ifdef WIN32
#include "../../cocos2dx/platform/third_party/win32/pthread/pthread.h"
#else
#include "pthread.h"
#endif // WIN32

本项目TCP用的是ODSocket，直接加入ODSocket.h,ODSocket.cpp到工程目录即可。

顺便提一下通用的BSD Socket: ：

<span>//</span><span>创建一个socket连接</span>
<span>int</span> socket (<span>int</span> family, <span>int</span> type, <span>int</span> protocol);
<span>//</span><span>连接目标主机</span>
<span>int</span> connect(<span>int</span> s, <span>const</span> <span>struct</span> sockaddr *name, <span>int</span> namelen);
<span>//</span><span>关闭socket连接</span>
 <span>int</span> close(<span>int</span> fildes);
<span>//</span><span>发送内容</span>
ssize_t send(<span>int</span> s, <span>const</span> <span>void</span> *msg, size_t len, <span>int</span> flags);
<span>//</span><span>接收内容</span>
ssize_t recv(<span>int</span> s, <span>void</span> *buf, size_t len, <span>int</span> flags);

udp部分，使用通用的socket :

#ifdef WIN32
#include <winsock2.h>	
typedef int	socklen_t;
#endif

#if (CC_TARGET_PLATFORM == CC_PLATFORM_ANDROID)//android 平台,注意包含"cocos2d.h"
#include <android>
#define LOGI(...) __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__)
#define LOG_TAG "JWYGC_Thread"

#include <sys>
#include <netinet>
#include <netdb.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys>
#include <sys>
#include <arpa>
#include <errno.h>
typedef int	SOCKET;</errno.h></arpa></sys></sys></unistd.h></fcntl.h></netdb.h></netinet></sys></android></winsock2.h>

2. WIN32平台注意事项

1) 在链接器加入附加依赖项pthreadVCE2.lib.

2) 用以下代码对网络进行初始化,退出时进行清除.

<span>//</span><span>初始化, 放在网络使用之前</span>
WSADATA wsaData;
WSAStartup(MAKEWORD(<span>2</span>, <span>0</span>), &wsaData)

<span>//</span><span>清除网络使用, 放在网络使用完毕之后.</span>
WSACleanup()

3) 线程使用需要初始化, 退出时进行清除.

<span>//线程使用之前,</span><span>初始化线程</span>
pthread_win32_process_attach_np();  
<span>//线程使用之后,</span><span>清除线程使用</span>
pthread_win32_process_detach_np();

4) windows关闭连接使用closesocket，安卓和ios使用close.

#ifdef WIN32
closesocket(new_socket);
#else
close(new_socket); // android ,ios平台
#endif

5) 解析IP地址时,使用inet_addr, 详细如下:

<span>const</span> <span>char</span> *addr = <span>"</span><span>192.168.1.1</span><span>"</span>;
<span>struct</span> in_addr ip = {<span>0</span>};
<span>#ifdef</span> WIN32 
ip.s_addr = inet_addr(addr);
<span>if</span>(ip.s_addr == INADDR_NONE)
{
    CCLOG(<span>"</span><span>can't parse IP address %s</span><span>"</span>, addr);        
}
<span>#else</span> 
<span>if</span> (!inet_aton(addr, &ip))
{
    CCLOG(<span>"</span><span>can't parse IP address %s</span><span>"</span>, addr);
}
<span>#endif</span>
<span>struct</span> hostent *host;
host = gethostbyaddr((<span>char</span> *) &ip, <span>4</span>, AF_INET);

6) 判断主机连接是否关闭, 在此模块中本人使用recv返回值来判断连接是否被主机关闭, Win32和其他平台迥异的是recv返回0为主机关闭连接, 而其他平台(ios, android)返回-1为主机关闭连接.

3. ios平台注意事项

 1) 调试发现, ios平台sem_init总是返回-1, 网上求证得知可能由于ios不支持无名信号量导致, 使用以下方式用以代替sem_init.

<span>//</span><span>获取及初始化信号量</span>
sem_t *my_sem;
my_sem = sem_open(<span>"</span><span>/mysem1</span><span>"</span>, O_CREAT,<span>0664</span>,<span>0</span>);

<span>//</span><span>使用sem_open方式创建的信号量在使用完毕需清除.</span>
sem_unlink(<span>"</span><span>/mysem1</span><span>"</span>);

4. android平台注意事项

1)记得在AndroidManifest.xml中加上网络使用权限.

<span><span>uses-permission </span><span>android:name</span><span>=”android.permission.INTERNET”></span><span></span></span>

<span>给出几个小函数：</span>

<span>1，获取本机IP：</span>

<pre class="brush:php;toolbar:false">bool UdpSocket::getLocalIP(char *szLocalIP)
{
#ifdef	WIN32
	char name[255];//定义用于存放获得的主机名的变量 
	struct hostent *hostinfo;
	if( gethostname ( name, sizeof(name)) == 0) {
		if((hostinfo = gethostbyname(name)) != NULL) {
			strcpy(szLocalIP,inet_ntoa (*(struct in_addr *)*hostinfo->h_addr_list));
			strcpy(m_szLocalIP,szLocalIP);
		}
	}
	return true;
#else
	int sock_get_ip;   
	struct   sockaddr_in *sin;  
	struct   ifreq ifr_ip; 
	if ((sock_get_ip=socket(AF_INET, SOCK_STREAM, 0)) == -1) {  
		CCLOG("get_ip error");
		return false;  
	}  


	memset(&ifr_ip, 0, sizeof(ifr_ip));     
	strncpy(ifr_ip.ifr_name, "wlan0", sizeof(ifr_ip.ifr_name) - 1);     //无线是wlan0,有线是eth0。可能还需要判断有线无线，比较麻烦。
	if( ioctl( sock_get_ip, SIOCGIFADDR, &ifr_ip) sin_addr));            
	close( sock_get_ip );       
	strcpy(m_szLocalIP,szLocalIP);
	return true;
#endif
}