Posix本地通信用于同一设备或native和framework层之间

新建本地Socket：socket

同样socket函数能够被用来创建一个本地的socket。子通过指导者函数来创建这socket在这PF_LOCAL协议族。为了使它对于你试验所用类型的连接，代替修改原因的native帮助函数，一个新的native函数将被定义来创建这局部的sockets。

int localSocket=socket（PF_LOCAL,SOCK_STREAM,0);

这本地的socket端口地址仅仅只要一个名字组成。它并没有一个IP地址或者一个端口号。本地的socket名字通过以下两种命名空间来创建：

Abstract 命名空间在本地socket通信端口模块被维护。这socket名字以一个NULL字符为前缀用于绑定着socket名字。

Filesystem命名空间通过这文件系统作为一个特别的socket文件被维护。这socket名字被直接传递到了这sockaddr_un结构体来绑定着socket名字到这socket。

struct sockaddr_un address;
// Name length
const size_t nameLength = strlen(name);
// Path length is initiall equal to name length
size_t pathLength = nameLength;
// If name is not starting with a slash it is
// in the abstract namespace
bool abstractNamespace = ('/' != name[0]);
// Abstract namespace requires having the first
// byte of the path to be the zero byte, update
// the path length to include the zero byte
if (abstractNamespace)
{
pathLength++;
}
// Check the path length
if (pathLength > sizeof(address.sun_path))
{
// Throw an exception with error number
ThrowException(env, "java/io/IOException", "Name is too big.");
}
else
{
// Clear the address bytes
memset(&address, 0, sizeof(address));
address.sun_family = PF_LOCAL;
// Socket path
char* sunPath = address.sun_path;
// First byte must be zero to use the abstract namespace
if (abstractNamespace)
{
*sunPath++ = NULL;
}
// Append the local name
strcpy(sunPath, name);
// Address length
socklen_t addressLength =
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268 CHAPTER 10: POSIX Socket API: Local Communication
(offsetof(struct sockaddr_un, sun_path))
+ pathLength;
// Unlink if the socket name is already binded
unlink(address.sun_path);
// Bind socket
LogMessage(env, obj, "Binding to local name %s%s.",
(abstractNamespace) ? "(null)" : "",
name);
if (−1 == bind(sd, (struct sockaddr*) &address, addressLength))
{
// Throw an exception with error number
ThrowErrnoException(env, "java/io/IOException", errno);
}
}