PR_Connect 编辑

Initiates a connection on a specified socket.

Syntax

#include <prio.h>

/wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRStatus PR_Connect(
  /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRFileDesc *fd,
  const /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRNetAddr *addr,
  /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRIntervalTime timeout);

Parameters

The function has the following parameters:

fd

A pointer to a /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRFileDesc object representing a socket.

addr

A pointer to the address of the peer to which the socket is to be connected.

timeout

A value of type /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PRIntervalTime specifying the time limit for completion of the connect operation.

Returns

The function returns one of the following values:

• Upon successful completion of connection setup, PR_SUCCESS.
• If unsuccessful, PR_FAILURE. Further information can be obtained by calling /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PR_GetError.

Description

PR_Connect is usually invoked on a TCP socket, but it may also be invoked on a UDP socket. Both cases are discussed here.

If the socket is a TCP socket, PR_Connect establishes a TCP connection to the peer. If the socket is not bound, it will be bound to an arbitrary local address.

PR_Connect blocks until either the connection is successfully established or an error occurs. The function uses the lesser of the provided timeout and the OS's connect timeout. In particular, if you specify PR_INTERVAL_NO_TIMEOUT as the timeout, the OS's connection time limit will be used.

If the socket is a UDP socket, there is no connection setup to speak of, since UDP is connectionless. If PR_Connect is invoked on a UDP socket, it has an overloaded meaning: PR_Connect merely saves the specified address as the default peer address for the socket, so that subsequently one can send and receive datagrams from the socket using /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PR_Send and /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PR_Recv instead of the usual /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PR_SendTo and /wiki/en-US/docs/Mozilla/Projects/NSPR/Reference/PR_RecvFrom.