Imports a native TCP socket into NSPR.
#include "private/pprio.h" PRFileDesc* PR_ImportTCPSocket(PROsfd osfd);
The function has the following parameters:
- The native file descriptor for the TCP socket to import. On POSIX systems, this is an
int. On Windows, this is a
The function returns one of the following values:
- Upon successful completion, a pointer to the
PRFileDescobject created for the newly imported native TCP socket.
- If the import of the native TCP socket failed,
A native TCP socket
osfd can be imported into NSPR with
PR_ImportTCPSocket. The caller gives up control of the native TCP socket
osfd and should use the
PRFileDesc* returned by
PR_ImportTCPSocket is a supported function, it is declared in
"private/pprio.h" to stress the fact that this function depends on the internals of the NSPR implementation. The caller needs to understand what NSPR will do to the native file descriptor and make sure that NSPR can use the native file descriptor successfully.
For example, on POSIX systems, NSPR will put the native file descriptor (an
int) in non-blocking mode by calling
fcntl to set the
O_NONBLOCK file status flag on the native file descriptor, and then NSPR will call socket functions such as
poll on the native file descriptor. The caller must not do anything to the native file descriptor before the
PR_ImportTCPSocket call that will prevent the native file descriptor from working in non-blocking mode.
In theory, code that uses
PR_ImportTCPSocket may break when NSPR's implementation changes. In practice, this is unlikely to happen because NSPR's implementation has been stable for years and because of NSPR's strong commitment to backward compatibility. Using
PR_ImportTCPSocket is much more convenient than writing an NSPR I/O layer that wraps your native TCP sockets. Of course, it is best if you just use
PR_NewTCPSocket. If you are not sure whether
PR_ImportTCPSocket is right for you, please ask in the mozilla.dev.tech.nspr newsgroup.