52       mSockFd(-1),  in SocketInterface()
62     VerifyOrExit(mSockFd == -1, error = OT_ERROR_ALREADY);  in Init()
66     mSockFd = OpenFile(mRadioUrl);  in Init()
67     VerifyOrExit(mSockFd != -1, error = OT_ERROR_FAILED);  in Init()
107     FD_SET(mSockFd, &readFds);  in WaitForFrame()
108     FD_SET(mSockFd, &errorFds);  in WaitForFrame()
110     rval = TEMP_FAILURE_RETRY(select(mSockFd + 1, &readFds, nullptr, &errorFds, &timeout));  in WaitForFrame()
113         if (FD_ISSET(mSockFd, &readFds)) {  in WaitForFrame()
115         } else if (FD_ISSET(mSockFd, &errorFds)) {  in WaitForFrame()
135     FD_SET(mSockFd, &context->mReadFdSet);  in UpdateFdSet()
137     if (context->mMaxFd < mSockFd) {  in UpdateFdSet()
138         context->mMaxFd = mSockFd;  in UpdateFdSet()
148     if (FD_ISSET(mSockFd, &context->mReadFdSet)) {  in Process()
156     ssize_t rval = TEMP_FAILURE_RETRY(read(mSockFd, buffer, sizeof(buffer)));  in Read()
169     ssize_t rval = TEMP_FAILURE_RETRY(write(mSockFd, aFrame, aLength));  in Write()
229     VerifyOrExit(mSockFd != -1);  in CloseFile()
231     VerifyOrExit(0 == close(mSockFd), LogCrit("close(): errno=%s", strerror(errno)));  in CloseFile()
235     mSockFd = -1;  in CloseFile()