this.sema.acquire();
this.checkContent(TransmissionConstants.CONTENT_PC);
int st = this.is.readInt();
PC p;
if(st == TransmissionConstants.STATUS_PC_AVAILABLE) {
String id = this.is.readUTF();
String ip = this.is.readUTF();
int status = this.is.readInt();
p = new PC(id, ip, status);
} else if (st == TransmissionConstants.STATUS_PC_NOT_AVAILABLE) {
p = null;
} else {
this.sema.release();
throw new ProtocolException("Unexpected data received");