IMDSim.C

00001 /***************************************************************************
00002 *cr
00003 *cr (C) Copyright 1995-2019 The Board of Trustees of the
00004 *cr University of Illinois
00005 *cr All Rights Reserved
00006 *cr
00007 ***************************************************************************/
00008 
00009 /***************************************************************************
00010 * RCS INFORMATION:
00011 *
00012 * $RCSfile: IMDSim.C,v $
00013 * $Author: johns $ $Locker: $ $State: Exp $
00014 * $Revision: 1.32 $ $Date: 2019年01月17日 21:20:59 $
00015 *
00016 ***************************************************************************
00017 * DESCRIPTION:
00018 * Routines to manage the low-level setup and teardown of Interactive MD 
00019 * simulations.
00020 ***************************************************************************/
00021 
00022 #include <stdlib.h>
00023 #include "IMDSim.h"
00024 #include "vmdsock.h"
00025 #include "IMDMgr.h"
00026 #include "Inform.h"
00027 
00028 IMDSim::IMDSim(const char *host, int port) {
00029 
00030 new_coords_ready = 0;
00031 numcoords = 0;
00032 simstate = IMDOFFLINE;
00033 
00034 vmdsock_init(); // make sure Winsock interfaces are initialized
00035 sock = vmdsock_create();
00036 if (sock == NULL) {
00037 msgErr << "Error connecting: could not create socket" << sendmsg;
00038 return;
00039 }
00040 int rc = vmdsock_connect(sock, host, port);
00041 if (rc < 0) {
00042 msgErr << "Error connecting to " << host << " on port "<< port <<sendmsg;
00043 vmdsock_destroy(sock);
00044 sock = 0;
00045 return;
00046 }
00047 handshake();
00048 simstate = IMDRUNNING;
00049 }
00050 
00051 void IMDSim::disconnect() {
00052 simstate = IMDOFFLINE;
00053 if (sock) {
00054 imd_disconnect(sock);
00055 vmdsock_shutdown(sock);
00056 vmdsock_destroy(sock);
00057 sock = 0;
00058 }
00059 }
00060 
00061 IMDSim::~IMDSim() {
00062 disconnect();
00063 }
00064 
00065 // Handshake: currently this is a 'one-way' handshake: after VMD connects,
00066 // NAMD sends to VMD an integer 1 in the length field of the header, without
00067 // converting network byte orer.
00068 
00069 void IMDSim::handshake() {
00070 
00071 need2flip = imd_recv_handshake(sock);
00072 switch (need2flip) {
00073 case 0:
00074 msgInfo << "Connected to same-endian machine" << sendmsg;
00075 break;
00076 case 1:
00077 msgInfo << "Connected to opposite-endian machine" << sendmsg;
00078 break;
00079 default:
00080 msgErr << "Unable to ascertain relative endianness of remote machine"
00081 << sendmsg;
00082 disconnect();
00083 }
00084 }
00085 
00086 /* Only works with aligned 4-byte quantities, will cause a bus error */
00087 /* on some platforms if used on unaligned data. */
00088 void IMDSim::swap4_aligned(void *v, long ndata) {
00089 int *data = (int *) v;
00090 long i;
00091 int *N;
00092 for (i=0; i<ndata; i++) {
00093 N = data + i;
00094 *N=(((*N>>24)&0xff) | ((*N&0xff)<<24) |
00095 ((*N>>8)&0xff00) | ((*N&0xff00)<<8));
00096 }
00097 }
00098