impls/socket/send.c

#include <petscsys.h>

#if defined(PETSC_NEEDS_UTYPE_TYPEDEFS)
/* Some systems have inconsistent include files that use but do not
   ensure that the following definitions are made */
typedef unsigned char   u_char;
typedef unsigned short  u_short;
typedef unsigned short  ushort;
typedef unsigned int    u_int;
typedef unsigned long   u_long;
#endif

#include <errno.h>
#include <ctype.h>
#if defined(PETSC_HAVE_MACHINE_ENDIAN_H)
#include <machine/endian.h>
#endif
#if defined(PETSC_HAVE_UNISTD_H)
#include <unistd.h>
#endif
#if defined(PETSC_HAVE_SYS_SOCKET_H)
#include <sys/socket.h>
#endif
#if defined(PETSC_HAVE_SYS_WAIT_H)
#include <sys/wait.h>
#endif
#if defined(PETSC_HAVE_NETINET_IN_H)
#include <netinet/in.h>
#endif
#if defined(PETSC_HAVE_NETDB_H)
#include <netdb.h>
#endif
#if defined(PETSC_HAVE_FCNTL_H)
#include <fcntl.h>
#endif
#if defined(PETSC_HAVE_IO_H)
#include <io.h>
#endif
#if defined(PETSC_HAVE_WINSOCK2_H)
#include <Winsock2.h>
#endif
#include <sys/stat.h>
#include <../src/sys/classes/viewer/impls/socket/socket.h>

#if defined(PETSC_NEED_CLOSE_PROTO)
PETSC_EXTERN int close(int);
#endif
#if defined(PETSC_NEED_SOCKET_PROTO)
PETSC_EXTERN int socket(int,int,int);
#endif
#if defined(PETSC_NEED_SLEEP_PROTO)
PETSC_EXTERN int sleep(unsigned);
#endif
#if defined(PETSC_NEED_CONNECT_PROTO)
PETSC_EXTERN int connect(int,struct sockaddr*,int);
#endif

/*--------------------------------------------------------------*/
#undef __FUNCT__
#define __FUNCT__ "PetscViewerDestroy_Socket"
static PetscErrorCode PetscViewerDestroy_Socket(PetscViewer viewer)
{
  PetscViewer_Socket *vmatlab = (PetscViewer_Socket*)viewer->data;
  PetscErrorCode     ierr;

  PetscFunctionBegin;
  if (vmatlab->port) {
#if defined(PETSC_HAVE_CLOSESOCKET)
    ierr = closesocket(vmatlab->port);
#else
    ierr = close(vmatlab->port);
#endif
    if (ierr) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SYS,"System error closing socket");
  }
  ierr = PetscFree(vmatlab);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

/*--------------------------------------------------------------*/
#undef __FUNCT__
#define __FUNCT__ "PetscOpenSocket"
/*
    PetscSocketOpen - handles connected to an open port where someone is waiting.

.seealso:   PetscSocketListen(), PetscSocketEstablish()
*/
PetscErrorCode  PetscOpenSocket(char *hostname,int portnum,int *t)
{
  struct sockaddr_in sa;
  struct hostent     *hp;
  int                s = 0;
  PetscErrorCode     ierr;
  PetscBool          flg = PETSC_TRUE;

  PetscFunctionBegin;
  if (!(hp=gethostbyname(hostname))) {
    perror("SEND: error gethostbyname: ");
    SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SYS,"system error open connection to %s",hostname);
  }
  ierr = PetscMemzero(&sa,sizeof(sa));CHKERRQ(ierr);
  ierr = PetscMemcpy(&sa.sin_addr,hp->h_addr_list[0],hp->h_length);CHKERRQ(ierr);

  sa.sin_family = hp->h_addrtype;
  sa.sin_port   = htons((u_short) portnum);
  while (flg) {
    if ((s=socket(hp->h_addrtype,SOCK_STREAM,0)) < 0) {
      perror("SEND: error socket");  SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SYS,"system error");
    }
    if (connect(s,(struct sockaddr*)&sa,sizeof(sa)) < 0) {
#if defined(PETSC_HAVE_WSAGETLASTERROR)
      ierr = WSAGetLastError();
      if (ierr == WSAEADDRINUSE)    (*PetscErrorPrintf)("SEND: address is in use\n");
      else if (ierr == WSAEALREADY) (*PetscErrorPrintf)("SEND: socket is non-blocking \n");
      else if (ierr == WSAEISCONN) {
        (*PetscErrorPrintf)("SEND: socket already connected\n");
        Sleep((unsigned) 1);
      } else if (ierr == WSAECONNREFUSED) {
        /* (*PetscErrorPrintf)("SEND: forcefully rejected\n"); */
        Sleep((unsigned) 1);
      } else {
        perror(NULL); SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SYS,"system error");
      }
#else
      if (errno == EADDRINUSE)    (*PetscErrorPrintf)("SEND: address is in use\n");
      else if (errno == EALREADY) (*PetscErrorPrintf)("SEND: socket is non-blocking \n");
      else if (errno == EISCONN) {
        (*PetscErrorPrintf)("SEND: socket already connected\n");
        sleep((unsigned) 1);
      } else if (errno == ECONNREFUSED) {
        /* (*PetscErrorPrintf)("SEND: forcefully rejected\n"); */
        ierr = PetscInfo(0,"Connection refused in attaching socket, trying again");CHKERRQ(ierr);
        sleep((unsigned) 1);
      } else {
        perror(NULL); SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SYS,"system error");
      }
#endif
      flg = PETSC_TRUE;
#if defined(PETSC_HAVE_CLOSESOCKET)
      closesocket(s);
#else
      close(s);
#endif
    } else flg = PETSC_FALSE;
  }
  *t = s;
  PetscFunctionReturn(0);
}

#define MAXHOSTNAME 100
#undef __FUNCT__
#define __FUNCT__ "PetscSocketEstablish"
/*
   PetscSocketEstablish - starts a listener on a socket

.seealso:   PetscSocketListen()
*/
PetscErrorCode PetscSocketEstablish(int portnum,int *ss)
{
  char               myname[MAXHOSTNAME+1];
  int                s;
  PetscErrorCode     ierr;
  struct sockaddr_in sa;
  struct hostent     *hp;

  PetscFunctionBegin;
  ierr = PetscGetHostName(myname,MAXHOSTNAME);CHKERRQ(ierr);

  ierr = PetscMemzero(&sa,sizeof(struct sockaddr_in));CHKERRQ(ierr);

  hp = gethostbyname(myname);
  if (!hp) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SYS,"Unable to get hostent information from system");

  sa.sin_family = hp->h_addrtype;
  sa.sin_port   = htons((u_short)portnum);

  if ((s = socket(AF_INET,SOCK_STREAM,0)) < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SYS,"Error running socket() command");
#if defined(PETSC_HAVE_SO_REUSEADDR)
  {
    int optval = 1; /* Turn on the option */
    ierr = setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char*)&optval,sizeof(optval));CHKERRQ(ierr);
  }
#endif

  while (bind(s,(struct sockaddr*)&sa,sizeof(sa)) < 0) {
#if defined(PETSC_HAVE_WSAGETLASTERROR)
    ierr = WSAGetLastError();
    if (ierr != WSAEADDRINUSE) {
#else
    if (errno != EADDRINUSE) {
#endif
      close(s);
      SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SYS,"Error from bind()");
    }
  }
  listen(s,0);
  *ss = s;
  return(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscSocketListen"
/*
   PetscSocketListens - Listens at a socket created with PetscSocketEstablish()

.seealso:   PetscSocketEstablish()
*/
PetscErrorCode PetscSocketListen(int listenport,int *t)
{
  struct sockaddr_in isa;
#if defined(PETSC_HAVE_ACCEPT_SIZE_T)
  size_t             i;
#else
  int                i;
#endif

  PetscFunctionBegin;
  /* wait for someone to try to connect */
  i = sizeof(struct sockaddr_in);
  if ((*t = accept(listenport,(struct sockaddr*)&isa,(socklen_t*)&i)) < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SYS,"error from accept()\n");
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerSocketOpen"
/*@C
   PetscViewerSocketOpen - Opens a connection to a MATLAB or other socket
        based server.

   Collective on MPI_Comm

   Input Parameters:
+  comm - the MPI communicator
.  machine - the machine the server is running on,, use NULL for the local machine, use "server" to passively wait for
             a connection from elsewhere
-  port - the port to connect to, use PETSC_DEFAULT for the default

   Output Parameter:
.  lab - a context to use when communicating with the server

   Level: intermediate

   Notes:
   Most users should employ the following commands to access the
   MATLAB PetscViewers
$
$    PetscViewerSocketOpen(MPI_Comm comm, char *machine,int port,PetscViewer &viewer)
$    MatView(Mat matrix,PetscViewer viewer)
$
$                or
$
$    PetscViewerSocketOpen(MPI_Comm comm,char *machine,int port,PetscViewer &viewer)
$    VecView(Vec vector,PetscViewer viewer)

   Options Database Keys:
   For use with  PETSC_VIEWER_SOCKET_WORLD, PETSC_VIEWER_SOCKET_SELF,
   PETSC_VIEWER_SOCKET_() or if
    NULL is passed for machine or PETSC_DEFAULT is passed for port
$    -viewer_socket_machine <machine>
$    -viewer_socket_port <port>

   Environmental variables:
+   PETSC_VIEWER_SOCKET_PORT portnumber
-   PETSC_VIEWER_SOCKET_MACHINE machine name

     Currently the only socket client available is MATLAB. See
     src/dm/da/examples/tests/ex12.c and ex12.m for an example of usage.

   Notes: The socket viewer is in some sense a subclass of the binary viewer, to read and write to the socket
          use PetscViewerBinaryRead/Write/GetDescriptor().

   Concepts: MATLAB^sending data
   Concepts: sockets^sending data

.seealso: MatView(), VecView(), PetscViewerDestroy(), PetscViewerCreate(), PetscViewerSetType(),
          PetscViewerSocketSetConnection(), PETSC_VIEWER_SOCKET_, PETSC_VIEWER_SOCKET_WORLD,
          PETSC_VIEWER_SOCKET_SELF, PetscViewerBinaryWrite(), PetscViewerBinaryRead(), PetscViewerBinaryWriteStringArray(),
          PetscBinaryViewerGetDescriptor()
@*/
PetscErrorCode  PetscViewerSocketOpen(MPI_Comm comm,const char machine[],int port,PetscViewer *lab)
{
  PetscErrorCode ierr;

  PetscFunctionBegin;
  ierr = PetscViewerCreate(comm,lab);CHKERRQ(ierr);
  ierr = PetscViewerSetType(*lab,PETSCVIEWERSOCKET);CHKERRQ(ierr);
  ierr = PetscViewerSocketSetConnection(*lab,machine,port);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerSetFromOptions_Socket"
static PetscErrorCode PetscViewerSetFromOptions_Socket(PetscViewer v)
{
  PetscErrorCode ierr;
  PetscInt       def = -1;
  char           sdef[256];
  PetscBool      tflg;

  PetscFunctionBegin;
  /*
       These options are not processed here, they are processed in PetscViewerSocketSetConnection(), they
    are listed here for the GUI to display
  */
  ierr = PetscOptionsHead("Socket PetscViewer Options");CHKERRQ(ierr);
  ierr = PetscOptionsGetenv(PetscObjectComm((PetscObject)v),"PETSC_VIEWER_SOCKET_PORT",sdef,16,&tflg);CHKERRQ(ierr);
  if (tflg) {
    ierr = PetscOptionsStringToInt(sdef,&def);CHKERRQ(ierr);
  } else def = PETSCSOCKETDEFAULTPORT;
  ierr = PetscOptionsInt("-viewer_socket_port","Port number to use for socket","PetscViewerSocketSetConnection",def,0,0);CHKERRQ(ierr);

  ierr = PetscOptionsString("-viewer_socket_machine","Machine to use for socket","PetscViewerSocketSetConnection",sdef,0,0,0);CHKERRQ(ierr);
  ierr = PetscOptionsGetenv(PetscObjectComm((PetscObject)v),"PETSC_VIEWER_SOCKET_MACHINE",sdef,256,&tflg);CHKERRQ(ierr);
  if (!tflg) {
    ierr = PetscGetHostName(sdef,256);CHKERRQ(ierr);
  }
  ierr = PetscOptionsTail();CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerCreate_Socket"
PETSC_EXTERN PetscErrorCode PetscViewerCreate_Socket(PetscViewer v)
{
  PetscViewer_Socket *vmatlab;
  PetscErrorCode     ierr;

  PetscFunctionBegin;
  ierr                   = PetscNewLog(v,PetscViewer_Socket,&vmatlab);CHKERRQ(ierr);
  vmatlab->port          = 0;
  v->data                = (void*)vmatlab;
  v->ops->destroy        = PetscViewerDestroy_Socket;
  v->ops->flush          = 0;
  v->ops->setfromoptions = PetscViewerSetFromOptions_Socket;

  /* lie and say this is a binary viewer; then all the XXXView_Binary() methods will work correctly on it */
  ierr                   = PetscObjectChangeTypeName((PetscObject)v,PETSCVIEWERBINARY);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscViewerSocketSetConnection"
/*@C
      PetscViewerSocketSetConnection - Sets the machine and port that a PETSc socket
             viewer is to use

  Logically Collective on PetscViewer

  Input Parameters:
+   v - viewer to connect
.   machine - host to connect to, use NULL for the local machine,use "server" to passively wait for
             a connection from elsewhere
-   port - the port on the machine one is connecting to, use PETSC_DEFAULT for default

    Level: advanced

.seealso: PetscViewerSocketOpen()
@*/
PetscErrorCode  PetscViewerSocketSetConnection(PetscViewer v,const char machine[],int port)
{
  PetscErrorCode     ierr;
  PetscMPIInt        rank;
  char               mach[256];
  PetscBool          tflg;
  PetscViewer_Socket *vmatlab = (PetscViewer_Socket*)v->data;

  PetscFunctionBegin;
  /* PetscValidLogicalCollectiveInt(v,port,3); not a PetscInt */
  if (port <= 0) {
    char portn[16];
    ierr = PetscOptionsGetenv(PetscObjectComm((PetscObject)v),"PETSC_VIEWER_SOCKET_PORT",portn,16,&tflg);CHKERRQ(ierr);
    if (tflg) {
      PetscInt pport;
      ierr = PetscOptionsStringToInt(portn,&pport);CHKERRQ(ierr);
      port = (int)pport;
    } else port = PETSCSOCKETDEFAULTPORT;
  }
  if (!machine) {
    ierr = PetscOptionsGetenv(PetscObjectComm((PetscObject)v),"PETSC_VIEWER_SOCKET_MACHINE",mach,256,&tflg);CHKERRQ(ierr);
    if (!tflg) {
      ierr = PetscGetHostName(mach,256);CHKERRQ(ierr);
    }
  } else {
    ierr = PetscStrncpy(mach,machine,256);CHKERRQ(ierr);
  }

  ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)v),&rank);CHKERRQ(ierr);
  if (!rank) {
    ierr = PetscStrcmp(mach,"server",&tflg);CHKERRQ(ierr);
    if (tflg) {
      int listenport;
      ierr = PetscInfo1(v,"Waiting for connection from socket process on port %D\n",port);CHKERRQ(ierr);
      ierr = PetscSocketEstablish(port,&listenport);CHKERRQ(ierr);
      ierr = PetscSocketListen(listenport,&vmatlab->port);CHKERRQ(ierr);
      close(listenport);
    } else {
      ierr = PetscInfo2(v,"Connecting to socket process on port %D machine %s\n",port,mach);CHKERRQ(ierr);
      ierr = PetscOpenSocket(mach,port,&vmatlab->port);CHKERRQ(ierr);
    }
  }
  PetscFunctionReturn(0);
}

/* ---------------------------------------------------------------------*/
/*
    The variable Petsc_Viewer_Socket_keyval is used to indicate an MPI attribute that
  is attached to a communicator, in this case the attribute is a PetscViewer.
*/
static PetscMPIInt Petsc_Viewer_Socket_keyval = MPI_KEYVAL_INVALID;


#undef __FUNCT__
#define __FUNCT__ "PETSC_VIEWER_SOCKET_"
/*@C
     PETSC_VIEWER_SOCKET_ - Creates a socket viewer shared by all processors in a communicator.

     Collective on MPI_Comm

     Input Parameter:
.    comm - the MPI communicator to share the socket PetscViewer

     Level: intermediate

   Options Database Keys:
   For use with the default PETSC_VIEWER_SOCKET_WORLD or if
    NULL is passed for machine or PETSC_DEFAULT is passed for port
$    -viewer_socket_machine <machine>
$    -viewer_socket_port <port>

   Environmental variables:
+   PETSC_VIEWER_SOCKET_PORT portnumber
-   PETSC_VIEWER_SOCKET_MACHINE machine name

     Notes:
     Unlike almost all other PETSc routines, PetscViewer_SOCKET_ does not return
     an error code.  The socket PetscViewer is usually used in the form
$       XXXView(XXX object,PETSC_VIEWER_SOCKET_(comm));

     Currently the only socket client available is MATLAB. See
     src/dm/da/examples/tests/ex12.c and ex12.m for an example of usage.

     Connects to a waiting socket and stays connected until PetscViewerDestroy() is called.

     Use this for communicating with an interactive MATLAB session, see PETSC_VIEWER_MATLAB_() for communicating with the MATLAB engine.

.seealso: PETSC_VIEWER_SOCKET_WORLD, PETSC_VIEWER_SOCKET_SELF, PetscViewerSocketOpen(), PetscViewerCreate(),
          PetscViewerSocketSetConnection(), PetscViewerDestroy(), PETSC_VIEWER_SOCKET_(), PetscViewerBinaryWrite(), PetscViewerBinaryRead(),
          PetscViewerBinaryWriteStringArray(), PetscBinaryViewerGetDescriptor(), PETSC_VIEWER_MATLAB_()
@*/
PetscViewer  PETSC_VIEWER_SOCKET_(MPI_Comm comm)
{
  PetscErrorCode ierr;
  PetscBool      flg;
  PetscViewer    viewer;
  MPI_Comm       ncomm;

  PetscFunctionBegin;
  ierr = PetscCommDuplicate(comm,&ncomm,NULL);if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_VIEWER_SOCKET_",__FILE__,__SDIR__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," ");PetscFunctionReturn(0);}
  if (Petsc_Viewer_Socket_keyval == MPI_KEYVAL_INVALID) {
    ierr = MPI_Keyval_create(MPI_NULL_COPY_FN,MPI_NULL_DELETE_FN,&Petsc_Viewer_Socket_keyval,0);
    if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_VIEWER_SOCKET_",__FILE__,__SDIR__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," ");PetscFunctionReturn(0);}
  }
  ierr = MPI_Attr_get(ncomm,Petsc_Viewer_Socket_keyval,(void**)&viewer,(int*)&flg);
  if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_VIEWER_SOCKET_",__FILE__,__SDIR__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," ");PetscFunctionReturn(0);}
  if (!flg) { /* PetscViewer not yet created */
    ierr = PetscViewerSocketOpen(ncomm,0,0,&viewer);
    if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_VIEWER_SOCKET_",__FILE__,__SDIR__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," ");PetscFunctionReturn(0);}
    ierr = PetscObjectRegisterDestroy((PetscObject)viewer);
    if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_VIEWER_SOCKET_",__FILE__,__SDIR__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," ");PetscFunctionReturn(0);}
    ierr = MPI_Attr_put(ncomm,Petsc_Viewer_Socket_keyval,(void*)viewer);
    if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_VIEWER_SOCKET_",__FILE__,__SDIR__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," ");PetscFunctionReturn(0);}
  }
  ierr = PetscCommDestroy(&ncomm);
  if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_VIEWER_SOCKET_",__FILE__,__SDIR__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," ");PetscFunctionReturn(0);}
  PetscFunctionReturn(viewer);
}

/* ---------------------------------------------------------------------*/
#if defined(PETSC_USE_SERVER)

#include <pthread.h>
#include <time.h>
#define PROTOCOL   "HTTP/1.1"
#define RFC1123FMT "%a, %d %b %Y %H:%M:%S GMT"

#undef __FUNCT__
#define __FUNCT__ "PetscWebSendHeader"
PetscErrorCode PetscWebSendHeader(FILE *f, int status, const char *title, const char *extra, const char *mime, int length)
{
  time_t now;
  char   timebuf[128];

  PetscFunctionBegin;
  fprintf(f, "%s %d %s\r\n", PROTOCOL, status, title);
  fprintf(f, "Server: %s\r\n", "petscserver/1.0");
  now = time(NULL);
  strftime(timebuf, sizeof(timebuf), RFC1123FMT, gmtime(&now));
  fprintf(f, "Date: %s\r\n", timebuf);
  if (extra) fprintf(f, "%s\r\n", extra);
  if (mime) fprintf(f, "Content-Type: %s\r\n", mime);
  if (length >= 0) fprintf(f, "Content-Length: %d\r\n", length);
  fprintf(f, "Connection: close\r\n");
  fprintf(f, "\r\n");
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscWebSendFooter"
PetscErrorCode PetscWebSendFooter(FILE *fd)
{
  PetscFunctionBegin;
  fprintf(fd, "</BODY></HTML>\r\n");
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscWebSendError"
PetscErrorCode PetscWebSendError(FILE *f, int status, const char *title, const char *extra, const char *text)
{
  PetscErrorCode ierr;

  PetscFunctionBegin;
  ierr = PetscWebSendHeader(f, status, title, extra, "text/html", -1);CHKERRQ(ierr);
  fprintf(f, "<HTML><HEAD><TITLE>%d %s</TITLE></HEAD>\r\n", status, title);
  fprintf(f, "<BODY><H4>%d %s</H4>\r\n", status, title);
  fprintf(f, "%s\r\n", text);
  ierr = PetscWebSendFooter(f);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#if defined(PETSC_HAVE_AMS)
#undef __FUNCT__
#define __FUNCT__ "PetscAMSObjectsDisplayList"
/*
    Displays all the PETSc objects published with AMS in a simple HTML list

    Does NOT use Javascript or JSON-RPC
*/
static PetscErrorCode PetscAMSObjectsDisplayList(FILE *fd)
{
  PetscErrorCode     ierr;
  char               host[256],**comm_list,**mem_list,**fld_list;
  AMS_Comm           ams;
  PetscInt           i = 0,j;
  AMS_Memory_type    mtype;
  AMS_Data_type      dtype;
  AMS_Shared_type    stype;
  AMS_Reduction_type rtype;
  AMS_Memory         memory;
  int                len;
  void               *addr;

  ierr = PetscGetHostName(host,256);CHKERRQ(ierr);
  ierr = AMS_Connect(host, -1, &comm_list);CHKERRQ(ierr);
  ierr = PetscWebSendHeader(fd, 200, "OK", NULL, "text/html", -1);CHKERRQ(ierr);
  if (!comm_list || !comm_list[0]) fprintf(fd, "AMS Communicator not running</p>\r\n");
  else {
    ierr = AMS_Comm_attach(comm_list[0],&ams);CHKERRQ(ierr);
    ierr = AMS_Comm_get_memory_list(ams,&mem_list);CHKERRQ(ierr);
    if (!mem_list[0]) fprintf(fd, "AMS Communicator %s has no published memories</p>\r\n",comm_list[0]);
    else {
      fprintf(fd, "<HTML><HEAD><TITLE>Petsc Application Server</TITLE></HEAD>\r\n<BODY>");
      fprintf(fd,"<ul>\r\n");
      while (mem_list[i]) {
        fprintf(fd,"<li> %s</li>\r\n",mem_list[i]);
        ierr = AMS_Memory_attach(ams,mem_list[i],&memory,NULL);CHKERRQ(ierr);
        ierr = AMS_Memory_get_field_list(memory, &fld_list);CHKERRQ(ierr);
        j    = 0;
        fprintf(fd,"<ul>\r\n");
        while (fld_list[j]) {
          fprintf(fd,"<li> %s",fld_list[j]);
          ierr = AMS_Memory_get_field_info(memory, fld_list[j], &addr, &len, &dtype, &mtype, &stype, &rtype);CHKERRQ(ierr);
          if (len == 1) {
            if (dtype == AMS_INT)         fprintf(fd," %d",*(int*)addr);
            else if (dtype == AMS_STRING) fprintf(fd," %s",*(char**)addr);
          }
          fprintf(fd,"</li>\r\n");
          j++;
        }
        fprintf(fd,"</ul>\r\n");
        i++;
      }
      fprintf(fd,"</ul>\r\n");
    }
  }
  ierr = PetscWebSendFooter(fd);CHKERRQ(ierr);
  ierr = AMS_Disconnect();CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscAMSObjectsDisplayTree"
/*
    Displays all the PETSc objects published with AMS in very crude HTML 5 graphics

    Does NOT use Javascript or JSON-RPC
*/
static PetscErrorCode PetscAMSObjectsDisplayTree(FILE *fd)
{
  PetscErrorCode     ierr;
  char               host[256],**comm_list,**mem_list,**fld_list;
  AMS_Comm           ams;
  PetscInt           i = 0,j;
  AMS_Memory_type    mtype;
  AMS_Data_type      dtype;
  AMS_Shared_type    stype;
  AMS_Reduction_type rtype;
  AMS_Memory         memory;
  int                len;
  void               *addr2,*addr3,*addr,*addr4;

  ierr = PetscGetHostName(host,256);CHKERRQ(ierr);
  ierr = AMS_Connect(host, -1, &comm_list);CHKERRQ(ierr);
  ierr = PetscWebSendHeader(fd, 200, "OK", NULL, "text/html", -1);CHKERRQ(ierr);
  if (!comm_list || !comm_list[0]) fprintf(fd, "AMS Communicator not running</p>\r\n");
  else {
    ierr = AMS_Comm_attach(comm_list[0],&ams);CHKERRQ(ierr);
    ierr = AMS_Comm_get_memory_list(ams,&mem_list);CHKERRQ(ierr);
    if (!mem_list[0]) fprintf(fd, "AMS Communicator %s has no published memories</p>\r\n",comm_list[0]);
    else {
      PetscInt  Nlevels,*Level,*Levelcnt,*Idbylevel,*Column,*parentid,*Id,maxId = 0,maxCol = 0,*parentId,id,cnt,Nlevelcnt = 0;
      PetscBool *mask;
      char      **classes,*clas,**subclasses,*sclas;

      /* get maximum number of objects */
      while (mem_list[i]) {
        ierr  = AMS_Memory_attach(ams,mem_list[i],&memory,NULL);CHKERRQ(ierr);
        ierr  = AMS_Memory_get_field_list(memory, &fld_list);CHKERRQ(ierr);
        ierr  = AMS_Memory_get_field_info(memory, "Id", &addr2, &len, &dtype, &mtype, &stype, &rtype);CHKERRQ(ierr);
        Id    = (int*) addr2;
        maxId = PetscMax(maxId,*Id);
        i++;
      }
      maxId++;

      /* Gets everyone's parent ID and which nodes are masked */
      ierr = PetscMalloc4(maxId,PetscInt,&parentid,maxId,PetscBool,&mask,maxId,char**,&classes,maxId,char**,&subclasses);CHKERRQ(ierr);
      ierr = PetscMemzero(classes,maxId*sizeof(char*));CHKERRQ(ierr);
      ierr = PetscMemzero(subclasses,maxId*sizeof(char*));CHKERRQ(ierr);
      for (i=0; i<maxId; i++) mask[i] = PETSC_TRUE;
      i = 0;
      while (mem_list[i]) {
        ierr          = AMS_Memory_attach(ams,mem_list[i],&memory,NULL);CHKERRQ(ierr);
        ierr          = AMS_Memory_get_field_list(memory, &fld_list);CHKERRQ(ierr);
        ierr          = AMS_Memory_get_field_info(memory, "Id", &addr2, &len, &dtype, &mtype, &stype, &rtype);CHKERRQ(ierr);
        Id            = (int*) addr2;
        ierr          = AMS_Memory_get_field_info(memory, "ParentId", &addr3, &len, &dtype, &mtype, &stype, &rtype);CHKERRQ(ierr);
        parentId      = (int*) addr3;
        ierr          = AMS_Memory_get_field_info(memory, "Class", &addr, &len, &dtype, &mtype, &stype, &rtype);CHKERRQ(ierr);
        clas          = *(char**)addr;
        ierr          = AMS_Memory_get_field_info(memory, "Type", &addr4, &len, &dtype, &mtype, &stype, &rtype);CHKERRQ(ierr);
        sclas         = *(char**)addr4;
        parentid[*Id] = *parentId;
        mask[*Id]     = PETSC_FALSE;

        ierr = PetscStrallocpy(clas,classes+*Id);CHKERRQ(ierr);
        ierr = PetscStrallocpy(sclas,subclasses+*Id);CHKERRQ(ierr);
        i++;
      }

      /* if the parent is masked then relabel the parent as 0 since the true parent was deleted */
      for (i=0; i<maxId; i++) {
        if (!mask[i] && parentid[i] > 0 && mask[parentid[i]]) parentid[i] = 0;
      }

      ierr = PetscProcessTree(maxId,mask,parentid,&Nlevels,&Level,&Levelcnt,&Idbylevel,&Column);CHKERRQ(ierr);

      for (i=0; i<Nlevels; i++) maxCol    = PetscMax(maxCol,Levelcnt[i]);
      for (i=0; i<Nlevels; i++) Nlevelcnt = PetscMax(Nlevelcnt,Levelcnt[i]);

      /* print all the top-level objects */
      fprintf(fd, "<HTML><HEAD><TITLE>Petsc Application Server</TITLE>\r\n");
      fprintf(fd, "<canvas width=800 height=600 id=\"tree\"></canvas>\r\n");
      fprintf(fd, "<script type=\"text/javascript\">\r\n");
      fprintf(fd, "  function draw() {\r\n");
      fprintf(fd, "  var example = document.getElementById('tree');\r\n");
      fprintf(fd, "  var context = example.getContext('2d');\r\n");
      /* adjust font size based on how big a tree is printed */
      if (Nlevels > 5 || Nlevelcnt > 10) fprintf(fd, "  context.font         = \"normal 12px sans-serif\";\r\n");
      else                               fprintf(fd, "  context.font         = \"normal 24px sans-serif\";\r\n");
      fprintf(fd, "  context.fillStyle = \"rgb(255,0,0)\";\r\n");
      fprintf(fd, "  context.textBaseline = \"top\";\r\n");
      fprintf(fd, "  var xspacep = 0;\r\n");
      fprintf(fd, "  var yspace = example.height/%d;\r\n",(Nlevels+1));
      /* estimate the height of a string as twice the width of a character */
      fprintf(fd, "  var wheight = context.measureText(\"K\");\r\n");
      fprintf(fd, "  var height = 1.6*wheight.width;\r\n");

      cnt = 0;
      for (i=0; i<Nlevels; i++) {
        fprintf(fd, "  var xspace = example.width/%d;\r\n",Levelcnt[i]+1);
        for (j=0; j<Levelcnt[i]; j++) {
          id    = Idbylevel[cnt++];
          clas  = classes[id];
          sclas = subclasses[id];
          fprintf(fd, "  var width = context.measureText(\"%s\");\r\n",clas);
          fprintf(fd, "  var swidth = context.measureText(\"%s\");\r\n",sclas);
          fprintf(fd, "  context.fillStyle = \"rgb(255,0,0)\";\r\n");
          fprintf(fd, "  context.fillRect((%d)*xspace-width.width/2, %d*yspace-height/2, width.width, height);\r\n",j+1,i+1);
          fprintf(fd, "  context.fillRect((%d)*xspace-swidth.width/2, %d*yspace+height/2, swidth.width, height);\r\n",j+1,i+1);
          fprintf(fd, "  context.fillStyle = \"rgb(0,0,0)\";\r\n");
          fprintf(fd, "  context.fillText(\"%s\",(%d)*xspace-width.width/2, %d*yspace-height/2);\r\n",clas,j+1,i+1);
          fprintf(fd, "  context.fillText(\"%s\",(%d)*xspace-swidth.width/2, %d*yspace+height/2);\r\n",sclas,j+1,i+1);
          if (parentid[id]) {
            fprintf(fd, "  context.moveTo(%d*xspace,%d*yspace-height/2);\r\n",j+1,i+1);
            fprintf(fd, "  context.lineTo(%d*xspacep,%d*yspace+3*height/2);\r\n",Column[parentid[id]]+1,i);
            fprintf(fd, "  context.stroke();\r\n");
          }
        }
        fprintf(fd, "  xspacep = xspace;\r\n");
      }
      ierr = PetscFree(Level);CHKERRQ(ierr);
      ierr = PetscFree(Levelcnt);CHKERRQ(ierr);
      ierr = PetscFree(Idbylevel);CHKERRQ(ierr);
      ierr = PetscFree(Column);CHKERRQ(ierr);
      for (i=0; i<maxId; i++) {
        ierr = PetscFree(classes[i]);CHKERRQ(ierr);
        ierr = PetscFree(subclasses[i]);CHKERRQ(ierr);
      }
      ierr = PetscFree4(mask,parentid,classes,subclasses);CHKERRQ(ierr);

      ierr = AMS_Disconnect();CHKERRQ(ierr);
      fprintf(fd, "}\r\n");
      fprintf(fd, "</script>\r\n");
      fprintf(fd, "<body onload=\"draw();\">\r\n");
      fprintf(fd, "</body></html>\r\n");
    }
  }
  ierr = PetscWebSendFooter(fd);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
#endif

#undef __FUNCT__
#define __FUNCT__ "PetscWebServeRequestGet"
/*@C
      PetscWebServeRequestGet - serves a single web Get request

    Not collective

  Input Parameters:
+   port - the network file to read and write from
-   path - the command from the server

    Level: developer

.seealso: PetscWebServe()
@*/
static PetscErrorCode  PetscWebServeRequestGet(FILE *fd,const char path[])
{
  PetscErrorCode ierr;
  FILE           *fdo;
  char           fullpath[PETSC_MAX_PATH_LEN],truefullpath[PETSC_MAX_PATH_LEN];
  const char     *type;
  PetscBool      flg;

  PetscFunctionBegin;
  fseek(fd, 0, SEEK_CUR); /* Force change of stream direction */

  ierr = PetscStrcmp(path,"/favicon.ico",&flg);CHKERRQ(ierr);
  if (flg) {
    /* should have cool PETSc icon */;
    PetscFunctionReturn(0);
  }
  ierr = PetscStrcmp(path,"/",&flg);CHKERRQ(ierr);
  if (flg) {
    char        program[128];
    PetscMPIInt size;
    PetscViewer viewer;

    ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
    ierr = PetscGetProgramName(program,128);CHKERRQ(ierr);
    ierr = PetscWebSendHeader(fd, 200, "OK", NULL, "text/html", -1);CHKERRQ(ierr);
    fprintf(fd, "<HTML><HEAD><TITLE>Petsc Application Server</TITLE></HEAD>\r\n<BODY>");
    fprintf(fd, "<H4>Serving PETSc application code %s </H4>\r\n\n",program);
    fprintf(fd, "Number of processes %d\r\n\n",size);
    fprintf(fd, "<HR>\r\n");
    ierr = PetscViewerASCIIOpenWithFILE(PETSC_COMM_WORLD,fd,&viewer);CHKERRQ(ierr);
    ierr = PetscOptionsView(viewer);CHKERRQ(ierr);
    ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
    fprintf(fd, "<HR>\r\n");
#if defined(PETSC_HAVE_AMS)
    if (PetscAMSPublishAll) {
      fprintf(fd, "<a href=\"./ams-tree\">Connect to Memory Snooper--Tree Display</a></p>\r\n\r\n");
      fprintf(fd, "<a href=\"./ams-list\">Connect to Memory Snooper--List Display</a></p>\r\n\r\n");
    }
#endif
    fprintf(fd, "<a href=\"./AMSJavascript.html\">Connect to Memory Snooper--Interactive Javascript</a></p>\r\n\r\n");
    ierr = PetscWebSendFooter(fd);CHKERRQ(ierr);
    PetscFunctionReturn(0);
  }

#if defined(PETSC_HAVE_AMS)
  ierr = PetscStrcmp(path,"/ams-list",&flg);CHKERRQ(ierr);
  if (flg) {
    ierr = PetscAMSObjectsDisplayList(fd);CHKERRQ(ierr);
    PetscFunctionReturn(0);
  }
  ierr = PetscStrcmp(path,"/ams-tree",&flg);CHKERRQ(ierr);
  if (flg) {
    ierr = PetscAMSObjectsDisplayTree(fd);CHKERRQ(ierr);
    PetscFunctionReturn(0);
  }
#endif
  ierr = PetscStrcpy(fullpath,"${PETSC_DIR}/include/web");CHKERRQ(ierr);
  ierr = PetscStrcat(fullpath,path);CHKERRQ(ierr);
  ierr = PetscInfo1(NULL,"Checking for file %s\n",fullpath);CHKERRQ(ierr);
  ierr = PetscStrreplace(PETSC_COMM_SELF,fullpath,truefullpath,PETSC_MAX_PATH_LEN);CHKERRQ(ierr);
  fdo  = fopen(truefullpath,"r");
  if (fdo) {
    PetscInt    length,index;
    char        data[4096];
    struct stat statbuf;
    int         n;
    const char  *suffixes[] = {".html",".js",".gif",0}, *mimes[] = {"text/html","text/javascript","image/gif","text/unknown"};

    ierr = PetscStrendswithwhich(fullpath,suffixes,&index);CHKERRQ(ierr);
    type = mimes[index];
    if (!stat(truefullpath, &statbuf)) length = -1;
    else length = S_ISREG(statbuf.st_mode) ? statbuf.st_size : -1;
    ierr = PetscWebSendHeader(fd, 200, "OK", NULL, type, length);CHKERRQ(ierr);
    while ((n = fread(data, 1, sizeof(data), fdo)) > 0) fwrite(data, 1, n, fd);
    fclose(fdo);
    ierr = PetscInfo2(NULL,"Sent file %s to browser using format %s\n",fullpath,type);CHKERRQ(ierr);
    PetscFunctionReturn(0);
  }
  ierr = PetscWebSendError(fd, 501, "Not supported", NULL, "Unknown request.");CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#if defined(PETSC_HAVE_YAML)

/*
    Toy YAML/JSON-RPC function that returns all the arguments it is passed
*/
#undef __FUNCT__
#define __FUNCT__ "YAML_echo"
PETSC_UNUSED static PetscErrorCode YAML_echo(PetscInt argc,char **args,PetscInt *argco,char ***argso)
{
  PetscErrorCode ierr;
  PetscInt       i;

  ierr = PetscPrintf(PETSC_COMM_SELF,"Number of arguments to function %d\n",argc);CHKERRQ(ierr);
  for (i=0; i<argc; i++) {
    ierr = PetscPrintf(PETSC_COMM_SELF,"  %s\n",args[i]);CHKERRQ(ierr);
  }
  *argco = argc;
  ierr   = PetscMalloc(argc*sizeof(char*),argso);CHKERRQ(ierr);
  for (i=0; i<argc; i++) {
    ierr = PetscStrallocpy(args[i],&(*argso)[i]);CHKERRQ(ierr);
  }
  PetscFunctionReturn(0);
}

/* -------------------------------------------------------------------------------------------
     The following set of functions are wrapper functions for AMS functions that

    1)  convert from string arguments to appropriate AMS arguments (int, double, char*, etc)
    2)  call the AMS function
    3)  convert from the AMS result arguments to string arguments
*/

#undef __FUNCT__
#define __FUNCT__ "YAML_AMS_Connect"
/*
      Connects to the local AMS and gets only the first communication name

   Input Parameters:
.     none

   Output Parameter:
.     oarg1 - the string name of the first communicator

*/
PETSC_EXTERN PetscErrorCode YAML_AMS_Connect(PetscInt argc,char **args,PetscInt *argco,char ***argso)
{
  PetscErrorCode ierr;
  char           **list = 0;

  PetscFunctionBegin;
  ierr = AMS_Connect(0,-1,&list);
  if (ierr) {
    ierr = PetscInfo1(NULL,"AMS_Connect() error %d\n",ierr);CHKERRQ(ierr);
  } else if (!list) {
    ierr = PetscInfo(NULL,"AMS_Connect() list empty, not running AMS server\n");CHKERRQ(ierr);
  }
  *argco = 1;
  ierr   = PetscMalloc(sizeof(char*),argso);CHKERRQ(ierr);
  if (list) {
    ierr = PetscStrallocpy(list[0],&(*argso)[0]);CHKERRQ(ierr);
  } else {
    ierr = PetscStrallocpy("No AMS publisher running",&(*argso)[0]);CHKERRQ(ierr);
  }
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "YAML_AMS_Comm_attach"
/*
      Attaches to an AMS communicator

   Input Parameter:
.     arg1 - string name of the communicator

   Output Parameter:
.     oarg1 - the integer name of the communicator

*/
PETSC_EXTERN PetscErrorCode YAML_AMS_Comm_attach(PetscInt argc,char **args,PetscInt *argco,char ***argso)
{
  PetscErrorCode ierr;
  AMS_Comm       comm = -1;

  PetscFunctionBegin;
  ierr = AMS_Comm_attach(args[0],&comm);
  if (ierr) {ierr = PetscInfo1(NULL,"AMS_Comm_attach() error %d\n",ierr);CHKERRQ(ierr);}
  *argco = 1;
  ierr   = PetscMalloc(sizeof(char*),argso);CHKERRQ(ierr);
  ierr   = PetscMalloc(3*sizeof(char*),&argso[0][0]);CHKERRQ(ierr);
  sprintf(argso[0][0],"%d",(int)comm);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "YAML_AMS_Comm_get_memory_list"
/*
      Gets the list of memories on an AMS Comm

   Input Parameter:
.     arg1 - integer name of the communicator

   Output Parameter:
.     oarg1 - the list of names

*/
PETSC_EXTERN PetscErrorCode YAML_AMS_Comm_get_memory_list(PetscInt argc,char **args,PetscInt *argco,char ***argso)
{
  PetscErrorCode ierr;
  char           **mem_list;
  AMS_Comm       comm;
  PetscInt       i,iargco = 0;

  PetscFunctionBegin;
  sscanf(args[0],"%d",&comm);
  ierr = AMS_Comm_get_memory_list(comm,&mem_list);
  if (ierr) {
    ierr = PetscInfo1(NULL,"AMS_Comm_get_memory_list() error %d\n",ierr);CHKERRQ(ierr);
  } else {
    while (mem_list[iargco++]) ;
    iargco--;

    ierr = PetscMalloc((iargco)*sizeof(char*),argso);CHKERRQ(ierr);
    for (i=0; i<iargco; i++) {
      ierr = PetscStrallocpy(mem_list[i],(*argso)+i);CHKERRQ(ierr);
    }
  }
  *argco = iargco;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "YAML_AMS_Memory_attach"
/*
      Attaches to an AMS memory in a communicator

   Input Parameter:
.     arg1 - communicator
.     arg2 - string name of the memory

   Output Parameter:
.     oarg1 - the integer name of the memory
.     oarg2 - the integer step of the memory

*/
PETSC_EXTERN PetscErrorCode YAML_AMS_Memory_attach(PetscInt argc,char **args,PetscInt *argco,char ***argso)
{
  PetscErrorCode ierr;
  AMS_Comm       comm;
  AMS_Memory     mem;
  unsigned int   step;

  PetscFunctionBegin;
  sscanf(args[0],"%d",&comm);
  ierr = AMS_Memory_attach(comm,args[1],&mem,&step);
  if (ierr) {ierr = PetscInfo1(NULL,"AMS_Memory_attach() error %d\n",ierr);CHKERRQ(ierr);}
  *argco = 2;
  ierr   = PetscMalloc(2*sizeof(char*),argso);CHKERRQ(ierr);
  ierr   = PetscMalloc(3*sizeof(char*),&argso[0][0]);CHKERRQ(ierr);
  sprintf(argso[0][0],"%d",(int)mem);
  ierr = PetscMalloc(3*sizeof(char*),&argso[0][1]);CHKERRQ(ierr);
  sprintf(argso[0][1],"%d",(int)step);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "YAML_AMS_Memory_get_field_list"
/*
      Gets the list of fields on an AMS Memory

   Input Parameter:
.     arg1 - integer name of the memory

   Output Parameter:
.     oarg1 - the list of names

*/
PETSC_EXTERN PetscErrorCode YAML_AMS_Memory_get_field_list(PetscInt argc,char **args,PetscInt *argco,char ***argso)
{
  PetscErrorCode ierr;
  char           **field_list;
  AMS_Memory     mem;
  PetscInt       i,iargco = 0;

  PetscFunctionBegin;
  sscanf(args[0],"%d",&mem);
  ierr = AMS_Memory_get_field_list(mem,&field_list);
  if (ierr) {
    ierr = PetscInfo1(NULL,"AMS_Memory_get_field_list() error %d\n",ierr);CHKERRQ(ierr);
  } else {
    while (field_list[iargco++]) ;
    iargco--;

    ierr = PetscMalloc((iargco)*sizeof(char*),argso);CHKERRQ(ierr);
    for (i=0; i<iargco; i++) {
      ierr = PetscStrallocpy(field_list[i],(*argso)+i);CHKERRQ(ierr);
    }
  }
  *argco = iargco;
  PetscFunctionReturn(0);
}

const char *AMS_Data_types[] = {"AMS_DATA_UNDEF","AMS_BOOLEAN","AMS_INT","AMS_FLOAT","AMS_DOUBLE","AMS_STRING","AMS_Data_type","AMS_",0};
const char *AMS_Memory_types[] = {"AMS_MEMORY_UNDEF","AMS_READ","AMS_WRITE","AMS_Memory_type","AMS_",0};
const char *AMS_Shared_types[] = {"AMS_SHARED_UNDEF","AMS_COMMON","AMS_REDUCED","AMS_DISTRIBUTED","AMS_Shared_type","AMS_",0};
const char *AMS_Reduction_types[] = {"AMS_REDUCTION_WHY_NOT_UNDEF?","AMS_SUM","AMS_MAX","AMS_MIN","AMS_REDUCTION_UNDEF","AMS_Reduction_type","AMS_",0};

#undef __FUNCT__
#define __FUNCT__ "YAML_AMS_Utility_ArrayToString"
static PetscErrorCode YAML_AMS_Utility_ArrayToString(PetscInt n,void *addr,AMS_Data_type dtype,char **result)
{
  PetscErrorCode ierr;

  PetscFunctionBegin;
  if (n == 1) {
    if (dtype == AMS_STRING) {
      ierr = PetscStrallocpy(*(const char**)addr,result);CHKERRQ(ierr);
    } else if (dtype == AMS_DOUBLE) {
      ierr = PetscMalloc(20*sizeof(char),result);CHKERRQ(ierr);
      sprintf(*result,"%18.16e",*(double*)addr);
    } else if (dtype == AMS_INT) {
      ierr = PetscMalloc(10*sizeof(char),result);CHKERRQ(ierr);
      sprintf(*result,"%d",*(int*)addr);
    } else if (dtype == AMS_BOOLEAN) {
      if (*(PetscBool*)addr) {
        ierr = PetscStrallocpy("true",result);CHKERRQ(ierr);
      } else {
        ierr = PetscStrallocpy("false",result);CHKERRQ(ierr);
      }
    } else {
      ierr = PetscStrallocpy("Not yet done",result);CHKERRQ(ierr);
    }
  } else {
    PetscInt i;
    size_t   len = 0,lent;
    char     buff[25],**array = (char**)addr;

    if (dtype == AMS_STRING) {
      for (i=0; i<n; i++) {
        ierr = PetscStrlen(array[i],&lent);CHKERRQ(ierr);
        len += lent + 3;
      }
      ierr = PetscMalloc(len*sizeof(char),result);CHKERRQ(ierr);
      ierr = PetscStrcpy(*result,"[\"");CHKERRQ(ierr);
      for (i=0; i<n-1; i++) {
        ierr = PetscStrcat(*result,array[i]);CHKERRQ(ierr);
        ierr = PetscStrcat(*result,"\",\"");CHKERRQ(ierr);
      }
      ierr = PetscStrcat(*result,array[n-1]);CHKERRQ(ierr);
      ierr = PetscStrcat(*result,"\"]");CHKERRQ(ierr);
    } else if (dtype == AMS_DOUBLE) {
      ierr = PetscMalloc(30*n*sizeof(char),result);CHKERRQ(ierr);
      ierr = PetscStrcpy(*result,"[\"");CHKERRQ(ierr);
      for (i=0; i<n-1; i++) {
        sprintf(buff,"%18.16e",*(double*)addr);
        ierr = PetscStrcat(*result,buff);CHKERRQ(ierr);
        ierr = PetscStrcat(*result,"\",\"");CHKERRQ(ierr);
        addr = (void *) ((char *)addr + sizeof(PetscReal));
      }
      sprintf(buff,"%18.16e",*(double*)addr);
      ierr = PetscStrcat(*result,buff);CHKERRQ(ierr);
      ierr = PetscStrcat(*result,"\"]");CHKERRQ(ierr);
    } else if (dtype == AMS_INT) {
      ierr = PetscMalloc(13*n*sizeof(char),result);CHKERRQ(ierr);
      ierr = PetscStrcpy(*result,"[\"");CHKERRQ(ierr);
      for (i=0; i<n-1; i++) {
        sprintf(buff,"%d",*(int*)addr);
        ierr = PetscStrcat(*result,buff);CHKERRQ(ierr);
        ierr = PetscStrcat(*result,"\",\"");CHKERRQ(ierr);
        addr = (void *) ((char *)addr + sizeof(PetscInt));
      }
      sprintf(buff,"%d",*(int*)addr);
      ierr = PetscStrcat(*result,buff);CHKERRQ(ierr);
      ierr = PetscStrcat(*result,"\"]");CHKERRQ(ierr);
    } else if (dtype == AMS_BOOLEAN) {
      ierr = PetscMalloc(7*n*sizeof(char),result);CHKERRQ(ierr);
      ierr = PetscStrcpy(*result,"[\"");CHKERRQ(ierr);
      for (i=0; i<n-1; i++) {
      ierr = PetscStrcat(*result,*(PetscBool*)addr ? "true" : "false");CHKERRQ(ierr);
        addr = (void *) ((char *)addr + sizeof(int));
      }
      ierr = PetscStrcat(*result,*(PetscBool*)addr ? "true" : "false");CHKERRQ(ierr);
      ierr = PetscStrcat(*result,"\"]");CHKERRQ(ierr);
    } else {
      ierr = PetscStrallocpy("Not yet done",result);CHKERRQ(ierr);
    }
  }
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "YAML_AMS_Memory_get_field_info"
/*
      Gets information about a field

   Input Parameter:
.     arg1 - memory
.     arg2 - string name of the field

   Output Parameter:

*/
PETSC_EXTERN PetscErrorCode YAML_AMS_Memory_get_field_info(PetscInt argc,char **args,PetscInt *argco,char ***argso)
{
  PetscErrorCode     ierr;
  AMS_Memory         mem;
  char               *addr;
  int                len;
  AMS_Data_type      dtype;
  AMS_Memory_type    mtype;
  AMS_Shared_type    stype;
  AMS_Reduction_type rtype;

  PetscFunctionBegin;
  sscanf(args[0],"%d",&mem);
  ierr = AMS_Memory_get_field_info(mem,args[1],(void*)&addr,&len,&dtype,&mtype,&stype,&rtype);
  if (ierr) {ierr = PetscInfo1(NULL,"AMS_Memory_get_field_info() error %d\n",ierr);CHKERRQ(ierr);}
  *argco = 5;
  ierr   = PetscMalloc((*argco)*sizeof(char*),argso);CHKERRQ(ierr);
  ierr   = PetscStrallocpy(AMS_Data_types[dtype],&argso[0][0]);CHKERRQ(ierr);
  ierr   = PetscStrallocpy(AMS_Memory_types[mtype],&argso[0][1]);CHKERRQ(ierr);
  ierr   = PetscStrallocpy(AMS_Shared_types[stype],&argso[0][2]);CHKERRQ(ierr);
  ierr   = PetscStrallocpy(AMS_Reduction_types[rtype],&argso[0][3]);CHKERRQ(ierr);
  ierr = YAML_AMS_Utility_ArrayToString(len,addr,dtype,&argso[0][4]);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#include "yaml.h"
#undef __FUNCT__
#define __FUNCT__ "PetscProcessYAMLRPC"
/*
     1) Parses a YAML/JSON-RPC function call generating a function name for an AMS wrapper function and the arguments to the function
     2) loads the function with dlsym(),
     3) calls the wrapper function with the arguments
     4) converts the result arguments back to YAML/JSON.
*/
static PetscErrorCode PetscProcessYAMLRPC(const char *request,char **result)
{
  yaml_parser_t  parser;
  yaml_event_t   event;
  int            done  = 0;
  int            count = 0;
  size_t         len;
  PetscErrorCode ierr;
  PetscBool      method,params,id;
  char           *methodname,*idname,**args,**argso = 0;
  PetscInt       argc = 0,argco,i;
  PetscErrorCode (*fun)(PetscInt,char**,PetscInt*,char***);

  PetscFunctionBegin;
  ierr = PetscMalloc(sizeof(char*),&args);CHKERRQ(ierr);
  yaml_parser_initialize(&parser);
  PetscStrlen(request,&len);
  yaml_parser_set_input_string(&parser, (unsigned char*)request, len);

  /* this is totally bogus; it only handles the simple JSON-RPC messages */
  while (!done) {
    if (!yaml_parser_parse(&parser, &event)) {
      ierr = PetscInfo(NULL,"Found error in yaml/json\n");CHKERRQ(ierr);
      break;
    }
    done = (event.type == YAML_STREAM_END_EVENT);
    switch (event.type) {
    case YAML_STREAM_START_EVENT:
      ierr = PetscInfo(NULL,"Stream start\n");CHKERRQ(ierr);
      break;
    case YAML_STREAM_END_EVENT:
      ierr = PetscInfo(NULL,"Stream end\n");CHKERRQ(ierr);
      break;
    case YAML_DOCUMENT_START_EVENT:
      ierr = PetscInfo(NULL,"Document start\n");CHKERRQ(ierr);
      break;
    case YAML_DOCUMENT_END_EVENT:
      ierr = PetscInfo(NULL,"Document end\n");CHKERRQ(ierr);
      break;
    case YAML_MAPPING_START_EVENT:
      ierr = PetscInfo(NULL,"Mapping start event\n");CHKERRQ(ierr);
      break;
    case YAML_MAPPING_END_EVENT:
      ierr = PetscInfo(NULL,"Mapping end event \n");CHKERRQ(ierr);
      break;
    case YAML_ALIAS_EVENT:
      ierr = PetscInfo1(NULL,"Alias event %s\n",event.data.alias.anchor);CHKERRQ(ierr);
      break;
    case YAML_SCALAR_EVENT:
      ierr = PetscInfo1(NULL,"Scalar event %s\n",event.data.scalar.value);CHKERRQ(ierr);
      ierr = PetscStrcmp((char*)event.data.scalar.value,"method",&method);CHKERRQ(ierr);
      ierr = PetscStrcmp((char*)event.data.scalar.value,"params",&params);CHKERRQ(ierr);
      ierr = PetscStrcmp((char*)event.data.scalar.value,"id",&id);CHKERRQ(ierr);
      if (method) {
        yaml_event_delete(&event);
        ierr = yaml_parser_parse(&parser, &event);CHKERRQ(!ierr);
        ierr = PetscInfo1(NULL,"Method %s\n",event.data.scalar.value);CHKERRQ(ierr);
        ierr = PetscStrallocpy((char*)event.data.scalar.value,&methodname);CHKERRQ(ierr);
      } else if (id) {
        yaml_event_delete(&event);
        ierr = yaml_parser_parse(&parser, &event);CHKERRQ(!ierr);
        ierr = PetscInfo1(NULL,"Id %s\n",event.data.scalar.value);CHKERRQ(ierr);
        ierr = PetscStrallocpy((char*)event.data.scalar.value,&idname);CHKERRQ(ierr);
      } else if (params) {
        yaml_event_delete(&event);
        ierr = yaml_parser_parse(&parser, &event);CHKERRQ(!ierr);
        yaml_event_delete(&event);
        ierr = yaml_parser_parse(&parser, &event);CHKERRQ(!ierr);
        while (event.type != YAML_SEQUENCE_END_EVENT) {
          ierr = PetscInfo1(NULL,"  Parameter %s\n",event.data.scalar.value);CHKERRQ(ierr);
          ierr = PetscStrallocpy((char*)event.data.scalar.value,&args[argc++]);CHKERRQ(ierr);
          yaml_event_delete(&event);
          ierr = yaml_parser_parse(&parser, &event);CHKERRQ(!ierr);
        }
      } else { /* ignore all the other variables in the mapping */
        yaml_event_delete(&event);
        ierr = yaml_parser_parse(&parser, &event);CHKERRQ(!ierr);
      }
      break;
    case YAML_SEQUENCE_START_EVENT:
      ierr = PetscInfo(NULL,"Sequence start event \n");CHKERRQ(ierr);
      break;
    case YAML_SEQUENCE_END_EVENT:
      ierr = PetscInfo(NULL,"Sequence end event \n");CHKERRQ(ierr);
      break;
    default:
      /* It couldn't really happen. */
      break;
    }

    yaml_event_delete(&event);
    count++;
  }
  yaml_parser_delete(&parser);

  ierr = PetscDLLibrarySym(PETSC_COMM_SELF,NULL,NULL,methodname,(void**)&fun);CHKERRQ(ierr);
  if (fun) {
    ierr = PetscInfo1(NULL,"Located function %s and running it\n",methodname);CHKERRQ(ierr);
    ierr = (*fun)(argc,args,&argco,&argso);CHKERRQ(ierr);
  } else {
    ierr = PetscInfo1(NULL,"Did not locate function %s skipping it\n",methodname);CHKERRQ(ierr);
  }

  for (i=0; i<argc; i++) {
    ierr = PetscFree(args[i]);CHKERRQ(ierr);
  }
  ierr = PetscFree(args);CHKERRQ(ierr);
  ierr = PetscFree(methodname);CHKERRQ(ierr);

  /* convert the result back to YAML/JSON; should use YAML/JSON encoder, does not handle zero return arguments */
  ierr = PetscMalloc(16000,result);CHKERRQ(ierr);
  ierr = PetscStrcpy(*result,"{\"error\": null, \"id\": \"");CHKERRQ(ierr);
  ierr = PetscStrcat(*result,idname);CHKERRQ(ierr);
  ierr = PetscStrcat(*result,"\", \"result\" : ");CHKERRQ(ierr);
  if (argco > 1) {ierr = PetscStrcat(*result,"[");CHKERRQ(ierr);}
  for (i=0; i<argco; i++) {
    if (argso[i][0] != '[') {
      ierr = PetscStrcat(*result,"\"");CHKERRQ(ierr);
    }
    ierr = PetscStrcat(*result,argso[i]);CHKERRQ(ierr);
    if (argso[i][0] != '[') {
      ierr = PetscStrcat(*result,"\"");CHKERRQ(ierr);
    }
    if (i < argco-1) {ierr = PetscStrcat(*result,",");CHKERRQ(ierr);}
  }
  if (argco > 1) {ierr = PetscStrcat(*result,"]");CHKERRQ(ierr);}
  ierr = PetscStrcat(*result,"}");CHKERRQ(ierr);
  ierr = PetscInfo1(NULL,"YAML/JSON result of function %s\n",*result);CHKERRQ(ierr);

  /* free work space */
  ierr = PetscFree(idname);CHKERRQ(ierr);
  for (i=0; i<argco; i++) {
    ierr = PetscFree(argso[i]);CHKERRQ(ierr);
  }
  ierr = PetscFree(argso);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscWebServeRequestPostAMSJSONRPC"
/*@C
      PetscWebServeRequestPostAMSJSONRPC - serves a single web POST request based on JSON-RPC

       This function allows a Javascript program (running in the browser) to make an AMS function
       call via JSON-RPC

       The currently available Javascript programs are in ${PETSC_DIR}/include/web

    Not collective

  Input Parameters:
.   fd - the network file to read and write from
-   path - the command from the server

    Level: developer

.seealso: PetscWebServe()
@*/
static PetscErrorCode  PetscWebServeRequestPostAMSJSONRPC(FILE *fd,const char path[])
{
  PetscErrorCode ierr;
  char           buf[16000];
  char           *result;
  int            len = -1;
  size_t         elen;
  char           *fnd;

  PetscFunctionBegin;
  while (PETSC_TRUE) {
    if (!fgets(buf, sizeof(buf), fd)) {
      ierr = PetscInfo(NULL,"Cannot read POST data, giving up\n");CHKERRQ(ierr);
      PetscFunctionReturn(0);
    }
    ierr = PetscInfo1(NULL,"POSTED header: %s",buf);CHKERRQ(ierr);
    ierr = PetscStrstr(buf,"Content-Type:",&fnd);CHKERRQ(ierr);
    if (fnd) {
      ierr = PetscStrstr(buf,"application/json-rpc",&fnd);CHKERRQ(ierr);
      if (!fnd) {
        ierr = PetscInfo(NULL,"POSTED content is not json-rpc, skipping post\n");CHKERRQ(ierr);
        PetscFunctionReturn(0);
      }
    }
    ierr = PetscStrstr(buf,"Content-Length:",&fnd);CHKERRQ(ierr);
    if (fnd) {
      sscanf(buf,"Content-Length: %d\n",&len);
      ierr = PetscInfo1(NULL,"POSTED Content-Length: %d\n",len);CHKERRQ(ierr);
    }
    if (buf[0] == '\r') break;
  }
  if (len == -1) {
    ierr = PetscInfo(NULL,"Did not find POST Content-Length in header, giving up\n");CHKERRQ(ierr);
  }

  if (!fgets(buf, len+1, fd)) { /* why is this len + 1? */
    ierr = PetscInfo(NULL,"Cannot read POST data, giving up\n");CHKERRQ(ierr);
    PetscFunctionReturn(0);
  }
  ierr = PetscInfo1(NULL,"POSTED JSON/RPC request: %s\n",buf);CHKERRQ(ierr);
  fseek(fd, 0, SEEK_CUR); /* Force change of stream direction */
  ierr = PetscProcessYAMLRPC(buf,&result);CHKERRQ(ierr);
  ierr = PetscStrlen(result,&elen);CHKERRQ(ierr);
  ierr = PetscWebSendHeader(fd, 200, "OK", NULL, "application/json-rpc",(int)elen);CHKERRQ(ierr);
  fprintf(fd, "%s",result);
  ierr = PetscInfo(NULL,"Completed AMS JSON-RPC function call\n");CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
#endif

#undef __FUNCT__
#define __FUNCT__ "PetscWebServeRequest"
/*@C
      PetscWebServeRequest - serves a single web request

    Not collective

  Input Parameters:
.   port - the port

    Level: developer

.seealso: PetscWebServe()
@*/
static PetscErrorCode  PetscWebServeRequest(int port)
{
  PetscErrorCode ierr;
  FILE           *fd;
  char           buf[4096];
  char           *method, *path, *protocol;
  PetscBool      flg;
  PetscToken     tok;

  PetscFunctionBegin;
  fd = fdopen(port, "r+");

  ierr = PetscInfo(NULL,"Processing web request\n");CHKERRQ(ierr);
  if (!fgets(buf, sizeof(buf), fd)) {
    ierr = PetscInfo(NULL,"Cannot read web request, giving up\n");CHKERRQ(ierr);
    goto theend;
  }
  ierr = PetscInfo1(NULL,"Processing web request %s",buf);CHKERRQ(ierr);

  ierr = PetscTokenCreate(buf,' ',&tok);CHKERRQ(ierr);
  ierr = PetscTokenFind(tok,&method);CHKERRQ(ierr);
  ierr = PetscTokenFind(tok,&path);CHKERRQ(ierr);
  ierr = PetscTokenFind(tok,&protocol);CHKERRQ(ierr);

  if (!method || !path || !protocol) {
    ierr = PetscInfo(NULL,"Web request not well formatted, giving up\n");CHKERRQ(ierr);
    goto theend;
  }

  ierr = PetscStrcmp(method,"GET",&flg);
  if (flg) {
      ierr = PetscWebServeRequestGet(fd,path);CHKERRQ(ierr);
  } else {
#if defined(PETSC_HAVE_YAML)
    ierr = PetscStrcmp(method,"POST",&flg);
    if (flg) {
      ierr = PetscWebServeRequestPostAMSJSONRPC(fd,path);CHKERRQ(ierr);
    } else {
#else
    {
#endif
      ierr = PetscWebSendError(fd, 501, "Not supported", NULL, "Method is not supported.");CHKERRQ(ierr);
      ierr = PetscInfo(NULL,"Web request not a GET or POST, giving up\n");CHKERRQ(ierr);
    }
  }
theend:
  ierr = PetscTokenDestroy(&tok);CHKERRQ(ierr);
  fclose(fd);
  ierr = PetscInfo1(NULL,"Finished processing request %s\n",method);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "PetscWebServeWait"
/*@C
      PetscWebServeWait - waits for requests on a thread

    Not collective

  Input Parameter:
.   port - port to listen on

    Level: developer

.seealso: PetscViewerSocketOpen(), PetscWebServe()
@*/
void *PetscWebServeWait(int *port)
{
  PetscErrorCode ierr;
  int            iport,listenport,tport = *port;

  ierr = PetscInfo1(NULL,"Starting webserver at port %d\n",tport);if (ierr) return 0;
  ierr = PetscFree(port);if (ierr) return 0;
  ierr = PetscSocketEstablish(tport,&listenport);if (ierr) return 0;
  while (1) {
    ierr = PetscSocketListen(listenport,&iport);if (ierr) return 0;
    ierr = PetscWebServeRequest(iport);if (ierr) return 0;
    close(iport);
  }
  close(listenport);
  return 0;
}

#undef __FUNCT__
#define __FUNCT__ "PetscWebServe"
/*@C
      PetscWebServe - start up the PETSc web server and respond to requests

    Not collective - only does something on process zero of the communicator

  Input Parameters:
+   comm - the MPI communicator
-   port - port to listen on

  Options Database Key:
+  -server <port> - start PETSc webserver (default port is 8080)
-  -ams_publish_objects


   Notes: Point your browser to http://hostname:8080   to access the PETSc web server, where hostname is the name of your machine.
      If you are running PETSc on your local machine you can use http://localhost:8080

      If the PETSc program completes before you connect with the browser you will not be able to connect to the PETSc webserver.

      Read the top of $PETSC_DIR/include/web/AMSJavascript.py before running.

    Level: intermediate

.seealso: PetscViewerSocketOpen()
@*/
PetscErrorCode  PetscWebServe(MPI_Comm comm,int port)
{
  PetscErrorCode ierr;
  PetscMPIInt    rank;
  pthread_t      thread;
  int            *trueport;

  PetscFunctionBegin;
  if (port < 1 && port != PETSC_DEFAULT && port != PETSC_DECIDE) SETERRQ1(PETSC_COMM_WORLD,PETSC_ERR_ARG_WRONG,"Cannot use negative port number %d",port);
  ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
  if (rank) PetscFunctionReturn(0);

  if (port == PETSC_DECIDE || port == PETSC_DEFAULT) port = 8080;
  ierr = PetscMalloc(1*sizeof(int),&trueport);CHKERRQ(ierr); /* malloc this so it still exists in thread */
  *trueport = port;
  ierr = pthread_create(&thread, NULL, (void *(*)(void*))PetscWebServeWait, trueport);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
#endif