Actual source code: pdisplay.c


  2: #include <petscsys.h>

  4: /*@C
  5:      PetscOptionsGetenv - Gets an environmental variable, broadcasts to all
  6:           processors in communicator from first.

  8:      Collective

 10:    Input Parameters:
 11: +    comm - communicator to share variable
 12: .    name - name of environmental variable
 13: -    len - amount of space allocated to hold variable

 15:    Output Parameters:
 16: +    flag - if not NULL tells if variable found or not
 17: -    env - value of variable

 19:   Level: advanced

 21:    Notes:
 22:     You can also "set" the environmental variable by setting the options database value
 23:     -name "stringvalue" (with name in lower case). If name begins with PETSC_ this is
 24:     discarded before checking the database. For example, PETSC_VIEWER_SOCKET_PORT would
 25:     be given as -viewer_socket_port 9000

 27:     If comm does not contain the 0th process in the MPIEXEC it is likely on
 28:     many systems that the environmental variable will not be set unless you
 29:     put it in a universal location like a .chsrc file

 31: @*/
 32: PetscErrorCode  PetscOptionsGetenv(MPI_Comm comm,const char name[],char env[],size_t len,PetscBool  *flag)
 33: {
 34:   PetscMPIInt    rank;
 35:   char           *str,work[256];
 36:   PetscBool      flg = PETSC_FALSE,spetsc;

 38:   /* first check options database */
 39:   PetscStrncmp(name,"PETSC_",6,&spetsc);

 41:   PetscStrcpy(work,"-");
 42:   if (spetsc) {
 43:     PetscStrlcat(work,name+6,sizeof(work));
 44:   } else {
 45:     PetscStrlcat(work,name,sizeof(work));
 46:   }
 47:   PetscStrtolower(work);
 48:   if (env) {
 49:     PetscOptionsGetString(NULL,NULL,work,env,len,&flg);
 50:     if (flg) {
 51:       if (flag) *flag = PETSC_TRUE;
 52:     } else { /* now check environment */
 53:       PetscArrayzero(env,len);

 55:       MPI_Comm_rank(comm,&rank);
 56:       if (rank == 0) {
 57:         str = getenv(name);
 58:         if (str) flg = PETSC_TRUE;
 59:         if (str && env) PetscStrncpy(env,str,len);
 60:       }
 61:       MPI_Bcast(&flg,1,MPIU_BOOL,0,comm);
 62:       MPI_Bcast(env,len,MPI_CHAR,0,comm);
 63:       if (flag) *flag = flg;
 64:     }
 65:   } else {
 66:     PetscOptionsHasName(NULL,NULL,work,flag);
 67:   }
 68:   return 0;
 69: }

 71: /*
 72:      PetscSetDisplay - Tries to set the X Windows display variable for all processors.
 73:                        The variable PetscDisplay contains the X Windows display variable.

 75: */
 76: static char PetscDisplay[256];

 78: static PetscErrorCode PetscWorldIsSingleHost(PetscBool  *onehost)
 79: {
 80:   char           hostname[256],roothostname[256];
 81:   PetscMPIInt    localmatch,allmatch;
 82:   PetscBool      flag;

 84:   PetscGetHostName(hostname,sizeof(hostname));
 85:   PetscMemcpy(roothostname,hostname,sizeof(hostname));
 86:   MPI_Bcast(roothostname,sizeof(roothostname),MPI_CHAR,0,PETSC_COMM_WORLD);
 87:   PetscStrcmp(hostname,roothostname,&flag);

 89:   localmatch = (PetscMPIInt)flag;

 91:   MPIU_Allreduce(&localmatch,&allmatch,1,MPI_INT,MPI_LAND,PETSC_COMM_WORLD);

 93:   *onehost = (PetscBool)allmatch;
 94:   return 0;
 95: }

 97: PetscErrorCode  PetscSetDisplay(void)
 98: {
 99:   PetscMPIInt    size,rank;
100:   PetscBool      flag,singlehost=PETSC_FALSE;
101:   char           display[sizeof(PetscDisplay)];
102:   const char     *str;

104:   PetscOptionsGetString(NULL,NULL,"-display",PetscDisplay,sizeof(PetscDisplay),&flag);
105:   if (flag) return 0;

107:   MPI_Comm_size(PETSC_COMM_WORLD,&size);
108:   MPI_Comm_rank(PETSC_COMM_WORLD,&rank);

110:   PetscWorldIsSingleHost(&singlehost);

112:   str = getenv("DISPLAY");
113:   if (!str) str = ":0.0";
114: #if defined(PETSC_HAVE_X)
115:   flag = PETSC_FALSE;
116:   PetscOptionsGetBool(NULL,NULL,"-x_virtual",&flag,NULL);
117:   if (flag) {
118:     /*  this is a crude hack, but better than nothing */
119:     PetscPOpen(PETSC_COMM_WORLD,NULL,"pkill -9 Xvfb","r",NULL);
120:     PetscSleep(1);
121:     PetscPOpen(PETSC_COMM_WORLD,NULL,"Xvfb :15 -screen 0 1600x1200x24","r",NULL);
122:     PetscSleep(5);
123:     str  = ":15";
124:   }
125: #endif
126:   if (str[0] != ':' || singlehost) {
127:     PetscStrncpy(display,str,sizeof(display));
128:   } else if (rank == 0) {
129:     PetscGetHostName(display,sizeof(display));
130:     PetscStrlcat(display,str,sizeof(display));
131:   }
132:   MPI_Bcast(display,sizeof(display),MPI_CHAR,0,PETSC_COMM_WORLD);
133:   PetscMemcpy(PetscDisplay,display,sizeof(PetscDisplay));

135:   PetscDisplay[sizeof(PetscDisplay)-1] = 0;
136:   return 0;
137: }

139: /*
140:      PetscGetDisplay - Gets the display variable for all processors.

142:   Input Parameters:
143: .   n - length of string display

145:   Output Parameters:
146: .   display - the display string

148:   Options Database:
149: +  -display <display> - sets the display to use
150: -  -x_virtual - forces use of a X virtual display Xvfb that will not display anything but -draw_save will still work. Xvfb is automatically
151:                 started up in PetscSetDisplay() with this option

153: */
154: PetscErrorCode  PetscGetDisplay(char display[],size_t n)
155: {
156:   PetscStrncpy(display,PetscDisplay,n);
157:   return 0;
158: }