Actual source code: pdisplay.c
1: #include <petscsys.h>
3: /*@C
4: PetscOptionsGetenv - Gets an environmental variable, broadcasts to all
5: processors in communicator from MPI rank zero
7: Collective
9: Input Parameters:
10: + comm - communicator to share variable
11: . name - name of environmental variable
12: - len - amount of space allocated to hold variable
14: Output Parameters:
15: + flag - if not `NULL` indicates if the variable was found
16: - env - value of variable
18: Level: advanced
20: Notes:
21: You can also "set" the environmental variable by setting the options database value
22: -name "stringvalue" (with name in lower case). If name begins with PETSC_ this is
23: discarded before checking the database. For example, `PETSC_VIEWER_SOCKET_PORT` would
24: be given as `-viewer_socket_port 9000`
26: If comm does not contain the 0th process in the `MPI_COMM_WORLD` it is likely on
27: many systems that the environmental variable will not be set unless you
28: put it in a universal location like a .chsrc file
30: .seealso: `PetscOptionsHasName()`
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: PetscFunctionBegin;
39: /* first check options database */
40: PetscCall(PetscStrncmp(name, "PETSC_", 6, &spetsc));
42: PetscCall(PetscStrncpy(work, "-", sizeof(work)));
43: if (spetsc) {
44: PetscCall(PetscStrlcat(work, name + 6, sizeof(work)));
45: } else {
46: PetscCall(PetscStrlcat(work, name, sizeof(work)));
47: }
48: PetscCall(PetscStrtolower(work));
49: if (env) {
50: PetscCall(PetscOptionsGetString(NULL, NULL, work, env, len, &flg));
51: if (flg) {
52: if (flag) *flag = PETSC_TRUE;
53: } else { /* now check environment */
54: PetscCall(PetscArrayzero(env, len));
56: PetscCallMPI(MPI_Comm_rank(comm, &rank));
57: if (rank == 0) {
58: str = getenv(name);
59: if (str) flg = PETSC_TRUE;
60: if (str && env) PetscCall(PetscStrncpy(env, str, len));
61: }
62: PetscCallMPI(MPI_Bcast(&flg, 1, MPI_C_BOOL, 0, comm));
63: PetscCallMPI(MPI_Bcast(env, (PetscMPIInt)len, MPI_CHAR, 0, comm));
64: if (flag) *flag = flg;
65: }
66: } else {
67: PetscCall(PetscOptionsHasName(NULL, NULL, work, flag));
68: }
69: PetscFunctionReturn(PETSC_SUCCESS);
70: }
72: /*
73: PetscSetDisplay - Tries to set the X Windows display variable for all processors.
74: The variable `PetscDisplay` contains the X Windows display variable.
76: */
77: static char PetscDisplay[256];
79: static PetscErrorCode PetscWorldIsSingleHost(PetscBool *onehost)
80: {
81: char hostname[256], roothostname[256];
82: PetscMPIInt localmatch, allmatch;
83: PetscBool flag;
85: PetscFunctionBegin;
86: PetscCall(PetscGetHostName(hostname, sizeof(hostname)));
87: PetscCall(PetscMemcpy(roothostname, hostname, sizeof(hostname)));
88: PetscCallMPI(MPI_Bcast(roothostname, sizeof(roothostname), MPI_CHAR, 0, PETSC_COMM_WORLD));
89: PetscCall(PetscStrcmp(hostname, roothostname, &flag));
91: localmatch = (PetscMPIInt)flag;
93: PetscCallMPI(MPIU_Allreduce(&localmatch, &allmatch, 1, MPI_INT, MPI_LAND, PETSC_COMM_WORLD));
95: *onehost = (PetscBool)allmatch;
96: PetscFunctionReturn(PETSC_SUCCESS);
97: }
99: /*@C
100: PetscSetDisplay - Determine and set PETSc's X11 display string from the `-display` option, the `DISPLAY` environment variable, or the hostname of MPI rank 0 when running across multiple nodes
102: Collective; No Fortran Support
104: Level: developer
106: Note:
107: Called automatically by `PetscInitialize()` so that subsequent `PetscDraw` X11 windows have a usable display target.
109: .seealso: `PetscGetDisplay()`, `PetscDraw`, `PETSC_DRAW_X`
110: @*/
111: PetscErrorCode PetscSetDisplay(void)
112: {
113: PetscMPIInt size, rank;
114: PetscBool flag, singlehost = PETSC_FALSE;
115: char display[sizeof(PetscDisplay)];
116: const char *str;
118: PetscFunctionBegin;
119: PetscCall(PetscOptionsGetString(NULL, NULL, "-display", PetscDisplay, sizeof(PetscDisplay), &flag));
120: if (flag) PetscFunctionReturn(PETSC_SUCCESS);
122: PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
123: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
125: PetscCall(PetscWorldIsSingleHost(&singlehost));
127: str = getenv("DISPLAY");
128: if (!str) str = ":0.0";
129: #if defined(PETSC_HAVE_X)
130: flag = PETSC_FALSE;
131: PetscCall(PetscOptionsGetBool(NULL, NULL, "-x_virtual", &flag, NULL));
132: if (flag) {
133: /* this is a crude hack, but better than nothing */
134: PetscCall(PetscPOpen(PETSC_COMM_WORLD, NULL, "pkill -15 Xvfb", "r", NULL));
135: PetscCall(PetscSleep(1));
136: PetscCall(PetscPOpen(PETSC_COMM_WORLD, NULL, "Xvfb :15 -screen 0 1600x1200x24", "r", NULL));
137: PetscCall(PetscSleep(5));
138: str = ":15";
139: }
140: #endif
141: if (str[0] != ':' || singlehost) {
142: PetscCall(PetscStrncpy(display, str, sizeof(display)));
143: } else if (rank == 0) {
144: PetscCall(PetscGetHostName(display, sizeof(display)));
145: PetscCall(PetscStrlcat(display, str, sizeof(display)));
146: }
147: PetscCallMPI(MPI_Bcast(display, sizeof(display), MPI_CHAR, 0, PETSC_COMM_WORLD));
148: PetscCall(PetscMemcpy(PetscDisplay, display, sizeof(PetscDisplay)));
150: PetscDisplay[sizeof(PetscDisplay) - 1] = 0;
151: PetscFunctionReturn(PETSC_SUCCESS);
152: }
154: /*@C
155: PetscGetDisplay - Gets the X windows display variable for all processors.
157: Input Parameter:
158: . n - length of string display
160: Output Parameter:
161: . display - the display string
163: Options Database Keys:
164: + -display display - sets the display to use
165: - -x_virtual - forces use of a X virtual display Xvfb that will not display anything but -draw_save will still work. Xvfb is automatically
166: started up in PetscSetDisplay() with this option
168: Level: advanced
170: .seealso: `PETSC_DRAW_X`, `PetscDrawOpenX()`
171: @*/
172: PetscErrorCode PetscGetDisplay(char display[], size_t n)
173: {
174: PetscFunctionBegin;
175: PetscCall(PetscStrncpy(display, PetscDisplay, n));
176: PetscFunctionReturn(PETSC_SUCCESS);
177: }