1 #include <petscsys.h>
2
3 /*@C
4 PetscOptionsGetenv - Gets an environmental variable, broadcasts to all
5 processors in communicator from MPI rank zero
6
7 Collective
8
9 Input Parameters:
10 + comm - communicator to share variable
11 . name - name of environmental variable
12 - len - amount of space allocated to hold variable
13
14 Output Parameters:
15 + flag - if not `NULL` indicates if the variable was found
16 - env - value of variable
17
18 Level: advanced
19
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`
25
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
29
30 .seealso: `PetscOptionsHasName()`
31 @*/
PetscOptionsGetenv(MPI_Comm comm,const char name[],char env[],size_t len,PetscBool * flag)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;
37
38 PetscFunctionBegin;
39 /* first check options database */
40 PetscCall(PetscStrncmp(name, "PETSC_", 6, &spetsc));
41
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));
55
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 }
71
72 /*
73 PetscSetDisplay - Tries to set the X Windows display variable for all processors.
74 The variable `PetscDisplay` contains the X Windows display variable.
75
76 */
77 static char PetscDisplay[256];
78
PetscWorldIsSingleHost(PetscBool * onehost)79 static PetscErrorCode PetscWorldIsSingleHost(PetscBool *onehost)
80 {
81 char hostname[256], roothostname[256];
82 PetscMPIInt localmatch, allmatch;
83 PetscBool flag;
84
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));
90
91 localmatch = (PetscMPIInt)flag;
92
93 PetscCallMPI(MPIU_Allreduce(&localmatch, &allmatch, 1, MPI_INT, MPI_LAND, PETSC_COMM_WORLD));
94
95 *onehost = (PetscBool)allmatch;
96 PetscFunctionReturn(PETSC_SUCCESS);
97 }
98
PetscSetDisplay(void)99 PetscErrorCode PetscSetDisplay(void)
100 {
101 PetscMPIInt size, rank;
102 PetscBool flag, singlehost = PETSC_FALSE;
103 char display[sizeof(PetscDisplay)];
104 const char *str;
105
106 PetscFunctionBegin;
107 PetscCall(PetscOptionsGetString(NULL, NULL, "-display", PetscDisplay, sizeof(PetscDisplay), &flag));
108 if (flag) PetscFunctionReturn(PETSC_SUCCESS);
109
110 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
111 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
112
113 PetscCall(PetscWorldIsSingleHost(&singlehost));
114
115 str = getenv("DISPLAY");
116 if (!str) str = ":0.0";
117 #if defined(PETSC_HAVE_X)
118 flag = PETSC_FALSE;
119 PetscCall(PetscOptionsGetBool(NULL, NULL, "-x_virtual", &flag, NULL));
120 if (flag) {
121 /* this is a crude hack, but better than nothing */
122 PetscCall(PetscPOpen(PETSC_COMM_WORLD, NULL, "pkill -15 Xvfb", "r", NULL));
123 PetscCall(PetscSleep(1));
124 PetscCall(PetscPOpen(PETSC_COMM_WORLD, NULL, "Xvfb :15 -screen 0 1600x1200x24", "r", NULL));
125 PetscCall(PetscSleep(5));
126 str = ":15";
127 }
128 #endif
129 if (str[0] != ':' || singlehost) {
130 PetscCall(PetscStrncpy(display, str, sizeof(display)));
131 } else if (rank == 0) {
132 PetscCall(PetscGetHostName(display, sizeof(display)));
133 PetscCall(PetscStrlcat(display, str, sizeof(display)));
134 }
135 PetscCallMPI(MPI_Bcast(display, sizeof(display), MPI_CHAR, 0, PETSC_COMM_WORLD));
136 PetscCall(PetscMemcpy(PetscDisplay, display, sizeof(PetscDisplay)));
137
138 PetscDisplay[sizeof(PetscDisplay) - 1] = 0;
139 PetscFunctionReturn(PETSC_SUCCESS);
140 }
141
142 /*@C
143 PetscGetDisplay - Gets the X windows display variable for all processors.
144
145 Input Parameter:
146 . n - length of string display
147
148 Output Parameter:
149 . display - the display string
150
151 Options Database Keys:
152 + -display <display> - sets the display to use
153 - -x_virtual - forces use of a X virtual display Xvfb that will not display anything but -draw_save will still work. Xvfb is automatically
154 started up in PetscSetDisplay() with this option
155
156 Level: advanced
157
158 .seealso: `PETSC_DRAW_X`, `PetscDrawOpenX()`
159 @*/
PetscGetDisplay(char display[],size_t n)160 PetscErrorCode PetscGetDisplay(char display[], size_t n)
161 {
162 PetscFunctionBegin;
163 PetscCall(PetscStrncpy(display, PetscDisplay, n));
164 PetscFunctionReturn(PETSC_SUCCESS);
165 }
166