1 /* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
2 /*
3  *  (C) 2001 by Argonne National Laboratory.
4  *      See COPYRIGHT in top-level directory.
5  */
6 #include "mpi.h"
7 #include <stdio.h>
8 #include <string.h>
9 #include <stdlib.h>
10 
11 /* tests whether atomicity semantics are satisfied for overlapping accesses
12    in atomic mode. The probability of detecting errors is higher if you run
13    it on 8 or more processes. */
14 
15 /* The file name is taken as a command-line argument. */
16 
17 #define BUFSIZE 10000    /* no. of integers */
18 #define VERBOSE 0
main(int argc,char ** argv)19 int main(int argc, char **argv)
20 {
21     int *writebuf, *readbuf, i, mynod, nprocs, len, err;
22     char *filename;
23     int errs=0, toterrs;
24     MPI_Datatype newtype;
25     MPI_File fh;
26     MPI_Status status;
27     MPI_Info info;
28 
29     MPI_Init(&argc,&argv);
30     MPI_Comm_rank(MPI_COMM_WORLD, &mynod);
31     MPI_Comm_size(MPI_COMM_WORLD, &nprocs);
32 
33 /* process 0 takes the file name as a command-line argument and
34    broadcasts it to other processes */
35     if (!mynod) {
36 	i = 1;
37 	while ((i < argc) && strcmp("-fname", *argv)) {
38 	    i++;
39 	    argv++;
40 	}
41 	if (i >= argc) {
42 	    fprintf(stderr, "\n*#  Usage: coll_test -fname filename\n\n");
43 	    MPI_Abort(MPI_COMM_WORLD, 1);
44 	}
45 	argv++;
46 	len = strlen(*argv);
47 	filename = (char *) malloc(len+1);
48 	strcpy(filename, *argv);
49 	MPI_Bcast(&len, 1, MPI_INT, 0, MPI_COMM_WORLD);
50 	MPI_Bcast(filename, len+1, MPI_CHAR, 0, MPI_COMM_WORLD);
51     }
52     else {
53 	MPI_Bcast(&len, 1, MPI_INT, 0, MPI_COMM_WORLD);
54 	filename = (char *) malloc(len+1);
55 	MPI_Bcast(filename, len+1, MPI_CHAR, 0, MPI_COMM_WORLD);
56     }
57 
58     writebuf = (int *) malloc(BUFSIZE*sizeof(int));
59     readbuf = (int *) malloc(BUFSIZE*sizeof(int));
60 
61 /* test atomicity of contiguous accesses */
62 
63 /* initialize file to all zeros */
64     if (!mynod) {
65 	MPI_File_delete(filename, MPI_INFO_NULL);
66 	MPI_File_open(MPI_COMM_SELF, filename, MPI_MODE_CREATE |
67              MPI_MODE_RDWR, MPI_INFO_NULL, &fh);
68 	for (i=0; i<BUFSIZE; i++) writebuf[i] = 0;
69 	MPI_File_write(fh, writebuf, BUFSIZE, MPI_INT, &status);
70 	MPI_File_close(&fh);
71 #if VERBOSE
72 	fprintf(stderr, "\ntesting contiguous accesses\n");
73 #endif
74     }
75     MPI_Barrier(MPI_COMM_WORLD);
76 
77     for (i=0; i<BUFSIZE; i++) writebuf[i] = 10;
78     for (i=0; i<BUFSIZE; i++) readbuf[i] = 20;
79 
80     MPI_File_open(MPI_COMM_WORLD, filename, MPI_MODE_CREATE |
81              MPI_MODE_RDWR, MPI_INFO_NULL, &fh);
82 
83 /* set atomicity to true */
84     err = MPI_File_set_atomicity(fh, 1);
85     if (err != MPI_SUCCESS) {
86 	fprintf(stderr, "Atomic mode not supported on this file system.\n");fflush(stderr);
87 	MPI_Abort(MPI_COMM_WORLD, 1);
88     }
89 
90     MPI_Barrier(MPI_COMM_WORLD);
91 
92 /* process 0 writes and others concurrently read. In atomic mode,
93    the data read must be either all old values or all new values; nothing
94    in between. */
95 
96     if (!mynod) MPI_File_write(fh, writebuf, BUFSIZE, MPI_INT, &status);
97     else {
98 	err = MPI_File_read(fh, readbuf, BUFSIZE, MPI_INT, &status);
99 	if (err == MPI_SUCCESS) {
100 	    if (readbuf[0] == 0) { /* the rest must also be 0 */
101 		for (i=1; i<BUFSIZE; i++)
102 		    if (readbuf[i] != 0) {
103 			errs++;
104 			fprintf(stderr, "Process %d: readbuf[%d] is %d, should be 0\n", mynod, i, readbuf[i]);
105 			MPI_Abort(MPI_COMM_WORLD, 1);
106 		    }
107 	    }
108 	    else if (readbuf[0] == 10) { /* the rest must also be 10 */
109 		for (i=1; i<BUFSIZE; i++)
110 		    if (readbuf[i] != 10) {
111 			errs++;
112 			fprintf(stderr, "Process %d: readbuf[%d] is %d, should be 10\n", mynod, i, readbuf[i]);
113 			MPI_Abort(MPI_COMM_WORLD, 1);
114 		    }
115 	    }
116 	    else {
117 		errs++;
118 		fprintf(stderr, "Process %d: readbuf[0] is %d, should be either 0 or 10\n", mynod, readbuf[0]);
119 	    }
120 	}
121     }
122 
123     MPI_File_close(&fh);
124 
125     MPI_Barrier(MPI_COMM_WORLD);
126 
127 
128 /* repeat the same test with a noncontiguous filetype */
129 
130     MPI_Type_vector(BUFSIZE, 1, 2, MPI_INT, &newtype);
131     MPI_Type_commit(&newtype);
132 
133     MPI_Info_create(&info);
134     /* I am setting these info values for testing purposes only. It is
135        better to use the default values in practice. */
136     MPI_Info_set(info, "ind_rd_buffer_size", "1209");
137     MPI_Info_set(info, "ind_wr_buffer_size", "1107");
138 
139     if (!mynod) {
140 	MPI_File_delete(filename, MPI_INFO_NULL);
141 	MPI_File_open(MPI_COMM_SELF, filename, MPI_MODE_CREATE |
142              MPI_MODE_RDWR, info, &fh);
143 	for (i=0; i<BUFSIZE; i++) writebuf[i] = 0;
144 	MPI_File_set_view(fh, 0, MPI_INT, newtype, "native", info);
145 	MPI_File_write(fh, writebuf, BUFSIZE, MPI_INT, &status);
146 	MPI_File_close(&fh);
147 #if VERBOSE
148 	fprintf(stderr, "\ntesting noncontiguous accesses\n");
149 #endif
150     }
151     MPI_Barrier(MPI_COMM_WORLD);
152 
153     for (i=0; i<BUFSIZE; i++) writebuf[i] = 10;
154     for (i=0; i<BUFSIZE; i++) readbuf[i] = 20;
155 
156     MPI_File_open(MPI_COMM_WORLD, filename, MPI_MODE_CREATE |
157              MPI_MODE_RDWR, info, &fh);
158     MPI_File_set_atomicity(fh, 1);
159     MPI_File_set_view(fh, 0, MPI_INT, newtype, "native", info);
160     MPI_Barrier(MPI_COMM_WORLD);
161 
162     if (!mynod) MPI_File_write(fh, writebuf, BUFSIZE, MPI_INT, &status);
163     else {
164 	err = MPI_File_read(fh, readbuf, BUFSIZE, MPI_INT, &status);
165 	if (err == MPI_SUCCESS) {
166 	    if (readbuf[0] == 0) {
167 		for (i=1; i<BUFSIZE; i++)
168 		    if (readbuf[i] != 0) {
169 			errs++;
170 			fprintf(stderr, "Process %d: readbuf[%d] is %d, should be 0\n", mynod, i, readbuf[i]);
171 			MPI_Abort(MPI_COMM_WORLD, 1);
172 		    }
173 	    }
174 	    else if (readbuf[0] == 10) {
175 		for (i=1; i<BUFSIZE; i++)
176 		    if (readbuf[i] != 10) {
177 			errs++;
178 			fprintf(stderr, "Process %d: readbuf[%d] is %d, should be 10\n", mynod, i, readbuf[i]);
179 			MPI_Abort(MPI_COMM_WORLD, 1);
180 		    }
181 	    }
182 	    else {
183 		errs++;
184 		fprintf(stderr, "Process %d: readbuf[0] is %d, should be either 0 or 10\n", mynod, readbuf[0]);
185 	    }
186 	}
187     }
188 
189     MPI_File_close(&fh);
190 
191     MPI_Barrier(MPI_COMM_WORLD);
192 
193     MPI_Allreduce( &errs, &toterrs, 1, MPI_INT, MPI_SUM, MPI_COMM_WORLD );
194     if (mynod == 0) {
195 	if( toterrs > 0) {
196 	    fprintf( stderr, "Found %d errors\n", toterrs );
197 	}
198 	else {
199 	    fprintf( stdout, " No Errors\n" );
200 	}
201     }
202     MPI_Type_free(&newtype);
203     MPI_Info_free(&info);
204     free(writebuf);
205     free(readbuf);
206     free(filename);
207 
208     MPI_Finalize();
209     return 0;
210 }
211