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+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group. *
+ * All rights reserved. *
+ * *
+ * This file is part of HDF5. The full HDF5 copyright notice, including *
+ * terms governing use, modification, and redistribution, is contained in *
+ * the files COPYING and Copyright.html. COPYING can be found at the root *
+ * of the source code distribution tree; Copyright.html can be found at the *
+ * root level of an installed copy of the electronic HDF5 document set and *
+ * is linked from the top-level documents page. It can also be found at *
+ * http://hdfgroup.org/HDF5/doc/Copyright.html. If you do not have *
+ * access to either file, you may request a copy from help@hdfgroup.org. *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+/*-------------------------------------------------------------------------
+ *
+ * Created: atomic_reader.c
+ *
+ * Purpose: This is the "reader" part of the standalone test to check
+ * atomic read-write operation on a system.
+ * a) atomic_reader.c--the reader (this file)
+ * a) atomic_writer.c--the writer
+ * c) atomic_data--the name of the data file used by writer and reader
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/***********/
+/* Headers */
+/***********/
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if !defined(WIN32) && !defined(__MINGW32__)
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+/****************/
+/* Local Macros */
+/****************/
+
+#define FILENAME "atomic_data"
+#define READ_TRIES 20
+#define OPEN_TRIES 50
+
+/********************/
+/* Local Prototypes */
+/********************/
+
+static void usage(void);
+int verify(int fd, unsigned int k);
+void print_info(int *info, unsigned int lastr, unsigned iteration);
+
+
+
+/*-------------------------------------------------------------------------
+ * Function: usage
+ *
+ * Purpose: To print the command line options
+ *
+ * Parameters: None
+ *
+ * Return: void
+ *
+ *-------------------------------------------------------------------------
+ */
+static void
+usage(void)
+{
+ printf("\n");
+ printf("Usage error!\n");
+ printf("Usage: atomic_reader -n <number of integers to read> -i <number of iterations for reader>\n");
+ printf(" Note**The number of integers for option n has to be positive\n");
+ printf(" Note**The number of integers for option i has to be positive\n");
+ printf("\n");
+} /* usage() */
+
+
+/*-------------------------------------------------------------------------
+ * Function: verify
+ *
+ * Purpose: To verify that the data read is the pattern expected.
+ * Each integer read should be the same as the index.
+ * When a difference is encountered, the remaining integers
+ * read should be the same as the previous index.
+ * For example, the pattern expected should be either:
+ * a) 01234567....n-1
+ * or
+ * b) if at index 4, a difference is encountered,
+ * the remaining integers should be all "3"s as:
+ * 012333333333333
+ *
+ * Parameters:
+ * fd -- the file descriptor
+ * k -- the number of integers to read
+ *
+ * Return:
+ * positive on success
+ * negative on failure
+ *
+ *-------------------------------------------------------------------------
+ */
+int
+verify(int fd, unsigned int k)
+{
+ unsigned int i; /* local index variable */
+ ssize_t bytes_read; /* the number of bytes read */
+ unsigned int *buf = NULL; /* buffer to hold data read */
+
+ /* Allocate buffer for data read */
+ if((buf = (unsigned int *)malloc(k * sizeof(unsigned int))) == NULL) {
+ printf("READER: error from malloc\n");
+ goto error;
+ } /* end if */
+
+ /* Position the file at the beginning */
+ if(lseek(fd, (off_t)0, SEEK_SET) < 0) {
+ printf("READER: error from lseek\n");
+ goto error;
+ } /* end if */
+
+ /* Read the whole file */
+ if((bytes_read = read(fd, buf, (k * sizeof(unsigned int)))) < 0) {
+ printf("READER: error from read\n");
+ goto error;
+ } /* end if */
+
+ /* Verify the bytes read are correct */
+ if(bytes_read != (ssize_t)(k*sizeof(unsigned int))) {
+ printf("READER: error from bytes read=%lu\n", (unsigned long)bytes_read);
+ goto error;
+ } /* end if */
+
+ /* Verify data read */
+ for(i=0; i < k; i++) {
+ if(buf[i] != i)
+ break;
+ } /* end for */
+
+ if(i < k) {
+ /* Compare the beginning and ending sentinel values */
+ if(buf[k-1] != (i-1)) {
+ printf("FAIL IN READER: ...beginning sentinel value=%u, i=%u\n", (i-1), i);
+ printf("FAIL IN READER: buf[%u]=%u\n", i-1, buf[i-1]);
+ printf("FAIL IN READER: buf[%u]=%u\n", i, buf[i]);
+ printf("FAIL IN READER: buf[%u]=%u\n", i+1, buf[i+1]);
+ printf("FAIL IN READER: ...ending sentinel value=%u\n", buf[k-1]);
+ goto error;
+ } /* end if */
+ } /* end if */
+
+ /* Free the buffer */
+ if(buf)
+ free(buf);
+ return 0;
+
+error:
+ /* Free the buffer */
+ if(buf)
+ free(buf);
+ return -1;
+} /* end verify() */
+
+
+
+/*-------------------------------------------------------------------------
+ * Function: print_info
+ *
+ * Purpose: To print the statistics gathered for re-reads
+ *
+ * Parameters:
+ * info -- the array storing the statistics for re-reads
+ * lastr -- the last read completed
+ * iteration -- the current iteration
+ *
+ * Return: void
+ *
+ *-------------------------------------------------------------------------
+ */
+void
+print_info(int *info, unsigned int lastr, unsigned iteration)
+{
+ unsigned j; /* local index variable */
+
+ printf("--------statistics for %u reads (iteration %u)--------\n", lastr, iteration);
+
+ for(j = 0; j <= READ_TRIES; j++)
+ printf("# of %u re-tries = %u\n", j, info[j]);
+
+ printf("--------end statistics for %u reads (iteration %u)--------\n", lastr, iteration);
+} /* print_info() */
+
+
+/*-------------------------------------------------------------------------
+ * Function: main
+ *
+ * Purpose: To verify that the data read is the pattern expected.
+ * (1) Make sure the file opens successfully and the # of bytes read is as expected
+ * (2) Iterate the reader with i iterations
+ * (3) Read and verify n integers for each iteration
+ * (4) On verification error, re-read the data at most READ_TRIES
+ * times to see if correct data can be obtained
+ * (5) Print out statistics for the number of re-retries for each iteration
+ *
+ * Note:
+ * (a) The # of integers (via -n option) used by the writer and reader should be the same.
+ * (b) The data file used by the writer and reader should be the same.
+ *
+ * Future enhancement:
+ * 1) Provide default values for n and i and allow user to run with either 0 or 1 option
+ * 2) Use HDF library HD<system calls> instead of the system calls
+ * 3) Handle large sized buffer (gigabytes) if needed
+ *
+ * Return: Success: EXIT_SUCCESS
+ * Failure: EXIT_FAILURE
+ *
+ *-------------------------------------------------------------------------
+ */
+int
+main(int argc, char *argv[])
+{
+ int fd = -1; /* file descriptor */
+ unsigned int j=0, i=0, m=0; /* local index variables */
+ int temp; /* temporary variable */
+ unsigned int iterations = 0; /* the input for "-i" */
+ unsigned num = 0; /* the input for "-n" */
+ int opt = 0; /* option char */
+ int info[READ_TRIES+1]; /* re-tries statistics */
+
+ /* Ensure the expected # of arguments */
+ if(argc != 5) {
+ usage();
+ exit(EXIT_FAILURE);
+ } /* end if */
+
+ /* Parse command line options */
+ while((opt = getopt(argc, argv, "n:i:")) != -1) {
+ switch(opt) {
+ case 'n':
+ if((temp = atoi(optarg)) < 0) {
+ usage();
+ exit(EXIT_FAILURE);
+ } /* end if */
+ num = (unsigned int)temp;
+ break;
+ case 'i':
+ if((temp = atoi(optarg)) < 0) {
+ usage();
+ exit(EXIT_FAILURE);
+ } /* end if */
+ iterations = (unsigned int)temp;
+ break;
+ default:
+ printf("Invalid option encountered\n");
+ break;
+ } /* end switch */
+ } /* end while */
+
+ printf("READER: number of integers to read = %u; # of iterations = %d\n", num, iterations);
+
+ printf("\n");
+ for(i = 1; i <= iterations; i++) {
+ unsigned opens = OPEN_TRIES;
+
+ printf("READER: *****start iteration %u*****\n", i);
+
+ /* Ensure open and file size are done properly */
+ while(opens--) {
+ struct stat sinfo;
+
+ memset(&sinfo, 0, sizeof(sinfo));
+
+ if((fd = open(FILENAME, O_RDONLY, 0644)) < 0) {
+ printf("READER: error from open--retry open again\n");
+ } else {
+ printf("READER: open succeed\n");
+
+ if((fstat(fd, &sinfo) == 0) &&
+ (sinfo.st_size == (off_t)(num * sizeof(unsigned int)))) {
+ printf("READER: file size is correct--%u\n", (unsigned int)sinfo.st_size);
+ break;
+ } /* end if */
+
+ printf("READER: error from fstat or file size of %u is incorrect--retry open again\n", (unsigned int)sinfo.st_size);
+ if(close(fd) < 0) {
+ printf("READER: error from close\n");
+ return EXIT_FAILURE;
+ } /* end if */
+ fd = -1;
+ } /* end else */
+
+ } /* end while */
+
+ if(fd < 0) {
+ printf("READER: *****open failure/incorrect file size for all %u tries, continue next iteration*****\n\n", OPEN_TRIES);
+ continue;
+ } /* end if */
+
+ memset(info, 0, sizeof(info));
+
+ /* Read and verify data */
+ for(j = 1; j <= num; j++) {
+
+ printf("READER: doing read %u\n", j);
+ if(verify(fd, num) < 0) {
+ printf("READER: error from read %u\n", j);
+
+ /* Perform re-read to see if correct data is obtained */
+ for(m = 1; m <= READ_TRIES; m++) {
+ printf("READER: ===============going to do re-read try %u\n", m);
+ if(verify(fd, num) < 0)
+ printf("READER: ===============error from re-read try %u\n", m);
+ else {
+ ++info[m];
+ printf("READER: ===============SUCCESS from re-read try %u\n", m);
+ break;
+ } /* end else */
+ } /* end for */
+
+ if(m > READ_TRIES) {
+ printf("READER: ===============error from all re-read tries: %u\n", READ_TRIES);
+ printf("READER:*****ERROR--stop on read %u\n", j);
+ break;
+ } /* end if */
+ } else {
+ ++info[0];
+ printf("READER: success from read %u\n", j);
+ } /* end else */
+
+ } /* end for */
+
+ /* Print the statistics for re-reads */
+ print_info(info, j-1, i);
+
+ /* Close the file */
+ if(close(fd) < 0) {
+ printf("READER: error from close\n");
+ return EXIT_FAILURE;
+ } /* end if */
+
+ printf("READER: *****end iteration %u*****\n\n", i);
+
+ } /* end for */
+
+ return EXIT_SUCCESS;
+}
+
+#else /* WIN32 / MINGW32 */
+
+int
+main(void)
+{
+ printf("Non-POSIX platform. Exiting.\n");
+ return EXIT_FAILURE;
+} /* end main() */
+
+#endif /* WIN32 / MINGW32 */
+