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Diffstat (limited to 'test/atomic_writer.c')
| -rw-r--r-- | test/atomic_writer.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/test/atomic_writer.c b/test/atomic_writer.c new file mode 100644 index 0000000..ec1e8c9 --- /dev/null +++ b/test/atomic_writer.c @@ -0,0 +1,245 @@ +/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * + * 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_writer.c + * + * Purpose: This is the "writer" part of the standalone test to check + * atomic read-write operation on a system. + * a) atomic_writer.c--the writer (this file) + * b) atomic_reader.c--the reader + * c) atomic_data--the name of the data file used by writer and reader + * + *------------------------------------------------------------------------- + */ + +/***********/ +/* Headers */ +/***********/ + +#include <assert.h> +#include <errno.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> +#include <sys/wait.h> + +/****************/ +/* Local Macros */ +/****************/ + +#define FILENAME "atomic_data" + +/********************/ +/* Local Prototypes */ +/********************/ + +static void usage(void); + + +/*------------------------------------------------------------------------- + * Function: usage + * + * Purpose: To print information about the command line options + * + * Parameters: None + * + * Return: void + * + *------------------------------------------------------------------------- + */ +static void +usage(void) +{ + printf("\n"); + printf("Usage error!\n"); + printf("Usage: atomic_writer -n <number of integers to write> -i <number of iterations for writer>\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: main + * + * Purpose: To write a series of integers to a file for the reader to verify the data. + * A write is atomic if the whole amount written in one operation is not interleaved + * with data from any other process. + * (1) Iterate with i iterations + * (2) Write a series of integers (0 to n-1) to the file with this pattern: + * offset 0: 0000000000000000000000000000000 + * offset 1: 111111111111111111111111111111 + * offset 2: 22222222222222222222222222222 + * offset 3: 3333333333333333333333333333 + * ... + * ... + * offset n-1: (n-1) + * + * At the end of the writes, the data in the file will be: + * 01234567........(n-1) + * + * 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 */ + ssize_t bytes_wrote; /* the nubmer of bytes written */ + unsigned int *buf = NULL; /* buffer to hold written data */ + unsigned int n, u, i; /* local index variable */ + int temp; /* temporary variable */ + unsigned int iterations = 0; /* the input for "-i" */ + unsigned int num = 0; /* the input for "-n" */ + int opt = 0; /* option char */ + + /* Ensure the # of arguments is as expected */ + 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("WRITER: # of integers to write = %u; # of iterations = %d\n", num, iterations); + + /* Remove existing data file if needed */ + if(remove(FILENAME) < 0) { + if(errno == ENOENT) + printf("WRITER: remove %s--%s\n", FILENAME, strerror(errno)); + else { + printf("WRITER: error from remove: %d--%s\n", errno, strerror(errno)); + goto error; + } /* end else */ + } else + printf("WRITER: %s is removed\n", FILENAME); + + /* Create the data file */ + if((fd = open(FILENAME, O_RDWR|O_TRUNC|O_CREAT, 0664)) < 0) { + printf("WRITER: error from open\n"); + goto error; + } /* end if */ + + /* Allocate buffer for holding data to be written */ + if((buf = (unsigned int *)malloc(num * sizeof(unsigned int))) == NULL) { + printf("WRITER: error from malloc\n"); + if(fd >= 0 && close(fd) < 0) + printf("WRITER: error from close\n"); + goto error; + } /* end if */ + + printf("\n"); + + for(i = 1; i <= iterations; i++) { + printf("WRITER: *****start iteration %u*****\n", i); + + /* Write the series of integers to the file */ + for(n = 0; n < num; n++) { + + /* Set up data to be written */ + for(u=0; u < num; u++) + buf[u] = n; + + /* Position the file to the proper location */ + if(lseek(fd, (off_t)(n*sizeof(unsigned int)), SEEK_SET) < 0) { + printf("WRITER: error from lseek\n"); + goto error; + } /* end if */ + + /* Write the data */ + if((bytes_wrote = write(fd, buf, ((num-n) * sizeof(unsigned int)))) < 0) { + printf("WRITER: error from write\n"); + goto error; + } /* end if */ + + /* Verify the bytes written is correct */ + if(bytes_wrote != (ssize_t)((num-n) * sizeof(unsigned int))) { + printf("WRITER: error from bytes written\n"); + goto error; + } /* end if */ + } /* end for */ + + printf("WRITER: *****end iteration %u*****\n\n", i); + + } /* end for */ + + /* Close the file */ + if(close(fd) < 0) { + printf("WRITER: error from close\n"); + goto error; + } /* end if */ + + /* Free the buffer */ + if(buf) + free(buf); + + return EXIT_SUCCESS; + +error: + return EXIT_FAILURE; +} /* end main() */ + +#else /* WIN32 / MINGW32 */ + +int +main(void) +{ + printf("Non-POSIX platform. Exiting.\n"); + return EXIT_FAILURE; +} /* end main() */ + +#endif /* WIN32 / MINGW32 */ + |