| #include <string.h> |
| #include <assert.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include "util.h" |
| |
| /* This file contains utility functions widely used in * |
| * my programs. Many are simply versions of file and * |
| * memory grabbing routines that take the same * |
| * arguments as the standard library ones, but exit * |
| * the program if they find an error condition. */ |
| |
| int linenum; /* Line in file being parsed. */ |
| char *OutFilePrefix = NULL; |
| static int cont; /* line continued? */ |
| |
| /* Returns the min of cur and max. If cur > max, a warning |
| * is emitted. */ |
| int |
| limit_value(int cur, int max, const char *name) |
| { |
| if(cur > max) |
| { |
| printf(WARNTAG "%s is being limited from [%d] to [%d]\n", |
| name, cur, max); |
| return max; |
| } |
| return cur; |
| } |
| |
| /* An alternate for strncpy since strncpy doesn't work as most |
| * people would expect. This ensures null termination */ |
| char * |
| my_strncpy(char *dest, const char *src, size_t size) |
| { |
| /* Find string's length */ |
| size_t len = strlen(src); |
| |
| /* Cap length at (num - 1) to leave room for \0 */ |
| if(size <= len) |
| len = (size - 1); |
| |
| /* Copy as much of string as we can fit */ |
| memcpy(dest, src, len); |
| |
| /* explicit null termination */ |
| dest[len] = '\0'; |
| |
| return dest; |
| } |
| |
| /* Uses global var 'OutFilePrefix' */ |
| FILE * |
| my_fopen(const char *fname, const char *flag, int prompt) |
| { |
| FILE *fp; |
| int Len; |
| char *new_fname = NULL; |
| char prompt_filename[256]; |
| |
| /* Appends a prefix string for output files */ |
| if(OutFilePrefix) |
| { |
| if(strchr(flag, 'w')) |
| { |
| Len = 1; /* NULL char */ |
| Len += strlen(OutFilePrefix); |
| Len += strlen(fname); |
| new_fname = (char *)my_malloc(Len * sizeof(char)); |
| strcpy(new_fname, OutFilePrefix); |
| strcat(new_fname, fname); |
| fname = new_fname; |
| } |
| } |
| |
| if (prompt) |
| { |
| scanf("%s",prompt_filename); |
| fname = prompt_filename; |
| } |
| |
| if(NULL == (fp = fopen(fname, flag))) |
| { |
| printf("Error opening file %s for %s access.\n", fname, flag); |
| exit(1); |
| } |
| |
| if(new_fname) |
| free(new_fname); |
| |
| return (fp); |
| } |
| |
| char * |
| my_strdup(const char *str) |
| { |
| int Len; |
| char *Dst; |
| |
| if(str == NULL) { |
| return NULL; |
| } |
| |
| Len = 1 + strlen(str); |
| Dst = (char *)my_malloc(Len * sizeof(char)); |
| memcpy(Dst, str, Len); |
| |
| return Dst; |
| } |
| |
| |
| int |
| my_atoi(const char *str) |
| { |
| |
| /* Returns the integer represented by the first part of the character * |
| * string. */ |
| |
| if(str[0] < '0' || str[0] > '9') |
| { |
| if(!(str[0] == '-' && str[1] >= '0' && str[1] <= '9')) |
| { |
| printf(ERRTAG "expected number instead of '%s'.\n", str); |
| exit(1); |
| } |
| } |
| return (atoi(str)); |
| } |
| |
| void * |
| my_calloc(size_t nelem, size_t size) |
| { |
| void *ret; |
| if(nelem == 0) { |
| return NULL; |
| } |
| |
| if((ret = calloc(nelem, size)) == NULL) |
| { |
| fprintf(stderr, "Error: Unable to calloc memory. Aborting.\n"); |
| exit(1); |
| } |
| return (ret); |
| } |
| |
| void * |
| my_malloc(size_t size) |
| { |
| void *ret; |
| if(size == 0) { |
| return NULL; |
| } |
| |
| if((ret = malloc(size)) == NULL) |
| { |
| fprintf(stderr, "Error: Unable to malloc memory. Aborting.\n"); |
| abort(); |
| exit(1); |
| } |
| return (ret); |
| } |
| |
| void * |
| my_realloc(void *ptr, size_t size) |
| { |
| void *ret; |
| |
| if(size <= 0) |
| { |
| printf("reallocating of size <= 0.\n"); |
| } |
| |
| ret = realloc(ptr, size); |
| if(NULL == ret) |
| { |
| printf(ERRTAG "Unable to realloc memory. Aborting. " |
| "ptr=%p, Size=%d.\n", ptr, (int)size); |
| if(ptr == NULL) |
| { |
| printf(ERRTAG "my_realloc: ptr == NULL. Aborting.\n"); |
| } |
| exit(1); |
| } |
| return (ret); |
| } |
| |
| void * |
| my_chunk_malloc(size_t size, struct s_linked_vptr **chunk_ptr_head, |
| int *mem_avail_ptr, char **next_mem_loc_ptr) |
| { |
| |
| /* This routine should be used for allocating fairly small data * |
| * structures where memory-efficiency is crucial. This routine allocates * |
| * large "chunks" of data, and parcels them out as requested. Whenever * |
| * it mallocs a new chunk it adds it to the linked list pointed to by * |
| * chunk_ptr_head. This list can be used to free the chunked memory. * |
| * If chunk_ptr_head is NULL, no list of chunked memory blocks will be kept * |
| * -- this is useful for data structures that you never intend to free as * |
| * it means you don't have to keep track of the linked lists. * |
| * Information about the currently open "chunk" must be stored by the * |
| * user program. mem_avail_ptr points to an int storing how many bytes are * |
| * left in the current chunk, while next_mem_loc_ptr is the address of a * |
| * pointer to the next free bytes in the chunk. To start a new chunk, * |
| * simply set *mem_avail_ptr = 0. Each independent set of data structures * |
| * should use a new chunk. */ |
| |
| /* To make sure the memory passed back is properly aligned, I must * |
| * only send back chunks in multiples of the worst-case alignment * |
| * restriction of the machine. On most machines this should be * |
| * a long, but on 64-bit machines it might be a long long or a * |
| * double. Change the typedef below if this is the case. */ |
| |
| typedef long Align; |
| |
| #define CHUNK_SIZE 32768 |
| #define FRAGMENT_THRESHOLD 100 |
| |
| char *tmp_ptr; |
| int aligned_size; |
| |
| assert(*mem_avail_ptr >= 0); |
| |
| if((size_t) (*mem_avail_ptr) < size) |
| { /* Need to malloc more memory. */ |
| if(size > CHUNK_SIZE) |
| { /* Too big, use standard routine. */ |
| tmp_ptr = my_malloc(size); |
| |
| /* When debugging, uncomment the code below to see if memory allocation size */ |
| /* makes sense */ |
| /*#ifdef DEBUG |
| printf("NB: my_chunk_malloc got a request for %d bytes.\n", |
| size); |
| printf("You should consider using my_malloc for such big requests.\n"); |
| #endif */ |
| |
| if(chunk_ptr_head != NULL) |
| *chunk_ptr_head = |
| insert_in_vptr_list(*chunk_ptr_head, tmp_ptr); |
| return (tmp_ptr); |
| } |
| |
| if(*mem_avail_ptr < FRAGMENT_THRESHOLD) |
| { /* Only a small scrap left. */ |
| *next_mem_loc_ptr = my_malloc(CHUNK_SIZE); |
| *mem_avail_ptr = CHUNK_SIZE; |
| if(chunk_ptr_head != NULL) |
| *chunk_ptr_head = insert_in_vptr_list(*chunk_ptr_head, |
| *next_mem_loc_ptr); |
| } |
| |
| /* Execute else clause only when the chunk we want is pretty big, * |
| * and would leave too big an unused fragment. Then we use malloc * |
| * to allocate normally. */ |
| |
| else |
| { |
| tmp_ptr = my_malloc(size); |
| if(chunk_ptr_head != NULL) |
| *chunk_ptr_head = |
| insert_in_vptr_list(*chunk_ptr_head, tmp_ptr); |
| return (tmp_ptr); |
| } |
| } |
| |
| /* Find the smallest distance to advance the memory pointer and keep * |
| * everything aligned. */ |
| |
| if(size % sizeof(Align) == 0) |
| { |
| aligned_size = size; |
| } |
| else |
| { |
| aligned_size = size + sizeof(Align) - size % sizeof(Align); |
| } |
| |
| tmp_ptr = *next_mem_loc_ptr; |
| *next_mem_loc_ptr += aligned_size; |
| *mem_avail_ptr -= aligned_size; |
| return (tmp_ptr); |
| } |
| |
| void |
| free_chunk_memory(struct s_linked_vptr *chunk_ptr_head) |
| { |
| |
| /* Frees the memory allocated by a sequence of calls to my_chunk_malloc. */ |
| |
| struct s_linked_vptr *curr_ptr, *prev_ptr; |
| |
| curr_ptr = chunk_ptr_head; |
| |
| while(curr_ptr != NULL) |
| { |
| free(curr_ptr->data_vptr); /* Free memory "chunk". */ |
| prev_ptr = curr_ptr; |
| curr_ptr = curr_ptr->next; |
| free(prev_ptr); /* Free memory used to track "chunk". */ |
| } |
| } |
| |
| struct s_linked_vptr * |
| insert_in_vptr_list(struct s_linked_vptr *head, void *vptr_to_add) |
| { |
| |
| /* Inserts a new element at the head of a linked list of void pointers. * |
| * Returns the new head of the list. */ |
| |
| struct s_linked_vptr *linked_vptr; |
| |
| linked_vptr = (struct s_linked_vptr *)my_malloc(sizeof(struct |
| s_linked_vptr)); |
| |
| linked_vptr->data_vptr = vptr_to_add; |
| linked_vptr->next = head; |
| return (linked_vptr); /* New head of the list */ |
| } |
| |
| /* Deletes the element at the head of a linked list of void pointers. * |
| * Returns the new head of the list. */ |
| struct s_linked_vptr * |
| delete_in_vptr_list(struct s_linked_vptr *head) |
| { |
| struct s_linked_vptr *linked_vptr; |
| |
| if (head == NULL) |
| return NULL; |
| linked_vptr = head->next; |
| free(head); |
| return linked_vptr; /* New head of the list */ |
| } |
| |
| t_linked_int * |
| insert_in_int_list(t_linked_int * head, int data, |
| t_linked_int ** free_list_head_ptr) |
| { |
| |
| /* Inserts a new element at the head of a linked list of integers. Returns * |
| * the new head of the list. One argument is the address of the head of * |
| * a list of free ilist elements. If there are any elements on this free * |
| * list, the new element is taken from it. Otherwise a new one is malloced. */ |
| |
| t_linked_int *linked_int; |
| |
| if(*free_list_head_ptr != NULL) |
| { |
| linked_int = *free_list_head_ptr; |
| *free_list_head_ptr = linked_int->next; |
| } |
| else |
| { |
| linked_int = (t_linked_int *) my_malloc(sizeof(t_linked_int)); |
| } |
| |
| linked_int->data = data; |
| linked_int->next = head; |
| return (linked_int); |
| } |
| |
| void |
| free_int_list(t_linked_int ** int_list_head_ptr) |
| { |
| |
| /* This routine truly frees (calls free) all the integer list elements * |
| * on the linked list pointed to by *head, and sets head = NULL. */ |
| |
| t_linked_int *linked_int, *next_linked_int; |
| |
| linked_int = *int_list_head_ptr; |
| |
| while(linked_int != NULL) |
| { |
| next_linked_int = linked_int->next; |
| free(linked_int); |
| linked_int = next_linked_int; |
| } |
| |
| *int_list_head_ptr = NULL; |
| } |
| |
| void |
| alloc_ivector_and_copy_int_list(t_linked_int ** list_head_ptr, int num_items, |
| struct s_ivec *ivec, t_linked_int ** free_list_head_ptr) |
| { |
| |
| /* Allocates an integer vector with num_items elements and copies the * |
| * integers from the list pointed to by list_head (of which there must be * |
| * num_items) over to it. The int_list is then put on the free list, and * |
| * the list_head_ptr is set to NULL. */ |
| |
| t_linked_int *linked_int, *list_head; |
| int i, *list; |
| |
| list_head = *list_head_ptr; |
| |
| if(num_items == 0) |
| { /* Empty list. */ |
| ivec->nelem = 0; |
| ivec->list = NULL; |
| |
| if(list_head != NULL) |
| { |
| printf(ERRTAG |
| "alloc_ivector_and_copy_int_list: Copied %d elements, " |
| "but list at %p contains more.\n", num_items, |
| (void *)list_head); |
| exit(1); |
| } |
| return; |
| } |
| |
| ivec->nelem = num_items; |
| list = (int *)my_malloc(num_items * sizeof(int)); |
| ivec->list = list; |
| linked_int = list_head; |
| |
| for(i = 0; i < num_items - 1; i++) |
| { |
| list[i] = linked_int->data; |
| linked_int = linked_int->next; |
| } |
| |
| list[num_items - 1] = linked_int->data; |
| |
| if(linked_int->next != NULL) |
| { |
| printf |
| ("Error in alloc_ivector_and_copy_int_list:\n Copied %d elements, " |
| "but list at %p contains more.\n", num_items, |
| (void *)list_head); |
| exit(1); |
| } |
| |
| linked_int->next = *free_list_head_ptr; |
| *free_list_head_ptr = list_head; |
| *list_head_ptr = NULL; |
| } |
| |
| char * |
| my_fgets(char *buf, int max_size, FILE * fp) |
| { |
| /* Get an input line, update the line number and cut off * |
| * any comment part. A \ at the end of a line with no * |
| * comment part (#) means continue. */ |
| |
| char *val; |
| int i; |
| |
| cont = 0; |
| val = fgets(buf, max_size, fp); |
| linenum++; |
| if(val == NULL) |
| return (val); |
| |
| /* Check that line completely fit into buffer. (Flags long line * |
| * truncation). */ |
| |
| for(i = 0; i < max_size; i++) |
| { |
| if(buf[i] == '\n') |
| break; |
| if(buf[i] == '\0') |
| { |
| printf |
| ("Error on line %d -- line is too long for input buffer.\n", |
| linenum); |
| printf("All lines must be at most %d characters long.\n", |
| BUFSIZE - 2); |
| printf |
| ("The problem could also be caused by a missing newline.\n"); |
| exit(1); |
| } |
| } |
| |
| |
| for(i = 0; i < max_size && buf[i] != '\0'; i++) |
| { |
| if(buf[i] == '#') |
| { |
| buf[i] = '\0'; |
| break; |
| } |
| } |
| |
| if(i < 2) |
| return (val); |
| if(buf[i - 1] == '\n' && buf[i - 2] == '\\') |
| { |
| cont = 1; /* line continued */ |
| buf[i - 2] = '\n'; /* May need this for tokens */ |
| buf[i - 1] = '\0'; |
| } |
| return (val); |
| } |
| |
| char * |
| my_strtok(char *ptr, char *tokens, FILE * fp, char *buf) |
| { |
| |
| /* Get next token, and wrap to next line if \ at end of line. * |
| * There is a bit of a "gotcha" in strtok. It does not make a * |
| * copy of the character array which you pass by pointer on the * |
| * first call. Thus, you must make sure this array exists for * |
| * as long as you are using strtok to parse that line. Don't * |
| * use local buffers in a bunch of subroutines calling each * |
| * other; the local buffer may be overwritten when the stack is * |
| * restored after return from the subroutine. */ |
| |
| char *val; |
| |
| val = strtok(ptr, tokens); |
| for(;;) |
| { |
| if(val != NULL || cont == 0) |
| return (val); |
| |
| /* return unless we have a null value and a continuation line */ |
| if(my_fgets(buf, BUFSIZE, fp) == NULL) |
| return (NULL); |
| |
| val = strtok(buf, tokens); |
| } |
| } |
| |
| void |
| free_ivec_vector(struct s_ivec *ivec_vector, int nrmin, int nrmax) |
| { |
| |
| /* Frees a 1D array of integer vectors. */ |
| |
| int i; |
| |
| for(i = nrmin; i <= nrmax; i++) |
| if(ivec_vector[i].nelem != 0) |
| free(ivec_vector[i].list); |
| |
| free(ivec_vector + nrmin); |
| } |
| |
| void |
| free_ivec_matrix(struct s_ivec **ivec_matrix, int nrmin, int nrmax, int ncmin, |
| int ncmax) |
| { |
| |
| /* Frees a 2D matrix of integer vectors (ivecs). */ |
| |
| int i, j; |
| |
| for(i = nrmin; i <= nrmax; i++) |
| { |
| for(j = ncmin; j <= ncmax; j++) |
| { |
| if(ivec_matrix[i][j].nelem != 0) |
| { |
| free(ivec_matrix[i][j].list); |
| } |
| } |
| } |
| |
| free_matrix(ivec_matrix, nrmin, nrmax, ncmin, sizeof(struct s_ivec)); |
| } |
| |
| void |
| free_ivec_matrix3(struct s_ivec ***ivec_matrix3, int nrmin, int nrmax, |
| int ncmin, int ncmax, int ndmin, int ndmax) |
| { |
| |
| /* Frees a 3D matrix of integer vectors (ivecs). */ |
| |
| int i, j, k; |
| |
| for(i = nrmin; i <= nrmax; i++) |
| { |
| for(j = ncmin; j <= ncmax; j++) |
| { |
| for(k = ndmin; k <= ndmax; k++) |
| { |
| if(ivec_matrix3[i][j][k].nelem != 0) |
| { |
| free(ivec_matrix3[i][j][k].list); |
| } |
| } |
| } |
| } |
| |
| free_matrix3(ivec_matrix3, nrmin, nrmax, ncmin, ncmax, ndmin, |
| sizeof(struct s_ivec)); |
| } |
| |
| void ** |
| alloc_matrix(int nrmin, int nrmax, int ncmin, int ncmax, size_t elsize) |
| { |
| |
| /* allocates an generic matrix with nrmax-nrmin + 1 rows and ncmax - * |
| * ncmin + 1 columns, with each element of size elsize. i.e. * |
| * returns a pointer to a storage block [nrmin..nrmax][ncmin..ncmax].* |
| * Simply cast the returned array pointer to the proper type. */ |
| |
| int i; |
| char **cptr; |
| |
| cptr = (char **)my_malloc((nrmax - nrmin + 1) * sizeof(char *)); |
| cptr -= nrmin; |
| for(i = nrmin; i <= nrmax; i++) |
| { |
| cptr[i] = (char *)my_malloc((ncmax - ncmin + 1) * elsize); |
| cptr[i] -= ncmin * elsize / sizeof(char); /* sizeof(char) = 1 */ |
| } |
| return ((void **)cptr); |
| } |
| |
| /* NB: need to make the pointer type void * instead of void ** to allow * |
| * any pointer to be passed in without a cast. */ |
| |
| void |
| free_matrix(void *vptr, int nrmin, int nrmax, int ncmin, size_t elsize) |
| { |
| int i; |
| char **cptr; |
| |
| cptr = (char **)vptr; |
| |
| for(i = nrmin; i <= nrmax; i++) |
| free(cptr[i] + ncmin * elsize / sizeof(char)); |
| free(cptr + nrmin); |
| } |
| |
| void *** |
| alloc_matrix3(int nrmin, int nrmax, int ncmin, int ncmax, int ndmin, |
| int ndmax, size_t elsize) |
| { |
| |
| /* allocates a 3D generic matrix with nrmax-nrmin + 1 rows, ncmax - * |
| * ncmin + 1 columns, and a depth of ndmax-ndmin + 1, with each * |
| * element of size elsize. i.e. returns a pointer to a storage block * |
| * [nrmin..nrmax][ncmin..ncmax][ndmin..ndmax]. Simply cast the * |
| * returned array pointer to the proper type. */ |
| |
| int i, j; |
| char ***cptr; |
| |
| cptr = (char ***)my_malloc((nrmax - nrmin + 1) * sizeof(char **)); |
| cptr -= nrmin; |
| for(i = nrmin; i <= nrmax; i++) |
| { |
| cptr[i] = |
| (char **)my_malloc((ncmax - ncmin + 1) * sizeof(char *)); |
| cptr[i] -= ncmin; |
| for(j = ncmin; j <= ncmax; j++) |
| { |
| cptr[i][j] = |
| (char *)my_malloc((ndmax - ndmin + 1) * elsize); |
| cptr[i][j] -= ndmin * elsize / sizeof(char); /* sizeof(char) = 1) */ |
| } |
| } |
| return ((void ***)cptr); |
| } |
| |
| void **** |
| alloc_matrix4(int nrmin, int nrmax, int ncmin, int ncmax, int ndmin, |
| int ndmax, int nemin, int nemax, size_t elsize) |
| { |
| |
| /* allocates a 3D generic matrix with nrmax-nrmin + 1 rows, ncmax - * |
| * ncmin + 1 columns, and a depth of ndmax-ndmin + 1, with each * |
| * element of size elsize. i.e. returns a pointer to a storage block * |
| * [nrmin..nrmax][ncmin..ncmax][ndmin..ndmax]. Simply cast the * |
| * returned array pointer to the proper type. */ |
| |
| int i, j, k; |
| char ****cptr; |
| |
| cptr = (char ****)my_malloc((nrmax - nrmin + 1) * sizeof(char ***)); |
| cptr -= nrmin; |
| for(i = nrmin; i <= nrmax; i++) |
| { |
| cptr[i] = |
| (char ***)my_malloc((ncmax - ncmin + 1) * sizeof(char **)); |
| cptr[i] -= ncmin; |
| for(j = ncmin; j <= ncmax; j++) |
| { |
| cptr[i][j] = |
| (char **)my_malloc((ndmax - ndmin + 1) * |
| sizeof(char *)); |
| cptr[i][j] -= ndmin; |
| for(k = ndmin; k <= ndmax; k++) |
| { |
| cptr[i][j][k] = |
| (char *)my_malloc((nemax - nemin + 1) * |
| elsize); |
| cptr[i][j][k] -= nemin * elsize / sizeof(char); /* sizeof(char) = 1) */ |
| } |
| } |
| } |
| return ((void ****)cptr); |
| } |
| |
| void |
| print_int_matrix3(int ***vptr, int nrmin, int nrmax, int ncmin, int ncmax, |
| int ndmin, int ndmax, char *file) |
| { |
| FILE *outfile; |
| int i, j, k; |
| |
| outfile = my_fopen(file, "w", 0); |
| |
| for(k = nrmin; k <= nrmax; ++k) |
| { |
| fprintf(outfile, "Plane %d\n", k); |
| for(j = ncmin; j <= ncmax; ++j) |
| { |
| for(i = ndmin; i <= ndmax; ++i) |
| { |
| fprintf(outfile, "%d ", vptr[k][j][i]); |
| } |
| fprintf(outfile, "\n"); |
| } |
| fprintf(outfile, "\n"); |
| } |
| |
| fclose(outfile); |
| } |
| |
| void |
| free_matrix3(void *vptr, int nrmin, int nrmax, int ncmin, int ncmax, |
| int ndmin, size_t elsize) |
| { |
| int i, j; |
| char ***cptr; |
| |
| cptr = (char ***)vptr; |
| |
| for(i = nrmin; i <= nrmax; i++) |
| { |
| for(j = ncmin; j <= ncmax; j++) |
| free(cptr[i][j] + ndmin * elsize / sizeof(char)); |
| free(cptr[i] + ncmin); |
| } |
| free(cptr + nrmin); |
| } |
| |
| void |
| free_matrix4(void *vptr, int nrmin, int nrmax, int ncmin, int ncmax, int ndmin, |
| int ndmax, int nemin, size_t elsize) |
| { |
| int i, j, k; |
| char ****cptr; |
| |
| cptr = (char ****)vptr; |
| |
| for(i = nrmin; i <= nrmax; i++) |
| { |
| for(j = ncmin; j <= ncmax; j++) |
| { |
| for(k = ndmin; k <= ndmax; k++) |
| free(cptr[i][j][k] + nemin * elsize / sizeof(char)); |
| free(cptr[i][j] + ndmin * elsize / sizeof(char)); |
| } |
| free(cptr[i] + ncmin); |
| } |
| free(cptr + nrmin); |
| } |
| |
| /* Portable random number generator defined below. Taken from ANSI C by * |
| * K & R. Not a great generator, but fast, and good enough for my needs. */ |
| |
| #define IA 1103515245u |
| #define IC 12345u |
| #define IM 2147483648u |
| #define CHECK_RAND |
| |
| static unsigned int current_random = 0; |
| |
| void |
| my_srandom(int seed) |
| { |
| current_random = (unsigned int)seed; |
| } |
| |
| int |
| my_irand(int imax) |
| { |
| |
| /* Creates a random integer between 0 and imax, inclusive. i.e. [0..imax] */ |
| |
| int ival; |
| |
| /* current_random = (current_random * IA + IC) % IM; */ |
| current_random = current_random * IA + IC; /* Use overflow to wrap */ |
| ival = current_random & (IM - 1); /* Modulus */ |
| ival = (int)((float)ival * (float)(imax + 0.999) / (float)IM); |
| |
| #ifdef CHECK_RAND |
| if((ival < 0) || (ival > imax)) |
| { |
| if(ival == imax + 1) { |
| /* Due to random floating point rounding, sometimes above calculation gives number greater than ival by 1 */ |
| ival = imax; |
| } else { |
| printf("Bad value in my_irand, imax = %d ival = %d\n", imax, |
| ival); |
| exit(1); |
| } |
| } |
| #endif |
| |
| return (ival); |
| } |
| |
| float |
| my_frand(void) |
| { |
| |
| /* Creates a random float between 0 and 1. i.e. [0..1). */ |
| |
| float fval; |
| int ival; |
| |
| current_random = current_random * IA + IC; /* Use overflow to wrap */ |
| ival = current_random & (IM - 1); /* Modulus */ |
| fval = (float)ival / (float)IM; |
| |
| #ifdef CHECK_RAND |
| if((fval < 0) || (fval > 1.)) |
| { |
| printf("Bad value in my_frand, fval = %g\n", fval); |
| exit(1); |
| } |
| #endif |
| |
| return (fval); |
| } |
| |