/[cvs]/joko/Uni/BSArch/04/bmp_fractal.c
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Contents of /joko/Uni/BSArch/04/bmp_fractal.c

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Revision 1.7 - (show annotations)
Sat Jul 1 20:31:31 2006 UTC (18 years, 2 months ago) by joko
Branch: MAIN
Changes since 1.6: +30 -10 lines
File MIME type: text/plain
first working version with threads as workers

1 /* Betriebssystem & Middleware
2 *
3 * Betriebssystemarchitektur SS 2006
4 *
5 * Uebung 4.4
6 */
7
8 // $Id: bmp_fractal.c,v 1.6 2006/07/01 13:56:54 joko Exp $
9
10 #include <windows.h>
11 #include <stdio.h>
12 #include <errno.h>
13
14 #define XSIZE 500
15 #define YSIZE 500
16 #include "algorithm.h"
17
18
19 /* BMP Header */
20 unsigned char header[54]={0x42,0x4d, // signature BM
21 0xe6,0x71,0x0b,0x0, // filesize 750054
22 0x0,0x0,0x0,0x0, // reserved
23 0x36,0x0,0x0,0x0, // image offset 54
24 0x28,0x0,0x0,0x0, // size of header follows 40
25 0xf4,0x1,0x0,0x0, // with of image 500
26 0xf4,0x1,0x0,0x0, // height of image 500
27 0x1,0x0, // number of planes 1
28 0x18,0x0, // number of pixel 24
29 0x0,0x0,0x0,0x0, // compression
30 0xb0,0x71,0x0b,0x0, // size of image 750000
31 0x0,0x0,0x0,0x0, // xres
32 0x0,0x0,0x0,0x0, // yres
33 0x0,0x0,0x0,0x0, // number of colortables
34 0x0,0x0,0x0,0x0 // number of important colors
35 };
36
37
38 void printErrorAndExit(const char *msg, DWORD err) {
39 LPSTR lpMsgBuf;
40 if(FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER|
41 FORMAT_MESSAGE_FROM_SYSTEM |
42 FORMAT_MESSAGE_IGNORE_INSERTS,
43 NULL,
44 err,
45 MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
46 (LPTSTR) &lpMsgBuf,
47 0,
48 NULL ))
49 {
50 fprintf(stderr,"%s : %s\n",msg,lpMsgBuf);
51 LocalFree(lpMsgBuf);
52 }
53 else
54 {
55 fprintf(stderr,"Error at FormatMesage: %d\n",err=GetLastError());
56 }
57 exit(err);
58 }
59
60
61 void write_blank_file(char *filename) {
62
63 FILE *fd;
64 int len, i, img_size;
65
66 // open file handle
67 fd = fopen(filename, "wb+");
68 if (NULL == fd) {
69 perror("open");
70 exit(1);
71 }
72
73 // write bmp header to file
74 len = fwrite(header, 1, sizeof(header), fd);
75
76 // error checking
77 if (-1 == len || len != sizeof(header)) {
78 perror("write");
79 exit(2);
80 }
81
82 // write three null-bytes for each pixel to file to create a black picture
83 img_size = XSIZE * YSIZE;
84 for (i = 0; i < img_size; i++) {
85 len = fwrite("\0\0\0", 1, 3, fd);
86 if (-1 == len || len != 3) {
87 perror("write");
88 exit(4);
89 }
90 }
91
92 // close file handle
93 fclose(fd);
94 }
95
96
97 // arguments for each thread
98 typedef struct _WorkerArguments {
99 int start_row;
100 int number_of_rows;
101 unsigned char * pBitmap;
102 } WORKERARGS, *PWORKERARGS;
103
104 // worker thread - main entry function
105 DWORD WINAPI fractal_thread (LPVOID lpParam) {
106
107 // thread stuff
108 int thread_id;
109 PWORKERARGS args;
110 unsigned char *pDataBitmapSegment;
111
112 // fractal calculation
113 int x, y;
114 char bgr[3];
115
116 thread_id = GetCurrentThreadId();
117
118 // get worker arguments
119 args = (PWORKERARGS)lpParam;
120
121 printf("----------------------------------------------\n");
122 printf("thread_id: %i\n", thread_id);
123 printf("arg.start_row: %i\n", args->start_row);
124 printf("arg.number_of_rows: %i\n", args->number_of_rows);
125
126 // calculate pointer to beginning of segment
127 pDataBitmapSegment = (unsigned char *)((INT_PTR)args->pBitmap + (YSIZE - (args->start_row + args->number_of_rows)) * 3 * XSIZE);
128 printf("segment_start: %p\n", pDataBitmapSegment);
129
130 // calculate fractal
131 for (y = (args->start_row + args->number_of_rows) - 1; y >= args->start_row; y--) {
132 //printf("calc: thread=%i; y=%i limits: %i,%i p: %p\n", thread_id, y, args->start_row, args->number_of_rows, pDataBitmapSegment);
133 for (x = 0; x < XSIZE; x++) {
134 getColorValuesAt(x * (2.0 / XSIZE) - 1.5, y * (2.0 / YSIZE) - 1.0, &bgr[2], &bgr[1], &bgr[0]);
135
136 // debugging
137 //printf("pointer: %p\n", pDataBitmapCurrent);
138
139 // transfer color values to current pixel
140 pDataBitmapSegment[0] = bgr[0];
141 pDataBitmapSegment[1] = bgr[1];
142 pDataBitmapSegment[2] = bgr[2];
143
144 // move pointer to next pixel
145 pDataBitmapSegment += 3;
146
147 }
148 //no padding required because 1500%4 =0
149 }
150
151 printf("thread finished: %i\n", thread_id);
152 return 0;
153
154 }
155
156
157 int main(int argc, char *argv[]) {
158
159 // MMF support
160 DWORD err;
161 HANDLE hMap, hFile;
162 LPVOID pData;
163 unsigned char *pDataBitmap, *pDataBitmapCurrent;
164
165 // workers
166 int workers = 10;
167 int worker_index, worker_rows, worker_startrow;
168 HANDLE *worker_handles;
169 //struct WorkerArguments *worker_args;
170 PWORKERARGS worker_args;
171
172
173 // create empty bmp-file (black background)
174 write_blank_file("test.bmp");
175
176 /* open file for reading and writing */
177 hFile = CreateFile("test.bmp", GENERIC_WRITE|GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
178 if (INVALID_HANDLE_VALUE == hFile) {
179 err = GetLastError();
180 printErrorAndExit("Error at CreateFile",err);
181 }
182
183 /* create the file mapping object */
184 hMap = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 0, 0, NULL);
185 if (NULL == hMap) {
186 printErrorAndExit("Error at CreateFileMapping", GetLastError());
187 }
188
189 /* map the whole file into the process context */
190 pData = MapViewOfFile(hMap, FILE_MAP_WRITE, 0, 0, 0);
191 if (NULL == pData) {
192 printErrorAndExit("Error at MapViewOfFile", GetLastError());
193 }
194
195
196 // calculate pointer to beginning of bitmap
197 pDataBitmap = (unsigned char *)((INT_PTR)pData + sizeof(header));
198
199 // debugging
200 printf("pos. of file: %p\n", pData);
201 printf("pos. of bitmap: %p\n", pDataBitmap);
202
203 // pointer to current pixel
204 pDataBitmapCurrent = pDataBitmap;
205
206 /*
207 // turn bitmap into white wand
208 for (offset = 0; offset < 500 * 500 * 3; offset++) {
209 //pDataBitmap[offset] = 255;
210 *pDataBitmapCurrent = 255;
211 pDataBitmapCurrent++;
212 }
213 */
214
215
216 // allocate memory for table of all worker handles
217 if ((worker_handles = malloc(workers * sizeof worker_handles[0])) == NULL)
218 perror("malloc"), exit(1);
219
220 /*
221 // allocate memory for table of all worker arguments
222 if ((worker_args = malloc(workers * sizeof worker_args[0])) == NULL)
223 perror("malloc"), exit(1);
224 */
225 // allocate memory for table of all worker arguments
226 worker_args = (PWORKERARGS) HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, workers * sizeof(WORKERARGS));
227
228 // calculate segments of bitmap for worker threads/processes and start them
229 worker_rows = YSIZE / workers;
230 printf("rows for each worker: %i\n", worker_rows);
231 for (worker_index = 0; worker_index < workers; worker_index++) {
232
233 // debugging: just run with single thread
234 //if (worker_index == 1)
235 // continue;
236
237 // number of row to start for each worker
238 worker_startrow = worker_index * worker_rows;
239
240 // recalculate number of rows for last worker if (YSIZE mod workers) != 0
241 if (worker_index == workers - 1) {
242 worker_rows = YSIZE - worker_startrow;
243 printf("rows for last worker: %i\n", worker_rows);
244 }
245
246 worker_args[worker_index].start_row = worker_startrow;
247 worker_args[worker_index].number_of_rows = worker_rows;
248 worker_args[worker_index].pBitmap = pDataBitmap;
249
250 worker_handles[worker_index] = CreateThread(
251 NULL, // LPSECURITY_ATTRIBUTES lpThreadAttributes,
252 0, // SIZE_T dwStackSize,
253 fractal_thread, // LPTHREAD_START_ROUTINE lpStartAddress,
254 &worker_args[worker_index], // LPVOID lpParameter,
255 0, // DWORD dwCreationFlags,
256 NULL // LPDWORD lpThreadId
257 );
258
259 }
260
261 // wait for all threads
262 if (WaitForMultipleObjects(workers, worker_handles, TRUE, INFINITE) == WAIT_FAILED)
263 perror("WaitForMultipleObjects");
264
265 // debugging: just run with single thread
266 //if (WaitForSingleObject(worker_handles[0], INFINITE) == WAIT_FAILED)
267 // perror("WaitForSingleObject");
268
269 // close all worker handles
270 for (worker_index = 0; worker_index < workers; worker_index++)
271 CloseHandle(worker_handles[worker_index]);
272
273 /* write the result into the file */
274 if (!FlushViewOfFile(pData, 0)) {
275 err = GetLastError();
276 printErrorAndExit("Error at UnmapViewOfFile", err);
277 }
278
279 /* remove the mapped file */
280 if (!UnmapViewOfFile(pData)) {
281 err = GetLastError();
282 printErrorAndExit("Error at UnmapViewOfFile", err);
283 exit(err);
284 }
285
286 /* cleanup handles */
287 if (!CloseHandle(hMap) || !CloseHandle(hFile) ) {
288 err = GetLastError();
289 printErrorAndExit("Error at CloseHandle", err);
290 }
291
292 }

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