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

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Revision 1.7 - (hide 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 joko 1.1 /* Betriebssystem & Middleware
2     *
3     * Betriebssystemarchitektur SS 2006
4     *
5     * Uebung 4.4
6     */
7 joko 1.3
8 joko 1.7 // $Id: bmp_fractal.c,v 1.6 2006/07/01 13:56:54 joko Exp $
9 joko 1.3
10     #include <windows.h>
11 joko 1.1 #include <stdio.h>
12     #include <errno.h>
13    
14     #define XSIZE 500
15     #define YSIZE 500
16     #include "algorithm.h"
17    
18 joko 1.3
19 joko 1.2 /* BMP Header */
20 joko 1.1 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 joko 1.3
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 joko 1.1 }
90 joko 1.3 }
91    
92     // close file handle
93     fclose(fd);
94     }
95    
96    
97 joko 1.6 // arguments for each thread
98     typedef struct _WorkerArguments {
99 joko 1.7 int start_row;
100     int number_of_rows;
101 joko 1.6 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 joko 1.7 unsigned char *pDataBitmapSegment;
111 joko 1.6
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 joko 1.7 printf("----------------------------------------------\n");
122 joko 1.6 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 joko 1.7
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 joko 1.6
130     // calculate fractal
131     for (y = (args->start_row + args->number_of_rows) - 1; y >= args->start_row; y--) {
132 joko 1.7 //printf("calc: thread=%i; y=%i limits: %i,%i p: %p\n", thread_id, y, args->start_row, args->number_of_rows, pDataBitmapSegment);
133 joko 1.6 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 joko 1.7 pDataBitmapSegment[0] = bgr[0];
141     pDataBitmapSegment[1] = bgr[1];
142     pDataBitmapSegment[2] = bgr[2];
143 joko 1.6
144     // move pointer to next pixel
145 joko 1.7 pDataBitmapSegment += 3;
146 joko 1.6
147     }
148     //no padding required because 1500%4 =0
149     }
150    
151 joko 1.7 printf("thread finished: %i\n", thread_id);
152 joko 1.6 return 0;
153    
154     }
155    
156    
157 joko 1.3 int main(int argc, char *argv[]) {
158    
159 joko 1.4 // MMF support
160     DWORD err;
161 joko 1.3 HANDLE hMap, hFile;
162     LPVOID pData;
163     unsigned char *pDataBitmap, *pDataBitmapCurrent;
164 joko 1.4
165 joko 1.5 // workers
166 joko 1.7 int workers = 10;
167     int worker_index, worker_rows, worker_startrow;
168 joko 1.6 HANDLE *worker_handles;
169     //struct WorkerArguments *worker_args;
170     PWORKERARGS worker_args;
171    
172 joko 1.3
173 joko 1.4 // create empty bmp-file (black background)
174 joko 1.3 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 joko 1.6
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 joko 1.5 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 joko 1.7 // debugging: just run with single thread
234     //if (worker_index == 1)
235     // continue;
236    
237 joko 1.5 // 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 joko 1.6
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 joko 1.5 }
260    
261 joko 1.6 // wait for all threads
262     if (WaitForMultipleObjects(workers, worker_handles, TRUE, INFINITE) == WAIT_FAILED)
263     perror("WaitForMultipleObjects");
264 joko 1.7
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 joko 1.3 /* 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 joko 1.1
292     }

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