/[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 1.6 - (hide annotations)
Sat Jul 1 13:56:54 2006 UTC (18 years, 2 months ago) by joko
Branch: MAIN
Changes since 1.5: +88 -27 lines
File MIME type: text/plain
calculation via multiple threads (still erroneous)

1 joko 1.1 /* Betriebssystem & Middleware
2     *
3     * Betriebssystemarchitektur SS 2006
4     *
5     * Uebung 4.4
6     */
7 joko 1.3
8 joko 1.6 // $Id: bmp_fractal.c,v 1.5 2006/07/01 12:19:46 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     unsigned int start_row;
100     unsigned 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    
111     // fractal calculation
112     int x, y;
113     char bgr[3];
114    
115     thread_id = GetCurrentThreadId();
116    
117     // get worker arguments
118     args = (PWORKERARGS)lpParam;
119    
120     printf("thread_id: %i\n", thread_id);
121     printf("arg.start_row: %i\n", args->start_row);
122     printf("arg.number_of_rows: %i\n", args->number_of_rows);
123    
124     // calculate fractal
125     for (y = (args->start_row + args->number_of_rows) - 1; y >= args->start_row; y--) {
126     for (x = 0; x < XSIZE; x++) {
127     getColorValuesAt(x * (2.0 / XSIZE) - 1.5, y * (2.0 / YSIZE) - 1.0, &bgr[2], &bgr[1], &bgr[0]);
128    
129     // debugging
130     //printf("pointer: %p\n", pDataBitmapCurrent);
131    
132     // transfer color values to current pixel
133     args->pBitmap[0] = bgr[0];
134     args->pBitmap[1] = bgr[1];
135     args->pBitmap[2] = bgr[2];
136    
137     // move pointer to next pixel
138     args->pBitmap += 3;
139    
140     }
141     //no padding required because 1500%4 =0
142     }
143    
144     return 0;
145    
146     }
147    
148    
149 joko 1.3 int main(int argc, char *argv[]) {
150    
151 joko 1.4 // MMF support
152     DWORD err;
153 joko 1.3 HANDLE hMap, hFile;
154     LPVOID pData;
155     unsigned char *pDataBitmap, *pDataBitmapCurrent;
156 joko 1.4
157 joko 1.5 // workers
158     unsigned int workers = 3;
159     unsigned int worker_index, worker_rows, worker_startrow;
160 joko 1.6 HANDLE *worker_handles;
161     //struct WorkerArguments *worker_args;
162     PWORKERARGS worker_args;
163    
164 joko 1.3
165 joko 1.4 // create empty bmp-file (black background)
166 joko 1.3 write_blank_file("test.bmp");
167    
168     /* open file for reading and writing */
169     hFile = CreateFile("test.bmp", GENERIC_WRITE|GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
170     if (INVALID_HANDLE_VALUE == hFile) {
171     err = GetLastError();
172     printErrorAndExit("Error at CreateFile",err);
173     }
174    
175     /* create the file mapping object */
176     hMap = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 0, 0, NULL);
177     if (NULL == hMap) {
178     printErrorAndExit("Error at CreateFileMapping", GetLastError());
179     }
180    
181     /* map the whole file into the process context */
182     pData = MapViewOfFile(hMap, FILE_MAP_WRITE, 0, 0, 0);
183     if (NULL == pData) {
184     printErrorAndExit("Error at MapViewOfFile", GetLastError());
185     }
186    
187    
188     // calculate pointer to beginning of bitmap
189     pDataBitmap = (unsigned char *)((INT_PTR)pData + sizeof(header));
190    
191     // debugging
192     printf("pos. of file: %p\n", pData);
193     printf("pos. of bitmap: %p\n", pDataBitmap);
194    
195     // pointer to current pixel
196     pDataBitmapCurrent = pDataBitmap;
197    
198     /*
199     // turn bitmap into white wand
200     for (offset = 0; offset < 500 * 500 * 3; offset++) {
201     //pDataBitmap[offset] = 255;
202     *pDataBitmapCurrent = 255;
203     pDataBitmapCurrent++;
204     }
205     */
206    
207 joko 1.6
208     // allocate memory for table of all worker handles
209     if ((worker_handles = malloc(workers * sizeof worker_handles[0])) == NULL)
210     perror("malloc"), exit(1);
211    
212     /*
213     // allocate memory for table of all worker arguments
214     if ((worker_args = malloc(workers * sizeof worker_args[0])) == NULL)
215     perror("malloc"), exit(1);
216     */
217     // allocate memory for table of all worker arguments
218     worker_args = (PWORKERARGS) HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, workers * sizeof(WORKERARGS));
219    
220     // calculate segments of bitmap for worker threads/processes and start them
221 joko 1.5 worker_rows = YSIZE / workers;
222     printf("rows for each worker: %i\n", worker_rows);
223     for (worker_index = 0; worker_index < workers; worker_index++) {
224    
225     // number of row to start for each worker
226     worker_startrow = worker_index * worker_rows;
227    
228     // recalculate number of rows for last worker if (YSIZE mod workers) != 0
229     if (worker_index == workers - 1) {
230     worker_rows = YSIZE - worker_startrow;
231     printf("rows for last worker: %i\n", worker_rows);
232     }
233 joko 1.6
234     worker_args[worker_index].start_row = worker_startrow;
235     worker_args[worker_index].number_of_rows = worker_rows;
236     worker_args[worker_index].pBitmap = pDataBitmap;
237    
238     worker_handles[worker_index] = CreateThread(
239     NULL, // LPSECURITY_ATTRIBUTES lpThreadAttributes,
240     0, // SIZE_T dwStackSize,
241     fractal_thread, // LPTHREAD_START_ROUTINE lpStartAddress,
242     &worker_args[worker_index], // LPVOID lpParameter,
243     0, // DWORD dwCreationFlags,
244     NULL // LPDWORD lpThreadId
245     );
246    
247 joko 1.5 }
248    
249 joko 1.6 // wait for all threads
250     if (WaitForMultipleObjects(workers, worker_handles, TRUE, INFINITE) == WAIT_FAILED)
251     perror("WaitForMultipleObjects");
252 joko 1.3
253     /* write the result into the file */
254     if (!FlushViewOfFile(pData, 0)) {
255     err = GetLastError();
256     printErrorAndExit("Error at UnmapViewOfFile", err);
257     }
258    
259     /* remove the mapped file */
260     if (!UnmapViewOfFile(pData)) {
261     err = GetLastError();
262     printErrorAndExit("Error at UnmapViewOfFile", err);
263     exit(err);
264     }
265    
266     /* cleanup handles */
267     if (!CloseHandle(hMap) || !CloseHandle(hFile) ) {
268     err = GetLastError();
269     printErrorAndExit("Error at CloseHandle", err);
270     }
271 joko 1.1
272     }

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