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

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revision 1.3 by joko, Sat Jul 1 11:45:35 2006 UTC revision 1.7 by joko, Sat Jul 1 20:31:31 2006 UTC
# Line 94  void write_blank_file(char *filename) { Line 94  void write_blank_file(char *filename) {
94  }  }
95    
96    
97  int main(int argc, char *argv[]) {  // arguments for each thread
98    int len,x,y;  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];    char bgr[3];
   short svalue;  
   int lvalue;  
115    
116    HANDLE hMap, hFile;    thread_id = GetCurrentThreadId();
117    DWORD err, size;    
118    int elems;    // 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;    LPVOID pData;
163    unsigned char *pDataBitmap, *pDataBitmapCurrent;    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    int offset;    // create empty bmp-file (black background)
     
   // create empty file (black background)  
174    write_blank_file("test.bmp");    write_blank_file("test.bmp");
     
175    
176    /* open file for reading and writing */    /* open file for reading and writing */
177    hFile = CreateFile("test.bmp", GENERIC_WRITE|GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);    hFile = CreateFile("test.bmp", GENERIC_WRITE|GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
# Line 152  int main(int argc, char *argv[]) { Line 212  int main(int argc, char *argv[]) {
212    }    }
213    */    */
214    
   // calculate fractal  
   for (y=YSIZE-1; y>=0; y--) {  
           for (x=0; x<XSIZE; x++) {  
             getColorValuesAt(x * (2.0 / XSIZE) - 1.5, y * (2.0 / YSIZE) - 1.0, &bgr[2], &bgr[1], &bgr[0]);  
               
             // debugging  
             //printf("pointer: %p\n", pDataBitmapCurrent);  
               
             // transfer color values to current pixel  
             //*pDataBitmapCurrent = (unsigned char *)bgr;  
             pDataBitmapCurrent[0] = bgr[0];  
             pDataBitmapCurrent[1] = bgr[1];  
             pDataBitmapCurrent[2] = bgr[2];  
               
             // move pointer to next pixel  
             pDataBitmapCurrent += 3;  
               
           }  
           //no padding required because 1500%4 =0  
   }  
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 */    /* write the result into the file */
274    if (!FlushViewOfFile(pData, 0)) {    if (!FlushViewOfFile(pData, 0)) {
275      err = GetLastError();      err = GetLastError();
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