BSArch/04/bmp_fractal.c

/* Betriebssystem & Middleware
 *
 * Betriebssystemarchitektur SS 2006
 *
 * Uebung 4.4 
 */

// $Id: bmp_fractal.c,v 1.14 2006/07/02 11:44:57 joko Exp $

#include <windows.h>
#include <stdio.h>
#include <errno.h>

#define XSIZE 500
#define YSIZE 500
#include "algorithm.h"

BOOL VERBOSE = FALSE;


/* BMP Header */
unsigned char header[54]={0x42,0x4d,              // signature BM
                            0xe6,0x71,0x0b,0x0,   // filesize 750054
                            0x0,0x0,0x0,0x0,      // reserved 
                            0x36,0x0,0x0,0x0,     // image offset 54
                            0x28,0x0,0x0,0x0,     // size of header follows 40
                            0xf4,0x1,0x0,0x0,     // with of image 500
                            0xf4,0x1,0x0,0x0,     // height of image 500
                            0x1,0x0,              // number of planes  1
                            0x18,0x0,             // number of pixel 24
                            0x0,0x0,0x0,0x0,      // compression  
                            0xb0,0x71,0x0b,0x0,   // size of image 750000
                            0x0,0x0,0x0,0x0,      // xres
                            0x0,0x0,0x0,0x0,      // yres   
                            0x0,0x0,0x0,0x0,      // number of colortables    
                            0x0,0x0,0x0,0x0       // number of important colors
                        };


void printErrorAndExit(const char *msg, DWORD err) {
        LPSTR lpMsgBuf;
        if(FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER|
                                  FORMAT_MESSAGE_FROM_SYSTEM | 
                                          FORMAT_MESSAGE_IGNORE_INSERTS,
                                                NULL,
                                                err,
                                          MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
                                          (LPTSTR) &lpMsgBuf,
                                          0,
                                          NULL ))
        {
                fprintf(stderr, "%s: %s\n", msg, lpMsgBuf);
                LocalFree(lpMsgBuf);
        }
        else
        {
                fprintf(stderr, "Error at FormatMesage: %d\n",err=GetLastError());
        }
        exit(err);
}


void write_blank_file(char *filename) {

  FILE *fd;
  int len, i, img_size;

  // open file handle
  fd = fopen(filename, "wb+");
  if (NULL == fd) {
    perror("Error while opening file for writing");
    exit(1);
  }

  // write bmp header to file
  len = fwrite(header, 1, sizeof(header), fd);
  
  // error checking
  if (-1 == len || len != sizeof(header)) {
    perror("Error while writing header to file");
    exit(2);
  }
  
  // write three null-bytes for each pixel to file to create a black picture
  img_size = XSIZE * YSIZE;
  for (i = 0; i < img_size; i++) {
    len = fwrite("\0\0\0", 1, 3, fd);
    if (-1 == len || len != 3) {
      perror("Error while writing data to file");
      exit(4);
    }
  }
  
  // close file handle
  fclose(fd);
}


// arguments for each thread
typedef struct _WorkerArguments {
  int start_row;
  int number_of_rows;
  unsigned char * pBitmap;
} WORKERARGS, *PWORKERARGS;

// worker thread - main entry function
DWORD WINAPI fractal_create_segment (LPVOID lpParam) {
  
  // thread stuff
  int thread_id;
  PWORKERARGS args;
  unsigned char *pDataBitmapSegment;

  // fractal calculation
  int x, y;
  char bgr[3];

  thread_id = GetCurrentThreadId();
  
  // get worker arguments
  args = (PWORKERARGS)lpParam;

  // calculate pointer to beginning of segment
  pDataBitmapSegment = (unsigned char *)((INT_PTR)args->pBitmap + (YSIZE - (args->start_row + args->number_of_rows)) * 3 * XSIZE);

  // debugging
  if (VERBOSE) {
    fprintf(stdout, "----------------------------------------------\n");
    fprintf(stdout, "thread_id: %i\n", thread_id);
    fprintf(stdout, "arg.start_row: %i\n", args->start_row);
    fprintf(stdout, "arg.number_of_rows: %i\n", args->number_of_rows);
    fprintf(stdout, "segment_start: %p\n", pDataBitmapSegment);
  }
  
  // calculate fractal
  for (y = (args->start_row + args->number_of_rows) - 1; y >= args->start_row; y--) {
    //fprintf(stdout, "calc: thread=%i; y=%i            limits: %i,%i    p: %p\n", thread_id, y, args->start_row, args->number_of_rows, pDataBitmapSegment);
    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]); 
      
      // transfer color values to current pixel
      pDataBitmapSegment[0] = bgr[0];
      pDataBitmapSegment[1] = bgr[1];
      pDataBitmapSegment[2] = bgr[2];
      
      // move pointer to next pixel
      pDataBitmapSegment += 3;
      
    }
    //no padding required because 1500%4 =0 ???
  }

  if (VERBOSE)
    fprintf(stdout, "thread finished: %i\n", thread_id);
  return 0;

}

BOOL scan_argv(int argc, char *argv[], char opt_name[], char *opt_value) {
  int i;
  char * opt_current_name;
  char * opt_current_value;

  //printf("searching for: '%s'\n", opt_name);
  
  for (i = 1; i < argc; i++) {
    opt_current_name = argv[i];
    if (strcmp(opt_current_name, opt_name) == 0) {
      opt_current_value = argv[i+1];
      if (opt_current_value != NULL) {
        strcpy(opt_value, opt_current_value);
      }
      return TRUE;
    }
  }
  return FALSE;
}


int main(int argc, char *argv[]) {

  // MMF support
  DWORD err;
  HANDLE hMap, hFile;
  LPVOID pData;
  unsigned char *pDataBitmap;

  // workers
  int workers;
  int worker_index, worker_rows, worker_startrow;
  HANDLE *worker_handles;
  PWORKERARGS worker_args;
  int worker_count;

  // threads or processes?
  BOOL use_processes = FALSE;
  BOOL is_worker_process = FALSE;
  
  // information for creating processes
  STARTUPINFO si;
  PROCESS_INFORMATION pi;
  char szCmdline[65536];
  
  // command line stuff
  char arg_option[1024];
  char arg_value[1024];
  char *bmp_filename;
  char *verbose_option = "";
  

  // parse command line arguments
  if (argc < 2) {
    fprintf(stderr, "Can not run without arguments!\nPlease specify '-t {number of threads}' or '-p {number of processes}' and an image filename.\n");
    exit(EXIT_FAILURE);
  }
  
  if (scan_argv(argc, argv, "--verbose", arg_value)) {
    VERBOSE = TRUE;
  }
  
  if (scan_argv(argc, argv, "--worker", arg_value)) {
    use_processes = TRUE;
    is_worker_process = TRUE;
  
  } else if (scan_argv(argc, argv, "-p", arg_value)) {
    if (strlen(arg_value) == 0) {
      fprintf(stderr, "Please specify number of processes!\n");
      exit(EXIT_FAILURE);
    }
    use_processes = TRUE;
    is_worker_process = FALSE;
    workers = atoi(arg_value);
  
  } else if (scan_argv(argc, argv, "-t", arg_value)) {
    if (strlen(arg_value) == 0) {
      fprintf(stderr, "Please specify number of threads!\n");
      exit(EXIT_FAILURE);
    }
    use_processes = FALSE;
    is_worker_process = FALSE;
    workers = atoi(arg_value);
    
  }
  
  
  if (VERBOSE && use_processes) {
    fprintf(stdout, "===================================================== ");
    if (is_worker_process)
      fprintf(stdout, "WORKER-PROCESS\n");
    else
      fprintf(stdout, "MASTER-PROCESS\n");
  }

  
  // master creates memory mapped file ("empty" image)
  if (!is_worker_process) {
    
    if (argc < 4) {
      fprintf(stderr, "Must give filename of image as third argument!\n");
      exit(EXIT_FAILURE);
    }
    
    bmp_filename = argv[3];
    
    // create empty bmp-file (black background)
    write_blank_file(bmp_filename);

    // open file for reading and writing
    hFile = CreateFile(bmp_filename, GENERIC_WRITE|GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
    if (INVALID_HANDLE_VALUE == hFile) {
      err = GetLastError();
      printErrorAndExit("Error at CreateFile",err);
    }

    // create the file mapping object
    hMap = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 0, 0, "bmp_fractal");
    if (NULL == hMap) {
      printErrorAndExit("Error at CreateFileMapping", GetLastError());
    }
  
  // worker uses existing memory mapped file
  } else {
    
    // open existing mapping object
    hMap = OpenFileMapping(FILE_MAP_WRITE, FALSE, "bmp_fractal");
    if (NULL == hMap)
      printErrorAndExit("Error at OpenFileMapping", GetLastError());
  }
  
  // map the whole file into the process context
  pData = MapViewOfFile(hMap, FILE_MAP_WRITE, 0, 0, 0);
  if (NULL == pData) {
    printErrorAndExit("Error at MapViewOfFile", GetLastError());
  }

  
  // calculate pointer to beginning of bitmap
  pDataBitmap = (unsigned char *)((INT_PTR)pData + sizeof(header));
  
  // debugging
  if (VERBOSE) {
    fprintf(stdout, "pos. of file: %p\n", pData);
    fprintf(stdout, "pos. of bitmap: %p\n", pDataBitmap);
  }

  
  if (use_processes && is_worker_process) {
  
    if (VERBOSE)
      fprintf(stdout, "inside worker-process\n");
    
    // get segment information from command line
    worker_startrow = atoi(argv[2]);
    worker_rows = atoi(argv[3]);
    
    // allocate memory for one worker's arguments
    if ((worker_args = malloc(sizeof(worker_args[0]))) == NULL)
      perror("Error while allocating memory for worker arguments via malloc"), exit(1);
    
    // assign worker's arguments
    worker_args[0].start_row = worker_startrow;
    worker_args[0].number_of_rows = worker_rows;
    worker_args[0].pBitmap = pDataBitmap;

    fractal_create_segment(&worker_args[0]);

    // cleanup mmap-handle
    if (!CloseHandle(hMap))
      printErrorAndExit("Error at CloseHandle", GetLastError());
    
    return 0;
  }
  
  /*
  // turn bitmap into white canvas
  for (offset = 0; offset < 500 * 500 * 3; offset++) {
    *pDataBitmap = 255;
    pDataBitmap++;
  }
  exit(0);
  */

  // allocate memory for bitmap
  /*
  if ((pDataBitmap = malloc(XSIZE * YSIZE * 3 * sizeof(pDataBitmap[0]))) == NULL)
    perror("malloc"), exit(1);
  */
  
  // allocate memory for table of all worker handles
  if ((worker_handles = malloc(workers * sizeof(worker_handles[0]))) == NULL)
    perror("Error while allocating memory for worker handles via malloc"), exit(1);

  // allocate memory for table of all worker arguments
  if ((worker_args = malloc(workers * sizeof(worker_args[0]))) == NULL)
    perror("Error while allocating memory for worker arguments via malloc"), exit(1);
  
  
  // calculate bitmap segment length for workers
  worker_rows = YSIZE / workers;
  if (VERBOSE)
    fprintf(stdout, "rows for each worker: %i\n", worker_rows);
  
  // start workers
  for (worker_index = 0; worker_index < workers; worker_index++) {
    
    // debugging: just run single thread
    //if (worker_index == 1)
    //  continue;
    
    // number of row to start for each worker
    worker_startrow = worker_index * worker_rows;
    
    // recalculate number of rows for last worker if (YSIZE mod workers) != 0
    if (worker_index == workers - 1) {
      worker_rows = YSIZE - worker_startrow;
      if (VERBOSE)
        fprintf(stdout, "rows for last worker: %i\n", worker_rows);
    }
    
    // assign each worker's arguments
    worker_args[worker_index].start_row = worker_startrow;
    worker_args[worker_index].number_of_rows = worker_rows;
    worker_args[worker_index].pBitmap = pDataBitmap;
    
    if (!use_processes) {
    
      worker_handles[worker_index] = CreateThread(
        NULL,                          // LPSECURITY_ATTRIBUTES lpThreadAttributes,
        0,                             // SIZE_T dwStackSize,
        &fractal_create_segment,                // LPTHREAD_START_ROUTINE lpStartAddress,
        &worker_args[worker_index],    // LPVOID lpParameter,
        0,                             // DWORD dwCreationFlags,
        NULL                           // LPDWORD lpThreadId
      );

      if (!worker_handles[worker_index]) 
        printErrorAndExit("CreateThread failed", GetLastError());
      
    } else {

      if (VERBOSE)
        verbose_option = "--verbose";
      _snprintf(szCmdline, 1023, "%s %s %i %i %s", argv[0], "--worker", worker_startrow, worker_rows, verbose_option);
      if (VERBOSE)
        fprintf(stdout, "starting worker process: %s\n", szCmdline);
      ZeroMemory( &si, sizeof(si) );
      si.cb = sizeof(si);
      ZeroMemory( &pi, sizeof(pi) );
      
      if (!CreateProcess(
          NULL,           // No module name (use command line)
          szCmdline,      // Command line
          NULL,           // Process handle not inheritable
          NULL,           // Thread handle not inheritable
          FALSE,          // Set handle inheritance to FALSE
          0,              // No creation flags
          NULL,           // Use parent's environment block
          NULL,           // Use parent's starting directory 
          &si,            // Pointer to STARTUPINFO structure
          &pi             // Pointer to PROCESS_INFORMATION structure
      ))
        printErrorAndExit("CreateProcess failed", GetLastError());
    
      worker_handles[worker_index] = pi.hProcess;
      
    }

  }

  if (VERBOSE)
    fprintf(stdout, "waiting for workers to finish...\n");
  
  // wait for all workers
  for (worker_index = 0; worker_index < workers; worker_index += MAXIMUM_WAIT_OBJECTS) {
    worker_count = ((workers - worker_index) > MAXIMUM_WAIT_OBJECTS) ? MAXIMUM_WAIT_OBJECTS : (workers - worker_index);
    if (WaitForMultipleObjects(worker_count, &worker_handles[worker_index], TRUE, INFINITE) == WAIT_FAILED)
      printErrorAndExit("Error at WaitForMultipleObjects", GetLastError());
  }

  // debugging: just run single thread
  //if (WaitForSingleObject(worker_handles[0], INFINITE) == WAIT_FAILED)
  //  perror("WaitForSingleObject");

  // close all worker handles
  for (worker_index = 0; worker_index < workers; worker_index++)
    CloseHandle(worker_handles[worker_index]);
    
  // write the result into the file
  if (!FlushViewOfFile(pData, 0)) {
    err = GetLastError();
    printErrorAndExit("Error at UnmapViewOfFile", err);
  }

  // remove the mapped file
  if (!UnmapViewOfFile(pData)) {
    err = GetLastError();
    printErrorAndExit("Error at UnmapViewOfFile", err);
    exit(err);
  }
  
  // cleanup handles
  if (!CloseHandle(hMap) || !CloseHandle(hFile) ) {
    err = GetLastError();
    printErrorAndExit("Error at CloseHandle", err);
  }

  free(worker_args);
  free(worker_handles);
  
  return 0;
  
}
1	/* Betriebssystem & Middleware
2	*
3	* Betriebssystemarchitektur SS 2006
4	*
5	* Uebung 4.4
6	*/
7
8	// $Id: bmp_fractal.c,v 1.14 2006/07/02 11:44:57 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	BOOL VERBOSE = FALSE;
19
20
21	/* BMP Header */
22	unsigned char header[54]={0x42,0x4d, // signature BM
23	0xe6,0x71,0x0b,0x0, // filesize 750054
24	0x0,0x0,0x0,0x0, // reserved
25	0x36,0x0,0x0,0x0, // image offset 54
26	0x28,0x0,0x0,0x0, // size of header follows 40
27	0xf4,0x1,0x0,0x0, // with of image 500
28	0xf4,0x1,0x0,0x0, // height of image 500
29	0x1,0x0, // number of planes 1
30	0x18,0x0, // number of pixel 24
31	0x0,0x0,0x0,0x0, // compression
32	0xb0,0x71,0x0b,0x0, // size of image 750000
33	0x0,0x0,0x0,0x0, // xres
34	0x0,0x0,0x0,0x0, // yres
35	0x0,0x0,0x0,0x0, // number of colortables
36	0x0,0x0,0x0,0x0 // number of important colors
37	};
38
39
40	void printErrorAndExit(const char *msg, DWORD err) {
41	LPSTR lpMsgBuf;
42	if(FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER\|
43	FORMAT_MESSAGE_FROM_SYSTEM \|
44	FORMAT_MESSAGE_IGNORE_INSERTS,
45	NULL,
46	err,
47	MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
48	(LPTSTR) &lpMsgBuf,
49	0,
50	NULL ))
51	{
52	fprintf(stderr, "%s: %s\n", msg, lpMsgBuf);
53	LocalFree(lpMsgBuf);
54	}
55	else
56	{
57	fprintf(stderr, "Error at FormatMesage: %d\n",err=GetLastError());
58	}
59	exit(err);
60	}
61
62
63	void write_blank_file(char *filename) {
64
65	FILE *fd;
66	int len, i, img_size;
67
68	// open file handle
69	fd = fopen(filename, "wb+");
70	if (NULL == fd) {
71	perror("Error while opening file for writing");
72	exit(1);
73	}
74
75	// write bmp header to file
76	len = fwrite(header, 1, sizeof(header), fd);
77
78	// error checking
79	if (-1 == len \|\| len != sizeof(header)) {
80	perror("Error while writing header to file");
81	exit(2);
82	}
83
84	// write three null-bytes for each pixel to file to create a black picture
85	img_size = XSIZE * YSIZE;
86	for (i = 0; i < img_size; i++) {
87	len = fwrite("\0\0\0", 1, 3, fd);
88	if (-1 == len \|\| len != 3) {
89	perror("Error while writing data to file");
90	exit(4);
91	}
92	}
93
94	// close file handle
95	fclose(fd);
96	}
97
98
99	// arguments for each thread
100	typedef struct _WorkerArguments {
101	int start_row;
102	int number_of_rows;
103	unsigned char * pBitmap;
104	} WORKERARGS, *PWORKERARGS;
105
106	// worker thread - main entry function
107	DWORD WINAPI fractal_create_segment (LPVOID lpParam) {
108
109	// thread stuff
110	int thread_id;
111	PWORKERARGS args;
112	unsigned char *pDataBitmapSegment;
113
114	// fractal calculation
115	int x, y;
116	char bgr[3];
117
118	thread_id = GetCurrentThreadId();
119
120	// get worker arguments
121	args = (PWORKERARGS)lpParam;
122
123	// calculate pointer to beginning of segment
124	pDataBitmapSegment = (unsigned char )((INT_PTR)args->pBitmap + (YSIZE - (args->start_row + args->number_of_rows)) 3 * XSIZE);
125
126	// debugging
127	if (VERBOSE) {
128	fprintf(stdout, "----------------------------------------------\n");
129	fprintf(stdout, "thread_id: %i\n", thread_id);
130	fprintf(stdout, "arg.start_row: %i\n", args->start_row);
131	fprintf(stdout, "arg.number_of_rows: %i\n", args->number_of_rows);
132	fprintf(stdout, "segment_start: %p\n", pDataBitmapSegment);
133	}
134
135	// calculate fractal
136	for (y = (args->start_row + args->number_of_rows) - 1; y >= args->start_row; y--) {
137	//fprintf(stdout, "calc: thread=%i; y=%i limits: %i,%i p: %p\n", thread_id, y, args->start_row, args->number_of_rows, pDataBitmapSegment);
138	for (x = 0; x < XSIZE; x++) {
139	getColorValuesAt(x * (2.0 / XSIZE) - 1.5, y * (2.0 / YSIZE) - 1.0, &bgr[2], &bgr[1], &bgr[0]);
140
141	// transfer color values to current pixel
142	pDataBitmapSegment[0] = bgr[0];
143	pDataBitmapSegment[1] = bgr[1];
144	pDataBitmapSegment[2] = bgr[2];
145
146	// move pointer to next pixel
147	pDataBitmapSegment += 3;
148
149	}
150	//no padding required because 1500%4 =0 ???
151	}
152
153	if (VERBOSE)
154	fprintf(stdout, "thread finished: %i\n", thread_id);
155	return 0;
156
157	}
158
159	BOOL scan_argv(int argc, char argv[], char opt_name[], char opt_value) {
160	int i;
161	char * opt_current_name;
162	char * opt_current_value;
163
164	//printf("searching for: '%s'\n", opt_name);
165
166	for (i = 1; i < argc; i++) {
167	opt_current_name = argv[i];
168	if (strcmp(opt_current_name, opt_name) == 0) {
169	opt_current_value = argv[i+1];
170	if (opt_current_value != NULL) {
171	strcpy(opt_value, opt_current_value);
172	}
173	return TRUE;
174	}
175	}
176	return FALSE;
177	}
178
179
180	int main(int argc, char *argv[]) {
181
182	// MMF support
183	DWORD err;
184	HANDLE hMap, hFile;
185	LPVOID pData;
186	unsigned char *pDataBitmap;
187
188	// workers
189	int workers;
190	int worker_index, worker_rows, worker_startrow;
191	HANDLE *worker_handles;
192	PWORKERARGS worker_args;
193	int worker_count;
194
195	// threads or processes?
196	BOOL use_processes = FALSE;
197	BOOL is_worker_process = FALSE;
198
199	// information for creating processes
200	STARTUPINFO si;
201	PROCESS_INFORMATION pi;
202	char szCmdline[65536];
203
204	// command line stuff
205	char arg_option[1024];
206	char arg_value[1024];
207	char *bmp_filename;
208	char *verbose_option = "";
209
210
211	// parse command line arguments
212	if (argc < 2) {
213	fprintf(stderr, "Can not run without arguments!\nPlease specify '-t {number of threads}' or '-p {number of processes}' and an image filename.\n");
214	exit(EXIT_FAILURE);
215	}
216
217	if (scan_argv(argc, argv, "--verbose", arg_value)) {
218	VERBOSE = TRUE;
219	}
220
221	if (scan_argv(argc, argv, "--worker", arg_value)) {
222	use_processes = TRUE;
223	is_worker_process = TRUE;
224
225	} else if (scan_argv(argc, argv, "-p", arg_value)) {
226	if (strlen(arg_value) == 0) {
227	fprintf(stderr, "Please specify number of processes!\n");
228	exit(EXIT_FAILURE);
229	}
230	use_processes = TRUE;
231	is_worker_process = FALSE;
232	workers = atoi(arg_value);
233
234	} else if (scan_argv(argc, argv, "-t", arg_value)) {
235	if (strlen(arg_value) == 0) {
236	fprintf(stderr, "Please specify number of threads!\n");
237	exit(EXIT_FAILURE);
238	}
239	use_processes = FALSE;
240	is_worker_process = FALSE;
241	workers = atoi(arg_value);
242
243	}
244
245
246	if (VERBOSE && use_processes) {
247	fprintf(stdout, "===================================================== ");
248	if (is_worker_process)
249	fprintf(stdout, "WORKER-PROCESS\n");
250	else
251	fprintf(stdout, "MASTER-PROCESS\n");
252	}
253
254
255	// master creates memory mapped file ("empty" image)
256	if (!is_worker_process) {
257
258	if (argc < 4) {
259	fprintf(stderr, "Must give filename of image as third argument!\n");
260	exit(EXIT_FAILURE);
261	}
262
263	bmp_filename = argv[3];
264
265	// create empty bmp-file (black background)
266	write_blank_file(bmp_filename);
267
268	// open file for reading and writing
269	hFile = CreateFile(bmp_filename, GENERIC_WRITE\|GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
270	if (INVALID_HANDLE_VALUE == hFile) {
271	err = GetLastError();
272	printErrorAndExit("Error at CreateFile",err);
273	}
274
275	// create the file mapping object
276	hMap = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 0, 0, "bmp_fractal");
277	if (NULL == hMap) {
278	printErrorAndExit("Error at CreateFileMapping", GetLastError());
279	}
280
281	// worker uses existing memory mapped file
282	} else {
283
284	// open existing mapping object
285	hMap = OpenFileMapping(FILE_MAP_WRITE, FALSE, "bmp_fractal");
286	if (NULL == hMap)
287	printErrorAndExit("Error at OpenFileMapping", GetLastError());
288	}
289
290	// map the whole file into the process context
291	pData = MapViewOfFile(hMap, FILE_MAP_WRITE, 0, 0, 0);
292	if (NULL == pData) {
293	printErrorAndExit("Error at MapViewOfFile", GetLastError());
294	}
295
296
297	// calculate pointer to beginning of bitmap
298	pDataBitmap = (unsigned char *)((INT_PTR)pData + sizeof(header));
299
300	// debugging
301	if (VERBOSE) {
302	fprintf(stdout, "pos. of file: %p\n", pData);
303	fprintf(stdout, "pos. of bitmap: %p\n", pDataBitmap);
304	}
305
306
307	if (use_processes && is_worker_process) {
308
309	if (VERBOSE)
310	fprintf(stdout, "inside worker-process\n");
311
312	// get segment information from command line
313	worker_startrow = atoi(argv[2]);
314	worker_rows = atoi(argv[3]);
315
316	// allocate memory for one worker's arguments
317	if ((worker_args = malloc(sizeof(worker_args[0]))) == NULL)
318	perror("Error while allocating memory for worker arguments via malloc"), exit(1);
319
320	// assign worker's arguments
321	worker_args[0].start_row = worker_startrow;
322	worker_args[0].number_of_rows = worker_rows;
323	worker_args[0].pBitmap = pDataBitmap;
324
325	fractal_create_segment(&worker_args[0]);
326
327	// cleanup mmap-handle
328	if (!CloseHandle(hMap))
329	printErrorAndExit("Error at CloseHandle", GetLastError());
330
331	return 0;
332	}
333
334	/*
335	// turn bitmap into white canvas
336	for (offset = 0; offset < 500 * 500 * 3; offset++) {
337	*pDataBitmap = 255;
338	pDataBitmap++;
339	}
340	exit(0);
341	*/
342
343	// allocate memory for bitmap
344	/*
345	if ((pDataBitmap = malloc(XSIZE * YSIZE * 3 * sizeof(pDataBitmap[0]))) == NULL)
346	perror("malloc"), exit(1);
347	*/
348
349	// allocate memory for table of all worker handles
350	if ((worker_handles = malloc(workers * sizeof(worker_handles[0]))) == NULL)
351	perror("Error while allocating memory for worker handles via malloc"), exit(1);
352
353	// allocate memory for table of all worker arguments
354	if ((worker_args = malloc(workers * sizeof(worker_args[0]))) == NULL)
355	perror("Error while allocating memory for worker arguments via malloc"), exit(1);
356
357
358	// calculate bitmap segment length for workers
359	worker_rows = YSIZE / workers;
360	if (VERBOSE)
361	fprintf(stdout, "rows for each worker: %i\n", worker_rows);
362
363	// start workers
364	for (worker_index = 0; worker_index < workers; worker_index++) {
365
366	// debugging: just run single thread
367	//if (worker_index == 1)
368	// continue;
369
370	// number of row to start for each worker
371	worker_startrow = worker_index * worker_rows;
372
373	// recalculate number of rows for last worker if (YSIZE mod workers) != 0
374	if (worker_index == workers - 1) {
375	worker_rows = YSIZE - worker_startrow;
376	if (VERBOSE)
377	fprintf(stdout, "rows for last worker: %i\n", worker_rows);
378	}
379
380	// assign each worker's arguments
381	worker_args[worker_index].start_row = worker_startrow;
382	worker_args[worker_index].number_of_rows = worker_rows;
383	worker_args[worker_index].pBitmap = pDataBitmap;
384
385	if (!use_processes) {
386
387	worker_handles[worker_index] = CreateThread(
388	NULL, // LPSECURITY_ATTRIBUTES lpThreadAttributes,
389	0, // SIZE_T dwStackSize,
390	&fractal_create_segment, // LPTHREAD_START_ROUTINE lpStartAddress,
391	&worker_args[worker_index], // LPVOID lpParameter,
392	0, // DWORD dwCreationFlags,
393	NULL // LPDWORD lpThreadId
394	);
395
396	if (!worker_handles[worker_index])
397	printErrorAndExit("CreateThread failed", GetLastError());
398
399	} else {
400
401	if (VERBOSE)
402	verbose_option = "--verbose";
403	_snprintf(szCmdline, 1023, "%s %s %i %i %s", argv[0], "--worker", worker_startrow, worker_rows, verbose_option);
404	if (VERBOSE)
405	fprintf(stdout, "starting worker process: %s\n", szCmdline);
406	ZeroMemory( &si, sizeof(si) );
407	si.cb = sizeof(si);
408	ZeroMemory( &pi, sizeof(pi) );
409
410	if (!CreateProcess(
411	NULL, // No module name (use command line)
412	szCmdline, // Command line
413	NULL, // Process handle not inheritable
414	NULL, // Thread handle not inheritable
415	FALSE, // Set handle inheritance to FALSE
416	0, // No creation flags
417	NULL, // Use parent's environment block
418	NULL, // Use parent's starting directory
419	&si, // Pointer to STARTUPINFO structure
420	&pi // Pointer to PROCESS_INFORMATION structure
421	))
422	printErrorAndExit("CreateProcess failed", GetLastError());
423
424	worker_handles[worker_index] = pi.hProcess;
425
426	}
427
428	}
429
430	if (VERBOSE)
431	fprintf(stdout, "waiting for workers to finish...\n");
432
433	// wait for all workers
434	for (worker_index = 0; worker_index < workers; worker_index += MAXIMUM_WAIT_OBJECTS) {
435	worker_count = ((workers - worker_index) > MAXIMUM_WAIT_OBJECTS) ? MAXIMUM_WAIT_OBJECTS : (workers - worker_index);
436	if (WaitForMultipleObjects(worker_count, &worker_handles[worker_index], TRUE, INFINITE) == WAIT_FAILED)
437	printErrorAndExit("Error at WaitForMultipleObjects", GetLastError());
438	}
439
440	// debugging: just run single thread
441	//if (WaitForSingleObject(worker_handles[0], INFINITE) == WAIT_FAILED)
442	// perror("WaitForSingleObject");
443
444	// close all worker handles
445	for (worker_index = 0; worker_index < workers; worker_index++)
446	CloseHandle(worker_handles[worker_index]);
447
448	// write the result into the file
449	if (!FlushViewOfFile(pData, 0)) {
450	err = GetLastError();
451	printErrorAndExit("Error at UnmapViewOfFile", err);
452	}
453
454	// remove the mapped file
455	if (!UnmapViewOfFile(pData)) {
456	err = GetLastError();
457	printErrorAndExit("Error at UnmapViewOfFile", err);
458	exit(err);
459	}
460
461	// cleanup handles
462	if (!CloseHandle(hMap) \|\| !CloseHandle(hFile) ) {
463	err = GetLastError();
464	printErrorAndExit("Error at CloseHandle", err);
465	}
466
467	free(worker_args);
468	free(worker_handles);
469
470	return 0;
471
472	}
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