--- joko/Uni/BSArch/04/bmp_fractal.c	2006/07/02 12:08:10	1.15
+++ joko/Uni/BSArch/04/bmp_fractal.c	2006/07/02 12:41:56	1.18
@@ -5,7 +5,7 @@
  * Uebung 4.4 
  */
 
-// $Id: bmp_fractal.c,v 1.15 2006/07/02 12:08:10 joko Exp $
+// $Id: bmp_fractal.c,v 1.18 2006/07/02 12:41:56 joko Exp $
 
 #include <windows.h>
 #include <stdio.h>
@@ -15,6 +15,9 @@
 #define YSIZE 500
 #include "algorithm.h"
 
+#define MAX_COMMAND_LINE 65536
+#define MMAP_NAME "bmp_fractal"
+
 BOOL VERBOSE = FALSE;
 
 
@@ -92,7 +95,10 @@
   }
   
   // close file handle
-  fclose(fd);
+  if (fclose(fd) != 0) {
+    perror("Error while closing file handle");
+    exit(1);
+  }
 }
 
 
@@ -115,8 +121,6 @@
   int x, y;
   char bgr[3];
 
-  thread_id = GetCurrentThreadId();
-  
   // get worker arguments
   args = (PWORKERARGS)lpParam;
 
@@ -125,6 +129,7 @@
 
   // debugging
   if (VERBOSE) {
+    thread_id = GetCurrentThreadId();
     fprintf(stdout, "----------------------------------------------\n");
     fprintf(stdout, "thread_id: %i\n", thread_id);
     fprintf(stdout, "arg.start_row: %i\n", args->start_row);
@@ -136,6 +141,8 @@
   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++) {
+      
+      // call to function in static linked library
       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
@@ -156,7 +163,6 @@
 
 }
 
-//BOOL scan_argv(int argc, char *argv[], char opt_name[], char *opt_value[]) {
 BOOL scan_argv(int argc, char *argv[], char opt_name[], char *opt_value) {
   int i;
   char * opt_current_name;
@@ -187,10 +193,11 @@
   unsigned char *pDataBitmap;
 
   // workers
-  int workers = 5;
+  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;
@@ -199,7 +206,7 @@
   // information for creating processes
   STARTUPINFO si;
   PROCESS_INFORMATION pi;
-  char szCmdline[65536];
+  char szCmdline[MAX_COMMAND_LINE];
   
   // command line stuff
   char arg_option[1024];
@@ -208,12 +215,14 @@
   char *verbose_option = "";
   
 
-  // parse command line arguments
+  // check 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");
+    fprintf(stderr, "Error: Can not run without arguments!\nPlease specify '-t {number of threads}' or '-p {number of processes}' and an image filename.\n");
     exit(EXIT_FAILURE);
   }
+
   
+  // parse command line arguments
   if (scan_argv(argc, argv, "--verbose", arg_value)) {
     VERBOSE = TRUE;
   }
@@ -224,7 +233,7 @@
   
   } else if (scan_argv(argc, argv, "-p", arg_value)) {
     if (strlen(arg_value) == 0) {
-      fprintf(stderr, "Please specify number of processes!\n");
+      fprintf(stderr, "Error: Please specify number of processes!\n");
       exit(EXIT_FAILURE);
     }
     use_processes = TRUE;
@@ -232,16 +241,20 @@
     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");
+    
+    if (strlen(arg_value) == 0)
+      fprintf(stderr, "Error: Please specify number of threads!\n"),
       exit(EXIT_FAILURE);
-    }
+    
     use_processes = FALSE;
     is_worker_process = FALSE;
     workers = atoi(arg_value);
     
   }
-  
+
+  if (!is_worker_process && workers < 1)
+    fprintf(stderr, "Error: Number of threads/processes must be >0!\n"),
+    exit(EXIT_FAILURE);
   
   if (VERBOSE && use_processes) {
     fprintf(stdout, "===================================================== ");
@@ -256,7 +269,7 @@
   if (!is_worker_process) {
     
     if (argc < 4) {
-      fprintf(stderr, "Must give filename of image as third argument!\n");
+      fprintf(stderr, "Error: Must give filename of image as third argument!\n");
       exit(EXIT_FAILURE);
     }
     
@@ -273,7 +286,7 @@
     }
 
     // create the file mapping object
-    hMap = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 0, 0, "bmp_fractal");
+    hMap = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 0, 0, MMAP_NAME);
     if (NULL == hMap) {
       printErrorAndExit("Error at CreateFileMapping", GetLastError());
     }
@@ -282,7 +295,7 @@
   } else {
     
     // open existing mapping object
-    hMap = OpenFileMapping(FILE_MAP_WRITE, FALSE, "bmp_fractal");
+    hMap = OpenFileMapping(FILE_MAP_WRITE, FALSE, MMAP_NAME);
     if (NULL == hMap)
       printErrorAndExit("Error at OpenFileMapping", GetLastError());
   }
@@ -400,9 +413,11 @@
 
       if (VERBOSE)
         verbose_option = "--verbose";
-      _snprintf(szCmdline, 1023, "%s %s %i %i %s", argv[0], "--worker", worker_startrow, worker_rows, verbose_option);
+      _snprintf(szCmdline, MAX_COMMAND_LINE - 1, "%s %s %i %i %s", argv[0], "--worker", worker_startrow, worker_rows, verbose_option);
       if (VERBOSE)
         fprintf(stdout, "starting worker process: %s\n", szCmdline);
+      
+      // prepare data structures for CreateProcess
       ZeroMemory( &si, sizeof(si) );
       si.cb = sizeof(si);
       ZeroMemory( &pi, sizeof(pi) );
@@ -427,38 +442,37 @@
 
   }
 
-  // wait for all threads
   if (VERBOSE)
     fprintf(stdout, "waiting for workers to finish...\n");
-  if (WaitForMultipleObjects(workers, worker_handles, TRUE, INFINITE) == WAIT_FAILED)
-    printErrorAndExit("Error at WaitForMultipleObjects", GetLastError());
+  
+  // 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]);
+  for (worker_index = 0; worker_index < workers; worker_index++) {
+    if (!CloseHandle(worker_handles[worker_index]))
+      printErrorAndExit("Error at CloseHandle for worker handles", GetLastError());
+  }
     
   // write the result into the file
-  if (!FlushViewOfFile(pData, 0)) {
-    err = GetLastError();
-    printErrorAndExit("Error at UnmapViewOfFile", err);
-  }
+  if (!FlushViewOfFile(pData, 0))
+    printErrorAndExit("Error at UnmapViewOfFile", GetLastError());
 
   // remove the mapped file
-  if (!UnmapViewOfFile(pData)) {
-    err = GetLastError();
-    printErrorAndExit("Error at UnmapViewOfFile", err);
-    exit(err);
-  }
+  if (!UnmapViewOfFile(pData))
+    printErrorAndExit("Error at UnmapViewOfFile", GetLastError());
   
   // cleanup handles
-  if (!CloseHandle(hMap) || !CloseHandle(hFile) ) {
-    err = GetLastError();
-    printErrorAndExit("Error at CloseHandle", err);
-  }
+  if (!CloseHandle(hMap) || !CloseHandle(hFile) )
+    printErrorAndExit("Error at CloseHandle for memory mapped file", GetLastError());
 
   free(worker_args);
   free(worker_handles);