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PODebug recursive thread call in C
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I have been trying to debug my code whenever I had free-time for the past day and a half and I don't know what is wrong with my code. When I add the <code>close()</code> function to a recursive call, the program gives me an invalid pointer. But when I remove the <code>close()</code> function call the program runs fine, except it does not do what it is supposed to do, which is: <ul> <li>add up all the file sizes in a user input directory</li> <li>open sub-directories, if any, and add up all the files inside the sub-directory</li> </ul> Instead, it adds up all the file sizes in the input directory and is able to open the last sub-directory and add the files within that directory to the total file size count. I am trying to do this with threads. The <code>main()</code> function creates one main thread from the user input directory and runs <code>opendirectory()</code> off the bat. <pre><code>/* * Iterates through given directory */ void *opendirectory(void *t) { pthread_mutex_lock(&dirlock); DIR *dpntr; struct dirent *dentry; char new_directory[512], dir = t; printf("OPENING DIRECTORY ... %s\n", t); /* Checks if given directory can be opened */ if((dpntr = opendir(t)) == NULL) { printf("DIRECTORY FAILED ...%s\n",t); perror("ERROR -- COULD NOT OPEN DIR"); pthread_exit(NULL); } printf("DIRECTORY OPENED: %s\n", t); /* Read each file in current directory */ while ((dentry = readdir(dpntr)) != NULL ) { /* Ignore special directories */ if(strcmp(dentry -> d_name, ".") == 0 || strcmp(dentry -> d_name, "..") == 0) { continue; } else { compilelist( t, dentry->d_name ); } } pthread_mutex_unlock(&dirlock); /* Checks if directory can be closed */ if(closedir(dpntr) < 0) printf("ERROR CLOSING %s.\n", t); } </code></pre> This is the function that will determine if a new thread should be created and is supposed to run recursively. <pre><code>/* * Determines if current file is a directory * Creates a new thread if true */ void compilelist (const char* dirname, const char *filename) { pthread_mutex_lock(&filelock); struct stat statdata; char *filepathname, *dpntr; /* Allocate memory for filepathname */ if((filepathname = (char *) malloc(sizeof(char) * strlen(dirname))) == NULL) { printf("CANNOT ALLOCATE MEMORY FOR FILE PATH NAME."); pthread_exit(NULL); } /* Concats directory name with file name */ if(dirname[strlen(dirname) -1] == '/') { pthread_mutex_lock(&pathlock); sprintf(filepathname, "%s%s", dirname, filename); pthread_mutex_unlock(&pathlock); }else { pthread_mutex_lock(&pathlock); sprintf(filepathname, "%s/%s", dirname, filename); pthread_mutex_unlock(&pathlock); } lstat(filepathname, &statdata); /* Calls print_statdata() if current item is a file */ if(!(S_ISDIR(statdata.st_mode))) { printf("FILE: %s\n", filepathname); if(!stat( filepathname, &statdata)) { print_statdata( filename, &statdata ); } else { fprintf (stderr, "GETTING STAT FOR %s", filepathname); perror( "ERROR IN STATDATA WHILE GETTING STAT"); } } /* Recursive call to opendirectory() */ else { pthread_mutex_lock(&dircountlock); dirCount++; pthread_mutex_unlock(&dircountlock); dpntr = filepathname; free(filepathname); printf("SUB-DIRECTORY THREAD: %s\nTHREAD ID NUMBER: %d\n", dpntr, dirCount); pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE); pthread_create(&threads[dirCount-1], &attr, opendirectory, (void *)dpntr); } pthread_mutex_unlock(&filelock); } </code></pre> Here is the <code>main()</code> <pre><code>/* * Main function prompts user for a directory */ int main(int argc, char *argv[]) { int i; char *dPtr; // pthread_attr_t attr; printf("ENTER A DIRECTORY:\n\t"); scanf("%s", directory); dPtr = directory; /* Initialize mutex and condition variable objects */ pthread_mutex_init(&mutex, NULL); pthread_mutex_init(&filelock, NULL); pthread_mutex_init(&dirlock, NULL); pthread_mutex_init(&dircountlock, NULL); pthread_cond_init (&count_threshold_cv, NULL); /* For portability, explicitly create threads in a joinable state */ pthread_attr_init(&attr); pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE); pthread_create(&threads[0], &attr, opendirectory, (void *)dPtr); /* Wait for all threads to complete */ for (i = 0; i < dirCount; i++) { pthread_join(threads[i], NULL); } printf("TOTAL DIRECTORY SIZE: %d\n", dirSize); /* Clean up and exit */ pthread_attr_destroy(&attr); pthread_mutex_destroy(&mutex); pthread_mutex_destroy(&filelock); pthread_mutex_destroy(&dirlock); pthread_mutex_destroy(&dircountlock); pthread_cond_destroy(&count_threshold_cv); pthread_exit (NULL); } </code></pre> And the global variables ... <pre><code>pthread_mutex_t mutex; pthread_mutex_t dirlock; pthread_mutex_t filelock; pthread_mutex_t dircountlock; pthread_mutex_t threadlock; pthread_cond_t count_threshold_cv; pthread_attr_t attr; pthread_t threads[128]; // handles up to 128 threads (i.e. 128 directories, change accordingly) char directory[512]; int dirSize = 0; int dirCount = 1; // user's input directory </code></pre> I feel that the <code>pthread_create()</code> called at the bottom of the <code>compilelist()</code> function is not working properly. The threads[] refers to a global array of threads that has a default size of 20, assuming that there will be no more than 20 total directories. dirCount starts off at 1 because of the user's input directory and increases as new directories are encountered.
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<c><multithreading><directory>
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Debug recursive thread call in C
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