Technical help with pthread_create_key and other key calls

["Mead, Jennifer L - VSCM" <Mead dot Jennifer at vectorscm dot com>]

-----Original Message-----
From: Mead, Jennifer L - VSCM 
Sent: Friday, September 15, 2006 4:03 PM
To: 'gcc-help@gcc.gnu.org'
Subject: Technical help with pthread_create_key and other key calls


Hi C folks,

I am just getting back into C from a 15 hiatus, oh how I missed it.  Now
I am trying to write a multi-threaded application that is very very
simple but somehow I cannot make the pthread_setspecific key calls work
for me.  I have tried malloc-ing space, and moving all the code calls
everywhere but loose.  I think I need help.  Below is a skeleton of what
I am trying to do.  Can someone tell me how to fix this?  Mucho
appreciato.

Background: this C program is redirected in a file with directory names,
I am trying to spin a thread for every directory in the file.  There are
over 200 threads I need to start.  I don't seem to have a problem doing
that, but the key that I send at the create statement gets written over
everytime and then all the previous threads are looking at the same
directory.


MAIN
--------
   pthread_t main_thr;
   pthread_t thr;
   pthread_attr_t attr;

   main_thr = pthread_self();
   p=malloc(2);
   p = buffer;void *watch_dir(void *arg)

   pthread_key_t key;

   pthread_key_create(&key, NULL);
   thread_setspecific(key, arg);
   arg=pthread_getspecific(key);
   pthread_attr_init(&attr);
   pthread_attr_setdetachstate(&attr, 1);

         if (pthread_create(&thr, &attr, watch_dir, p))
         {
            fprintf(fplog, "Can't create thr\n"), exit(1);
         }

WATCH_DIR
------------------
void *watch_dir(void *arg)
{

   FILE *fplog;
   time_t curtime;
   struct tm *loctime;
   DIR           *dir_p;
   struct dirent *dir_entry_p;
   pthread_key_t key;
   pthread_key_create(&key, NULL);
   pthread_setspecific(key, arg);
   arg=pthread_getspecific(key);

   for (;;)
   {
      fplog=fopen(FTP_LOG, "a");

      curtime = time (NULL); /* get current time */
      loctime = localtime (&curtime);
      fputs (asctime (loctime), fplog);
      sleep(3);


      dir_p = opendir(arg);
      while( NULL != (dir_entry_p = readdir(dir_p)))
      {
         if (!((strcmp(dir_entry_p->d_name, ".") == 0) ||
               (strcmp(dir_entry_p->d_name, "..") == 0)))
         {
             fprintf(fplog," %s \n", dir_entry_p->d_name);
             /*
             holder for FTP Control PERL script
             send: arg & dir_entry_p->d_name
             directory & filename
             */
         }
        /*
printf("p is %s\n",p);



Regards,
Jen

Jennifer L Mead
ICC Operations Sr Sys Engineer
Con-way Enterprise Services
503.450.8578 		desk
503.550.6589		cell
mead.jennifer@vectorscm.com