use usleep in locking to avoid 100% CPU

darcs-hash:20060115105943-4b825-c15733992e9bbf26621d4431da3171bcb8d24057.gz

lib/exe/indexer.php

@@ -50,6 +50,7 @@ function runIndexer(){
     // try to aquire a lock
     $lock = $conf['lockdir'].'/_indexer.lock';
     while(!@mkdir($lock,0777)){
+        usleep(50);
         if(time()-@filemtime($lock) > 60*5){
             // looks like a stale lock - remove it
             @rmdir($lock);