PHP5 and File Locking

I started to put together a few classes that reads/writes files, using the fopen() function, injunction with flock() to lock files while reading/writing. And I also was wrapping fopen()/flock() around copy()/unlink()/rename() with the thinking that they needed file locking *features* while modifying the filesystem. I initially chose to use flock() to cut down possibilities of *race conditions*. Now Im beginning to question even using the fopen()/flock() way of reading/writing files, and instead go to file_[get|put]_contents(). As I understand it, race conditions *can* occur during the php steps of reading/writing files using the fopen() method -> fopen(...); // read or write to file with fread()/fwrite() fclose(...); Now my thinking is that if I were to start using file_[get|put]_contents(), and do away with fopen()/flock(), there would be no need for file locking, since file_[get|put]_contents() is just one php operation. I may be wrong with this assumption. Im looking to see what others may think about file locking using php functions, file_[get|put]_contents()/copy()/unlink()/rename() to read/write/modify the filesystem. Is it even neccessary in php5? Thanks for any insight that you can provide...