您可以尝试php的flock变体( http: //www.php.net/flock )

You could try php's variant of flock (http://www.php.net/flock)

我会设想类似的内容(这假设文件/tmp/counter.txt已经存在并且文件中有一个计数器):

I would envision something similar to (this assumes that the file /tmp/counter.txt already exists and has a counter in the file):

<?php

$fp = fopen("/tmp/counter.txt", "r+");

echo "Attempt to lock\n";
if (flock($fp, LOCK_EX)) {
  echo "Locked\n";
  // Read current value of the counter and increment
  $cntr = fread($fp, 80);
  $cntr = intval($cntr) + 1;

  // Pause to prove that race condition doesn't exist
  sleep(5);

  // Write new value to the file
  ftruncate($fp, 0);
  fseek($fp, 0, SEEK_SET);
  fwrite($fp, $cntr);
  flock($fp, LOCK_UN); // release the lock
  fclose($fp);
}

?>