如果在运行php实例的情况下编辑php脚本会发生什么？

When you overwrite a php file on a server (say, via SFTP) while it is being processed somewhere (perhaps it's a script that takes several seconds to compelete) does it cancel the currently running script or does that finish out even after the overwrite occurs? I suppose I'm asking: does apache load a php script into memory before executing it (and does it hold on to that in memory for the duration of execution)?When you overwrite a php file on a server (say,