The phantom flush — that mysterious phenomenon in which your toilet seems to flush itself — can be little jarring late at night, not to mention a waste of water.
灵异冲水——你家厕所会自己冲水的神秘现象——不仅半夜有点吵，而且浪费水。
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If the application had been doing writes to the file instead of reads, the permanent storage pages would be "modified," and AIX would have to flush the pages to disk before releasing the pages.
From that point everything is similar except you will need to flush the output stream or it is possible that the last bit of the stream buffer will not be sent.