I/O callbacks in blocking mode

Why would the backend hang because of a read callback? Isn't the read callback only called when there is data to be read, and can't hang?

/ Mirar

Previous text:

2003-03-19 13:29: Subject: I/O callbacks in blocking mode

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It was added to detect races where some code changes a socket to blocking code while other code (i.e. the callbacks) are still using it in nonblocking mode. Without that check, the result is typically a disastrous hang of the backend thread in that situation.

I can't think of a situation where one want to combine callbacks with blocking mode, because of the obvious risk to get a hanging backend. When and why is that used?

/ Martin Stjernholm, Roxen IS