.cfiles, does the compiler "see" all of them at once?
/sys- what's in them?
So what happens when blocking call? The entire process is blocked! This seems counterproductive! Think of a GUI program with background I/O thread Now the I/O thread stalls it every time it accesses I/O, making GUI unresponsive... We've lost the entire benefit of threading! How can user threads get around this? Which kinds of system calls block? I/O, mostly. so what if... the user threading library intercepted these calls? and then does... what? could switch to another thread... but that I/O call has to be made sometime. We can't get any further without some support from the OS.