wait_on_bit_lock — wait for a bit to be cleared, when wanting to set it
int wait_on_bit_lock ( | unsigned long * word, |
| int bit, | |
unsigned mode); |
wordthe word being waited on, a kernel virtual address
bitthe bit of the word being waited on
modethe task state to sleep in
There is a standard hashed waitqueue table for generic use. This
is the part of the hashtable's accessor API that waits on a bit
when one intends to set it, for instance, trying to lock bitflags.
For instance, if one were to have waiters trying to set bitflag
and waiting for it to clear before setting it, one would call
wait_on_bit in threads waiting to be able to set the bit.
One uses wait_on_bit_lock where one is waiting for the bit to
clear with the intention of setting it, and when done, clearing it.
Returns zero if the bit was (eventually) found to be clear and was
set. Returns non-zero if a signal was delivered to the process and
the mode allows that signal to wake the process.