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| WAIT_ON_BIT(9) | Driver Basics | WAIT_ON_BIT(9) |
NAME¶
wait_on_bit - wait for a bit to be cleared
SYNOPSIS¶
int wait_on_bit(unsigned long * word, int bit, unsigned mode);
ARGUMENTS¶
word
the word being waited on, a kernel virtual address
bit
the bit of the word being waited on
mode
the task state to sleep in
DESCRIPTION¶
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. For instance, if one were to have waiters on a bitflag, one would call wait_on_bit in threads waiting for the bit to clear. One uses wait_on_bit where one is waiting for the bit to clear, but has no intention of setting it. Returned value will be zero if the bit was cleared, or non-zero if the process received a signal and the mode permitted wakeup on that signal.
COPYRIGHT¶
| January 2017 | Kernel Hackers Manual 4.8. |