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>Read/Write Lock Variants</H1
><P
> Both spinlocks and semaphores have read/write variants:
<SPAN
CLASS="TYPE"
>rwlock_t</SPAN
> and <SPAN
CLASS="STRUCTNAME"
>struct rw_semaphore</SPAN
>.
These divide users into two classes: the readers and the writers. If
you are only reading the data, you can get a read lock, but to write to
the data you need the write lock. Many people can hold a read lock,
but a writer must be sole holder.
</P
><P
> This means much smoother locking if your code divides up
neatly along reader/writer lines. All the discussions below
also apply to read/write variants.
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