While less susceptible to optimization problems than left and right,
interval_tree_iter_next also reads rb_parent(), so make sure that
stores and loads are atomic.
This goes further than technically required, changing all loads to
be atomic, rather than simply the ones in the iteration side. But
it doesn't really affect the code generation on the rebalance side
and is cleaner to handle everything the same.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Ensure that the stores to rb_left and rb_right are complete before
inserting the new node into the tree. Otherwise a concurrent reader
could see garbage in the new leaf.
Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Fixes a race condition (generally without optimization) in which
the subtree is re-read after the protecting if condition.
Cc: qemu-stable@nongnu.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Copy and simplify the Linux kernel's interval_tree_generic.h,
instantiating for uint64_t.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Richard Henderson