The sys_dlist_insert_*() functions had a behavior where a NULL
argument for the insertion position to sys_dlist_insert_after/before()
was interpreted as "the end of the list". We never used that
convention (except in one spot internal to dlist.h which was not
itself used anywhere), and of course already have an API for appending
and prepending to a list.
In practice this was a performance disaster. The NULL check is
virtually never provable statically by the compiler, so that test and
branch is present always. And worse, the check and call to another
function was pushing this beyond the complexity limit for gcc to
inline a function (at -Os optimization anyway), forcing us to use
function calls for what should be a ~8 instruction sequence. The
upshot is that dlist insertions were 2-3x slower than they needed to
be.
Deprecate these older APIs and introduce a new sys_dlist_insert() call
which can be much better optimized.
Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
The original implementation allows a list to be corrupted by list
operations on the removed node. Existing code attempts to avoid this by
using external state to determine whether a node is in a list, but this
is fragile and fails when the state that holds the flag value is changed
after the node is removed, e.g. in preparation for re-using the node.
Follow Linux in invalidating the link pointers in a removed node. Add
API so that detection of particpation in a list is available at the node
abstraction.
This solution relies on the following steady-state invariants:
* A node (as opposed to a list) will never be adjacent to itself in a
list;
* The next and prev pointers of a node are always either both null or
both non-null.
Signed-off-by: Peter A. Bigot <pab@pabigot.com>
Add test description, RTM links and doxygen links for common,
interrupt and boot page table test cases.
Signed-off-by: Spoorthi K <spoorthi.k@intel.com>
ztest has a number of assert style macros and used a baseline assert()
that varies from the system definition of assert() so lets rename
everything as zassert to be clear.
Change-Id: I7f176b3bae94d1045054d665be8b5bda947e5bb0
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
