This change takes the existing typedefs for weight, duration and
distance, and makes them proper types, using the existing Alias
functionality.
Primarily this is to prevent bugs where the metrics are switched,
but it also adds additional documentation. For example, it now
makes it clear (despite the naming of variables) that most of the
trip algorithm is running on the duration metric.
I've not made any changes to the casts performed between metrics
and numeric types, they now just more explicit.
- separates node-based graph creation and compression from edge-based graph creation
- moves usage of edge-based node data-container to pre-processing as well, unifying access to node-based data
- single struct instead of separate vectors for annotation data in engine (single place of modification)
PR uses TBB internal atomic's for atomic CAS on non-atomic data
Corresponding PR https://github.com/Project-OSRM/osrm-backend/pull/4199
Other options:
* use sequential update
* use an internal packed vector lock -> makes packed vector non-movable
* use boost.interprocess atomics implementation -> outdated and only 32 bit version
* use glib atomic's -> requires new dependency
* wait for https://isocpp.org/blog/2014/05/n4013 as_atomic
* use c11 _Atomic and atomic_compare_exchange_weak -> not possible to mix c++11 and c11
* use builtin functions gcc __sync_bool_compare_and_swap and msvc _InterlockedCompareExchange64 -> possible, but requires proper testing
boolean CompareAndSwapPointer(volatile * void * ptr,
void * new_value,
void * old_value) {
if defined(_MSC_VER)
if (InterlockedCompareExchange(ptr, new_value, old_value) == old_value) return false;
else return true;
elif (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) > 40100
return __sync_bool_compare_and_swap(ptr, old_value, new_value);
else
error No implementation
endif
}
* use Boost.Atomic -> requires new dependency
WordT local_lower_word = lower_word, new_lower_word;
do
{
new_lower_word = set_lower_value<WordT, T>(local_lower_word,
lower_mask[internal_index.element],
lower_offset[internal_index.element],
value);
} while (!boost::atomics::detail::operations<sizeof(WordT), false>::compare_exchange_weak(
lower_word,
local_lower_word,
new_lower_word,
boost::memory_order_release,
boost::memory_order_relaxed));
This fixes issues #3952. The new approach pre-computes masks for fast
access. Since elements can potentially span multiple words we need masks
and offsets for each upper and lower word.
Due to a bug in the C++14 standart the mask computation is not
recognized as constexpr, but would work on C++17.
