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Reworked bonus caching locking scheme:

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- use concurrent map from tbb for faster access to already cached values
- use std::shared_mutex instead of boost::mutex to access bonuses
- accessing to values existing in cache is now done without locking main
mutex
This commit is contained in:
Ivan Savenko
2024-12-18 14:01:31 +00:00
parent 4f80ccd648
commit 42b960417c
3 changed files with 67 additions and 44 deletions
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90
lib/bonuses/CBonusSystemNode.cpp
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@@ -63,22 +63,10 @@ void CBonusSystemNode::getAllParents(TCNodes & out) const //retrieves list of pa
void CBonusSystemNode::getAllBonusesRec(BonusList &out, const CSelector & selector) const
{
//out has been reserved sufficient capacity at getAllBonuses() call
BonusList beforeUpdate;
TCNodes lparents;
getAllParents(lparents);
if(!lparents.empty())
{
//estimate on how many bonuses are missing yet - must be positive
beforeUpdate.reserve(std::max(out.capacity() - out.size(), bonuses.size()));
}
else
{
beforeUpdate.reserve(bonuses.size()); //at most all local bonuses
}
for(const auto * parent : lparents)
{
parent->getAllBonusesRec(beforeUpdate, selector);
@@ -111,46 +99,64 @@ TConstBonusListPtr CBonusSystemNode::getAllBonuses(const CSelector &selector, co
{
if (CBonusSystemNode::cachingEnabled)
{
// Exclusive access for one thread
boost::lock_guard<boost::mutex> lock(sync);
// If the bonus system tree changes(state of a single node or the relations to each other) then
// cache all bonus objects. Selector objects doesn't matter.
if (cachedLast != treeChanged)
{
BonusList allBonuses;
allBonuses.reserve(cachedBonuses.capacity()); //we assume we'll get about the same number of bonuses
cachedBonuses.clear();
cachedRequests.clear();
getAllBonusesRec(allBonuses, Selector::all);
limitBonuses(allBonuses, cachedBonuses);
cachedBonuses.stackBonuses();
cachedLast = treeChanged;
}
// If a bonus system request comes with a caching string then look up in the map if there are any
// pre-calculated bonus results. Limiters can't be cached so they have to be calculated.
if(!cachingStr.empty())
if (cachedLast == treeChanged && !cachingStr.empty())
{
auto it = cachedRequests.find(cachingStr);
if(it != cachedRequests.end())
{
//Cached list contains bonuses for our query with applied limiters
return it->second;
}
RequestsMap::const_accessor accessor;
//Cached list contains bonuses for our query with applied limiters
if (cachedRequests.find(accessor, cachingStr) && accessor->second.first == cachedLast)
return accessor->second.second;
}
//We still don't have the bonuses (didn't returned them from cache)
//Perform bonus selection
auto ret = std::make_shared<BonusList>();
cachedBonuses.getBonuses(*ret, selector, limit);
if (cachedLast == treeChanged)
{
// Cached bonuses are up-to-date - use shared/read access and compute results
std::shared_lock lock(sync);
cachedBonuses.getBonuses(*ret, selector, limit);
}
else
{
// If the bonus system tree changes(state of a single node or the relations to each other) then
// cache all bonus objects. Selector objects doesn't matter.
std::lock_guard lock(sync);
if (cachedLast == treeChanged)
{
// While our thread was waiting, another one have updated bonus tree. Use cached bonuses.
cachedBonuses.getBonuses(*ret, selector, limit);
}
else
{
// Cached bonuses may be outdated - regenerate them
BonusList allBonuses;
cachedBonuses.clear();
getAllBonusesRec(allBonuses, Selector::all);
limitBonuses(allBonuses, cachedBonuses);
cachedBonuses.stackBonuses();
cachedLast = treeChanged;
cachedBonuses.getBonuses(*ret, selector, limit);
}
}
// Save the results in the cache
if(!cachingStr.empty())
cachedRequests[cachingStr] = ret;
if (!cachingStr.empty())
{
RequestsMap::accessor accessor;
if (cachedRequests.find(accessor, cachingStr))
{
accessor->second.second = ret;
accessor->second.first = cachedLast;
}
else
cachedRequests.emplace(cachingStr, std::pair<int64_t, TBonusListPtr>{ cachedLast, ret });
}
return ret;
}