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processGraph(): Call getEdges in parallel

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Eelco Dolstra 2017-06-28 16:38:02 +02:00
parent 63d6e0ad3f
commit 90da34e421
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GPG key ID: 8170B4726D7198DE
1 changed files with 46 additions and 27 deletions
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73
src/libutil/thread-pool.hh
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@ -70,50 +70,69 @@ void processGraph(
struct Graph {
std::set<T> left;
std::map<T, std::set<T>> refs, rrefs;
std::function<void(T)> wrap;
};
ref<Sync<Graph>> graph_ = make_ref<Sync<Graph>>();
Sync<Graph> graph_(Graph{nodes, {}, {}});
auto wrapWork = [&pool, graph_, processNode](const T & node) {
std::function<void(const T &)> worker;
worker = [&](const T & node) {
{
auto graph(graph_.lock());
auto i = graph->refs.find(node);
if (i == graph->refs.end())
goto getRefs;
goto doWork;
}
getRefs:
{
auto refs = getEdges(node);
refs.erase(node);
{
auto graph(graph_.lock());
for (auto & ref : refs)
if (graph->left.count(ref)) {
graph->refs[node].insert(ref);
graph->rrefs[ref].insert(node);
}
if (graph->refs[node].empty())
goto doWork;
}
}
return;
doWork:
processNode(node);
/* Enqueue work for all nodes that were waiting on this one. */
/* Enqueue work for all nodes that were waiting on this one
and have no unprocessed dependencies. */
{
auto graph(graph_->lock());
graph->left.erase(node);
auto graph(graph_.lock());
for (auto & rref : graph->rrefs[node]) {
auto & refs(graph->refs[rref]);
auto i = refs.find(node);
assert(i != refs.end());
refs.erase(i);
if (refs.empty())
pool.enqueue(std::bind(graph->wrap, rref));
pool.enqueue(std::bind(worker, rref));
}
graph->left.erase(node);
graph->refs.erase(node);
graph->rrefs.erase(node);
}
};
{
auto graph(graph_->lock());
graph->left = nodes;
graph->wrap = wrapWork;
}
for (auto & node : nodes)
pool.enqueue(std::bind(worker, std::ref(node)));
/* Build the dependency graph; enqueue all nodes with no
dependencies. */
for (auto & node : nodes) {
auto refs = getEdges(node);
{
auto graph(graph_->lock());
for (auto & ref : refs)
if (ref != node && graph->left.count(ref)) {
graph->refs[node].insert(ref);
graph->rrefs[ref].insert(node);
}
if (graph->refs[node].empty())
pool.enqueue(std::bind(graph->wrap, node));
}
}
pool.process();
if (!graph_.lock()->left.empty())
throw Error("graph processing incomplete (cyclic reference?)");
}
}