[c++] Add async query support

libtiledbsoma/src/soma/managed_query.cc

@@ -158,7 +158,12 @@ void ManagedQuery::submit_read() {
 
     // Do not submit if the query contains only empty ranges
     if (!is_empty_query()) {
-        query_->submit();
+        // Submit query in a separate thread, so we can return immediately
+        query_future_ = std::async(std::launch::async, [&]() {
+            LOG_DEBUG("[ManagedQuery] submit thread start");
+            query_->submit();
+            LOG_DEBUG("[ManagedQuery] submit thread done");
+        });
     }
     query_submitted_ = true;
 }
@@ -179,11 +184,10 @@ std::shared_ptr<ArrayBuffers> ManagedQuery::results() {
     }
     query_submitted_ = false;
 
-    // Poll status until query is not INPROGRESS
-    Query::Status status;
-    do {
-        status = query_->query_status();
-    } while (status == Query::Status::INPROGRESS);
+    // Wait for query to complete
+    LOG_DEBUG(fmt::format("[ManagedQuery] [{}] Waiting for query", name_));
+    query_future_.wait();
+    auto status = query_->query_status();
 
     LOG_DEBUG(fmt::format(
         "[ManagedQuery] [{}] Query status = {}", name_, (int)status));

libtiledbsoma/src/soma/managed_query.h

@@ -33,6 +33,7 @@
 #ifndef MANAGED_QUERY_H
 #define MANAGED_QUERY_H
 
+#include <future>
 #include <stdexcept>  // for windows: error C2039: 'runtime_error': is not a member of 'std'
 #include <unordered_set>
 
@@ -467,6 +468,9 @@ class ManagedQuery {
 
     // True if the query has been submitted and the results have not been read
     bool query_submitted_ = false;
+
+    // Future for asyncronous query
+    std::future<void> query_future_;
 };
 
 };  // namespace tiledbsoma