[c++] Modify ManagedQuery to perform async queries

libtiledbsoma/src/soma/managed_query.cc

@@ -54,9 +54,16 @@ ManagedQuery::ManagedQuery(
     reset();
 }
 
+void ManagedQuery::close() {
+    if (query_future_.valid()) {
+        query_future_.wait();
+    }
+    array_->close();
+}
+
 void ManagedQuery::reset() {
-    query_ = std::make_unique<Query>(schema_->context(), *array_);
-    subarray_ = std::make_unique<Subarray>(schema_->context(), *array_);
+    query_ = std::make_unique<Query>(*ctx_, *array_);
+    subarray_ = std::make_unique<Subarray>(*ctx_, *array_);
 
     subarray_range_set_ = false;
     subarray_range_empty_ = {};
@@ -145,21 +152,24 @@ void ManagedQuery::submit_write() {
     query_->submit();
 }
 
-std::shared_ptr<ArrayBuffers> ManagedQuery::submit_read() {
+void ManagedQuery::submit_read() {
+    query_submitted_ = true;
+    query_future_ = std::async(std::launch::async, [&]() {
+        LOG_DEBUG("[ManagedQuery] submit thread start");
+        query_->submit();
+        LOG_DEBUG("[ManagedQuery] submit thread done");
+    });
+}
+
+std::shared_ptr<ArrayBuffers> ManagedQuery::results() {
     if (is_empty_query()) {
         return buffers_;
     }
 
-    query_->submit();
-
-    // Poll status until query is not INPROGRESS
-    Query::Status status;
-    do {
-        status = query_->query_status();
-    } while (status == Query::Status::INPROGRESS);
+    LOG_DEBUG(fmt::format("[ManagedQuery] [{}] Waiting for query", name_));
+    query_future_.wait();
 
-    LOG_DEBUG(fmt::format(
-        "[ManagedQuery] [{}] Query status = {}", name_, (int)status));
+    auto status = query_->query_status();
 
     if (status == Query::Status::FAILED) {
         throw TileDBSOMAError(

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>
 
@@ -68,6 +69,13 @@ class ManagedQuery {
     ManagedQuery(ManagedQuery&&) = default;
     ~ManagedQuery() = default;
 
+    /**
+     * @brief Close the array after waiting for any asynchronous queries to
+     * complete.
+     *
+     */
+    void close();
+
     /**
      * @brief Reset the state of this ManagedQuery object to prepare for a new
      * query, while holding the array open.
@@ -373,11 +381,17 @@ class ManagedQuery {
     }
 
     /**
-     * @brief Submit and return results from the query.
+     * @brief Submit the query.
+     *
+     */
+    void submit_read();
+
+    /**
+     * @brief Return results from the query.
      *
      * @return std::shared_ptr<ArrayBuffers>
      */
-    std::shared_ptr<ArrayBuffers> submit_read();
+    std::shared_ptr<ArrayBuffers> results();
 
     /**
      * @brief Submit the write query.
@@ -469,8 +483,10 @@ class ManagedQuery {
 
     // True if the query has been submitted
     bool query_submitted_ = false;
-};
 
+    // Future for asyncronous query
+    std::future<void> query_future_;
+};
 };  // namespace tiledbsoma
 
 #endif

libtiledbsoma/src/soma/soma_array.cc

@@ -182,7 +182,9 @@ void SOMAArray::open(
 }
 
 void SOMAArray::close() {
-    arr_->close();
+    // Close the array through the managed query to ensure any pending queries
+    // are completed.
+    mq_->close();
 }
 
 void SOMAArray::reset(
@@ -234,16 +236,18 @@ std::optional<std::shared_ptr<ArrayBuffers>> SOMAArray::read_next() {
     if (mq_->is_empty_query()) {
         if (first_read_next_) {
             first_read_next_ = false;
-            return mq_->submit_read();
+            return mq_->results();
         } else {
             return std::nullopt;
         }
     }
 
     first_read_next_ = false;
 
+    mq_->submit_read();
+
     // Return the results, possibly incomplete
-    return mq_->submit_read();
+    return mq_->results();
 }
 
 void SOMAArray::write(std::shared_ptr<ArrayBuffers> buffers) {

libtiledbsoma/test/unit_managed_query.cc

@@ -124,7 +124,8 @@ TEST_CASE("ManagedQuery: Basic execution test") {
     auto mq = ManagedQuery(array, ctx);
     mq.setup_read();
 
-    auto results = mq.submit_read();
+    mq.submit_read();
+    auto results = mq.results();
     REQUIRE(mq.results_complete());
 
     auto num_cells = mq.total_num_cells();
@@ -144,7 +145,8 @@ TEST_CASE("ManagedQuery: Select test") {
     mq.select_points<std::string>("d0", {"a"});
     mq.setup_read();
 
-    auto results = mq.submit_read();
+    mq.submit_read();
+    auto results = mq.results();
     REQUIRE(mq.results_complete());
 
     auto num_cells = mq.total_num_cells();
@@ -166,7 +168,8 @@ TEST_CASE("ManagedQuery: Validity test") {
     auto mq = ManagedQuery(array, ctx);
     mq.setup_read();
 
-    auto results = mq.submit_read();
+    mq.submit_read();
+    auto results = mq.results();
     REQUIRE(mq.results_complete());
 
     auto num_cells = mq.total_num_cells();