better polling wait

Author: d-led

src/test/fixtures.cpp

@@ -46,12 +46,23 @@ bool connected_test::database_exists(std::string const & name)
 
 void connected_test::wait_for(std::function<bool()> predicate, unsigned retries)
 {
+    // Use exponential backoff: start with short waits, increase gradually
+    // This is more efficient for slow systems (especially Windows async operations)
+    unsigned wait_ms = milliseconds_waiting_time;
+    const unsigned max_wait_ms = 500;  // Cap at 500ms
+    
     for (unsigned i = 0; i < retries; i++) {
         if (predicate()) {
             return;
         }
 
-        std::this_thread::sleep_for(std::chrono::milliseconds(milliseconds_waiting_time));
+        std::this_thread::sleep_for(std::chrono::milliseconds(wait_ms));
+        
+        // Exponential backoff: increase wait time gradually, cap at max_wait_ms
+        wait_ms += milliseconds_waiting_time;
+        if (wait_ms > max_wait_ms) {
+            wait_ms = max_wait_ms;
+        }
     }
 }
 

src/test/simple_api_test.cpp

@@ -197,9 +197,10 @@ SCENARIO_METHOD(simple_connected_test, "more than 1000 inserts per second") {
 
 
                 AND_THEN("All entries arrive at the database") {
-                    // wait for asynchronous fill
+                    // wait for asynchronous fill - Windows needs more time for async batching
                     auto query = std::string("select count(*) from ") + db_name + "..asynctest";
-                    wait_for([this, query, many_times] { return raw_db.get(query).find(std::to_string(many_times.count)) != std::string::npos; }, 200);
+                    // Use more retries for slower systems (400 retries * 100ms = 40 seconds max)
+                    wait_for([this, query, many_times] { return raw_db.get(query).find(std::to_string(many_times.count)) != std::string::npos; }, 400);
                     bool all_entries_arrived = raw_db.get(query).find(std::to_string(many_times.count)) != std::string::npos;
 
                     CHECK(all_entries_arrived);