Use interfaces for executor classes

scm-webapp/src/main/java/sonia/scm/lifecycle/modules/ApplicationModuleProvider.java

@@ -12,6 +12,7 @@ import sonia.scm.debug.DebugModule;
 import sonia.scm.filter.WebElementModule;
 import sonia.scm.plugin.ExtensionProcessor;
 import sonia.scm.plugin.PluginLoader;
+import sonia.scm.repository.ExecutorModule;
 
 import javax.servlet.ServletContext;
 import java.util.ArrayList;
@@ -51,6 +52,7 @@ public class ApplicationModuleProvider implements ModuleProvider {
       moduleList.add(new DebugModule());
     }
     moduleList.add(new MapperModule());
+    moduleList.add(new ExecutorModule());
 
     return moduleList;
   }

scm-webapp/src/main/java/sonia/scm/repository/DefaultSyncAsyncExecutor.java

@@ -0,0 +1,41 @@
+package sonia.scm.repository;
+
+import sonia.scm.repository.spi.SyncAsyncExecutor;
+
+import java.time.Instant;
+import java.util.concurrent.Executor;
+import java.util.function.Consumer;
+
+import static sonia.scm.repository.spi.SyncAsyncExecutor.ExecutionType.ASYNCHRONOUS;
+import static sonia.scm.repository.spi.SyncAsyncExecutor.ExecutionType.SYNCHRONOUS;
+
+public class DefaultSyncAsyncExecutor implements SyncAsyncExecutor {
+
+  private final Executor executor;
+  private final Instant switchToAsyncTime;
+  private boolean executedAllSynchronously = true;
+
+  DefaultSyncAsyncExecutor(Executor executor, Instant switchToAsyncTime) {
+    this.executor = executor;
+    this.switchToAsyncTime = switchToAsyncTime;
+  }
+
+  public ExecutionType execute(Runnable runnable) {
+    return execute(ignored -> runnable.run());
+  }
+
+  public ExecutionType execute(Consumer<ExecutionType> runnable) {
+    if (Instant.now().isAfter(switchToAsyncTime)) {
+      executor.execute(() -> runnable.accept(ASYNCHRONOUS));
+      executedAllSynchronously = false;
+      return ASYNCHRONOUS;
+    } else {
+      runnable.accept(SYNCHRONOUS);
+      return SYNCHRONOUS;
+    }
+  }
+
+  public boolean hasExecutedAllSynchronously() {
+    return executedAllSynchronously;
+  }
+}

scm-webapp/src/main/java/sonia/scm/repository/DefaultSyncAsyncExecutorProvider.java

@@ -0,0 +1,32 @@
+package sonia.scm.repository;
+
+import sonia.scm.repository.spi.SyncAsyncExecutor;
+import sonia.scm.repository.spi.SyncAsyncExecutorProvider;
+
+import java.io.Closeable;
+import java.time.Instant;
+import java.time.temporal.ChronoUnit;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+public class DefaultSyncAsyncExecutorProvider implements SyncAsyncExecutorProvider, Closeable {
+
+  private final ExecutorService executor;
+
+  public DefaultSyncAsyncExecutorProvider() {
+    this(Executors.newFixedThreadPool(4));
+  }
+
+  public DefaultSyncAsyncExecutorProvider(ExecutorService executor) {
+    this.executor = executor;
+  }
+
+  public SyncAsyncExecutor createExecutorWithSecondsToTimeout(int seconds) {
+    return new DefaultSyncAsyncExecutor(executor, Instant.now().plus(seconds, ChronoUnit.SECONDS));
+  }
+
+  @Override
+  public void close() {
+    executor.shutdownNow();
+  }
+}

scm-webapp/src/main/java/sonia/scm/repository/ExecutorModule.java

@@ -0,0 +1,12 @@
+package sonia.scm.repository;
+
+import com.google.inject.AbstractModule;
+import sonia.scm.lifecycle.modules.CloseableModule;
+import sonia.scm.repository.spi.SyncAsyncExecutorProvider;
+
+public class ExecutorModule extends AbstractModule {
+  @Override
+  protected void configure() {
+    bind(SyncAsyncExecutorProvider.class).to(DefaultSyncAsyncExecutorProvider.class);
+  }
+}