diff --git a/src/test/immutable_object_cache/test_DomainSocket.cc b/src/test/immutable_object_cache/test_DomainSocket.cc
index d167d96dcae..bbac47044fc 100644
--- a/src/test/immutable_object_cache/test_DomainSocket.cc
+++ b/src/test/immutable_object_cache/test_DomainSocket.cc
@@ -6,50 +6,15 @@
 
 #include "gtest/gtest.h"
 #include "include/Context.h"
-#include "common/Mutex.h"
-#include "common/Cond.h"
 #include "global/global_init.h"
 #include "global/global_context.h"
 
+#include "test/immutable_object_cache/test_common.h"
 #include "tools/immutable_object_cache/CacheClient.h"
 #include "tools/immutable_object_cache/CacheServer.h"
 
 using namespace ceph::immutable_obj_cache;
 
-// sequentialize async_operation
-class WaitEvent {
-public:
-  WaitEvent() : m_signaled(false) {
-    pthread_mutex_init(&m_lock, NULL);
-    pthread_cond_init(&m_cond, NULL);
-  }
-
-  ~WaitEvent() {
-    pthread_mutex_destroy(&m_lock);
-    pthread_cond_destroy(&m_cond);
-  }
-
-  void wait() {
-    pthread_mutex_lock(&m_lock);
-    while (!m_signaled) {
-      pthread_cond_wait(&m_cond, &m_lock);
-    }
-    m_signaled = false;
-    pthread_mutex_unlock(&m_lock);
-   }
-
-  void signal() {
-    pthread_mutex_lock(&m_lock);
-    m_signaled = true;
-    pthread_cond_signal(&m_cond);
-    pthread_mutex_unlock(&m_lock);
-  }
-private:
-    pthread_mutex_t m_lock;
-    pthread_cond_t m_cond;
-    bool m_signaled;
-};
-
 class TestCommunication :public ::testing::Test {
 public:
   CacheServer* m_cache_server;
diff --git a/src/test/immutable_object_cache/test_common.h b/src/test/immutable_object_cache/test_common.h
new file mode 100644
index 00000000000..9fe944ffd62
--- /dev/null
+++ b/src/test/immutable_object_cache/test_common.h
@@ -0,0 +1,42 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+#ifndef CACHE_TEST_COMMON_H
+#define CACHE_TEST_COMMON_H
+
+#include "common/Mutex.h"
+#include "common/Cond.h"
+
+class WaitEvent {
+public:
+  WaitEvent() : m_signaled(false) {
+    pthread_mutex_init(&m_lock, NULL);
+    pthread_cond_init(&m_cond, NULL);
+  }
+
+  ~WaitEvent() {
+    pthread_mutex_destroy(&m_lock);
+    pthread_cond_destroy(&m_cond);
+  }
+
+  void wait() {
+    pthread_mutex_lock(&m_lock);
+    while (!m_signaled) {
+      pthread_cond_wait(&m_cond, &m_lock);
+    }
+    m_signaled = false;
+    pthread_mutex_unlock(&m_lock);
+   }
+
+  void signal() {
+    pthread_mutex_lock(&m_lock);
+    m_signaled = true;
+    pthread_cond_signal(&m_cond);
+    pthread_mutex_unlock(&m_lock);
+  }
+private:
+    pthread_mutex_t m_lock;
+    pthread_cond_t m_cond;
+    bool m_signaled;
+};
+
+#endif