add an implementation of python-style events

This is another synchronization primitive. It will be used in a couple
of extra tests coming right after this.

Change-Id: I536f04f0b5f4f87a0c0a4c8e531c526c7a56bb49
diff --git a/aos/common/common.gyp b/aos/common/common.gyp
index a0750fe..f5db470 100644
--- a/aos/common/common.gyp
+++ b/aos/common/common.gyp
@@ -252,6 +252,20 @@
       ],
     },
     {
+      'target_name': 'event',
+      'type': 'static_library',
+      'sources': [
+        '<(AOS)/linux_code/ipc_lib/event.cc',
+      ],
+      'dependencies': [
+        '<(AOS)/linux_code/ipc_lib/ipc_lib.gyp:aos_sync',
+        '<(AOS)/build/aos.gyp:logging_interface',
+      ],
+      'export_dependent_settings': [
+        '<(AOS)/linux_code/ipc_lib/ipc_lib.gyp:aos_sync',
+      ],
+    },
+    {
       'target_name': 'mutex_test',
       'type': 'executable',
       'sources': [
@@ -269,6 +283,19 @@
       ],
     },
     {
+      'target_name': 'event_test',
+      'type': 'executable',
+      'sources': [
+        'event_test.cc',
+      ],
+      'dependencies': [
+        '<(EXTERNALS):gtest',
+        'event',
+        'queue_testutils',
+        'time',
+      ],
+    },
+    {
       'target_name': 'condition_test',
       'type': 'executable',
       'sources': [