Upintegrate the common_time service from ics-aah.

Move the common_time service developed in the ics-aah branch back into
master.

The common_time service is a small service build to synchronize an
arbitrary timeline amongst peers on a local sub-net.  While running
and configured, the service will elect a master from the set of
available devices within the subnet, define a relationship between the
common_time timeline the local time timeline (provided by the local
time HAL), and then attempt to maintain synchronization between common
and local time by controlling the frequency of the local time clock
via the HAL, or by disciplining local time in the digital domain if
the local time HAL implementation does not support HW slewing.

On its own, the native common time service will do nothing until it is
configured.  The CommonTimeManagementService (running out of the
system server process) is responsible for implementing policy
regarding configuration and operation of the common_time service and
will be added in a subsequent CL.

Change-Id: I71292f9b9b1797665865689c4572c9d3a0552f64
Signed-off-by: John Grossman <johngro@google.com>

1 files changed, 72 insertions, 0 deletions

diff --git a/include/common_time/cc_helper.h b/include/common_time/cc_helper.h
new file mode 100644
index 0000000..8c4d5c0
--- /dev/null
+++ b/include/common_time/cc_helper.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __CC_HELPER_H__
+#define __CC_HELPER_H__
+
+#include <stdint.h>
+#include <common_time/ICommonClock.h>
+#include <utils/threads.h>
+
+namespace android {
+
+// CCHelper is a simple wrapper class to help with centralizing access to the
+// Common Clock service and implementing lifetime managment, as well as to
+// implement a simple policy of making a basic attempt to reconnect to the
+// common clock service when things go wrong.
+//
+// On platforms which run the native common_time service in auto-disable mode,
+// the service will go into networkless mode whenever it has no active clients.
+// It tracks active clients using registered CommonClockListeners (the callback
+// interface for onTimelineChanged) since this provides a convienent death
+// handler notification for when the service's clients die unexpectedly.  This
+// means that users of the common time service should really always have a
+// CommonClockListener, unless they know that the time service is not running in
+// auto disabled mode, or that there is at least one other registered listener
+// active in the system.  The CCHelper makes this a little easier by sharing a
+// ref counted ICommonClock interface across all clients and automatically
+// registering and unregistering a listener whenever there are CCHelper
+// instances active in the process.
+class CCHelper {
+  public:
+    CCHelper();
+    ~CCHelper();
+
+    status_t isCommonTimeValid(bool* valid, uint32_t* timelineID);
+    status_t commonTimeToLocalTime(int64_t commonTime, int64_t* localTime);
+    status_t localTimeToCommonTime(int64_t localTime, int64_t* commonTime);
+    status_t getCommonTime(int64_t* commonTime);
+    status_t getCommonFreq(uint64_t* freq);
+    status_t getLocalTime(int64_t* localTime);
+    status_t getLocalFreq(uint64_t* freq);
+
+  private:
+    class CommonClockListener : public BnCommonClockListener {
+      public:
+        void onTimelineChanged(uint64_t timelineID);
+    };
+
+    static bool verifyClock_l();
+
+    static Mutex lock_;
+    static sp<ICommonClock> common_clock_;
+    static sp<ICommonClockListener> common_clock_listener_;
+    static uint32_t ref_count_;
+};
+
+
+}  // namespace android
+#endif  // __CC_HELPER_H__