add HAL socket

this patch contains the following changes:
1. added header and implemenation files of socket util apis
in libgps.utils; 2. updated XtraSystemStatusObserver to use
the new apis; 3. added HAL socket and new thread to listen to it.

Change-Id: If1f6b4b4d6ea2d03640f68e96f0286300404f42b
CRs-fixed: 2108635

1 files changed, 88 insertions, 0 deletions

diff --git a/utils/LocIpc.h b/utils/LocIpc.h
new file mode 100644
index 0000000..258fd42
--- /dev/null
+++ b/utils/LocIpc.h
@@ -0,0 +1,88 @@
+/* Copyright (c) 2017 The Linux Foundation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ *       copyright notice, this list of conditions and the following
+ *       disclaimer in the documentation and/or other materials provided
+ *       with the distribution.
+ *     * Neither the name of The Linux Foundation, nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+ * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+ * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef __LOC_SOCKET__
+#define __LOC_SOCKET__
+
+#include <string>
+#include <memory>
+#include <LocThread.h>
+
+namespace loc_util {
+
+class LocIpc {
+public:
+    inline LocIpc() : mIpcFd(-1), mStopRequested(false), mRunnable(nullptr) {}
+    inline virtual ~LocIpc() { stopListening(); }
+
+    // Listen for new messages in current thread. Calling this funciton will
+    // block current thread. The listening can be stopped by calling stopListening().
+    //
+    // Argument name is the path of the unix local socket to be listened.
+    // The function will return true on success, and false on failure.
+    bool startListeningBlocking(const std::string& name);
+
+    // Create a new LocThread and listen for new messages in it.
+    // Calling this function will return immediately and won't block current thread.
+    // The listening can be stopped by calling stopListening().
+    //
+    // Argument name is the path of the unix local socket to be be listened.
+    // The function will return true on success, and false on failure.
+    bool startListeningNonBlocking(const std::string& name);
+
+    // Stop listening to new messages.
+    void stopListening();
+
+    // Callback function for receiving incoming messages.
+    // Override this function in your derived class to process incoming messages.
+    // For each received message, this callback function will be called once.
+    // This callback function will be called in the calling thread of startListeningBlocking
+    // or in the new LocThread created by startListeningNonBlocking.
+    //
+    // Argument data contains the received message. You need to parse it.
+    virtual void onReceive(const std::string& /*data*/) {}
+
+    // Send out a message.
+    // Call this function to send a message in argument data to socket in argument name.
+    //
+    // Argument name contains the name of the target unix socket. data contains the
+    // message to be sent out. Convert your message to a string before calling this function.
+    // The function will return true on success, and false on failure.
+    bool send(const char name[], const std::string& data);
+
+private:
+    int mIpcFd;
+    bool mStopRequested;
+    LocThread mThread;
+    std::unique_ptr<LocRunnable> mRunnable;
+};
+
+}
+
+#endif //__LOC_SOCKET__