Combine duplicate code & document wp<> in mClients

Change-Id: Iea8cfe8e57563337fb2484a1246ef79d6ad3db18
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index d05e9d9..93c91fb 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -370,6 +370,18 @@
     return NO_ERROR;
 }
 
+sp<AudioFlinger::Client> AudioFlinger::registerPid_l(pid_t pid)
+{
+    // If pid is already in the mClients wp<> map, then use that entry
+    // (for which promote() is always != 0), otherwise create a new entry and Client.
+    sp<Client> client = mClients.valueFor(pid).promote();
+    if (client == 0) {
+        client = new Client(this, pid);
+        mClients.add(pid, client);
+    }
+
+    return client;
+}
 
 // IAudioFlinger interface
 
@@ -390,7 +402,6 @@
     sp<PlaybackThread::Track> track;
     sp<TrackHandle> trackHandle;
     sp<Client> client;
-    wp<Client> wclient;
     status_t lStatus;
     int lSessionId;
 
@@ -412,14 +423,7 @@
             goto Exit;
         }
 
-        wclient = mClients.valueFor(pid);
-
-        if (wclient != NULL) {
-            client = wclient.promote();
-        } else {
-            client = new Client(this, pid);
-            mClients.add(pid, client);
-        }
+        client = registerPid_l(pid);
 
         ALOGV("createTrack() sessionId: %d", (sessionId == NULL) ? -2 : *sessionId);
         if (sessionId != NULL && *sessionId != AUDIO_SESSION_OUTPUT_MIX) {
@@ -4131,7 +4135,6 @@
     sp<RecordThread::RecordTrack> recordTrack;
     sp<RecordHandle> recordHandle;
     sp<Client> client;
-    wp<Client> wclient;
     status_t lStatus;
     RecordThread *thread;
     size_t inFrameCount;
@@ -4152,13 +4155,7 @@
             goto Exit;
         }
 
-        wclient = mClients.valueFor(pid);
-        if (wclient != NULL) {
-            client = wclient.promote();
-        } else {
-            client = new Client(this, pid);
-            mClients.add(pid, client);
-        }
+        client = registerPid_l(pid);
 
         // If no audio session id is provided, create one here
         if (sessionId != NULL && *sessionId != AUDIO_SESSION_OUTPUT_MIX) {
@@ -5405,10 +5402,8 @@
     status_t lStatus = NO_ERROR;
     sp<EffectHandle> handle;
     effect_descriptor_t desc;
-    sp<Client> client;
-    wp<Client> wclient;
 
-    ALOGV("createEffect pid %d, client %p, priority %d, sessionId %d, io %d",
+    ALOGV("createEffect pid %d, effectClient %p, priority %d, sessionId %d, io %d",
             pid, effectClient.get(), priority, sessionId, io);
 
     if (pDesc == NULL) {
@@ -5559,14 +5554,7 @@
             }
         }
 
-        wclient = mClients.valueFor(pid);
-
-        if (wclient != NULL) {
-            client = wclient.promote();
-        } else {
-            client = new Client(this, pid);
-            mClients.add(pid, client);
-        }
+        sp<Client> client = registerPid_l(pid);
 
         // create effect on selected output thread
         handle = thread->createEffect_l(client, effectClient, priority, sessionId,
@@ -6923,6 +6911,7 @@
             mCblk->~effect_param_cblk_t();   // destroy our shared-structure.
         }
         mCblkMemory.clear();    // free the shared memory before releasing the heap it belongs to
+        // Client destructor must run with AudioFlinger mutex locked
         Mutex::Autolock _l(mClient->audioFlinger()->mLock);
         mClient.clear();
     }
diff --git a/services/audioflinger/AudioFlinger.h b/services/audioflinger/AudioFlinger.h
index dac9986..97103c4 100644
--- a/services/audioflinger/AudioFlinger.h
+++ b/services/audioflinger/AudioFlinger.h
@@ -1231,7 +1231,7 @@
 
         sp<EffectModule> mEffect;           // pointer to controlled EffectModule
         sp<IEffectClient> mEffectClient;    // callback interface for client notifications
-        sp<Client>          mClient;        // client for shared memory allocation
+        /*const*/ sp<Client> mClient;       // client for shared memory allocation, see disconnect()
         sp<IMemory>         mCblkMemory;    // shared memory for control block
         effect_param_cblk_t* mCblk;         // control block for deferred parameter setting via shared memory
         uint8_t*            mBuffer;        // pointer to parameter area in shared memory
@@ -1403,7 +1403,7 @@
 
     mutable     Mutex                               mLock;
 
-                DefaultKeyedVector< pid_t, wp<Client> >     mClients;
+                DefaultKeyedVector< pid_t, wp<Client> >     mClients;   // see ~Client()
 
                 mutable     Mutex                   mHardwareLock;
                 audio_hw_device_t*                  mPrimaryHardwareDev;
@@ -1429,6 +1429,10 @@
 
                 float       masterVolume_l() const  { return mMasterVolume; }
                 bool        masterMute_l() const    { return mMasterMute; }
+
+private:
+    sp<Client>  registerPid_l(pid_t pid);    // always returns non-0
+
 };