some work to try to reduce the code size of some native libraries

- make sure that all binder Bn classes define a ctor and dtor in their respective library.
  This avoids duplication of the ctor/dtor in libraries where these objects are instantiated.
  This is also cleaner, should we want these ctor/dtor to do something one day.

- same change as above for some Bp classes and various other non-binder classes

- moved the definition of CHECK_INTERFACE() in IInterface.h instead of having it everywhere.

- improved the CHECK_INTERFACE() macro so it calls a single method in Parcel, instead of inlining its code everywhere

- IBinder::getInterfaceDescriptor() now returns a "const String16&" instead of String16, which saves calls to String16 and ~String16

- implemented a cache for BpBinder::getInterfaceDescriptor(), since this does an IPC. HOWEVER, this method never seems to be called.
  The cache makes BpBinder bigger, so we need to figure out if we need this method at all.

9 files changed, 82 insertions, 34 deletions

diff --git a/libs/binder/Binder.cpp b/libs/binder/Binder.cpp
index 26f29f8..0dd7622 100644
--- a/libs/binder/Binder.cpp
+++ b/libs/binder/Binder.cpp
@@ -27,6 +27,17 @@ namespace android {
 
 // ---------------------------------------------------------------------------
 
+IBinder::IBinder()
+    : RefBase()
+{
+}
+
+IBinder::~IBinder()
+{
+}
+
+// ---------------------------------------------------------------------------
+
 sp<IInterface>  IBinder::queryLocalInterface(const String16& descriptor)
 {
     return NULL;
@@ -58,6 +69,8 @@ public:
 
 // ---------------------------------------------------------------------------
 
+String16 BBinder::sEmptyDescriptor;
+
 BBinder::BBinder()
     : mExtras(NULL)
 {
@@ -73,10 +86,10 @@ status_t BBinder::pingBinder()
     return NO_ERROR;
 }
 
-String16 BBinder::getInterfaceDescriptor() const
+const String16& BBinder::getInterfaceDescriptor() const
 {
     LOGW("reached BBinder::getInterfaceDescriptor (this=%p)", this);
-    return String16();
+    return sEmptyDescriptor;
 }
 
 status_t BBinder::transact(
diff --git a/libs/binder/BpBinder.cpp b/libs/binder/BpBinder.cpp
index 56bf413..5de87ec 100644
--- a/libs/binder/BpBinder.cpp
+++ b/libs/binder/BpBinder.cpp
@@ -98,16 +98,33 @@ BpBinder::BpBinder(int32_t handle)
     IPCThreadState::self()->incWeakHandle(handle);
 }
 
-String16 BpBinder::getInterfaceDescriptor() const
+bool BpBinder::isDescriptorCached() const {
+    Mutex::Autolock _l(mLock);
+    return mDescriptorCache.size() ? true : false;
+}
+
+const String16& BpBinder::getInterfaceDescriptor() const
 {
-    String16 res;
-    Parcel send, reply;
-    status_t err = const_cast<BpBinder*>(this)->transact(
-            INTERFACE_TRANSACTION, send, &reply);
-    if (err == NO_ERROR) {
-        res = reply.readString16();
+    if (isDescriptorCached() == false) {
+        Parcel send, reply;
+        // do the IPC without a lock held.
+        status_t err = const_cast<BpBinder*>(this)->transact(
+                INTERFACE_TRANSACTION, send, &reply);
+        if (err == NO_ERROR) {
+            String16 res(reply.readString16());
+            Mutex::Autolock _l(mLock);
+            // mDescriptorCache could have been assigned while the lock was
+            // released.
+            if (mDescriptorCache.size() == 0)
+                mDescriptorCache = res;
+        }
     }
-    return res;
+    
+    // we're returning a reference to a non-static object here. Usually this
+    // is not something smart to do, however, with binder objects it is 
+    // (usually) safe because they are reference-counted.
+    
+    return mDescriptorCache;
 }
 
 bool BpBinder::isBinderAlive() const
diff --git a/libs/binder/IInterface.cpp b/libs/binder/IInterface.cpp
index 9f1192f..29acf5d 100644
--- a/libs/binder/IInterface.cpp
+++ b/libs/binder/IInterface.cpp
@@ -20,6 +20,13 @@ namespace android {
 
 // ---------------------------------------------------------------------------
 
+IInterface::IInterface() 
+    : RefBase() {
+}
+
+IInterface::~IInterface() {
+}
+
 sp<IBinder> IInterface::asBinder()
 {
     return this ? onAsBinder() : NULL;
diff --git a/libs/binder/IMemory.cpp b/libs/binder/IMemory.cpp
index 13d67c0..6c1d225 100644
--- a/libs/binder/IMemory.cpp
+++ b/libs/binder/IMemory.cpp
@@ -205,11 +205,11 @@ sp<IMemoryHeap> BpMemory::getMemory(ssize_t* offset, size_t* size) const
 
 IMPLEMENT_META_INTERFACE(Memory, "android.utils.IMemory");
 
-#define CHECK_INTERFACE(interface, data, reply) \
-        do { if (!data.enforceInterface(interface::getInterfaceDescriptor())) { \
-            LOGW("Call incorrectly routed to " #interface); \
-            return PERMISSION_DENIED; \
-        } } while (0)
+BnMemory::BnMemory() {
+}
+
+BnMemory::~BnMemory() { 
+}
 
 status_t BnMemory::onTransact(
     uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
@@ -299,11 +299,11 @@ void BpMemoryHeap::assertReallyMapped() const
         ssize_t size = reply.readInt32();
         uint32_t flags = reply.readInt32();
 
-        LOGE_IF(err, "binder=%p transaction failed fd=%d, size=%d, err=%d (%s)",
+        LOGE_IF(err, "binder=%p transaction failed fd=%d, size=%ld, err=%d (%s)",
                 asBinder().get(), parcel_fd, size, err, strerror(-err));
 
         int fd = dup( parcel_fd );
-        LOGE_IF(fd==-1, "cannot dup fd=%d, size=%d, err=%d (%s)",
+        LOGE_IF(fd==-1, "cannot dup fd=%d, size=%ld, err=%d (%s)",
                 parcel_fd, size, err, strerror(errno));
 
         int access = PROT_READ;
@@ -316,7 +316,7 @@ void BpMemoryHeap::assertReallyMapped() const
             mRealHeap = true;
             mBase = mmap(0, size, access, MAP_SHARED, fd, 0);
             if (mBase == MAP_FAILED) {
-                LOGE("cannot map BpMemoryHeap (binder=%p), size=%d, fd=%d (%s)",
+                LOGE("cannot map BpMemoryHeap (binder=%p), size=%ld, fd=%d (%s)",
                         asBinder().get(), size, fd, strerror(errno));
                 close(fd);
             } else {
@@ -357,8 +357,14 @@ uint32_t BpMemoryHeap::getFlags() const {
 
 IMPLEMENT_META_INTERFACE(MemoryHeap, "android.utils.IMemoryHeap");
 
+BnMemoryHeap::BnMemoryHeap() { 
+}
+
+BnMemoryHeap::~BnMemoryHeap() { 
+}
+
 status_t BnMemoryHeap::onTransact(
-    uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
+        uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
 {
     switch(code) {
        case HEAP_ID: {
diff --git a/libs/binder/IPermissionController.cpp b/libs/binder/IPermissionController.cpp
index a61debf..bff4c9b 100644
--- a/libs/binder/IPermissionController.cpp
+++ b/libs/binder/IPermissionController.cpp
@@ -55,12 +55,6 @@ IMPLEMENT_META_INTERFACE(PermissionController, "android.os.IPermissionController
 
 // ----------------------------------------------------------------------
 
-#define CHECK_INTERFACE(interface, data, reply) \
-        do { if (!data.enforceInterface(interface::getInterfaceDescriptor())) { \
-            LOGW("Call incorrectly routed to " #interface); \
-            return PERMISSION_DENIED; \
-        } } while (0)
-
 status_t BnPermissionController::onTransact(
     uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
 {
diff --git a/libs/binder/IServiceManager.cpp b/libs/binder/IServiceManager.cpp
index 2f265b8..88774e7 100644
--- a/libs/binder/IServiceManager.cpp
+++ b/libs/binder/IServiceManager.cpp
@@ -178,12 +178,6 @@ IMPLEMENT_META_INTERFACE(ServiceManager, "android.os.IServiceManager");
 
 // ----------------------------------------------------------------------
 
-#define CHECK_INTERFACE(interface, data, reply) \
-        do { if (!data.enforceInterface(interface::getInterfaceDescriptor())) { \
-            LOGW("Call incorrectly routed to " #interface); \
-            return PERMISSION_DENIED; \
-        } } while (0)
-
 status_t BnServiceManager::onTransact(
     uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
 {
diff --git a/libs/binder/MemoryDealer.cpp b/libs/binder/MemoryDealer.cpp
index fd6ab7a..d5ffe7f 100644
--- a/libs/binder/MemoryDealer.cpp
+++ b/libs/binder/MemoryDealer.cpp
@@ -38,7 +38,15 @@
 #include <sys/file.h>
 
 namespace android {
+// ----------------------------------------------------------------------------
 
+HeapInterface::HeapInterface() { }
+HeapInterface::~HeapInterface() { }
+
+// ----------------------------------------------------------------------------
+
+AllocatorInterface::AllocatorInterface() { }
+AllocatorInterface::~AllocatorInterface() { }
 
 // ----------------------------------------------------------------------------
 
@@ -107,7 +115,7 @@ sp<IMemory> MemoryDealer::allocate(size_t size, uint32_t flags)
         if (new_memory != 0) {
             memory = new Allocation(this, offset, size, new_memory);
         } else {
-            LOGE("couldn't map [%8x, %d]", offset, size);
+            LOGE("couldn't map [%8lx, %u]", offset, size);
             if (size) {
                 /* NOTE: it's VERY important to not free allocations of size 0
                  * because they're special as they don't have any record in the 
@@ -339,6 +347,10 @@ void SimpleBestFitAllocator::dump_l(String8& result,
         
 // ----------------------------------------------------------------------------
 
+SharedHeap::SharedHeap() 
+    : HeapInterface(), MemoryHeapBase() 
+{ 
+}
 
 SharedHeap::SharedHeap(size_t size, uint32_t flags, char const * name)
     : MemoryHeapBase(size, flags, name)
diff --git a/libs/binder/MemoryHeapPmem.cpp b/libs/binder/MemoryHeapPmem.cpp
index 599c9ae..3806a42 100644
--- a/libs/binder/MemoryHeapPmem.cpp
+++ b/libs/binder/MemoryHeapPmem.cpp
@@ -108,7 +108,7 @@ void SubRegionMemory::revoke()
     // promote() it.
     
 #if HAVE_ANDROID_OS
-    if (mSize != NULL) {
+    if (mSize != 0) {
         const sp<MemoryHeapPmem>& heap(getHeap());
         int our_fd = heap->heapID();
         struct pmem_region sub;
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index 3747de6..f40e4bd 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -441,9 +441,14 @@ status_t Parcel::writeInterfaceToken(const String16& interface)
     return writeString16(interface);
 }
 
+bool Parcel::checkInterface(IBinder* binder) const
+{
+    return enforceInterface(binder->getInterfaceDescriptor()); 
+}
+
 bool Parcel::enforceInterface(const String16& interface) const
 {
-    String16 str = readString16();
+    const String16 str(readString16());
     if (str == interface) {
         return true;
     } else {