diff --git a/libhidlcache/Android.bp b/libhidlcache/Android.bp
new file mode 100644
index 0000000..7fd5aa7
--- /dev/null
+++ b/libhidlcache/Android.bp
@@ -0,0 +1,47 @@
+// Copyright (C) 2016 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.
+
+cc_library {
+    name: "libhidlcache",
+    vendor_available: true,
+    vndk: {
+        enabled: true,
+    },
+    defaults: ["libhidl-defaults"],
+    shared_libs: [
+        "libbase",
+        "liblog",
+        "libutils",
+        "libcutils",
+        "libhidlbase",
+        "libhidlmemory",
+        "libhwbinder",
+        "libhidltransport",
+        "android.hidl.memory@1.0",
+        "android.hidl.memory.block@1.0",
+        "android.hidl.memory.token@1.0",
+    ],
+    export_include_dirs: ["include"],
+
+    export_shared_lib_headers: [
+        "android.hidl.memory@1.0",
+        "android.hidl.memory.block@1.0",
+        "android.hidl.memory.token@1.0",
+        "libhidlbase"
+    ],
+    srcs: [
+        "HidlMemoryCache.cpp",
+        "mapping.cpp"
+    ],
+}
diff --git a/libhidlcache/HidlCache.h b/libhidlcache/HidlCache.h
new file mode 100644
index 0000000..db778d3
--- /dev/null
+++ b/libhidlcache/HidlCache.h
@@ -0,0 +1,143 @@
+/*
+ * Copyright (C) 2016 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 ANDROID_HARDWARE_HIDL_CACHE_H
+#define ANDROID_HARDWARE_HIDL_CACHE_H
+
+#include <utils/Log.h>
+
+namespace android {
+namespace hardware {
+
+// A generic cache to map Key to sp<Value>. The cache records are kept with
+// wp<Value>, so that it does not block the Value to be garbage collected
+// when there's no other sp<> externally.
+template <class Key, class Value, class Compare = std::less<Key>>
+class HidlCache : public virtual RefBase {
+    using Mutex = std::mutex;
+    using Lock = std::lock_guard<Mutex>;
+
+   public:
+    //  A RAII class to manage lock/unlock HidlCache.
+    class HidlCacheLock : public virtual RefBase {
+       public:
+        HidlCacheLock(sp<HidlCache> cache, const Key& key) : mCache(cache), mKey(key) {
+            mCache->lock(mKey);
+        }
+        ~HidlCacheLock() { mCache->unlock(mKey); }
+
+       private:
+        sp<HidlCache> mCache;
+        const Key mKey;
+    };
+    // lock the IMemory refered by key and keep it alive even if there's no
+    // other memory block refers to.
+    virtual bool lock(const Key& key);
+    virtual sp<Value> unlock(const Key& key);
+    virtual bool flush(const Key& key);
+    // fetch the sp<Value> with key from cache,
+    // make a new instance with fill() if it does not present currently.
+    virtual sp<Value> fetch(const Key& key);
+    virtual sp<HidlCacheLock> lockGuard(const Key& key) { return new HidlCacheLock(this, key); }
+
+    virtual ~HidlCache() {}
+
+   protected:
+    friend void HidlCacheWhiteBoxTest();
+    // This method shall be called with a lock held
+    virtual sp<Value> fillLocked(const Key& key) = 0;
+
+    // @return nullptr if it does not present currently.
+    // @note This method shall be called with a lock held
+    virtual sp<Value> getCachedLocked(const Key& key);
+    bool cached(Key key) const { return mCached.count(key) > 0; }
+    bool locked(Key key) const { return mLocked.count(key) > 0; }
+    Mutex mMutex;
+
+    std::map<Key, wp<Value>, Compare> mCached;
+    std::map<Key, sp<Value>, Compare> mLocked;
+};
+
+template <class Key, class Value, class Compare>
+bool HidlCache<Key, Value, Compare>::lock(const Key& key) {
+    {
+        Lock lock(mMutex);
+        if (cached(key)) {
+            sp<Value> im = mCached[key].promote();
+            if (im != nullptr) {
+                mLocked[key] = im;
+                return true;
+            } else {
+                mCached.erase(key);
+            }
+        }
+    }
+    sp<Value> value = fetch(key);
+    if (value == nullptr) {
+        return false;
+    } else {
+        Lock lock(mMutex);
+        mLocked[key] = value;
+        return true;
+    }
+}
+
+template <class Key, class Value, class Compare>
+sp<Value> HidlCache<Key, Value, Compare>::unlock(const Key& key) {
+    Lock lock(mMutex);
+    if (locked(key) > 0) {
+        sp<Value> v = mLocked[key];
+        mLocked.erase(key);
+        return v;
+    }
+    return nullptr;
+}
+
+template <class Key, class Value, class Compare>
+bool HidlCache<Key, Value, Compare>::flush(const Key& key) {
+    Lock lock(mMutex);
+    bool contain = cached(key);
+    mCached.erase(key);
+    return contain;
+}
+
+template <class Key, class Value, class Compare>
+sp<Value> HidlCache<Key, Value, Compare>::getCachedLocked(const Key& key) {
+    if (cached(key)) {
+        wp<Value> cache = mCached[key];
+        sp<Value> mem = cache.promote();
+        if (mem != nullptr) {
+            return mem;
+        } else {
+            mCached.erase(key);
+        }
+    }
+    return nullptr;
+}
+
+template <class Key, class Value, class Compare>
+sp<Value> HidlCache<Key, Value, Compare>::fetch(const Key& key) {
+    Lock lock(mMutex);
+    sp<Value> value = getCachedLocked(key);
+
+    if (value == nullptr) {
+        value = fillLocked(key);
+    }
+    return value;
+}
+
+}  // namespace hardware
+}  // namespace android
+#endif
diff --git a/libhidlcache/HidlMemoryCache.cpp b/libhidlcache/HidlMemoryCache.cpp
new file mode 100644
index 0000000..6f9c25c
--- /dev/null
+++ b/libhidlcache/HidlMemoryCache.cpp
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#define LOG_TAG "HidlMemoryCache"
+#include "HidlMemoryCache.h"
+#include <android/hidl/memory/1.0/IMemory.h>
+#include <android/hidl/memory/token/1.0/IMemoryToken.h>
+#include <hidlmemory/mapping.h>
+#include <sys/mman.h>
+#include <utils/Log.h>
+
+namespace android {
+namespace hardware {
+
+using IMemoryToken = ::android::hidl::memory::token::V1_0::IMemoryToken;
+using IMemory = ::android::hidl::memory::V1_0::IMemory;
+
+class IMemoryDecorator : public virtual IMemory {
+   public:
+    IMemoryDecorator(sp<IMemory> heap) : mHeap(heap) {}
+    virtual ~IMemoryDecorator(){};
+    Return<void> update() override { return mHeap->update(); }
+    Return<void> read() override { return mHeap->read(); };
+    Return<void> updateRange(uint64_t start, uint64_t length) override {
+        return mHeap->updateRange(start, length);
+    }
+    Return<void> readRange(uint64_t start, uint64_t length) override {
+        return mHeap->readRange(start, length);
+    }
+    Return<void> commit() override { return mHeap->commit(); }
+
+    Return<void*> getPointer() override { return mHeap->getPointer(); }
+    Return<uint64_t> getSize() override { return mHeap->getSize(); }
+
+   protected:
+    sp<IMemory> mHeap;
+};
+
+class IMemoryCacheable : public virtual IMemoryDecorator {
+   public:
+    IMemoryCacheable(sp<IMemory> heap, sp<IMemoryToken> key) : IMemoryDecorator(heap), mKey(key) {}
+    virtual ~IMemoryCacheable() { HidlMemoryCache::getInstance()->flush(mKey); }
+
+   protected:
+    sp<IMemoryToken> mKey;
+};
+
+class IMemoryBlock : public virtual IMemoryDecorator {
+   public:
+    IMemoryBlock(sp<IMemory> heap, uint64_t size, uint64_t offset)
+        : IMemoryDecorator(heap), mSize(size), mOffset(offset), mHeapSize(heap->getSize()) {}
+    bool validRange(uint64_t start, uint64_t length) {
+        return (start + length < mSize) && (start + length >= start) &&
+               (mOffset + mSize < mHeapSize);
+    }
+    Return<void> readRange(uint64_t start, uint64_t length) {
+        if (!validRange(start, length)) {
+            ALOGE("IMemoryBlock::readRange: out of range");
+            Status status;
+            status.setException(Status::EX_ILLEGAL_ARGUMENT, "out of range");
+            return Return<void>(status);
+        }
+        return mHeap->readRange(mOffset + start, length);
+    }
+    Return<void> updateRange(uint64_t start, uint64_t length) override {
+        if (!validRange(start, length)) {
+            ALOGE("IMemoryBlock::updateRange: out of range");
+            return Void();
+        }
+        return mHeap->updateRange(mOffset + start, length);
+    }
+    Return<uint64_t> getSize() override { return mSize; }
+    Return<void*> getPointer() override {
+        void* p = mHeap->getPointer();
+        return (static_cast<char*>(p) + mOffset);
+    }
+
+   protected:
+    uint64_t mSize;
+    uint64_t mOffset;
+    uint64_t mHeapSize;
+};
+
+sp<HidlMemoryCache> HidlMemoryCache::getInstance() {
+    static sp<HidlMemoryCache> instance = new HidlMemoryCache();
+    return instance;
+}
+
+sp<IMemory> HidlMemoryCache::fillLocked(const sp<IMemoryToken>& key) {
+    sp<IMemory> memory = nullptr;
+    Return<void> ret = key->get(
+        [&](const hidl_memory& mem) { memory = new IMemoryCacheable(mapMemory(mem), key); });
+    if (!ret.isOk()) {
+        ALOGE("HidlMemoryCache::fill: cannot IMemoryToken::get.");
+        return nullptr;
+    }
+    mCached[key] = memory;
+    return memory;
+}
+
+sp<IMemory> HidlMemoryCache::map(const MemoryBlock& memblk) {
+    sp<IMemoryToken> token = memblk.token;
+    sp<IMemory> heap = fetch(token);
+    if (heap == nullptr) {
+        return nullptr;
+    }
+    return new IMemoryBlock(heap, memblk.size, memblk.offset);
+}
+
+}  // namespace hardware
+}  // namespace android
diff --git a/libhidlcache/HidlMemoryCache.h b/libhidlcache/HidlMemoryCache.h
new file mode 100644
index 0000000..c9a533b
--- /dev/null
+++ b/libhidlcache/HidlMemoryCache.h
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2016 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 ANDROID_HARDWARD_HIDLMEMORY_CACHE_H
+#define ANDROID_HARDWARD_HIDLMEMORY_CACHE_H
+
+#include <android/hidl/memory/block/1.0/types.h>
+#include <android/hidl/memory/token/1.0/IMemoryToken.h>
+#include <hidl/HidlBinderSupport.h>
+#include <hwbinder/IBinder.h>
+#include <utils/RefBase.h>
+#include "HidlCache.h"
+
+namespace android {
+namespace hardware {
+
+struct IMemoryTokenCompare {
+    using IMemoryToken = ::android::hidl::memory::token::V1_0::IMemoryToken;
+    bool operator()(const sp<IMemoryToken>& lhs, const sp<IMemoryToken>& rhs) const {
+        sp<IBinder> lb = toBinder<IMemoryToken>(lhs);
+        sp<IBinder> rb = toBinder<IMemoryToken>(rhs);
+        return lb < rb;
+    }
+};
+
+// The HidlMemoryCache is a singleton class to provides cache for
+// IMemoryToken => ::android::hidl::memory::V1_0::IMemory
+// It's an abstraction layer on top of the IMapper and supports, but is
+// not limited to, the Ashmem type HidlMemory.
+class HidlMemoryCache
+    : public virtual HidlCache<sp<::android::hidl::memory::token::V1_0::IMemoryToken>,
+                               ::android::hidl::memory::V1_0::IMemory, IMemoryTokenCompare> {
+    using IMemoryToken = ::android::hidl::memory::token::V1_0::IMemoryToken;
+    using IMemory = ::android::hidl::memory::V1_0::IMemory;
+    using MemoryBlock = ::android::hidl::memory::block::V1_0::MemoryBlock;
+
+   public:
+    virtual sp<IMemory> map(const MemoryBlock& block);
+    // get the singleton
+    static sp<HidlMemoryCache> getInstance();
+
+   protected:
+    HidlMemoryCache() {}
+    virtual sp<IMemory> fillLocked(const sp<IMemoryToken>& key) override;
+};
+
+}  // namespace hardware
+}  // namespace android
+
+#endif
diff --git a/libhidlcache/include/hidlcache/mapping.h b/libhidlcache/include/hidlcache/mapping.h
new file mode 100644
index 0000000..972b7b5
--- /dev/null
+++ b/libhidlcache/include/hidlcache/mapping.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2016 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 ANDROID_HARDWARE_CACHE_MAPPING_H
+#define ANDROID_HARDWARE_CACHE_MAPPING_H
+
+#include <android/hidl/memory/1.0/IMemory.h>
+#include <android/hidl/memory/block/1.0/types.h>
+#include <android/hidl/memory/token/1.0/IMemoryToken.h>
+
+namespace android {
+namespace hardware {
+
+/**
+ * Returns the IMemory instance corresponding to a MemoryBlock. The heap that
+ * a MemoryBlock belongs to is stored in an internal cache to reduce the number
+ * of invocations to the mapMemory(hidl_memory)
+ *
+ * Note, a cache entry is maintained by reference count and may be flushed when
+ * the count decrease to zero. Performance critical part that does not want its
+ * caches to be flushed can use HidlMemoryCacheLock.
+ */
+sp<::android::hidl::memory::V1_0::IMemory> mapMemory(
+    const ::android::hidl::memory::block::V1_0::MemoryBlock& block);
+
+/**
+ * Internally, there's a cache pool to keep IMemory instances for heap regions
+ * that are referred by the MemoryBlock. During development, this
+ * lockMemoryCache(...) method helps to diagnosis whether the cache is effective
+ * for a specific key. It returns a RAII object used to lock an IMemory instance
+ * referred by the key and keep it alive even if the instance is not referred by
+ * any MemoryBlock. If the cache in interest is already effective. It won't differ
+ * much in performance w/ wo/ the lockMemoryCache()
+ *
+ * @note An IMemory instance that is returned from the mapMemory() is
+ *       initialized in an unlocked state.
+ */
+sp<RefBase> lockMemoryCache(const sp<::android::hidl::memory::token::V1_0::IMemoryToken> key);
+
+}  // namespace hardware
+}  // namespace android
+#endif
diff --git a/libhidlcache/mapping.cpp b/libhidlcache/mapping.cpp
new file mode 100644
index 0000000..2a23e6f
--- /dev/null
+++ b/libhidlcache/mapping.cpp
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+#define LOG_TAG "libhidlmemory"
+
+#include <map>
+#include <mutex>
+#include <string>
+
+#include <hidlmemory/mapping.h>
+
+#include <android-base/logging.h>
+#include <hidl/HidlSupport.h>
+#include "HidlMemoryCache.h"
+
+using android::hardware::HidlMemoryCache;
+using android::hidl::memory::block::V1_0::MemoryBlock;
+using android::hidl::memory::token::V1_0::IMemoryToken;
+using android::hidl::memory::V1_0::IMemory;
+
+namespace android {
+namespace hardware {
+
+sp<IMemory> mapMemory(const ::android::hidl::memory::block::V1_0::MemoryBlock& block) {
+    sp<HidlMemoryCache> c = HidlMemoryCache::getInstance();
+    return c->map(block);
+}
+
+sp<RefBase> lockMemoryCache(const sp<::android::hidl::memory::token::V1_0::IMemoryToken> key) {
+    sp<HidlMemoryCache> c = HidlMemoryCache::getInstance();
+    return c->lockGuard(key);
+}
+
+}  // namespace hardware
+}  // namespace android