liboboe: initial checkin of core and legacy files.

Oboe C++ files that calls AudioTrack and AudioRecord.
Main C API implemented by src/core/OboeAudio.cpp

Test: gunit tests for the Legacy mode and handle tracker in tests folder
Bug: 33347409
Change-Id: I50f9fd99377efbd8de6fef1601e9af4c22c6ab46
Signed-off-by: Phil Burk <philburk@google.com>
diff --git a/media/liboboe/src/utility/HandleTracker.cpp b/media/liboboe/src/utility/HandleTracker.cpp
new file mode 100644
index 0000000..be2a64c
--- /dev/null
+++ b/media/liboboe/src/utility/HandleTracker.cpp
@@ -0,0 +1,213 @@
+/*
+ * 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 "OboeAudio"
+//#define LOG_NDEBUG 0
+#include <utils/Log.h>
+
+#include <stdint.h>
+#include <assert.h>
+
+#include <oboe/OboeDefinitions.h>
+#include "HandleTracker.h"
+
+// Handle format is: tgggiiii
+// where each letter is 4 bits, t=type, g=generation, i=index
+
+#define TYPE_SIZE           4
+#define GENERATION_SIZE    12
+#define INDEX_SIZE         16
+
+#define GENERATION_INVALID  0
+#define GENERATION_SHIFT    INDEX_SIZE
+
+#define TYPE_MASK           ((1 << TYPE_SIZE) - 1)
+#define GENERATION_MASK     ((1 << GENERATION_SIZE) - 1)
+#define INDEX_MASK          ((1 << INDEX_SIZE) - 1)
+
+#define SLOT_UNAVAILABLE    (-1)
+
+// Error if handle is negative so type is limited to bottom half.
+#define HANDLE_INVALID_TYPE TYPE_MASK
+
+static_assert(HANDLE_TRACKER_MAX_TYPES == (1 << (TYPE_SIZE - 1)),
+    "Mismatch between header and cpp.");
+static_assert(HANDLE_TRACKER_MAX_HANDLES == (1 << (INDEX_SIZE)),
+    "Mismatch between header and cpp.");
+
+HandleTracker::HandleTracker(uint32_t maxHandles)
+        : mMaxHandleCount(maxHandles)
+        , mHandleAddresses(nullptr)
+        , mHandleHeaders(nullptr)
+{
+    assert(maxHandles <= HANDLE_TRACKER_MAX_HANDLES);
+    // Allocate arrays to hold addresses and validation info.
+    mHandleAddresses = (handle_tracker_address_t *) new handle_tracker_address_t[maxHandles];
+    if (mHandleAddresses != nullptr) {
+        mHandleHeaders = new handle_tracker_header_t[maxHandles];
+        if (mHandleHeaders != nullptr) {
+            // Initialize linked list of free nodes. NULL terminated.
+            for (uint32_t i = 0; i < (maxHandles - 1); i++) {
+                mHandleAddresses[i] = &mHandleAddresses[i + 1]; // point to next node
+                mHandleHeaders[i] = 0;
+            }
+            mNextFreeAddress = &mHandleAddresses[0];
+            mHandleAddresses[maxHandles - 1] = nullptr;
+            mHandleHeaders[maxHandles - 1] = 0;
+        } else {
+            delete[] mHandleAddresses; // so the class appears uninitialized
+        }
+    }
+}
+
+HandleTracker::~HandleTracker()
+{
+    delete[] mHandleAddresses;
+    delete[] mHandleHeaders;
+}
+
+bool HandleTracker::isInitialized() const {
+    return mHandleAddresses != nullptr;
+}
+
+handle_tracker_slot_t HandleTracker::allocateSlot() {
+    void **allocated = mNextFreeAddress;
+    if (allocated == nullptr) {
+        return SLOT_UNAVAILABLE;
+    }
+    // Remove this slot from the head of the linked list.
+    mNextFreeAddress = (void **) *allocated;
+    return (allocated - mHandleAddresses);
+}
+
+handle_tracker_generation_t HandleTracker::nextGeneration(handle_tracker_slot_t index) {
+    handle_tracker_generation_t generation = (mHandleHeaders[index] + 1) & GENERATION_MASK;
+    // Avoid generation zero so that 0x0 is not a valid handle.
+    if (generation == GENERATION_INVALID) {
+        generation++;
+    }
+    return generation;
+}
+
+oboe_handle_t HandleTracker::put(handle_tracker_type_t type, void *address)
+{
+    if (type < 0 || type >= HANDLE_TRACKER_MAX_TYPES) {
+        return static_cast<oboe_handle_t>(OBOE_ERROR_OUT_OF_RANGE);
+    }
+    if (!isInitialized()) {
+        return static_cast<oboe_handle_t>(OBOE_ERROR_NO_MEMORY);
+    }
+
+    // Find an empty slot.
+    handle_tracker_slot_t index = allocateSlot();
+    if (index == SLOT_UNAVAILABLE) {
+        ALOGE("HandleTracker::put() no room for more handles");
+        return static_cast<oboe_handle_t>(OBOE_ERROR_NO_FREE_HANDLES);
+    }
+
+    // Cycle the generation counter so stale handles can be detected.
+    handle_tracker_generation_t generation = nextGeneration(index); // reads header table
+    handle_tracker_header_t inputHeader = buildHeader(type, generation);
+
+    // These two writes may need to be observed by other threads or cores during get().
+    mHandleHeaders[index] = inputHeader;
+    mHandleAddresses[index] = address;
+    // TODO use store release to enforce memory order with get()
+
+    // Generate a handle.
+    oboe_handle_t handle = buildHandle(inputHeader, index);
+
+    //ALOGD("HandleTracker::put(%p) returns 0x%08x", address, handle);
+    return handle;
+}
+
+handle_tracker_slot_t HandleTracker::handleToIndex(handle_tracker_type_t type,
+                                                   oboe_handle_t handle) const
+{
+    // Validate the handle.
+    handle_tracker_slot_t index = extractIndex(handle);
+    if (index >= mMaxHandleCount) {
+        ALOGE("HandleTracker::handleToIndex() invalid handle = 0x%08X", handle);
+        return static_cast<oboe_handle_t>(OBOE_ERROR_INVALID_HANDLE);
+    }
+    handle_tracker_generation_t handleGeneration = extractGeneration(handle);
+    handle_tracker_header_t inputHeader = buildHeader(type, handleGeneration);
+    if (inputHeader != mHandleHeaders[index]) {
+        ALOGE("HandleTracker::handleToIndex() inputHeader = 0x%08x != mHandleHeaders[%d] = 0x%08x",
+             inputHeader, index, mHandleHeaders[index]);
+        return static_cast<oboe_handle_t>(OBOE_ERROR_INVALID_HANDLE);
+    }
+    return index;
+}
+
+handle_tracker_address_t HandleTracker::get(handle_tracker_type_t type, oboe_handle_t handle) const
+{
+    if (!isInitialized()) {
+        return nullptr;
+    }
+    handle_tracker_slot_t index = handleToIndex(type, handle);
+    if (index >= 0) {
+        return mHandleAddresses[index];
+    } else {
+        return nullptr;
+    }
+}
+
+handle_tracker_address_t HandleTracker::remove(handle_tracker_type_t type, oboe_handle_t handle) {
+    if (!isInitialized()) {
+        return nullptr;
+    }
+    handle_tracker_slot_t index = handleToIndex(type,handle);
+    if (index >= 0) {
+        handle_tracker_address_t address = mHandleAddresses[index];
+
+        // Invalidate the header type but preserve the generation count.
+        handle_tracker_generation_t generation = mHandleHeaders[index] & GENERATION_MASK;
+        handle_tracker_header_t inputHeader = buildHeader(
+                (handle_tracker_type_t) HANDLE_INVALID_TYPE, generation);
+        mHandleHeaders[index] = inputHeader;
+
+        // Add this slot to the head of the linked list.
+        mHandleAddresses[index] = mNextFreeAddress;
+        mNextFreeAddress = (handle_tracker_address_t *) &mHandleAddresses[index];
+        return address;
+    } else {
+        return nullptr;
+    }
+}
+
+oboe_handle_t HandleTracker::buildHandle(handle_tracker_header_t typeGeneration,
+                                         handle_tracker_slot_t index) {
+    return (oboe_handle_t)((typeGeneration << GENERATION_SHIFT) | (index & INDEX_MASK));
+}
+
+handle_tracker_header_t HandleTracker::buildHeader(handle_tracker_type_t type,
+                                    handle_tracker_generation_t generation)
+{
+    return (handle_tracker_header_t) (((type & TYPE_MASK) << GENERATION_SIZE)
+        | (generation & GENERATION_MASK));
+}
+
+handle_tracker_slot_t HandleTracker::extractIndex(oboe_handle_t handle)
+{
+    return handle & INDEX_MASK;
+}
+
+handle_tracker_generation_t HandleTracker::extractGeneration(oboe_handle_t handle)
+{
+    return (handle >> GENERATION_SHIFT) & GENERATION_MASK;
+}