services/surfaceflinger/Client.cpp

/*
 * Copyright (C) 2012 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.
 */

#include <stdint.h>
#include <sys/types.h>

#include <binder/PermissionCache.h>
#include <binder/IPCThreadState.h>

#include <private/android_filesystem_config.h>

#include "Client.h"
#include "Layer.h"
#include "SurfaceFlinger.h"

namespace android {

// ---------------------------------------------------------------------------

const String16 sAccessSurfaceFlinger("android.permission.ACCESS_SURFACE_FLINGER");

// ---------------------------------------------------------------------------

Client::Client(const sp<SurfaceFlinger>& flinger)
    : mFlinger(flinger)
{
}

Client::~Client()
{
    // We need to post a message to remove our remaining layers rather than
    // do so directly by acquiring the SurfaceFlinger lock. If we were to
    // attempt to directly call the lock it becomes effectively impossible
    // to use sp<Client> while holding the SF lock as descoping it could
    // then trigger a dead-lock.

    const size_t count = mLayers.size();
    for (size_t i=0 ; i<count ; i++) {
        sp<Layer> l = mLayers.valueAt(i).promote();
        if (l == nullptr) {
            continue;
        }
        mFlinger->postMessageAsync(new LambdaMessage([flinger = mFlinger, l]() {
            flinger->removeLayer(l);
        }));
    }
}

status_t Client::initCheck() const {
    return NO_ERROR;
}

void Client::attachLayer(const sp<IBinder>& handle, const sp<Layer>& layer)
{
    Mutex::Autolock _l(mLock);
    mLayers.add(handle, layer);
}

void Client::detachLayer(const Layer* layer)
{
    Mutex::Autolock _l(mLock);
    // we do a linear search here, because this doesn't happen often
    const size_t count = mLayers.size();
    for (size_t i=0 ; i<count ; i++) {
        if (mLayers.valueAt(i) == layer) {
            mLayers.removeItemsAt(i, 1);
            break;
        }
    }
}
sp<Layer> Client::getLayerUser(const sp<IBinder>& handle) const
{
    Mutex::Autolock _l(mLock);
    sp<Layer> lbc;
    wp<Layer> layer(mLayers.valueFor(handle));
    if (layer != 0) {
        lbc = layer.promote();
        ALOGE_IF(lbc==0, "getLayerUser(name=%p) is dead", handle.get());
    }
    return lbc;
}


status_t Client::createSurface(
        const String8& name,
        uint32_t w, uint32_t h, PixelFormat format, uint32_t flags,
        const sp<IBinder>& parentHandle, int32_t windowType, int32_t ownerUid,
        sp<IBinder>* handle,
        sp<IGraphicBufferProducer>* gbp)
{
    sp<Layer> parent = nullptr;
    if (parentHandle != nullptr) {
        auto layerHandle = reinterpret_cast<Layer::Handle*>(parentHandle.get());
        parent = layerHandle->owner.promote();
        if (parent == nullptr) {
            return NAME_NOT_FOUND;
        }
    }

    // We rely on createLayer to check permissions.
    return mFlinger->createLayer(name, this, w, h, format, flags, windowType,
                                 ownerUid, handle, gbp, &parent);
}

status_t Client::destroySurface(const sp<IBinder>& handle) {
    return mFlinger->onLayerRemoved(this, handle);
}

status_t Client::clearLayerFrameStats(const sp<IBinder>& handle) const {
    sp<Layer> layer = getLayerUser(handle);
    if (layer == nullptr) {
        return NAME_NOT_FOUND;
    }
    layer->clearFrameStats();
    return NO_ERROR;
}

status_t Client::getLayerFrameStats(const sp<IBinder>& handle, FrameStats* outStats) const {
    sp<Layer> layer = getLayerUser(handle);
    if (layer == nullptr) {
        return NAME_NOT_FOUND;
    }
    layer->getFrameStats(outStats);
    return NO_ERROR;
}

// ---------------------------------------------------------------------------
}; // namespace android