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/*
* Copyright (c) 2013 - 2015, The Linux Foundation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
* * Neither the name of The Linux Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <dlfcn.h>
#include <common/AVExtensionsCommon.h>
#include <cutils/properties.h>
namespace android {
static const char * CUSTOMIZATION_LIB_NAME = "libavenhancements.so";
/*
* Create strongly-typed objects of type T
* If the customization library exists and does contain a "named" constructor,
* invoke and create an instance
* Else create the object of type T itself
*
* Contains a static instance to dlopen'd library, But may end up
* opening the library mutiple times. Following snip from dlopen man page is
* reassuring "...Only a single copy of an object file is brought into the
* address space, even if dlopen() is invoked multiple times in reference to
* the file, and even if different pathnames are used to reference the file.."
*/
template <typename T>
T *ExtensionsLoader<T>::createInstance(const char *createFunctionName) {
(void)createFunctionName;
// create extended object if extensions-lib is available and
// AV_ENHANCEMENTS is enabled
#if ENABLE_AV_ENHANCEMENTS
bool enabled = property_get_bool("media.avenhancements.enabled", false);
if (enabled) {
createFunction_t createFunc = loadCreateFunction(createFunctionName);
if (createFunc) {
return reinterpret_cast<T *>((*createFunc)());
}
}
#endif
// Else, create the default object
return new T;
}
template <typename T>
void ExtensionsLoader<T>::loadLib() {
if (!mLibHandle) {
mLibHandle = ::dlopen(CUSTOMIZATION_LIB_NAME, RTLD_LAZY);
if (!mLibHandle) {
ALOGV("%s", dlerror());
return;
}
ALOGV("Opened %s", CUSTOMIZATION_LIB_NAME);
}
}
template <typename T>
createFunction_t ExtensionsLoader<T>::loadCreateFunction(const char *createFunctionName) {
loadLib();
if (!mLibHandle) {
return NULL;
}
createFunction_t func = (createFunction_t)dlsym(mLibHandle, createFunctionName);
if (!func) {
ALOGW("symbol %s not found: %s",createFunctionName, dlerror());
}
return func;
}
//static
template <typename T>
void *ExtensionsLoader<T>::mLibHandle = NULL;
} //namespace android
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