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/*
* Author: Sven Gothel <sgothel@jausoft.com>
* Copyright (c) 2020 Gothel Software e.K.
* Copyright (c) 2020 ZAFENA AB
*
* Author: Petre Eftime <petre.p.eftime@intel.com>
* Copyright (c) 2016 Intel Corporation.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef JAU_JNIMEM__HPP_
#define JAU_JNIMEM__HPP_
#include <jni.h>
#include <stdexcept>
#include <jau/basic_types.hpp>
extern JavaVM* vm;
/*
* This class provides a lifetime-managed JNIEnv object, which attaches or
* detaches the current thread from the JVM automatically
*/
class JNIEnvContainer {
private:
JNIEnv *env = nullptr;
bool needsDetach = false;
public:
/* Attaches this thread to the JVM if it is not already attached */
JNIEnvContainer();
/* Detaches this thread to the JVM if it is attached */
~JNIEnvContainer();
/* Provides access to the local thread's JNIEnv object */
JNIEnv *operator*();
/* Provides access to the local thread's JNIEnv object's methods */
JNIEnv *operator->();
/* Attaches this thread to the JVM if it is not already attached */
void attach();
/* Detaches this thread to the JVM if it is attached */
void detach();
};
/* Each thread has a local jni_env variable of JNIEnvContainer type */
extern thread_local JNIEnvContainer jni_env;
/*
* This class provides a lifetime-managed GlobalRef variable,
* which is automatically deleted when it goes out of scope.
*
* RAII-style acquire and relinquish via destructor
*/
class JNIGlobalRef {
private:
jobject object;
public:
static inline void check(jobject object, const char* file, int line) {
if( nullptr == object ) {
throw jau::RuntimeException("JNIGlobalRef::check: Null jobject", file, line);
}
}
/* Creates a GlobalRef using a nullptr for API convenience, lazy assignment. */
JNIGlobalRef() noexcept;
/* Creates a GlobalRef from an object passed to it */
JNIGlobalRef(jobject object);
JNIGlobalRef(const JNIGlobalRef &o);
JNIGlobalRef(JNIGlobalRef &&o) noexcept;
JNIGlobalRef& operator=(const JNIGlobalRef &o);
JNIGlobalRef& operator=(JNIGlobalRef &&o) noexcept;
/* Deletes the stored GlobalRef */
~JNIGlobalRef() noexcept;
/** Clears the java reference, i.e. nulling it, without deleting the global reference via JNI. */
void clear() noexcept;
/* Provides access to the stored GlobalRef as an jobject. */
jobject operator*() noexcept { return object; }
/* Provides access to the stored GlobalRef as an jobject. */
jobject getObject() const noexcept { return object; }
/* Provides access to the stored GlobalRef as a jclass. */
jclass getClass() const noexcept { return (jclass)object; }
bool operator==(const JNIGlobalRef& rhs) const noexcept;
bool operator!=(const JNIGlobalRef& rhs) const noexcept
{ return !( *this == rhs ); }
};
/*
* This class provides a lifetime-managed 'PrimitiveArrayCritical' pinned heap,
* which is automatically released when it goes out of scope.
* <p>
* RAII-style acquire and relinquish via destructor
* </p>
*/
template <typename T, typename U>
class JNICriticalArray {
public:
enum Mode : jint {
/** Like default 0: If 'isCopy': Update the java array data with the copy and free the copy. */
UPDATE_AND_RELEASE = 0,
/** Like JNI_COMMIT: If 'isCopy': Update the java array data with the copy, but do not free the copy. */
UPDATE_NO_RELEASE = JNI_COMMIT,
/** Like default JNI_ABORT: If 'isCopy': Do not update the java array data with the copy, but free the copy. */
NO_UPDATE_AND_RELEASE = JNI_ABORT,
};
private:
JNIEnv *env;
Mode mode = UPDATE_AND_RELEASE;
U jarray = nullptr;
T* narray = nullptr;
jboolean isCopy = false;
public:
JNICriticalArray(JNIEnv *env) : env(env) {}
JNICriticalArray(const JNICriticalArray &o) = delete;
JNICriticalArray(JNICriticalArray &&o) = delete;
JNICriticalArray& operator=(const JNICriticalArray &o) = delete;
JNICriticalArray& operator=(JNICriticalArray &&o) = delete;
/**
* Release the acquired primitive array, RAII style.
*/
~JNICriticalArray() {
release();
}
/**
* Manual release of the acquired primitive array,
* usually one likes to simply do this via the destructor, RAII style.
*/
void release() {
if( nullptr != narray ) {
env->ReleasePrimitiveArrayCritical(jarray, narray, mode);
this->jarray = nullptr;
this->narray = nullptr;
this->env = nullptr;
}
}
/**
* Acquired the primitive array.
*/
T* get(U jarray, Mode mode=UPDATE_AND_RELEASE) {
if( nullptr == jarray ) {
return nullptr;
}
T* narray = static_cast<T*>( env->GetPrimitiveArrayCritical(jarray, &isCopy) );
if( nullptr != narray ) {
this->mode = mode;
this->jarray = jarray;
this->narray = narray;
return narray;
}
return nullptr;
}
/**
* Returns true if the primitive array had been acquired
* and the JVM utilizes a copy of the underlying java array.
*/
bool getIsCopy() const { return isCopy; }
};
#endif /* JAU_JNIMEM__HPP_ */
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