blob: dde713728bdf665753e6e360de6f221e12c57635 [file] [log] [blame]
/*
* libjingle
* Copyright 2015 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHOR 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.
*
*/
// This file contain convenience functions and classes for JNI.
// Before using any of the methods, InitGlobalJniVariables must be called.
#ifndef TALK_APP_WEBRTC_JAVA_JNI_JNI_HELPERS_H_
#define TALK_APP_WEBRTC_JAVA_JNI_JNI_HELPERS_H_
#include <jni.h>
#include <string>
#include "webrtc/base/checks.h"
// Abort the process if |jni| has a Java exception pending.
// This macros uses the comma operator to execute ExceptionDescribe
// and ExceptionClear ignoring their return values and sending ""
// to the error stream.
#define CHECK_EXCEPTION(jni) \
CHECK(!jni->ExceptionCheck()) \
<< (jni->ExceptionDescribe(), jni->ExceptionClear(), "")
// Helper that calls ptr->Release() and aborts the process with a useful
// message if that didn't actually delete *ptr because of extra refcounts.
#define CHECK_RELEASE(ptr) \
CHECK_EQ(0, (ptr)->Release()) << "Unexpected refcount."
namespace webrtc_jni {
jint InitGlobalJniVariables(JavaVM *jvm);
// Return a |JNIEnv*| usable on this thread or NULL if this thread is detached.
JNIEnv* GetEnv();
JavaVM *GetJVM();
// Return a |JNIEnv*| usable on this thread. Attaches to |g_jvm| if necessary.
JNIEnv* AttachCurrentThreadIfNeeded();
// Return a |jlong| that will correctly convert back to |ptr|. This is needed
// because the alternative (of silently passing a 32-bit pointer to a vararg
// function expecting a 64-bit param) picks up garbage in the high 32 bits.
jlong jlongFromPointer(void* ptr);
// JNIEnv-helper methods that CHECK success: no Java exception thrown and found
// object/class/method/field is non-null.
jmethodID GetMethodID(
JNIEnv* jni, jclass c, const std::string& name, const char* signature);
jmethodID GetStaticMethodID(
JNIEnv* jni, jclass c, const char* name, const char* signature);
jfieldID GetFieldID(JNIEnv* jni, jclass c, const char* name,
const char* signature);
jclass GetObjectClass(JNIEnv* jni, jobject object);
jobject GetObjectField(JNIEnv* jni, jobject object, jfieldID id);
jstring GetStringField(JNIEnv* jni, jobject object, jfieldID id);
jlong GetLongField(JNIEnv* jni, jobject object, jfieldID id);
jint GetIntField(JNIEnv* jni, jobject object, jfieldID id);
bool GetBooleanField(JNIEnv* jni, jobject object, jfieldID id);
// Java references to "null" can only be distinguished as such in C++ by
// creating a local reference, so this helper wraps that logic.
bool IsNull(JNIEnv* jni, jobject obj);
// Given a UTF-8 encoded |native| string return a new (UTF-16) jstring.
jstring JavaStringFromStdString(JNIEnv* jni, const std::string& native);
// Given a (UTF-16) jstring return a new UTF-8 native string.
std::string JavaToStdString(JNIEnv* jni, const jstring& j_string);
// Return the (singleton) Java Enum object corresponding to |index|;
jobject JavaEnumFromIndex(JNIEnv* jni, jclass state_class,
const std::string& state_class_name, int index);
jobject NewGlobalRef(JNIEnv* jni, jobject o);
void DeleteGlobalRef(JNIEnv* jni, jobject o);
// Scope Java local references to the lifetime of this object. Use in all C++
// callbacks (i.e. entry points that don't originate in a Java callstack
// through a "native" method call).
class ScopedLocalRefFrame {
public:
explicit ScopedLocalRefFrame(JNIEnv* jni);
~ScopedLocalRefFrame();
private:
JNIEnv* jni_;
};
// Scoped holder for global Java refs.
template<class T> // T is jclass, jobject, jintArray, etc.
class ScopedGlobalRef {
public:
ScopedGlobalRef(JNIEnv* jni, T obj)
: obj_(static_cast<T>(jni->NewGlobalRef(obj))) {}
~ScopedGlobalRef() {
DeleteGlobalRef(AttachCurrentThreadIfNeeded(), obj_);
}
T operator*() const {
return obj_;
}
private:
T obj_;
};
} // namespace webrtc_jni
#endif // TALK_APP_WEBRTC_JAVA_JNI_JNI_HELPERS_H_