JniEnvAutoRef Class Reference

An implementation of JniEnvRef which can be used in contexts where no JNIEnv is available yet. More...

#include <JniUtil.h>

Inheritance diagram for JniEnvAutoRef:

List of all members.

Public Member Functions
	JniEnvAutoRef ()
	Uses GetEnv to access current thread's JNIEnv pointer.
void	suppressDetach ()
	Suppresses default detach-on-destruct behavior.
	~JniEnvAutoRef ()
JniExceptionChecker	operator-> () const
JNIEnv *	get ()
void	handleExcn (std::exception &ex)
Private Attributes
bool	needDetach

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Detailed Description

An implementation of JniEnvRef which can be used in contexts where no JNIEnv is available yet.

When an environment is already available, it is used automatically, but when unavailable, this class takes care of attaching the thread (in the constructor) and detaching it (in the destructor). For threads created within Fennel, attach/detach can be optimized by allocating a JniEnvAutoRef on a thread's initial stack frame so that it will be available to all methods called.

Definition at line 113 of file JniUtil.h.

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Constructor & Destructor Documentation

JniEnvAutoRef::JniEnvAutoRef

(

)

[explicit]

Uses GetEnv to access current thread's JNIEnv pointer.

Definition at line 523 of file JniUtil.cpp.

    : JniEnvRef(JniUtil::getAttachedJavaEnv(needDetach))
{
}

JniEnvAutoRef::~JniEnvAutoRef

(

)

Definition at line 528 of file JniUtil.cpp.

References JniUtil::detachJavaEnv(), and needDetach.

{
    if (needDetach) {
        JniUtil::detachJavaEnv();
    }
}

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Member Function Documentation

void JniEnvAutoRef::suppressDetach

(

)

Suppresses default detach-on-destruct behavior.

REVIEW jvs 13-Oct-2006: Get rid of this and arrange for all native-spawned threads to attach on start and detach on end.

Definition at line 535 of file JniUtil.cpp.

References needDetach.

Referenced by JavaTraceTarget::onThreadStart(), and JavaThreadTracker::onThreadStart().

{
    needDetach = false;
}

JniExceptionChecker JniEnvRef::operator->

(

)

const [inline, inherited]

Definition at line 91 of file JniUtil.h.

    {
        return JniExceptionChecker(pEnv);
    }

JNIEnv* JniEnvRef::get

(

)

[inline, inherited]

Definition at line 96 of file JniUtil.h.

Referenced by JniLocalRefReaper::JniLocalRefReaper().

    {
        return pEnv;
    }

void JniEnvRef::handleExcn

(

std::exception &

ex

)

[inherited]

Definition at line 540 of file JniUtil.cpp.

References JavaExcn::getJavaException(), FennelExcn::getMessage(), and JniEnvRef::pEnv.

Referenced by Java_com_lucidera_farrago_fennel_LucidEraJni_registerStreamFactory(), Java_net_sf_farrago_fennel_FennelStorage_executeJavaCmd(), Java_net_sf_farrago_fennel_FennelStorage_tupleStreamFetch(), Java_net_sf_farrago_fennel_FennelStorage_tupleStreamGraphClose(), Java_net_sf_farrago_fennel_FennelStorage_tupleStreamGraphGetInputStreams(), Java_net_sf_farrago_fennel_FennelStorage_tupleStreamGraphOpen(), Java_net_sf_farrago_fennel_FennelStorage_tupleStreamRestart(), Java_net_sf_farrago_fennel_FennelStorage_tupleStreamTransformFetch(), and JNI_OnLoad().

{
    JavaExcn *pJavaExcn = dynamic_cast<JavaExcn *>(&ex);
    if (pJavaExcn) {
        pEnv->Throw(pJavaExcn->getJavaException());
        return;
    }
    std::string what;
    FennelExcn *pFennelExcn = dynamic_cast<FennelExcn *>(&ex);
    if (pFennelExcn) {
        what = pFennelExcn->getMessage();
    } else {
        std::bad_alloc *pBadAllocExcn =
            dynamic_cast<std::bad_alloc *>(&ex);
        if (pBadAllocExcn) {
            // Convert bad_alloc's terrible error mesage into something fit for
            // human consumption.
            what = FennelResource::instance().internalError("malloc failed");
        } else {
            what = FennelResource::instance().internalError(ex.what());
        }
    }
    // TODO:  need special-case handling for out-of-memory here
    jclass classSQLException = pEnv->FindClass("java/sql/SQLException");
    jstring jMessage = pEnv->NewStringUTF(what.c_str());
    jmethodID constructor = pEnv->GetMethodID(
        classSQLException,"<init>","(Ljava/lang/String;)V");
    jthrowable t = (jthrowable)
        pEnv->NewObject(classSQLException,constructor,jMessage);
    pEnv->Throw(t);
}

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Member Data Documentation

bool JniEnvAutoRef::needDetach [private]

Definition at line 116 of file JniUtil.h.

Referenced by suppressDetach(), and ~JniEnvAutoRef().

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The documentation for this class was generated from the following files:

• /home/pub/open/dev/fennel/farrago/JniUtil.h
• /home/pub/open/dev/fennel/farrago/JniUtil.cpp

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