[lttng-dev] [LTTng-UST PATCH] Make the JNI interface actually work

Mathieu Desnoyers mathieu.desnoyers at efficios.com
Thu Apr 5 17:19:17 EDT 2012


* Alexandre Montplaisir (alexandre.montplaisir at polymtl.ca) wrote:
> Now a user can import LTTngUst.java (which is now in a proper
> package) and then define tracepoints in his application with:
> 
> LTTngUst.tracepointString(name, args);
> 
> We could eventually ship it in a .jar when the JNI interface is
> enabled. It's still very basic, only string payloads are
> implemented, and there is no mechanism to enable/disable trace
> points at runtime.

merged, thanks!

added to the stable-2.0 branch too.

Mathieu

> 
> Signed-off-by: Alexandre Montplaisir <alexandre.montplaisir at polymtl.ca>
> ---
>  liblttng-ust-java/.gitignore     |    4 +-
>  liblttng-ust-java/LTTNG_UST.c    |   36 -----------------------------------
>  liblttng-ust-java/LTTNG_UST.java |   25 ------------------------
>  liblttng-ust-java/LTTngUst.c     |   39 ++++++++++++++++++++++++++++++++++++++
>  liblttng-ust-java/LTTngUst.java  |   27 ++++++++++++++++++++++++++
>  liblttng-ust-java/Makefile.am    |   17 ++++++++-------
>  6 files changed, 77 insertions(+), 71 deletions(-)
>  delete mode 100644 liblttng-ust-java/LTTNG_UST.c
>  delete mode 100644 liblttng-ust-java/LTTNG_UST.java
>  create mode 100644 liblttng-ust-java/LTTngUst.c
>  create mode 100644 liblttng-ust-java/LTTngUst.java
> 
> diff --git a/liblttng-ust-java/.gitignore b/liblttng-ust-java/.gitignore
> index ab97d04..677373e 100644
> --- a/liblttng-ust-java/.gitignore
> +++ b/liblttng-ust-java/.gitignore
> @@ -1,2 +1,2 @@
> -UST.class
> -UST.h
> +org_lttng_ust_LTTngUst.h
> +org/
> diff --git a/liblttng-ust-java/LTTNG_UST.c b/liblttng-ust-java/LTTNG_UST.c
> deleted file mode 100644
> index af29c1e..0000000
> --- a/liblttng-ust-java/LTTNG_UST.c
> +++ /dev/null
> @@ -1,36 +0,0 @@
> -/*
> - * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
> - *
> - * This library is free software; you can redistribute it and/or
> - * modify it under the terms of the GNU Lesser General Public
> - * License as published by the Free Software Foundation; only
> - * version 2.1 of the License.
> - *
> - * This library is distributed in the hope that it will be useful,
> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> - * Lesser General Public License for more details.
> - *
> - * You should have received a copy of the GNU Lesser General Public
> - * License along with this library; if not, write to the Free Software
> - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> - */
> -
> -#include <jni.h>
> -
> -#define TRACEPOINT_DEFINE
> -#define TRACEPOINT_CREATE_PROBES
> -#include "lttng_ust_java.h"
> -
> -JNIEXPORT void JNICALL Java_LTTNG_UST_ust_1java_1event (JNIEnv *env,
> -						jobject jobj,
> -						jstring ev_name,
> -						jstring args)
> -{
> -	jboolean iscopy;
> -	const char *ev_name_cstr = (*env)->GetStringUTFChars(env, ev_name,
> -							&iscopy);
> -	const char *args_cstr = (*env)->GetStringUTFChars(env, args, &iscopy);
> -
> -	tracepoint(lttng_ust_java, string, ev_name_cstr, args_cstr);
> -}
> diff --git a/liblttng-ust-java/LTTNG_UST.java b/liblttng-ust-java/LTTNG_UST.java
> deleted file mode 100644
> index 7ec6110..0000000
> --- a/liblttng-ust-java/LTTNG_UST.java
> +++ /dev/null
> @@ -1,25 +0,0 @@
> -/*
> - * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
> - *
> - * This library is free software; you can redistribute it and/or
> - * modify it under the terms of the GNU Lesser General Public
> - * License as published by the Free Software Foundation; only
> - * version 2.1 of the License.
> - *
> - * This library is distributed in the hope that it will be useful,
> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> - * Lesser General Public License for more details.
> - *
> - * You should have received a copy of the GNU Lesser General Public
> - * License along with this library; if not, write to the Free Software
> - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> - */
> -
> -class LTTNG_UST {
> -	public static native void lttng_ust_java_string(String name, String arg);
> -	static {
> -		System.loadLibrary("lttng-ust-java");
> -	}
> -}
> -
> diff --git a/liblttng-ust-java/LTTngUst.c b/liblttng-ust-java/LTTngUst.c
> new file mode 100644
> index 0000000..3d23d6a
> --- /dev/null
> +++ b/liblttng-ust-java/LTTngUst.c
> @@ -0,0 +1,39 @@
> +/*
> + * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; only
> + * version 2.1 of the License.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#include <jni.h>
> +
> +#define TRACEPOINT_DEFINE
> +#define TRACEPOINT_CREATE_PROBES
> +#include "lttng_ust_java.h"
> +
> +JNIEXPORT void JNICALL Java_org_lttng_ust_LTTngUst_tracepointString(JNIEnv *env,
> +						jobject jobj,
> +						jstring ev_name,
> +						jstring args)
> +{
> +	jboolean iscopy;
> +	const char *ev_name_cstr = (*env)->GetStringUTFChars(env, ev_name,
> +							&iscopy);
> +	const char *args_cstr = (*env)->GetStringUTFChars(env, args, &iscopy);
> +
> +	tracepoint(lttng_ust_java, string, ev_name_cstr, args_cstr);
> +
> +	(*env)->ReleaseStringUTFChars(env, ev_name, ev_name_cstr);
> +	(*env)->ReleaseStringUTFChars(env, args, args_cstr);
> +}
> diff --git a/liblttng-ust-java/LTTngUst.java b/liblttng-ust-java/LTTngUst.java
> new file mode 100644
> index 0000000..d3f1eda
> --- /dev/null
> +++ b/liblttng-ust-java/LTTngUst.java
> @@ -0,0 +1,27 @@
> +/*
> + * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; only
> + * version 2.1 of the License.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +package org.lttng.ust;
> +
> +class LTTngUst {
> +	public static native void tracepointString(String name, String arg);
> +	static {
> +		System.loadLibrary("lttng-ust-java");
> +	}
> +}
> +
> diff --git a/liblttng-ust-java/Makefile.am b/liblttng-ust-java/Makefile.am
> index 31915d0..9e01e04 100644
> --- a/liblttng-ust-java/Makefile.am
> +++ b/liblttng-ust-java/Makefile.am
> @@ -3,19 +3,20 @@ if BUILD_JNI_INTERFACE
>  AM_CPPFLAGS = -I$(top_srcdir)/include
>  
>  lib_LTLIBRARIES = liblttng-ust-java.la
> -liblttng_ust_java_la_SOURCES = LTTNG_UST.c LTTNG_UST.h lttng_ust_java.h
> -dist_noinst_DATA = LTTNG_UST.java
> +liblttng_ust_java_la_SOURCES = LTTngUst.c org_lttng_ust_LTTngUst.h lttng_ust_java.h
> +dist_noinst_DATA = LTTngUst.java
>  liblttng_ust_java_la_LIBADD = -lc -L$(top_builddir)/liblttng-ust/.libs -llttng-ust
>  
> -all: LTTNG_UST.class LTTNG_UST.h
> +all: LTTngUst.class org_lttng_ust_LTTngUst.h
>  
>  clean-local:
> -	rm -rf LTTNG_UST.h LTTNG_UST.class
> +	rm  org_lttng_ust_LTTngUst.h
> +	rm -rf org/
>  
> -LTTNG_UST.class: LTTNG_UST.java
> -	javac -d "$(builddir)" "$(srcdir)/LTTNG_UST.java"
> +LTTngUst.class: LTTngUst.java
> +	javac -d "$(builddir)" "$(srcdir)/LTTngUst.java"
>  
> -LTTNG_UST.h: LTTNG_UST.class
> -	javah -classpath ./ -jni LTTNG_UST
> +org_lttng_ust_LTTngUst.h: LTTngUst.class
> +	javah org.lttng.ust.LTTngUst
>  
>  endif
> -- 
> 1.7.9.1
> 
> 
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-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com



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