poold/libjkstat/jkstat.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <stddef.h>
#include <kstat.h>

#include "jkstat.h"

/*
 * Class descriptors
 */
#define DOUBLE_CLASS_DESC   "java/lang/Double"
#define LONG_CLASS_DESC     "java/lang/Long"
#define UI64_CLASS_DESC     "com/sun/solaris/service/pools/UnsignedInt64"
#define HRTIME_CLASS_DESC   "com/sun/solaris/service/pools/HRTime"
#define KSTAT_CLASS_DESC    "com/sun/solaris/service/kstat/Kstat"
#define KSTATCTL_CLASS_DESC "com/sun/solaris/service/kstat/KstatCtl"
#define KSTAT_READ_EX_CLASS_DESC \
    "com/sun/solaris/service/kstat/KstatReadException"
#define KSTAT_TNS_EX_CLASS_DESC \
    "com/sun/solaris/service/kstat/KstatTypeNotSupportedException"
#define THROWABLE_CLASS_DESC    "java/lang/Throwable"

#define CLASS_FIELD_DESC(class_desc)    "L" class_desc ";"

/*
 * Cached class, method, and field IDs.
 */
static jclass doubleclass;
static jclass hrtimeclass;
static jclass kstatclass;
static jclass kstatctlclass;
static jclass longclass;
static jclass ui64class;
static jfieldID kstat_kctl_fieldid;
static jfieldID kstat_ksp_fieldid;
static jfieldID kstatctl_kctl_fieldid;
static jmethodID doublecons_mid;
static jmethodID hrtimecons_mid;
static jmethodID kstatcons_mid;
static jmethodID longcons_mid;
static jmethodID ui64cons_mid;

static jobject
makeUnsignedInt64(JNIEnv *env, uint64_t value)
{
    jobject valueObj;
    jobject byteArray;
    jbyte *bytes;
    int i;

    if (!(byteArray = (*env)->NewByteArray(env, 9)))
        return (NULL); /* OutOfMemoryError thrown */
    if (!(bytes = (*env)->GetByteArrayElements(env, byteArray, NULL)))
        return (NULL); /* OutOfMemoryError thrown */

    /*
     * Interpret the uint64_t as a 9-byte big-endian signed quantity
     * suitable for constructing an UnsignedInt64 or BigInteger.
     */
    for (i = 8; i >= 1; i--) {
        bytes[i] = value & 0xff;
        value >>= 8;
    }
    bytes[0] = 0;
    (*env)->ReleaseByteArrayElements(env, byteArray, bytes, 0);

    if (!(valueObj = (*env)->NewObject(env, ui64class, ui64cons_mid,
        byteArray)))
        return (NULL); /* exception thrown */

    return (valueObj);
}

/*
 * Return a Long object with the given value.
 */
static jobject
makeLong(JNIEnv *env, jlong value)
{
    jobject valueObj;

    if (!(valueObj = (*env)->NewObject(env, longclass, longcons_mid,
        value)))
        return (NULL); /* exception thrown */

    return (valueObj);
}

/*
 * Return a Double object with the given value.
 */
static jobject
makeDouble(JNIEnv *env, jdouble value)
{
    jobject valueObj;

    if (!(valueObj = (*env)->NewObject(env, doubleclass, doublecons_mid,
        value)))
        return (NULL); /* exception thrown */

    return (valueObj);
}

/*
 * Returns the kctl_t * from kstat_open(3kstat).
 */
/*ARGSUSED*/
JNIEXPORT jlong JNICALL
Java_com_sun_solaris_service_kstat_KstatCtl_open(JNIEnv *env, jobject obj)
{
    return ((jlong)(uintptr_t)kstat_open());
}

/*
 * Invokes kstat_close(3kstat).
 */
/*ARGSUSED*/
JNIEXPORT jint JNICALL
Java_com_sun_solaris_service_kstat_KstatCtl_close(JNIEnv *env, jobject obj,
    jlong kctl)
{
    if (kctl)
        return (kstat_close((kstat_ctl_t *)(uintptr_t)kctl));
    else
        return (0);
}

/*
 * Invoke kstat_read(3kstat) for the given Kstat object.
 */
JNIEXPORT void JNICALL Java_com_sun_solaris_service_kstat_Kstat_read(
    JNIEnv *env, jobject obj)
{
    kstat_ctl_t *kctl =
        ((kstat_ctl_t *)(uintptr_t)(*env)->GetLongField(env, obj,
        kstat_kctl_fieldid));
    kstat_t *ksp = ((kstat_t *)(uintptr_t)(*env)->GetLongField(env, obj,
        kstat_ksp_fieldid));
    kid_t kid;

    if (!ksp || !kctl)
        return; /* exception thronw */

    kid = kstat_read((kstat_ctl_t *)kctl, (kstat_t *)ksp, NULL);
    if (kid == -1) {
        jclass e;
        if (!(e = (*env)->FindClass(env, KSTAT_READ_EX_CLASS_DESC)))
            return; /* exception thrown */

        (*env)->Throw(env, (*env)->NewObject(env, e,
            (*env)->GetStaticMethodID(env, e, "<init>",
            "()" CLASS_FIELD_DESC(THROWABLE_CLASS_DESC))));
    }
}

/*
 * Return a Kstat object corresponding to the result of
 * kstat_lookup(3kstat).
 */
JNIEXPORT jobject JNICALL
Java_com_sun_solaris_service_kstat_KstatCtl_lookup(JNIEnv *env, jobject obj,
    jstring moduleObj, jint instance, jstring nameObj)
{
    const char *module = NULL;
    const char *name = NULL;
    kstat_ctl_t *kctl;
    kstat_t *ksp;
    jobject kstatObject = NULL;

    if (moduleObj == NULL || nameObj == NULL)
        return (NULL);

    if (!(module = (*env)->GetStringUTFChars(env, moduleObj, NULL)))
        goto done; /* exception thrown */
    if (!(name = (*env)->GetStringUTFChars(env, nameObj, NULL)))
        goto done; /* exception thrown */

    kctl = (kstat_ctl_t *)(uintptr_t)(*env)->GetLongField(env, obj,
        kstatctl_kctl_fieldid);
    ksp = kstat_lookup(kctl, (char *)module, instance, (char *)name);
    if (ksp)
        kstatObject = (*env)->NewObject(env, kstatclass, kstatcons_mid,
            (jlong)(uintptr_t)kctl, (jlong)(uintptr_t)ksp);

done:
    if (name)
        (*env)->ReleaseStringUTFChars(env, nameObj, name);
    if (module)
        (*env)->ReleaseStringUTFChars(env, moduleObj, module);

    return (kstatObject);
}

/*
 * Returns the named value -- the value of the named kstat, or field in
 * a raw kstat, as applicable, and available.  Returns <i>null</i> if no
 * such named kstat or field is available.
 *
 * Throws KstatTypeNotSupportedException if the raw kstat is not
 * understood.  (Presently, none are.)
 */
JNIEXPORT jobject JNICALL
Java_com_sun_solaris_service_kstat_Kstat_getValue(JNIEnv *env, jobject obj,
    jstring nameObj)
{
    kstat_t *ksp = ((kstat_t *)(uintptr_t)(*env)->GetLongField(env, obj,
        kstat_ksp_fieldid));
    jobject valueObj = NULL;
    kstat_named_t *ksnp;
    const char *name;
    jclass exceptionClass;

    if (!nameObj)
        return (NULL);

    if (!(name = (*env)->GetStringUTFChars(env, nameObj, NULL)))
        return (NULL); /* exception thrown */

    if (!(exceptionClass = (*env)->FindClass(env,
        KSTAT_TNS_EX_CLASS_DESC))) {
        (*env)->ReleaseStringUTFChars(env, nameObj, name);
        return (NULL); /* exception thrown */
    }

    switch (ksp->ks_type) {
    case KSTAT_TYPE_NAMED:
        ksnp = kstat_data_lookup(ksp, (char *)name);
        if (ksnp == NULL)
            break;
        switch (ksnp->data_type) {
        case KSTAT_DATA_CHAR:
            valueObj = makeLong(env, ksnp->value.c[0]);
            break;
        case KSTAT_DATA_INT32:
            valueObj = makeLong(env, ksnp->value.i32);
            break;
        case KSTAT_DATA_UINT32:
            valueObj = makeLong(env, ksnp->value.ui32);
            break;
        case KSTAT_DATA_INT64:
            valueObj = makeLong(env, ksnp->value.i64);
            break;
        case KSTAT_DATA_UINT64:
            valueObj = makeUnsignedInt64(env, ksnp->value.ui64);
            break;
        case KSTAT_DATA_STRING:
            valueObj = (*env)->NewStringUTF(env,
                KSTAT_NAMED_STR_PTR(ksnp));
            break;
        case KSTAT_DATA_FLOAT:
            valueObj = makeDouble(env, ksnp->value.f);
            break;
        case KSTAT_DATA_DOUBLE:
            valueObj = makeDouble(env, ksnp->value.d);
            break;
        default:
            goto fail;
        }
        break;
    default:
        goto fail;
    }

    (*env)->ReleaseStringUTFChars(env, nameObj, name);
    return (valueObj);

fail:
    (*env)->ReleaseStringUTFChars(env, nameObj, name);
    (*env)->Throw(env, (*env)->NewObject(env, exceptionClass,
        (*env)->GetStaticMethodID(env, exceptionClass, "<init>",
        "()" CLASS_FIELD_DESC(THROWABLE_CLASS_DESC))));

    return (valueObj);
}

/*
 * Given a Kstat object, return, as an HRTime object, its kstat_t's
 * field at the given offset.
 */
static jobject
ksobj_get_hrtime(JNIEnv *env, jobject obj, offset_t ksfieldoff)
{
    kstat_t *ksp = ((kstat_t *)(uintptr_t)(*env)->GetLongField(env, obj,
        kstat_ksp_fieldid));

    if (!ksp)
        return (NULL); /* exception thrown */

    return ((*env)->NewObject(env, hrtimeclass, hrtimecons_mid,
        makeUnsignedInt64(env, *((hrtime_t *)ksp + ksfieldoff *
        sizeof (hrtime_t)))));
}

/*
 * Given a Kstat object, return as an HRTime object its ks_snaptime
 * field.
 */
JNIEXPORT jobject JNICALL
Java_com_sun_solaris_service_kstat_Kstat_getSnapTime(JNIEnv *env, jobject obj)
{
    return (ksobj_get_hrtime(env, obj, offsetof(kstat_t, ks_snaptime)));
}

/*
 * Given a Kstat object, return as an HRTime object its ks_crtime
 * field.
 */
JNIEXPORT jobject JNICALL
Java_com_sun_solaris_service_kstat_Kstat_getCreationTime(JNIEnv *env,
    jobject obj)
{
    return (ksobj_get_hrtime(env, obj, offsetof(kstat_t, ks_crtime)));
}

/*
 * Invoke kstat_chain_update(3kstat) for the kstat chain corresponding
 * to the given KstatCtl object.
 */
JNIEXPORT void JNICALL
Java_com_sun_solaris_service_kstat_KstatCtl_chainUpdate(JNIEnv *env,
    jobject obj)
{
    kstat_ctl_t *kctl;

    kctl = (kstat_ctl_t *)(uintptr_t)(*env)->GetLongField(env, obj,
        kstatctl_kctl_fieldid);

    (void) kstat_chain_update(kctl);
}

/*
 * Cache class, method, and field IDs.
 */
/*ARGSUSED*/
JNIEXPORT void JNICALL
Java_com_sun_solaris_service_kstat_KstatCtl_init(JNIEnv *env, jclass clazz)
{
    jclass doubleclass_lref;
    jclass hrtimeclass_lref;
    jclass kstatclass_lref;
    jclass kstatctlclass_lref;
    jclass longclass_lref;
    jclass ui64class_lref;

    if (!(doubleclass_lref = (*env)->FindClass(env, DOUBLE_CLASS_DESC)))
        return; /* exception thrown */
    if (!(doubleclass = (*env)->NewGlobalRef(env, doubleclass_lref)))
        return; /* exception thrown */
    if (!(doublecons_mid = (*env)->GetMethodID(env, doubleclass, "<init>",
        "(D)V")))
        return; /* exception thrown */

    if (!(hrtimeclass_lref = (*env)->FindClass(env, HRTIME_CLASS_DESC)))
        return; /* exception thrown */
    if (!(hrtimeclass = (*env)->NewGlobalRef(env, hrtimeclass_lref)))
        return; /* exception thrown */
    if (!(hrtimecons_mid = (*env)->GetMethodID(env, hrtimeclass, "<init>",
        "(" CLASS_FIELD_DESC(UI64_CLASS_DESC) ")V")))
        return; /* exception thrown */

    if (!(kstatclass_lref = (*env)->FindClass(env, KSTAT_CLASS_DESC)))
        return; /* exception thrown */
    if (!(kstatclass = (*env)->NewGlobalRef(env, kstatclass_lref)))
        return; /* exception thrown */
    if (!(kstatcons_mid = (*env)->GetMethodID(env, kstatclass, "<init>",
        "(JJ)V")))
        return; /* exception thrown */
    if (!(kstat_kctl_fieldid = (*env)->GetFieldID(env, kstatclass, "kctl",
        "J")))
        return; /* exception thrown */
    if (!(kstat_ksp_fieldid = (*env)->GetFieldID(env, kstatclass, "ksp",
        "J")))
        return; /* exception thrown */

    if (!(kstatctlclass_lref = (*env)->FindClass(env, KSTATCTL_CLASS_DESC)))
        return; /* exception thrown */
    if (!(kstatctlclass = (*env)->NewGlobalRef(env, kstatctlclass_lref)))
        return; /* exception thrown */
    if (!(kstatctl_kctl_fieldid = (*env)->GetFieldID(env, kstatctlclass,
        "kctl", "J")))
        return; /* exception thrown */

    if (!(longclass_lref = (*env)->FindClass(env, LONG_CLASS_DESC)))
        return; /* exception thrown */
    if (!(longclass = (*env)->NewGlobalRef(env, longclass_lref)))
        return; /* exception thrown */
    if (!(longcons_mid = (*env)->GetMethodID(env, longclass, "<init>",
        "(J)V")))
        return; /* exception thrown */

    if (!(ui64class_lref = (*env)->FindClass(env, UI64_CLASS_DESC)))
        return; /* exception thrown */
    if (!(ui64class = (*env)->NewGlobalRef(env, ui64class_lref)))
        return; /* exception thrown */
    ui64cons_mid = (*env)->GetMethodID(env, ui64class, "<init>", "([B)V");
}