osmemoryinfo.c

来自「《透视Java》的源码」· C语言 代码 · 共 80 行

/*
 * Implementation of native methods that access OS thru Win32 API
 */

#include <windows.h>
#include "covertjava_nativecode_OSMemoryInfo.h"

JNIEXPORT jlong JNICALL Java_covertjava_nativecode_OSMemoryInfo_getPhysicalTotal
    (JNIEnv *env, jclass cls)
{
    MEMORYSTATUSEX memStat;
    memStat.dwLength = sizeof (memStat);
    if (GlobalMemoryStatusEx(&memStat) == 0 && (*env) != 0) {
        jclass exceptionCls = (*env)->FindClass(env, "java/lang/Exception");
        char msg[100];
        sprintf(msg, "Failed to get memory information from the OS, error code %li", 
            (long)GetLastError());
        if (exceptionCls != 0)  /* Raise Java exception */
            (*env)->ThrowNew(env, exceptionCls, msg);
        return -1;
    }
    return (jlong) (int) memStat.ullTotalPhys;
}


JNIEXPORT jlong JNICALL Java_covertjava_nativecode_OSMemoryInfo_getPhysicalAvail
    (JNIEnv *env, jclass cls)
{
    MEMORYSTATUSEX memStat;
    memStat.dwLength = sizeof (memStat);
    if (GlobalMemoryStatusEx(&memStat) == 0 && (*env) != 0) {
        jclass exceptionCls = (*env)->FindClass(env, "java/lang/Exception");
        char msg[100];
        sprintf(msg, "Failed to get memory information from the OS, error code %li", 
            (long)GetLastError());
        if (exceptionCls != 0)  /* Raise Java exception */
            (*env)->ThrowNew(env, exceptionCls, msg);
        return -1;
    }
    return (jlong) (int) memStat.ullAvailPhys;
}


JNIEXPORT jlong JNICALL Java_covertjava_nativecode_OSMemoryInfo_getVirtualTotal
    (JNIEnv *env, jclass cls)
{
    MEMORYSTATUSEX memStat;
    memStat.dwLength = sizeof (memStat);
    if (GlobalMemoryStatusEx(&memStat) == 0 && (*env) != 0) {
        jclass exceptionCls = (*env)->FindClass(env, "java/lang/Exception");
        char msg[100];
        sprintf(msg, "Failed to get memory information from the OS, error code %li", 
            (long)GetLastError());
        if (exceptionCls != 0)  /* Raise Java exception */
            (*env)->ThrowNew(env, exceptionCls, msg);
        return -1;
    }
    return (jlong) (int) memStat.ullTotalVirtual;
}


JNIEXPORT jlong JNICALL Java_covertjava_nativecode_OSMemoryInfo_getVirtualAvail
    (JNIEnv *env, jclass cls)
{
    MEMORYSTATUSEX memStat;
    memStat.dwLength = sizeof (memStat);
    if (GlobalMemoryStatusEx(&memStat) == 0 && (*env) != 0) {
        jclass exceptionCls = (*env)->FindClass(env, "java/lang/Exception");
        char msg[100];
        sprintf(msg, "Failed to get memory information from the OS, error code %li", 
            (long)GetLastError());
        if (exceptionCls != 0)  /* Raise Java exception */
            (*env)->ThrowNew(env, exceptionCls, msg);
        return -1;
    }
    return (jlong) (int) memStat.ullAvailVirtual;
}