Merge

make/java/management/Makefile

@@ -63,6 +63,20 @@ else # PLATFORM (i.e. solaris & linux)
 FILES_c     +=  UnixOperatingSystem_md.c
 
 FILES_export +=	com/sun/management/UnixOperatingSystem.java
+
+ifeq ($(PLATFORM),solaris)
+
+FILES_c     += SolarisOperatingSystem.c
+OTHER_LDLIBS += -lkstat
+
+endif # PLATFORM solaris
+
+ifeq ($(PLATFORM),linux)
+
+FILES_c     += LinuxOperatingSystem.c
+
+endif # PLATFORM linux
+
 endif # PLATFORM
 
 #

make/java/management/mapfile-vers

@@ -32,7 +32,9 @@ SUNWprivate_1.1 {
 	    Java_com_sun_management_UnixOperatingSystem_getFreeSwapSpaceSize;
 	    Java_com_sun_management_UnixOperatingSystem_getMaxFileDescriptorCount;
 	    Java_com_sun_management_UnixOperatingSystem_getOpenFileDescriptorCount;
+	    Java_com_sun_management_UnixOperatingSystem_getProcessCpuLoad;
 	    Java_com_sun_management_UnixOperatingSystem_getProcessCpuTime;
+	    Java_com_sun_management_UnixOperatingSystem_getSystemCpuLoad;
 	    Java_com_sun_management_UnixOperatingSystem_getTotalPhysicalMemorySize;
 	    Java_com_sun_management_UnixOperatingSystem_getTotalSwapSpaceSize;
 	    Java_com_sun_management_UnixOperatingSystem_initialize;

src/share/classes/com/sun/management/OperatingSystemMXBean.java

@@ -92,4 +92,39 @@ public interface OperatingSystemMXBean extends
      * @return the total amount of physical memory in  bytes.
      */
     public long getTotalPhysicalMemorySize();
+
+    /**
+     * Returns the "recent cpu usage" for the whole system. This value is a
+     * double in the [0.0,1.0] interval. A value of 0.0 means that all CPUs
+     * were idle during the recent period of time observed, while a value
+     * of 1.0 means that all CPUs were actively running 100% of the time
+     * during the recent period being observed. All values betweens 0.0 and
+     * 1.0 are possible depending of the activities going on in the system.
+     * If the system recent cpu usage is not available, the method returns a
+     * negative value.
+     *
+     * @return the "recent cpu usage" for the whole system; a negative
+     * value if not available.
+     * @since   1.7
+     */
+    public double getSystemCpuLoad();
+
+    /**
+     * Returns the "recent cpu usage" for the Java Virtual Machine process.
+     * This value is a double in the [0.0,1.0] interval. A value of 0.0 means
+     * that none of the CPUs were running threads from the JVM process during
+     * the recent period of time observed, while a value of 1.0 means that all
+     * CPUs were actively running threads from the JVM 100% of the time
+     * during the recent period being observed. Threads from the JVM include
+     * the application threads as well as the JVM internal threads. All values
+     * betweens 0.0 and 1.0 are possible depending of the activities going on
+     * in the JVM process and the whole system. If the Java Virtual Machine
+     * recent CPU usage is not available, the method returns a negative value.
+     *
+     * @return the "recent cpu usage" for the Java Virtual Machine process;
+     * a negative value if not available.
+     * @since   1.7
+     */
+    public double getProcessCpuLoad();
+
 }

src/solaris/classes/com/sun/management/UnixOperatingSystem.java

@@ -50,6 +50,8 @@ class UnixOperatingSystem
     public native long getTotalPhysicalMemorySize();
     public native long getOpenFileDescriptorCount();
     public native long getMaxFileDescriptorCount();
+    public native double getSystemCpuLoad();
+    public native double getProcessCpuLoad();
 
     static {
         initialize();

src/solaris/native/com/sun/management/LinuxOperatingSystem.c

+/*
+ * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdarg.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/resource.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <stdlib.h>
+#include <dlfcn.h>
+#include <pthread.h>
+#include "com_sun_management_UnixOperatingSystem.h"
+
+struct ticks {
+    uint64_t  used;
+    uint64_t  usedKernel;
+    uint64_t  total;
+};
+
+typedef struct ticks ticks;
+
+typedef enum {
+    CPU_LOAD_VM_ONLY,
+    CPU_LOAD_GLOBAL,
+} CpuLoadTarget;
+
+static struct perfbuf {
+    int   nProcs;
+    ticks jvmTicks;
+    ticks cpuTicks;
+    ticks *cpus;
+} counters;
+
+#define DEC_64 "%lld"
+
+static void next_line(FILE *f) {
+    while (fgetc(f) != '\n');
+}
+
+/**
+ * Return the total number of ticks since the system was booted.
+ * If the usedTicks parameter is not NULL, it will be filled with
+ * the number of ticks spent on actual processes (user, system or
+ * nice processes) since system boot. Note that this is the total number
+ * of "executed" ticks on _all_ CPU:s, that is on a n-way system it is
+ * n times the number of ticks that has passed in clock time.
+ *
+ * Returns a negative value if the reading of the ticks failed.
+ */
+static int get_totalticks(int which, ticks *pticks) {
+    FILE         *fh;
+    uint64_t        userTicks, niceTicks, systemTicks, idleTicks;
+    int             n;
+
+    if((fh = fopen("/proc/stat", "r")) == NULL) {
+        return -1;
+    }
+
+    n = fscanf(fh, "cpu " DEC_64 " " DEC_64 " " DEC_64 " " DEC_64,
+           &userTicks, &niceTicks, &systemTicks, &idleTicks);
+
+    // Move to next line
+    next_line(fh);
+
+    //find the line for requested cpu faster to just iterate linefeeds?
+    if (which != -1) {
+        int i;
+        for (i = 0; i < which; i++) {
+            if (fscanf(fh, "cpu%*d " DEC_64 " " DEC_64 " " DEC_64 " " DEC_64, &userTicks, &niceTicks, &systemTicks, &idleTicks) != 4) {
+                fclose(fh);
+                return -2;
+            }
+            next_line(fh);
+        }
+        n = fscanf(fh, "cpu%*d " DEC_64 " " DEC_64 " " DEC_64 " " DEC_64 "\n",
+           &userTicks, &niceTicks, &systemTicks, &idleTicks);
+    }
+
+    fclose(fh);
+    if (n != 4) {
+        return -2;
+    }
+
+    pticks->used       = userTicks + niceTicks;
+    pticks->usedKernel = systemTicks;
+    pticks->total      = userTicks + niceTicks + systemTicks + idleTicks;
+
+    return 0;
+}
+
+static int vread_statdata(const char *procfile, const char *fmt, va_list args) {
+    FILE    *f;
+    int     n;
+    char     buf[2048];
+
+    if ((f = fopen(procfile, "r")) == NULL) {
+        return -1;
+    }
+
+    if ((n = fread(buf, 1, sizeof(buf), f)) != -1) {
+    char *tmp;
+
+    buf[n-1] = '\0';
+    /** skip through pid and exec name. the exec name _could be wacky_ (renamed) and
+     *  make scanf go mupp.
+     */
+    if ((tmp = strrchr(buf, ')')) != NULL) {
+        // skip the ')' and the following space but check that the buffer is long enough
+        tmp += 2;
+        if (tmp < buf + n) {
+        n = vsscanf(tmp, fmt, args);
+        }
+    }
+    }
+
+    fclose(f);
+
+    return n;
+}
+
+static int read_statdata(const char *procfile, const char *fmt, ...) {
+    int       n;
+    va_list args;
+
+    va_start(args, fmt);
+    n = vread_statdata(procfile, fmt, args);
+    va_end(args);
+    return n;
+}
+
+/** read user and system ticks from a named procfile, assumed to be in 'stat' format then. */
+static int read_ticks(const char *procfile, uint64_t *userTicks, uint64_t *systemTicks) {
+    return read_statdata(procfile, "%*c %*d %*d %*d %*d %*d %*u %*u %*u %*u %*u "DEC_64" "DEC_64,
+             userTicks, systemTicks
+             );
+}
+
+/**
+ * Return the number of ticks spent in any of the processes belonging
+ * to the JVM on any CPU.
+ */
+static int get_jvmticks(ticks *pticks) {
+    uint64_t userTicks;
+    uint64_t systemTicks;
+
+    if (read_ticks("/proc/self/stat", &userTicks, &systemTicks) < 0) {
+        return -1;
+    }
+
+    // get the total
+    if (get_totalticks(-1, pticks) < 0) {
+        return -1;
+    }
+
+    pticks->used       = userTicks;
+    pticks->usedKernel = systemTicks;
+
+    return 0;
+}
+
+/**
+ * This method must be called first, before any data can be gathererd.
+ */
+int perfInit() {
+    static int initialized=1;
+
+    if (!initialized) {
+        int  i;
+
+        int n = sysconf(_SC_NPROCESSORS_ONLN);
+        if (n <= 0) {
+            n = 1;
+        }
+
+        counters.cpus = calloc(n,sizeof(ticks));
+        if (counters.cpus != NULL)  {
+            // For the CPU load
+            get_totalticks(-1, &counters.cpuTicks);
+
+            for (i = 0; i < n; i++) {
+                get_totalticks(i, &counters.cpus[i]);
+            }
+            // For JVM load
+            get_jvmticks(&counters.jvmTicks);
+            initialized = 1;
+        }
+    }
+
+    return initialized ? 0 : -1;
+}
+
+#define MAX(a,b) (a>b?a:b)
+#define MIN(a,b) (a<b?a:b)
+
+static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
+
+/**
+ * Return the load of the CPU as a double. 1.0 means the CPU process uses all
+ * available time for user or system processes, 0.0 means the CPU uses all time
+ * being idle.
+ *
+ * Returns a negative value if there is a problem in determining the CPU load.
+ */
+
+static double get_cpuload_internal(int which, double *pkernelLoad, CpuLoadTarget target) {
+    uint64_t udiff, kdiff, tdiff;
+    ticks *pticks, tmp;
+    double user_load = -1.0;
+    int failed = 0;
+
+    *pkernelLoad = 0.0;
+
+    pthread_mutex_lock(&lock);
+
+    if(perfInit() == 0) {
+
+        if (target == CPU_LOAD_VM_ONLY) {
+            pticks = &counters.jvmTicks;
+        } else if (which == -1) {
+            pticks = &counters.cpuTicks;
+        } else {
+            pticks = &counters.cpus[which];
+        }
+
+        tmp = *pticks;
+
+        if (target == CPU_LOAD_VM_ONLY) {
+            if (get_jvmticks(pticks) != 0) {
+                failed = 1;
+            }
+        } else if (get_totalticks(which, pticks) < 0) {
+            failed = 1;
+        }
+
+        if(!failed) {
+            // seems like we sometimes end up with less kernel ticks when
+            // reading /proc/self/stat a second time, timing issue between cpus?
+            if (pticks->usedKernel < tmp.usedKernel) {
+                kdiff = 0;
+            } else {
+                kdiff = pticks->usedKernel - tmp.usedKernel;
+            }
+            tdiff = pticks->total - tmp.total;
+            udiff = pticks->used - tmp.used;
+
+            if (tdiff == 0) {
+                user_load = 0;
+            } else {
+                if (tdiff < (udiff + kdiff)) {
+                    tdiff = udiff + kdiff;
+                }
+                *pkernelLoad = (kdiff / (double)tdiff);
+                // BUG9044876, normalize return values to sane values
+                *pkernelLoad = MAX(*pkernelLoad, 0.0);
+                *pkernelLoad = MIN(*pkernelLoad, 1.0);
+
+                user_load = (udiff / (double)tdiff);
+                user_load = MAX(user_load, 0.0);
+                user_load = MIN(user_load, 1.0);
+            }
+        }
+    }
+    pthread_mutex_unlock(&lock);
+    return user_load;
+}
+
+double get_cpu_load(int which) {
+    double u, s;
+    u = get_cpuload_internal(which, &s, CPU_LOAD_GLOBAL);
+    if (u < 0) {
+        return -1.0;
+    }
+    // Cap total systemload to 1.0
+    return MIN((u + s), 1.0);
+}
+
+double get_process_load() {
+    double u, s;
+    u = get_cpuload_internal(-1, &s, CPU_LOAD_VM_ONLY);
+    if (u < 0) {
+        return -1.0;
+    }
+    return u + s;
+}
+
+JNIEXPORT jdouble JNICALL
+Java_com_sun_management_UnixOperatingSystem_getSystemCpuLoad
+(JNIEnv *env, jobject dummy)
+{
+    if(perfInit() == 0) {
+        return get_cpu_load(-1);
+    } else {
+        return -1.0;
+    }
+}
+
+JNIEXPORT jdouble JNICALL
+Java_com_sun_management_UnixOperatingSystem_getProcessCpuLoad
+(JNIEnv *env, jobject dummy)
+{
+    if(perfInit() == 0) {
+        return get_process_load();
+    } else {
+        return -1.0;
+    }
+}

src/solaris/native/com/sun/management/SolarisOperatingSystem.c

+/*
+ * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#include <fcntl.h>
+#include <kstat.h>
+#include <procfs.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/sysinfo.h>
+#include <sys/lwp.h>
+#include <pthread.h>
+#include <utmpx.h>
+#include <dlfcn.h>
+#include <sys/loadavg.h>
+#include <jni.h>
+#include "jvm.h"
+#include "com_sun_management_UnixOperatingSystem.h"
+
+typedef struct {
+    kstat_t *kstat;
+    uint64_t  last_idle;
+    uint64_t  last_total;
+    double  last_ratio;
+} cpuload_t;
+
+static cpuload_t   *cpu_loads = NULL;
+static unsigned int num_cpus;
+static kstat_ctl_t *kstat_ctrl = NULL;
+
+static void map_cpu_kstat_counters() {
+    kstat_t     *kstat;
+    int          i;
+
+    // Get number of CPU(s)
+    if ((num_cpus = sysconf(_SC_NPROCESSORS_ONLN)) == -1) {
+        num_cpus = 1;
+    }
+
+    // Data structure for saving CPU load
+    if ((cpu_loads = calloc(num_cpus,sizeof(cpuload_t))) == NULL) {
+        return;
+    }
+
+    // Get kstat cpu_stat counters for every CPU
+    // (loop over kstat to find our cpu_stat(s)
+    i = 0;
+    for (kstat = kstat_ctrl->kc_chain; kstat != NULL; kstat = kstat->ks_next) {
+        if (strncmp(kstat->ks_module, "cpu_stat", 8) == 0) {
+
+            if (kstat_read(kstat_ctrl, kstat, NULL) == -1) {
+            // Failed to initialize kstat for this CPU so ignore it
+            continue;
+            }
+
+            if (i == num_cpus) {
+            // Found more cpu_stats than reported CPUs
+            break;
+            }
+
+            cpu_loads[i++].kstat = kstat;
+        }
+    }
+}
+
+static int init_cpu_kstat_counters() {
+    static int initialized = 0;
+
+    // Concurrence in this method is prevented by the lock in
+    // the calling method get_cpu_load();
+    if(!initialized) {
+        if ((kstat_ctrl = kstat_open()) != NULL) {
+            map_cpu_kstat_counters();
+            initialized = 1;
+        }
+    }
+    return initialized ? 0 : -1;
+}
+
+static void update_cpu_kstat_counters() {
+    if(kstat_chain_update(kstat_ctrl) != 0) {
+        free(cpu_loads);
+        map_cpu_kstat_counters();
+    }
+}
+
+int read_cpustat(cpuload_t *load, cpu_stat_t *cpu_stat) {
+    if (load->kstat == NULL) {
+        // no handle.
+        return -1;
+    }
+    if (kstat_read(kstat_ctrl, load->kstat, cpu_stat) == -1) {
+        //  disabling for now, a kstat chain update is likely to happen next time
+        load->kstat = NULL;
+        return -1;
+    }
+    return 0;
+}
+
+double get_single_cpu_load(unsigned int n) {
+    cpuload_t  *load;
+    cpu_stat_t  cpu_stat;
+    uint_t     *usage;
+    uint64_t          c_idle;
+    uint64_t          c_total;
+    uint64_t          d_idle;
+    uint64_t          d_total;
+    int           i;
+
+    if (n >= num_cpus) {
+        return -1.0;
+    }
+
+    load = &cpu_loads[n];
+    if (read_cpustat(load, &cpu_stat) < 0) {
+        return -1.0;
+    }
+
+    usage   = cpu_stat.cpu_sysinfo.cpu;
+    c_idle  = usage[CPU_IDLE];
+
+    for (c_total = 0, i = 0; i < CPU_STATES; i++) {
+        c_total += usage[i];
+    }
+
+    // Calculate diff against previous snapshot
+    d_idle  = c_idle - load->last_idle;
+    d_total = c_total - load->last_total;
+
+    /** update if weve moved */
+    if (d_total > 0) {
+        // Save current values for next time around
+        load->last_idle  = c_idle;
+        load->last_total = c_total;
+        load->last_ratio = (double) (d_total - d_idle) / d_total;
+    }
+
+    return load->last_ratio;
+}
+
+int get_info(const char *path, void *info, size_t s, off_t o) {
+    int fd;
+    int ret = 0;
+    if ((fd = open(path, O_RDONLY)) < 0) {
+        return -1;
+    }
+    if (pread(fd, info, s, o) != s) {
+        ret = -1;
+    }
+    close(fd);
+    return ret;
+}
+
+#define MIN(a, b)           ((a < b) ? a : b)
+
+static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
+
+/**
+ * Return the cpu load (0-1) for proc number 'which' (or average all if which == -1)
+ */
+double  get_cpu_load(int which) {
+    double load =.0;
+
+    pthread_mutex_lock(&lock);
+    if(init_cpu_kstat_counters()==0) {
+
+        update_cpu_kstat_counters();
+
+        if (which == -1) {
+            unsigned int i;
+            double       t;
+
+            for (t = .0, i = 0; i < num_cpus; i++) {
+                t += get_single_cpu_load(i);
+            }
+
+            // Cap total systemload to 1.0
+            load = MIN((t / num_cpus), 1.0);
+        } else {
+            load = MIN(get_single_cpu_load(which), 1.0);
+        }
+    } else {
+        load = -1.0;
+    }
+    pthread_mutex_unlock(&lock);
+
+    return load;
+}
+
+/**
+ * Return the cpu load (0-1) for the current process (i.e the JVM)
+ * or -1.0 if the get_info() call failed
+ */
+double get_process_load(void) {
+    psinfo_t info;
+
+    // Get the percentage of "recent cpu usage" from all the lwp:s in the JVM:s
+    // process. This is returned as a value between 0.0 and 1.0 multiplied by 0x8000.
+    if (get_info("/proc/self/psinfo",&info.pr_pctcpu, sizeof(info.pr_pctcpu), offsetof(psinfo_t, pr_pctcpu)) == 0) {
+        return (double) info.pr_pctcpu / 0x8000;
+    }
+    return -1.0;
+}
+
+JNIEXPORT jdouble JNICALL
+Java_com_sun_management_UnixOperatingSystem_getSystemCpuLoad
+(JNIEnv *env, jobject dummy)
+{
+    return get_cpu_load(-1);
+}
+
+JNIEXPORT jdouble JNICALL
+Java_com_sun_management_UnixOperatingSystem_getProcessCpuLoad
+(JNIEnv *env, jobject dummy)
+{
+    return get_process_load();
+}
+

src/windows/classes/com/sun/management/OperatingSystem.java

@@ -58,6 +58,8 @@ class OperatingSystem
     public native long getProcessCpuTime();
     public native long getFreePhysicalMemorySize();
     public native long getTotalPhysicalMemorySize();
+    public native double getSystemCpuLoad();
+    public native double getProcessCpuLoad();
 
     static {
         initialize();

test/com/sun/management/OperatingSystemMXBean/GetProcessCpuLoad.java

+/*
+ * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug     7028071
+ * @summary Basic unit test of OperatingSystemMXBean.getProcessCpuLoad()
+ *
+ * @run main GetProcessCpuLoad
+ */
+
+import java.lang.management.*;
+import com.sun.management.OperatingSystemMXBean;
+
+public class GetProcessCpuLoad {
+    public static void main(String[] argv) throws Exception {
+        OperatingSystemMXBean mbean = (com.sun.management.OperatingSystemMXBean)
+            ManagementFactory.getOperatingSystemMXBean();
+        double load;
+        for(int i=0; i<10; i++) {
+            load = mbean.getProcessCpuLoad();
+            if((load<0.0 || load>1.0) && load != -1.0) {
+                throw new RuntimeException("getProcessCpuLoad() returns " + load
+                       +   " which is not in the [0.0,1.0] interval");
+            }
+            try {
+                Thread.sleep(200);
+            } catch(InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+}

test/com/sun/management/OperatingSystemMXBean/GetSystemCpuLoad.java

+/*
+ * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug     7028071
+ * @summary Basic unit test of OperatingSystemMXBean.getProcessCpuLoad()
+ *
+ * @run main GetSystemCpuLoad
+ */
+
+import java.lang.management.*;
+import com.sun.management.OperatingSystemMXBean;
+
+public class GetSystemCpuLoad {
+    public static void main(String[] argv) throws Exception {
+        OperatingSystemMXBean mbean = (com.sun.management.OperatingSystemMXBean)
+            ManagementFactory.getOperatingSystemMXBean();
+        double load;
+        for(int i=0; i<10; i++) {
+            load = mbean.getSystemCpuLoad();
+            if((load<0.0 || load>1.0) && load != -1.0) {
+                throw new RuntimeException("getSystemCpuLoad() returns " + load
+                       +  " which is not in the [0.0,1.0] interval");
+            }
+            try {
+                Thread.sleep(200);
+            } catch(InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+}