/* * Copyright (c) 2011, 2025, 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 #include #include #include #include #include #include #include #include #include #include #include #include #include "management_ext.h" #include "com_sun_management_internal_OperatingSystemImpl.h" #include 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 "%"SCNd64 #define NS_PER_SEC 1000000000 static int next_line(FILE *f) { int c; do { c = fgetc(f); } while (c != '\n' && c != EOF); return c; } /** * 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; uint64_t iowTicks = 0, irqTicks = 0, sirqTicks= 0; int n; if((fh = fopen("/proc/stat", "r")) == NULL) { return -1; } n = fscanf(fh, "cpu " DEC_64 " " DEC_64 " " DEC_64 " " DEC_64 " " DEC_64 " " DEC_64 " " DEC_64, &userTicks, &niceTicks, &systemTicks, &idleTicks, &iowTicks, &irqTicks, &sirqTicks); // Move to next line if (next_line(fh) == EOF) { fclose(fh); return -2; } //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 " " DEC_64 " " DEC_64 " " DEC_64, &userTicks, &niceTicks, &systemTicks, &idleTicks, &iowTicks, &irqTicks, &sirqTicks) < 4) { fclose(fh); return -2; } if (next_line(fh) == EOF) { fclose(fh); return -2; } } n = fscanf(fh, "cpu%*d " DEC_64 " " DEC_64 " " DEC_64 " " DEC_64 " " DEC_64 " " DEC_64 " " DEC_64 "\n", &userTicks, &niceTicks, &systemTicks, &idleTicks, &iowTicks, &irqTicks, &sirqTicks); } fclose(fh); if (n < 4) { return -2; } pticks->used = userTicks + niceTicks; pticks->usedKernel = systemTicks + irqTicks + sirqTicks; pticks->total = userTicks + niceTicks + systemTicks + idleTicks + iowTicks + irqTicks + sirqTicks; 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) != 2) { 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 = 0; if (!initialized) { int i; // We need to allocate counters for all CPUs, including ones that // are currently offline as they could be turned online later. int n = sysconf(_SC_NPROCESSORS_CONF); if (n <= 0) { n = 1; } counters.cpus = calloc(n,sizeof(ticks)); counters.nProcs = n; 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) (ausedKernel >= tmp.usedKernel); 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; } static long read_vmem_usage(const char *procfile, unsigned long *vsize) { int n = read_statdata(procfile, "%*c %*d %*d %*d %*d %*d %*u %*u %*u %*u %*u %*d %*d %*d %*d %*d %*d %*u %*u %*d %lu %*[^\n]\n", vsize); if (n != 1) { return -1; } else { return *vsize; } } JNIEXPORT jlong JNICALL Java_com_sun_management_internal_OperatingSystemImpl_getCommittedVirtualMemorySize0 (JNIEnv *env, jobject mbean) { unsigned long vsize; if (read_vmem_usage("/proc/self/stat", &vsize) == -1) { throw_internal_error(env, "Unable to get virtual memory usage"); } return (jlong) vsize; } JNIEXPORT jdouble JNICALL Java_com_sun_management_internal_OperatingSystemImpl_getCpuLoad0 (JNIEnv *env, jobject dummy) { if (perfInit() == 0) { return get_cpu_load(-1); } else { return -1.0; } } JNIEXPORT jdouble JNICALL Java_com_sun_management_internal_OperatingSystemImpl_getProcessCpuLoad0 (JNIEnv *env, jobject dummy) { if (perfInit() == 0) { return get_process_load(); } else { return -1.0; } } JNIEXPORT jdouble JNICALL Java_com_sun_management_internal_OperatingSystemImpl_getSingleCpuLoad0 (JNIEnv *env, jobject mbean, jint cpu_number) { if (perfInit() == 0 && cpu_number >= 0 && cpu_number < counters.nProcs) { return get_cpu_load(cpu_number); } else { return -1.0; } } JNIEXPORT jint JNICALL Java_com_sun_management_internal_OperatingSystemImpl_getHostConfiguredCpuCount0 (JNIEnv *env, jobject mbean) { if (perfInit() == 0) { return counters.nProcs; } else { return -1; } } // Return the host cpu ticks since boot in nanoseconds JNIEXPORT jlong JNICALL Java_com_sun_management_internal_OperatingSystemImpl_getHostTotalCpuTicks0 (JNIEnv *env, jobject mbean) { if (perfInit() == 0) { if (get_totalticks(-1, &counters.cpuTicks) < 0) { return -1; } else { long ticks_per_sec = sysconf(_SC_CLK_TCK); jlong result = (jlong)counters.cpuTicks.total; if (ticks_per_sec <= NS_PER_SEC) { long scale_factor = NS_PER_SEC/ticks_per_sec; result = result * scale_factor; } else { long scale_factor = ticks_per_sec/NS_PER_SEC; result = result / scale_factor; } return result; } } else { return -1; } } JNIEXPORT jint JNICALL Java_com_sun_management_internal_OperatingSystemImpl_getHostOnlineCpuCount0 (JNIEnv *env, jobject mbean) { int n = sysconf(_SC_NPROCESSORS_ONLN); if (n <= 0) { n = 1; } return n; }