1 /* 2 * Copyright (c) 2011, 2019, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 #include <fcntl.h> 27 #include <kstat.h> 28 #include <procfs.h> 29 #include <unistd.h> 30 #include <stdlib.h> 31 #include <stdio.h> 32 #include <string.h> 33 #include <sys/sysinfo.h> 34 #include <sys/lwp.h> 35 #include <pthread.h> 36 #include <utmpx.h> 37 #include <dlfcn.h> 38 #include <sys/loadavg.h> 39 #include <jni.h> 40 #include "jvm.h" 41 #include "com_sun_management_internal_OperatingSystemImpl.h" 42 43 typedef struct { 44 kstat_t *kstat; 45 uint64_t last_idle; 46 uint64_t last_total; 47 double last_ratio; 48 } cpuload_t; 49 50 static cpuload_t *cpu_loads = NULL; 51 static unsigned int num_cpus; 52 static kstat_ctl_t *kstat_ctrl = NULL; 53 54 static void map_cpu_kstat_counters() { 55 kstat_t *kstat; 56 int i; 57 58 // Get number of CPU(s) 59 if ((num_cpus = sysconf(_SC_NPROCESSORS_ONLN)) == -1) { 60 num_cpus = 1; 61 } 62 63 // Data structure for saving CPU load 64 if ((cpu_loads = calloc(num_cpus,sizeof(cpuload_t))) == NULL) { 65 return; 66 } 67 68 // Get kstat cpu_stat counters for every CPU 69 // (loop over kstat to find our cpu_stat(s) 70 i = 0; 71 for (kstat = kstat_ctrl->kc_chain; kstat != NULL; kstat = kstat->ks_next) { 72 if (strncmp(kstat->ks_module, "cpu_stat", 8) == 0) { 73 74 if (kstat_read(kstat_ctrl, kstat, NULL) == -1) { 75 // Failed to initialize kstat for this CPU so ignore it 76 continue; 77 } 78 79 if (i == num_cpus) { 80 // Found more cpu_stats than reported CPUs 81 break; 82 } 83 84 cpu_loads[i++].kstat = kstat; 85 } 86 } 87 } 88 89 static int init_cpu_kstat_counters() { 90 static int initialized = 0; 91 92 // Concurrence in this method is prevented by the lock in 93 // the calling method get_cpu_load(); 94 if(!initialized) { 95 if ((kstat_ctrl = kstat_open()) != NULL) { 96 map_cpu_kstat_counters(); 97 initialized = 1; 98 } 99 } 100 return initialized ? 0 : -1; 101 } 102 103 static void update_cpu_kstat_counters() { 104 if(kstat_chain_update(kstat_ctrl) != 0) { 105 free(cpu_loads); 106 map_cpu_kstat_counters(); 107 } 108 } 109 110 int read_cpustat(cpuload_t *load, cpu_stat_t *cpu_stat) { 111 if (load->kstat == NULL) { 112 // no handle. 113 return -1; 114 } 115 if (kstat_read(kstat_ctrl, load->kstat, cpu_stat) == -1) { 116 // disabling for now, a kstat chain update is likely to happen next time 117 load->kstat = NULL; 118 return -1; 119 } 120 return 0; 121 } 122 123 double get_single_cpu_load(unsigned int n) { 124 cpuload_t *load; 125 cpu_stat_t cpu_stat; 126 uint_t *usage; 127 uint64_t c_idle; 128 uint64_t c_total; 129 uint64_t d_idle; 130 uint64_t d_total; 131 int i; 132 133 if (n >= num_cpus) { 134 return -1.0; 135 } 136 137 load = &cpu_loads[n]; 138 if (read_cpustat(load, &cpu_stat) < 0) { 139 return -1.0; 140 } 141 142 usage = cpu_stat.cpu_sysinfo.cpu; 143 c_idle = usage[CPU_IDLE]; 144 145 for (c_total = 0, i = 0; i < CPU_STATES; i++) { 146 c_total += usage[i]; 147 } 148 149 // Calculate diff against previous snapshot 150 d_idle = c_idle - load->last_idle; 151 d_total = c_total - load->last_total; 152 153 /** update if weve moved */ 154 if (d_total > 0) { 155 // Save current values for next time around 156 load->last_idle = c_idle; 157 load->last_total = c_total; 158 load->last_ratio = (double) (d_total - d_idle) / d_total; 159 } 160 161 return load->last_ratio; 162 } 163 164 int get_info(const char *path, void *info, size_t s, off_t o) { 165 int fd; 166 int ret = 0; 167 if ((fd = open(path, O_RDONLY)) < 0) { 168 return -1; 169 } 170 if (pread(fd, info, s, o) != s) { 171 ret = -1; 172 } 173 close(fd); 174 return ret; 175 } 176 177 #define MIN(a, b) ((a < b) ? a : b) 178 179 static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER; 180 181 /** 182 * Return the cpu load (0-1) for proc number 'which' (or average all if which == -1) 183 */ 184 double get_cpu_load(int which) { 185 double load =.0; 186 187 pthread_mutex_lock(&lock); 188 if(init_cpu_kstat_counters()==0) { 189 190 update_cpu_kstat_counters(); 191 192 if (which == -1) { 193 unsigned int i; 194 double t; 195 196 for (t = .0, i = 0; i < num_cpus; i++) { 197 t += get_single_cpu_load(i); 198 } 199 200 // Cap total systemload to 1.0 201 load = MIN((t / num_cpus), 1.0); 202 } else { 203 load = MIN(get_single_cpu_load(which), 1.0); 204 } 205 } else { 206 load = -1.0; 207 } 208 pthread_mutex_unlock(&lock); 209 210 return load; 211 } 212 213 /** 214 * Return the cpu load (0-1) for the current process (i.e the JVM) 215 * or -1.0 if the get_info() call failed 216 */ 217 double get_process_load(void) { 218 psinfo_t info; 219 220 // Get the percentage of "recent cpu usage" from all the lwp:s in the JVM:s 221 // process. This is returned as a value between 0.0 and 1.0 multiplied by 0x8000. 222 if (get_info("/proc/self/psinfo",&info.pr_pctcpu, sizeof(info.pr_pctcpu), offsetof(psinfo_t, pr_pctcpu)) == 0) { 223 return (double) info.pr_pctcpu / 0x8000; 224 } 225 return -1.0; 226 } 227 228 JNIEXPORT jdouble JNICALL 229 Java_com_sun_management_internal_OperatingSystemImpl_getCpuLoad0 230 (JNIEnv *env, jobject dummy) 231 { 232 return get_cpu_load(-1); 233 } 234 235 JNIEXPORT jdouble JNICALL 236 Java_com_sun_management_internal_OperatingSystemImpl_getProcessCpuLoad0 237 (JNIEnv *env, jobject dummy) 238 { 239 return get_process_load(); 240 } 241 242 JNIEXPORT jdouble JNICALL 243 Java_com_sun_management_internal_OperatingSystemImpl_getSingleCpuLoad0 244 (JNIEnv *env, jobject mbean, jint cpu_number) 245 { 246 return -1.0; 247 } 248 249 JNIEXPORT jint JNICALL 250 Java_com_sun_management_internal_OperatingSystemImpl_getHostConfiguredCpuCount0 251 (JNIEnv *env, jobject mbean) 252 { 253 return -1; 254 }