1 /*
2 * Copyright (c) 2011, 2020, 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 <stdio.h>
27 #include <stdint.h>
28 #include <stdarg.h>
29 #include <unistd.h>
30 #include <errno.h>
31 #include <string.h>
32 #include <sys/resource.h>
33 #include <sys/types.h>
34 #include <dirent.h>
35 #include <stdlib.h>
36 #include <dlfcn.h>
37 #include <pthread.h>
38 #include <inttypes.h>
39 #include "sun_management_OperatingSystemImpl.h"
40
41 struct ticks {
42 uint64_t used;
43 uint64_t usedKernel;
44 uint64_t total;
45 };
46
47 typedef struct ticks ticks;
48
49 typedef enum {
50 CPU_LOAD_VM_ONLY,
51 CPU_LOAD_GLOBAL,
52 } CpuLoadTarget;
53
54 static struct perfbuf {
55 int nProcs;
56 ticks jvmTicks;
57 ticks cpuTicks;
58 ticks *cpus;
59 } counters;
60
61 #define DEC_64 "%"SCNd64
62 #define NS_PER_SEC 1000000000
63
next_line(FILE * f)64 static void next_line(FILE *f) {
65 while (fgetc(f) != '\n');
66 }
67
68 /**
69 * Return the total number of ticks since the system was booted.
70 * If the usedTicks parameter is not NULL, it will be filled with
71 * the number of ticks spent on actual processes (user, system or
72 * nice processes) since system boot. Note that this is the total number
73 * of "executed" ticks on _all_ CPU:s, that is on a n-way system it is
74 * n times the number of ticks that has passed in clock time.
75 *
76 * Returns a negative value if the reading of the ticks failed.
77 */
get_totalticks(int which,ticks * pticks)78 static int get_totalticks(int which, ticks *pticks) {
79 FILE *fh;
80 uint64_t userTicks, niceTicks, systemTicks, idleTicks;
81 uint64_t iowTicks = 0, irqTicks = 0, sirqTicks= 0;
82 int n;
83
84 if((fh = fopen("/proc/stat", "r")) == NULL) {
85 return -1;
86 }
87
88 n = fscanf(fh, "cpu " DEC_64 " " DEC_64 " " DEC_64 " " DEC_64 " " DEC_64 " "
89 DEC_64 " " DEC_64,
90 &userTicks, &niceTicks, &systemTicks, &idleTicks,
91 &iowTicks, &irqTicks, &sirqTicks);
92
93 // Move to next line
94 next_line(fh);
95
96 //find the line for requested cpu faster to just iterate linefeeds?
97 if (which != -1) {
98 int i;
99 for (i = 0; i < which; i++) {
100 if (fscanf(fh, "cpu%*d " DEC_64 " " DEC_64 " " DEC_64 " " DEC_64 " "
101 DEC_64 " " DEC_64 " " DEC_64,
102 &userTicks, &niceTicks, &systemTicks, &idleTicks,
103 &iowTicks, &irqTicks, &sirqTicks) < 4) {
104 fclose(fh);
105 return -2;
106 }
107 next_line(fh);
108 }
109 n = fscanf(fh, "cpu%*d " DEC_64 " " DEC_64 " " DEC_64 " " DEC_64 " "
110 DEC_64 " " DEC_64 " " DEC_64 "\n",
111 &userTicks, &niceTicks, &systemTicks, &idleTicks,
112 &iowTicks, &irqTicks, &sirqTicks);
113 }
114
115 fclose(fh);
116 if (n < 4) {
117 return -2;
118 }
119
120 pticks->used = userTicks + niceTicks;
121 pticks->usedKernel = systemTicks + irqTicks + sirqTicks;
122 pticks->total = userTicks + niceTicks + systemTicks + idleTicks +
123 iowTicks + irqTicks + sirqTicks;
124
125 return 0;
126 }
127
vread_statdata(const char * procfile,const char * fmt,va_list args)128 static int vread_statdata(const char *procfile, const char *fmt, va_list args) {
129 FILE *f;
130 int n;
131 char buf[2048];
132
133 if ((f = fopen(procfile, "r")) == NULL) {
134 return -1;
135 }
136
137 if ((n = fread(buf, 1, sizeof(buf), f)) != -1) {
138 char *tmp;
139
140 buf[n-1] = '\0';
141 /** skip through pid and exec name. the exec name _could be wacky_ (renamed) and
142 * make scanf go mupp.
143 */
144 if ((tmp = strrchr(buf, ')')) != NULL) {
145 // skip the ')' and the following space but check that the buffer is long enough
146 tmp += 2;
147 if (tmp < buf + n) {
148 n = vsscanf(tmp, fmt, args);
149 }
150 }
151 }
152
153 fclose(f);
154
155 return n;
156 }
157
read_statdata(const char * procfile,const char * fmt,...)158 static int read_statdata(const char *procfile, const char *fmt, ...) {
159 int n;
160 va_list args;
161
162 va_start(args, fmt);
163 n = vread_statdata(procfile, fmt, args);
164 va_end(args);
165 return n;
166 }
167
168 /** read user and system ticks from a named procfile, assumed to be in 'stat' format then. */
read_ticks(const char * procfile,uint64_t * userTicks,uint64_t * systemTicks)169 static int read_ticks(const char *procfile, uint64_t *userTicks, uint64_t *systemTicks) {
170 return read_statdata(procfile, "%*c %*d %*d %*d %*d %*d %*u %*u %*u %*u %*u "DEC_64" "DEC_64,
171 userTicks, systemTicks
172 );
173 }
174
175 /**
176 * Return the number of ticks spent in any of the processes belonging
177 * to the JVM on any CPU.
178 */
get_jvmticks(ticks * pticks)179 static int get_jvmticks(ticks *pticks) {
180 uint64_t userTicks;
181 uint64_t systemTicks;
182
183 if (read_ticks("/proc/self/stat", &userTicks, &systemTicks) < 0) {
184 return -1;
185 }
186
187 // get the total
188 if (get_totalticks(-1, pticks) < 0) {
189 return -1;
190 }
191
192 pticks->used = userTicks;
193 pticks->usedKernel = systemTicks;
194
195 return 0;
196 }
197
198 /**
199 * This method must be called first, before any data can be gathererd.
200 */
perfInit()201 int perfInit() {
202 static int initialized = 0;
203
204 if (!initialized) {
205 int i;
206
207 // We need to allocate counters for all CPUs, including ones that
208 // are currently offline as they could be turned online later.
209 int n = sysconf(_SC_NPROCESSORS_CONF);
210 if (n <= 0) {
211 n = 1;
212 }
213
214 counters.cpus = calloc(n,sizeof(ticks));
215 counters.nProcs = n;
216 if (counters.cpus != NULL) {
217 // For the CPU load
218 get_totalticks(-1, &counters.cpuTicks);
219
220 for (i = 0; i < n; i++) {
221 get_totalticks(i, &counters.cpus[i]);
222 }
223 // For JVM load
224 get_jvmticks(&counters.jvmTicks);
225 initialized = 1;
226 }
227 }
228
229 return initialized ? 0 : -1;
230 }
231
232 #define MAX(a,b) (a>b?a:b)
233 #define MIN(a,b) (a<b?a:b)
234
235 static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
236
237 /**
238 * Return the load of the CPU as a double. 1.0 means the CPU process uses all
239 * available time for user or system processes, 0.0 means the CPU uses all time
240 * being idle.
241 *
242 * Returns a negative value if there is a problem in determining the CPU load.
243 */
244
get_cpuload_internal(int which,double * pkernelLoad,CpuLoadTarget target)245 static double get_cpuload_internal(int which, double *pkernelLoad, CpuLoadTarget target) {
246 uint64_t udiff, kdiff, tdiff;
247 ticks *pticks, tmp;
248 double user_load = -1.0;
249 int failed = 0;
250
251 *pkernelLoad = 0.0;
252
253 pthread_mutex_lock(&lock);
254
255 if(perfInit() == 0) {
256
257 if (target == CPU_LOAD_VM_ONLY) {
258 pticks = &counters.jvmTicks;
259 } else if (which == -1) {
260 pticks = &counters.cpuTicks;
261 } else {
262 pticks = &counters.cpus[which];
263 }
264
265 tmp = *pticks;
266
267 if (target == CPU_LOAD_VM_ONLY) {
268 if (get_jvmticks(pticks) != 0) {
269 failed = 1;
270 }
271 } else if (get_totalticks(which, pticks) < 0) {
272 failed = 1;
273 }
274
275 if(!failed) {
276 // seems like we sometimes end up with less kernel ticks when
277 // reading /proc/self/stat a second time, timing issue between cpus?
278 if (pticks->usedKernel < tmp.usedKernel) {
279 kdiff = 0;
280 } else {
281 kdiff = pticks->usedKernel - tmp.usedKernel;
282 }
283 tdiff = pticks->total - tmp.total;
284 udiff = pticks->used - tmp.used;
285
286 if (tdiff == 0) {
287 user_load = 0;
288 } else {
289 if (tdiff < (udiff + kdiff)) {
290 tdiff = udiff + kdiff;
291 }
292 *pkernelLoad = (kdiff / (double)tdiff);
293 // BUG9044876, normalize return values to sane values
294 *pkernelLoad = MAX(*pkernelLoad, 0.0);
295 *pkernelLoad = MIN(*pkernelLoad, 1.0);
296
297 user_load = (udiff / (double)tdiff);
298 user_load = MAX(user_load, 0.0);
299 user_load = MIN(user_load, 1.0);
300 }
301 }
302 }
303 pthread_mutex_unlock(&lock);
304 return user_load;
305 }
306
get_cpu_load(int which)307 double get_cpu_load(int which) {
308 double u, s;
309 u = get_cpuload_internal(which, &s, CPU_LOAD_GLOBAL);
310 if (u < 0) {
311 return -1.0;
312 }
313 // Cap total systemload to 1.0
314 return MIN((u + s), 1.0);
315 }
316
get_process_load()317 double get_process_load() {
318 double u, s;
319 u = get_cpuload_internal(-1, &s, CPU_LOAD_VM_ONLY);
320 if (u < 0) {
321 return -1.0;
322 }
323 return u + s;
324 }
325
326 JNIEXPORT jdouble JNICALL
Java_sun_management_OperatingSystemImpl_getSystemCpuLoad0(JNIEnv * env,jobject dummy)327 Java_sun_management_OperatingSystemImpl_getSystemCpuLoad0
328 (JNIEnv *env, jobject dummy)
329 {
330 if (perfInit() == 0) {
331 return get_cpu_load(-1);
332 } else {
333 return -1.0;
334 }
335 }
336
337 JNIEXPORT jdouble JNICALL
Java_sun_management_OperatingSystemImpl_getProcessCpuLoad0(JNIEnv * env,jobject dummy)338 Java_sun_management_OperatingSystemImpl_getProcessCpuLoad0
339 (JNIEnv *env, jobject dummy)
340 {
341 if (perfInit() == 0) {
342 return get_process_load();
343 } else {
344 return -1.0;
345 }
346 }
347
348 JNIEXPORT jdouble JNICALL
Java_sun_management_OperatingSystemImpl_getSingleCpuLoad0(JNIEnv * env,jobject mbean,jint cpu_number)349 Java_sun_management_OperatingSystemImpl_getSingleCpuLoad0
350 (JNIEnv *env, jobject mbean, jint cpu_number)
351 {
352 if (perfInit() == 0 && cpu_number >= 0 && cpu_number < counters.nProcs) {
353 return get_cpu_load(cpu_number);
354 } else {
355 return -1.0;
356 }
357 }
358
359 JNIEXPORT jint JNICALL
Java_sun_management_OperatingSystemImpl_getHostConfiguredCpuCount0(JNIEnv * env,jobject mbean)360 Java_sun_management_OperatingSystemImpl_getHostConfiguredCpuCount0
361 (JNIEnv *env, jobject mbean)
362 {
363 if (perfInit() == 0) {
364 return counters.nProcs;
365 } else {
366 return -1;
367 }
368 }
369
370 // Return the host cpu ticks since boot in nanoseconds
371 JNIEXPORT jlong JNICALL
Java_sun_management_OperatingSystemImpl_getHostTotalCpuTicks0(JNIEnv * env,jobject mbean)372 Java_sun_management_OperatingSystemImpl_getHostTotalCpuTicks0
373 (JNIEnv *env, jobject mbean)
374 {
375 if (perfInit() == 0) {
376 if (get_totalticks(-1, &counters.cpuTicks) < 0) {
377 return -1;
378 } else {
379 long ticks_per_sec = sysconf(_SC_CLK_TCK);
380 jlong result = (jlong)counters.cpuTicks.total;
381 if (ticks_per_sec <= NS_PER_SEC) {
382 long scale_factor = NS_PER_SEC/ticks_per_sec;
383 result = result * scale_factor;
384 } else {
385 long scale_factor = ticks_per_sec/NS_PER_SEC;
386 result = result / scale_factor;
387 }
388 return result;
389 }
390 } else {
391 return -1;
392 }
393 }
394
395 JNIEXPORT jint JNICALL
Java_sun_management_OperatingSystemImpl_getHostOnlineCpuCount0(JNIEnv * env,jobject mbean)396 Java_sun_management_OperatingSystemImpl_getHostOnlineCpuCount0
397 (JNIEnv *env, jobject mbean)
398 {
399 int n = sysconf(_SC_NPROCESSORS_ONLN);
400 if (n <= 0) {
401 n = 1;
402 }
403 return n;
404 }
405