1 /* |
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2 * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. Oracle designates this |
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8 * particular file as subject to the "Classpath" exception as provided |
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9 * by Oracle in the LICENSE file that accompanied this code. |
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10 * |
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11 * This code is distributed in the hope that it will be useful, but WITHOUT |
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12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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14 * version 2 for more details (a copy is included in the LICENSE file that |
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15 * accompanied this code). |
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16 * |
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17 * You should have received a copy of the GNU General Public License version |
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18 * 2 along with this work; if not, write to the Free Software Foundation, |
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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20 * |
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21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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22 * or visit www.oracle.com if you need additional information or have any |
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23 * questions. |
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24 */ |
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25 |
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26 #include <fcntl.h> |
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27 #include <kstat.h> |
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28 #include <procfs.h> |
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29 #include <unistd.h> |
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30 #include <stdlib.h> |
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31 #include <stdio.h> |
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32 #include <string.h> |
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33 #include <sys/sysinfo.h> |
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34 #include <sys/lwp.h> |
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35 #include <pthread.h> |
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36 #include <utmpx.h> |
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37 #include <dlfcn.h> |
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38 #include <sys/loadavg.h> |
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39 #include <jni.h> |
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40 #include "jvm.h" |
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41 #include "sun_management_OperatingSystemImpl.h" |
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42 |
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43 typedef struct { |
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44 kstat_t *kstat; |
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45 uint64_t last_idle; |
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46 uint64_t last_total; |
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47 double last_ratio; |
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48 } cpuload_t; |
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49 |
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50 static cpuload_t *cpu_loads = NULL; |
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51 static unsigned int num_cpus; |
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52 static kstat_ctl_t *kstat_ctrl = NULL; |
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53 |
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54 static void map_cpu_kstat_counters() { |
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55 kstat_t *kstat; |
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56 int i; |
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57 |
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58 // Get number of CPU(s) |
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59 if ((num_cpus = sysconf(_SC_NPROCESSORS_ONLN)) == -1) { |
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60 num_cpus = 1; |
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61 } |
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62 |
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63 // Data structure for saving CPU load |
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64 if ((cpu_loads = calloc(num_cpus,sizeof(cpuload_t))) == NULL) { |
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65 return; |
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66 } |
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67 |
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68 // Get kstat cpu_stat counters for every CPU |
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69 // (loop over kstat to find our cpu_stat(s) |
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70 i = 0; |
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71 for (kstat = kstat_ctrl->kc_chain; kstat != NULL; kstat = kstat->ks_next) { |
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72 if (strncmp(kstat->ks_module, "cpu_stat", 8) == 0) { |
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73 |
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74 if (kstat_read(kstat_ctrl, kstat, NULL) == -1) { |
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75 // Failed to initialize kstat for this CPU so ignore it |
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76 continue; |
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77 } |
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78 |
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79 if (i == num_cpus) { |
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80 // Found more cpu_stats than reported CPUs |
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81 break; |
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82 } |
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83 |
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84 cpu_loads[i++].kstat = kstat; |
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85 } |
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86 } |
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87 } |
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88 |
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89 static int init_cpu_kstat_counters() { |
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90 static int initialized = 0; |
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91 |
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92 // Concurrence in this method is prevented by the lock in |
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93 // the calling method get_cpu_load(); |
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94 if(!initialized) { |
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95 if ((kstat_ctrl = kstat_open()) != NULL) { |
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96 map_cpu_kstat_counters(); |
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97 initialized = 1; |
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98 } |
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99 } |
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100 return initialized ? 0 : -1; |
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101 } |
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102 |
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103 static void update_cpu_kstat_counters() { |
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104 if(kstat_chain_update(kstat_ctrl) != 0) { |
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105 free(cpu_loads); |
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106 map_cpu_kstat_counters(); |
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107 } |
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108 } |
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109 |
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110 int read_cpustat(cpuload_t *load, cpu_stat_t *cpu_stat) { |
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111 if (load->kstat == NULL) { |
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112 // no handle. |
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113 return -1; |
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114 } |
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115 if (kstat_read(kstat_ctrl, load->kstat, cpu_stat) == -1) { |
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116 // disabling for now, a kstat chain update is likely to happen next time |
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117 load->kstat = NULL; |
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118 return -1; |
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119 } |
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120 return 0; |
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121 } |
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122 |
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123 double get_single_cpu_load(unsigned int n) { |
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124 cpuload_t *load; |
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125 cpu_stat_t cpu_stat; |
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126 uint_t *usage; |
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127 uint64_t c_idle; |
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128 uint64_t c_total; |
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129 uint64_t d_idle; |
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130 uint64_t d_total; |
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131 int i; |
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132 |
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133 if (n >= num_cpus) { |
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134 return -1.0; |
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135 } |
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136 |
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137 load = &cpu_loads[n]; |
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138 if (read_cpustat(load, &cpu_stat) < 0) { |
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139 return -1.0; |
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140 } |
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141 |
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142 usage = cpu_stat.cpu_sysinfo.cpu; |
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143 c_idle = usage[CPU_IDLE]; |
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144 |
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145 for (c_total = 0, i = 0; i < CPU_STATES; i++) { |
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146 c_total += usage[i]; |
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147 } |
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148 |
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149 // Calculate diff against previous snapshot |
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150 d_idle = c_idle - load->last_idle; |
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151 d_total = c_total - load->last_total; |
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152 |
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153 /** update if weve moved */ |
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154 if (d_total > 0) { |
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155 // Save current values for next time around |
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156 load->last_idle = c_idle; |
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157 load->last_total = c_total; |
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158 load->last_ratio = (double) (d_total - d_idle) / d_total; |
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159 } |
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160 |
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161 return load->last_ratio; |
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162 } |
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163 |
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164 int get_info(const char *path, void *info, size_t s, off_t o) { |
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165 int fd; |
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166 int ret = 0; |
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167 if ((fd = open(path, O_RDONLY)) < 0) { |
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168 return -1; |
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169 } |
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170 if (pread(fd, info, s, o) != s) { |
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171 ret = -1; |
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172 } |
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173 close(fd); |
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174 return ret; |
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175 } |
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176 |
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177 #define MIN(a, b) ((a < b) ? a : b) |
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178 |
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179 static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER; |
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180 |
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181 /** |
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182 * Return the cpu load (0-1) for proc number 'which' (or average all if which == -1) |
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183 */ |
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184 double get_cpu_load(int which) { |
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185 double load =.0; |
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186 |
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187 pthread_mutex_lock(&lock); |
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188 if(init_cpu_kstat_counters()==0) { |
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189 |
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190 update_cpu_kstat_counters(); |
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191 |
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192 if (which == -1) { |
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193 unsigned int i; |
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194 double t; |
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195 |
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196 for (t = .0, i = 0; i < num_cpus; i++) { |
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197 t += get_single_cpu_load(i); |
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198 } |
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199 |
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200 // Cap total systemload to 1.0 |
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201 load = MIN((t / num_cpus), 1.0); |
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202 } else { |
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203 load = MIN(get_single_cpu_load(which), 1.0); |
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204 } |
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205 } else { |
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206 load = -1.0; |
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207 } |
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208 pthread_mutex_unlock(&lock); |
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209 |
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210 return load; |
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211 } |
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212 |
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213 /** |
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214 * Return the cpu load (0-1) for the current process (i.e the JVM) |
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215 * or -1.0 if the get_info() call failed |
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216 */ |
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217 double get_process_load(void) { |
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218 psinfo_t info; |
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219 |
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220 // Get the percentage of "recent cpu usage" from all the lwp:s in the JVM:s |
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221 // process. This is returned as a value between 0.0 and 1.0 multiplied by 0x8000. |
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222 if (get_info("/proc/self/psinfo",&info.pr_pctcpu, sizeof(info.pr_pctcpu), offsetof(psinfo_t, pr_pctcpu)) == 0) { |
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223 return (double) info.pr_pctcpu / 0x8000; |
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224 } |
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225 return -1.0; |
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226 } |
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227 |
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228 JNIEXPORT jdouble JNICALL |
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229 Java_sun_management_OperatingSystemImpl_getSystemCpuLoad0 |
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230 (JNIEnv *env, jobject dummy) |
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231 { |
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232 return get_cpu_load(-1); |
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233 } |
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234 |
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235 JNIEXPORT jdouble JNICALL |
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236 Java_sun_management_OperatingSystemImpl_getProcessCpuLoad0 |
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237 (JNIEnv *env, jobject dummy) |
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238 { |
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239 return get_process_load(); |
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240 } |
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241 |
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