Xinqi Bao's Git

cpu_perc: Check for division by zero
[slstatus.git] / components / cpu.c
index 3b29b8b..9e28003 100644 (file)
@@ -1,5 +1,5 @@
 /* See LICENSE file for copyright and license details. */
-#include <errno.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <string.h>
 
@@ -9,38 +9,44 @@
        const char *
        cpu_freq(void)
        {
-               int freq;
+               uintmax_t freq;
+
+               /* in kHz */
+               if (pscanf("/sys/devices/system/cpu/cpu0/cpufreq/"
+                          "scaling_cur_freq", "%ju", &freq) != 1) {
+                       return NULL;
+               }
 
-               return (pscanf("/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq",
-                              "%i", &freq) == 1) ?
-                      bprintf("%d", (freq + 500) / 1000) : NULL;
+               return fmt_human(freq * 1000, 1000);
        }
 
        const char *
        cpu_perc(void)
        {
-               int perc;
                static long double a[7];
-               static int valid;
-               long double b[7];
+               long double b[7], sum;
 
                memcpy(b, a, sizeof(b));
                /* cpu user nice system idle iowait irq softirq */
                if (pscanf("/proc/stat", "%*s %Lf %Lf %Lf %Lf %Lf %Lf %Lf",
-                          &a[0], &a[1], &a[2], &a[3], &a[4], &a[5], &a[6]) != 7) {
+                          &a[0], &a[1], &a[2], &a[3], &a[4], &a[5], &a[6])
+                   != 7) {
                        return NULL;
                }
-               if (!valid) {
-                       valid = 1;
+               if (b[0] == 0) {
                        return NULL;
                }
 
-               perc = 100 * ((b[0] + b[1] + b[2] + b[5] + b[6]) -
-                             (a[0] + a[1] + a[2] + a[5] + a[6])) /
-                            ((b[0] + b[1] + b[2] + b[3] + b[4] + b[5] + b[6]) -
-                             (a[0] + a[1] + a[2] + a[3] + a[4] + a[5] + a[6]));
+               sum = (b[0] + b[1] + b[2] + b[3] + b[4] + b[5] + b[6]) -
+                     (a[0] + a[1] + a[2] + a[3] + a[4] + a[5] + a[6]);
 
-               return bprintf("%d", perc);
+               if (sum == 0) {
+                       return NULL;
+               }
+
+               return bprintf("%d", (int)(100 *
+                              ((b[0] + b[1] + b[2] + b[5] + b[6]) -
+                               (a[0] + a[1] + a[2] + a[5] + a[6])) / sum));
        }
 #elif defined(__OpenBSD__)
        #include <sys/param.h>
 
                size = sizeof(freq);
 
+               /* in MHz */
                if (sysctl(mib, 2, &freq, &size, NULL, 0) < 0) {
-                       fprintf(stderr, "sysctl 'HW_CPUSPEED': %s\n", strerror(errno));
+                       warn("sysctl 'HW_CPUSPEED':");
                        return NULL;
                }
 
-               return bprintf("%d", freq);
+               return fmt_human(freq * 1E6, 1000);
        }
 
        const char *
        cpu_perc(void)
        {
-               int mib[2], perc;
-               static int valid;
-               static long int a[CPUSTATES];
-               long int b[CPUSTATES];
+               int mib[2];
+               static uintmax_t a[CPUSTATES];
+               uintmax_t b[CPUSTATES], sum;
                size_t size;
 
                mib[0] = CTL_KERN;
 
                memcpy(b, a, sizeof(b));
                if (sysctl(mib, 2, &a, &size, NULL, 0) < 0) {
-                       fprintf(stderr, "sysctl 'KERN_CPTIME': %s\n", strerror(errno));
+                       warn("sysctl 'KERN_CPTIME':");
+                       return NULL;
+               }
+               if (b[0] == 0) {
+                       return NULL;
+               }
+
+               sum = (a[CP_USER] + a[CP_NICE] + a[CP_SYS] + a[CP_INTR] + a[CP_IDLE]) -
+                     (b[CP_USER] + b[CP_NICE] + b[CP_SYS] + b[CP_INTR] + b[CP_IDLE]);
+
+               if (sum == 0) {
+                       return NULL;
+               }
+
+               return bprintf("%d", 100 *
+                              ((a[CP_USER] + a[CP_NICE] + a[CP_SYS] +
+                                a[CP_INTR]) -
+                               (b[CP_USER] + b[CP_NICE] + b[CP_SYS] +
+                                b[CP_INTR])) / sum);
+       }
+#elif defined(__FreeBSD__)
+       #include <sys/param.h>
+       #include <sys/sysctl.h>
+       #include <devstat.h>
+
+       const char *
+       cpu_freq(void)
+       {
+               int freq;
+               size_t size;
+
+               size = sizeof(freq);
+               /* in MHz */
+               if (sysctlbyname("hw.clockrate", &freq, &size, NULL, 0) == -1
+                               || !size) {
+                       warn("sysctlbyname 'hw.clockrate':");
                        return NULL;
                }
-               if (!valid) {
-                       valid = 1;
+
+               return fmt_human(freq * 1E6, 1000);
+       }
+
+       const char *
+       cpu_perc(void)
+       {
+               size_t size;
+               static long a[CPUSTATES];
+               long b[CPUSTATES], sum;
+
+               size = sizeof(a);
+               memcpy(b, a, sizeof(b));
+               if (sysctlbyname("kern.cp_time", &a, &size, NULL, 0) == -1
+                               || !size) {
+                       warn("sysctlbyname 'kern.cp_time':");
                        return NULL;
                }
+               if (b[0] == 0) {
+                       return NULL;
+               }
+
+               sum = (a[CP_USER] + a[CP_NICE] + a[CP_SYS] + a[CP_INTR] + a[CP_IDLE]) -
+                     (b[CP_USER] + b[CP_NICE] + b[CP_SYS] + b[CP_INTR] + b[CP_IDLE]);
 
-               perc = 100 *
-                     ((a[CP_USER] + a[CP_NICE] + a[CP_SYS] + a[CP_INTR]) -
-                      (b[CP_USER] + b[CP_NICE] + b[CP_SYS] + b[CP_INTR])) /
-                     ((a[CP_USER] + a[CP_NICE] + a[CP_SYS] + a[CP_INTR] + a[CP_IDLE]) -
-                      (b[CP_USER] + b[CP_NICE] + b[CP_SYS] + b[CP_INTR] + b[CP_IDLE]));
+               if (sum == 0) {
+                       return NULL;
+               }
 
-               return bprintf("%d", perc);
+               return bprintf("%d", 100 *
+                              ((a[CP_USER] + a[CP_NICE] + a[CP_SYS] +
+                                a[CP_INTR]) -
+                               (b[CP_USER] + b[CP_NICE] + b[CP_SYS] +
+                                b[CP_INTR])) / sum);
        }
 #endif