modules: add cpu module

CHANGELOG.md

@@ -17,6 +17,7 @@
 * i3/sway: new boolean tag: `empty`
   (https://codeberg.org/dnkl/yambar/issues/139).
 * mem: a module handling system memory monitoring
+* cpu: a module offering cpu usage monitoring
 
 
 ### Changed

doc/meson.build

@@ -13,6 +13,7 @@ foreach man_src : ['yambar.1.scd', 'yambar.5.scd', 'yambar-decorations.5.scd',
                    'yambar-modules-script.5.scd', 'yambar-modules-sway-xkb.5.scd',
                    'yambar-modules-sway.5.scd', 'yambar-modules-xkb.5.scd',
                    'yambar-modules-xwindow.5.scd', 'yambar-modules.5.scd',
+                   'yambar-modules-cpu.5.scd',
                    'yambar-modules-mem.5.scd',
                    'yambar-particles.5.scd', 'yambar-tags.5.scd']
   parts = man_src.split('.')

doc/yambar-modules-cpu.5.scd

@@ -0,0 +1,42 @@
+yambar-modules-cpu(5)
+
+# NAME
+cpu - This module provides the CPU usage
+
+# TAGS
+
+[[ *Name*
+:[ *Type*
+:[ *Description*
+|  cpu
+:  range
+:  Current usage of the whole CPU in percent
+|  cpu<0..X>
+:  range
+:  Current usage of CPU core X in percent
+
+# CONFIGURATION
+
+[[ *Name*
+:[ *Type*
+:[ *Req*
+:[ *Description*
+|  interval
+:  int
+:  no
+:  Refresh interval of the CPU usage stats in ms (default=500). Cannot be less then 500 ms
+
+# EXAMPLES
+
+```
+bar:
+  left:
+    - cpu:
+        interval: 2500
+        content:
+          string: {text: "{cpu1}%"}
+```
+
+# SEE ALSO
+
+*yambar-modules*(5), *yambar-particles*(5), *yambar-tags*(5), *yambar-decorations*(5)

modules/cpu.c

@@ -0,0 +1,294 @@
+#include <assert.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <math.h>
+#include <poll.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+#include <time.h>
+
+#define LOG_MODULE "cpu"
+#define LOG_ENABLE_DBG 0
+#define SMALLEST_INTERVAL 500
+#include "../bar/bar.h"
+#include "../config-verify.h"
+#include "../config.h"
+#include "../log.h"
+#include "../plugin.h"
+struct cpu_stats {
+    uint32_t *prev_cores_idle;
+    uint32_t *prev_cores_nidle;
+
+    uint32_t *cur_cores_idle;
+    uint32_t *cur_cores_nidle;
+};
+
+struct private
+{
+    struct particle *label;
+    uint16_t interval;
+    struct cpu_stats cpu_stats;
+};
+
+static void
+destroy(struct module *mod)
+{
+    struct private *m = mod->private;
+    m->label->destroy(m->label);
+    free(m->cpu_stats.prev_cores_idle);
+    free(m->cpu_stats.prev_cores_nidle);
+    free(m->cpu_stats.cur_cores_idle);
+    free(m->cpu_stats.cur_cores_nidle);
+    free(m);
+    module_default_destroy(mod);
+}
+
+static const char *
+description(struct module *mod)
+{
+    return "cpu";
+}
+
+static uint32_t
+get_cpu_nb_cores()
+{
+    uint32_t nb_cores = 0;
+    FILE *fp = NULL;
+    char *line = NULL;
+    size_t len = 0;
+    ssize_t read;
+
+    fp = fopen("/proc/cpuinfo", "r");
+    if (NULL == fp) {
+        LOG_ERRNO("unable to open /proc/cpuinfo");
+        return 0;
+    }
+    while ((read = getline(&line, &len, fp)) != -1) {
+        if (strncmp(line, "siblings", sizeof("siblings") - 1) == 0) {
+            char *pos = (char *)memchr(line, ':', read);
+            if (pos == NULL) {
+                LOG_ERR("unable to parse siblings field to find the number of cores");
+                return 0;
+            }
+            errno = 0;
+            nb_cores = strtoul(pos + 1, NULL, 10);
+            if (errno == ERANGE) {
+                LOG_ERR("number of cores is out of range");
+            }
+            break;
+        }
+    }
+    fclose(fp);
+    free(line);
+
+    return nb_cores;
+}
+
+static bool
+parse_proc_stat_line(const char *line, int32_t *core, uint32_t *user, uint32_t *nice, uint32_t *system, uint32_t *idle,
+                     uint32_t *iowait, uint32_t *irq, uint32_t *softirq, uint32_t *steal, uint32_t *guest,
+                     uint32_t *guestnice)
+{
+    if (line[sizeof("cpu") - 1] == ' ') {
+        int read = sscanf(line,
+                          "cpu %" SCNu32 " %" SCNu32 " %" SCNu32 " %" SCNu32 " %" SCNu32 " %" SCNu32 " %" SCNu32
+                          " %" SCNu32 " %" SCNu32 " %" SCNu32,
+                          user, nice, system, idle, iowait, irq, softirq, steal, guest, guestnice);
+        *core = -1;
+        return read == 10;
+    } else {
+        int read = sscanf(line,
+                          "cpu%" SCNu32 " %" SCNu32 " %" SCNu32 " %" SCNu32 " %" SCNu32 " %" SCNu32 " %" SCNu32
+                          " %" SCNu32 " %" SCNu32 " %" SCNu32 " %" SCNu32,
+                          core, user, nice, system, idle, iowait, irq, softirq, steal, guest, guestnice);
+        return read == 11;
+    }
+}
+
+static uint8_t
+get_cpu_usage_percent(const struct cpu_stats *cpu_stats, int8_t core_idx)
+{
+    uint32_t prev_total = cpu_stats->prev_cores_idle[core_idx + 1] + cpu_stats->prev_cores_nidle[core_idx + 1];
+    uint32_t cur_total = cpu_stats->cur_cores_idle[core_idx + 1] + cpu_stats->cur_cores_nidle[core_idx + 1];
+
+    double totald = cur_total - prev_total;
+    double nidled = cpu_stats->cur_cores_nidle[core_idx + 1] - cpu_stats->prev_cores_nidle[core_idx + 1];
+
+    double percent = (nidled * 100) / (totald + 1);
+
+    return round(percent);
+}
+
+static void
+refresh_cpu_stats(struct cpu_stats *cpu_stats)
+{
+    uint32_t nb_cores = get_cpu_nb_cores();
+    int32_t core = 0;
+    uint32_t user = 0;
+    uint32_t nice = 0;
+    uint32_t system = 0;
+    uint32_t idle = 0;
+    uint32_t iowait = 0;
+    uint32_t irq = 0;
+    uint32_t softirq = 0;
+    uint32_t steal = 0;
+    uint32_t guest = 0;
+    uint32_t guestnice = 0;
+
+    FILE *fp = NULL;
+    char *line = NULL;
+    size_t len = 0;
+    ssize_t read;
+
+    fp = fopen("/proc/stat", "r");
+    if (NULL == fp) {
+        LOG_ERRNO("unable to open /proc/stat");
+        return;
+    }
+
+    while ((read = getline(&line, &len, fp)) != -1) {
+        if (strncmp(line, "cpu", sizeof("cpu") - 1) == 0) {
+            if (!parse_proc_stat_line(line, &core, &user, &nice, &system, &idle, &iowait, &irq, &softirq, &steal,
+                                            &guest, &guestnice)
+                || core < -1 || core >= (int32_t)nb_cores) {
+                LOG_ERR("unable to parse /proc/stat line");
+                goto exit;
+            }
+
+            cpu_stats->prev_cores_idle[core + 1] = cpu_stats->cur_cores_idle[core + 1];
+            cpu_stats->prev_cores_nidle[core + 1] = cpu_stats->cur_cores_nidle[core + 1];
+
+            cpu_stats->cur_cores_idle[core + 1] = idle + iowait;
+            cpu_stats->cur_cores_nidle[core + 1] = user + nice + system + irq + softirq + steal;
+        }
+    }
+exit:
+    fclose(fp);
+    free(line);
+}
+
+static struct exposable *
+content(struct module *mod)
+{
+    const struct private *p = mod->private;
+    uint32_t nb_cores = get_cpu_nb_cores();
+
+    char cpu_name[32];
+    struct tag_set tags;
+    tags.count = nb_cores + 1;
+    tags.tags = calloc(tags.count, sizeof(*tags.tags));
+    mtx_lock(&mod->lock);
+    uint8_t cpu_usage = get_cpu_usage_percent(&p->cpu_stats, -1);
+    tags.tags[0] = tag_new_int_range(mod, "cpu", cpu_usage, 0, 100);
+
+    for (uint32_t i = 0; i < nb_cores; ++i) {
+        uint8_t cpu_usage = get_cpu_usage_percent(&p->cpu_stats, i);
+        snprintf(cpu_name, sizeof(cpu_name), "cpu%u", i);
+        tags.tags[i + 1] = tag_new_int_range(mod, cpu_name, cpu_usage, 0, 100);
+    }
+    mtx_unlock(&mod->lock);
+
+    struct exposable *exposable = p->label->instantiate(p->label, &tags);
+
+    tag_set_destroy(&tags);
+    free(tags.tags);
+    return exposable;
+}
+
+static int
+run(struct module *mod)
+{
+    const struct bar *bar = mod->bar;
+    bar->refresh(bar);
+    struct private *p = mod->private;
+    while (true) {
+        struct pollfd fds[] = {{.fd = mod->abort_fd, .events = POLLIN}};
+
+        int res = poll(fds, sizeof(fds) / sizeof(*fds), p->interval);
+
+        if (res < 0) {
+            if (EINTR == errno)
+                continue;
+            LOG_ERRNO("unable to poll abort fd");
+            return -1;
+        }
+
+        if (fds[0].revents & POLLIN)
+            break;
+
+        mtx_lock(&mod->lock);
+        refresh_cpu_stats(&p->cpu_stats);
+        mtx_unlock(&mod->lock);
+        bar->refresh(bar);
+    }
+
+    return 0;
+}
+
+static struct module *
+cpu_new(uint16_t interval, struct particle *label)
+{
+    struct private *p = calloc(1, sizeof(*p));
+    p->label = label;
+    uint32_t nb_cores = get_cpu_nb_cores();
+    p->interval = interval;
+    p->cpu_stats.prev_cores_nidle = calloc(nb_cores + 1, sizeof(*p->cpu_stats.prev_cores_nidle));
+    p->cpu_stats.prev_cores_idle = calloc(nb_cores + 1, sizeof(*p->cpu_stats.prev_cores_idle));
+
+    p->cpu_stats.cur_cores_nidle = calloc(nb_cores + 1, sizeof(*p->cpu_stats.cur_cores_nidle));
+    p->cpu_stats.cur_cores_idle = calloc(nb_cores + 1, sizeof(*p->cpu_stats.cur_cores_idle));
+
+    struct module *mod = module_common_new();
+    mod->private = p;
+    mod->run = &run;
+    mod->destroy = &destroy;
+    mod->content = &content;
+    mod->description = &description;
+    return mod;
+}
+
+static struct module *
+from_conf(const struct yml_node *node, struct conf_inherit inherited)
+{
+    const struct yml_node *interval = yml_get_value(node, "interval");
+    const struct yml_node *c = yml_get_value(node, "content");
+
+    return cpu_new(interval == NULL ? SMALLEST_INTERVAL : yml_value_as_int(interval), conf_to_particle(c, inherited));
+}
+
+static bool
+conf_verify_interval(keychain_t *chain, const struct yml_node *node)
+{
+    if (!conf_verify_unsigned(chain, node))
+        return false;
+
+    if (yml_value_as_int(node) < SMALLEST_INTERVAL) {
+        LOG_ERR("%s: interval value cannot be less than %d ms", conf_err_prefix(chain, node), SMALLEST_INTERVAL);
+        return false;
+    }
+
+    return true;
+}
+
+static bool
+verify_conf(keychain_t *chain, const struct yml_node *node)
+{
+    static const struct attr_info attrs[] = {
+        {"interval", false, &conf_verify_interval},
+        MODULE_COMMON_ATTRS,
+    };
+
+    return conf_verify_dict(chain, node, attrs);
+}
+
+const struct module_iface module_cpu_iface = {
+    .verify_conf = &verify_conf,
+    .from_conf = &from_conf,
+};
+
+#if defined(CORE_PLUGINS_AS_SHARED_LIBRARIES)
+extern const struct module_iface iface __attribute__((weak, alias("module_cpu_iface")));
+#endif

modules/meson.build

@@ -17,6 +17,7 @@ mod_data = {
   'backlight': [[], [m, udev]],
   'battery': [[], [udev]],
   'clock': [[], []],
+  'cpu': [[], []],
   'mem': [[], []],
   'i3': [['i3-common.c', 'i3-common.h'], [dynlist, json]],
   'label': [[], []],

plugin.c

@@ -49,6 +49,7 @@ EXTERN_MODULE(sway_xkb);
 EXTERN_MODULE(script);
 EXTERN_MODULE(xkb);
 EXTERN_MODULE(xwindow);
+EXTERN_MODULE(cpu);
 EXTERN_MODULE(mem);
 
 EXTERN_PARTICLE(empty);
@@ -138,6 +139,7 @@ init(void)
     REGISTER_CORE_MODULE(xwindow, xwindow);
 #endif
     REGISTER_CORE_MODULE(mem, mem);
+    REGISTER_CORE_MODULE(cpu, cpu);
 
     REGISTER_CORE_PARTICLE(empty, empty);
     REGISTER_CORE_PARTICLE(list, list);