Dynamically load libsensors at runtime

1 files changed, 105 insertions, 0 deletions

diff --git a/linux/LibSensors.c b/linux/LibSensors.c
new file mode 100644
index 00000000..1f3bd8de
--- /dev/null
+++ b/linux/LibSensors.c
@@ -0,0 +1,105 @@
+#include "LibSensors.h"
+
+#ifdef HAVE_SENSORS_SENSORS_H
+
+#include <dlfcn.h>
+#include <errno.h>
+#include <limits.h>
+#include <sensors/sensors.h>
+
+#include "XUtils.h"
+
+
+static int (*sym_sensors_init)(FILE*);
+static void (*sym_sensors_cleanup)(void);
+static const sensors_chip_name* (*sym_sensors_get_detected_chips)(const sensors_chip_name*, int*);
+static int (*sym_sensors_snprintf_chip_name)(char*, size_t, const sensors_chip_name*);
+static const sensors_feature* (*sym_sensors_get_features)(const sensors_chip_name*, int*);
+static const sensors_subfeature* (*sym_sensors_get_subfeature)(const sensors_chip_name*, const sensors_feature*, sensors_subfeature_type);
+static int (*sym_sensors_get_value)(const sensors_chip_name*, int, double*);
+
+static void* dlopenHandle = NULL;
+
+int LibSensors_init(FILE* input) {
+   if (!dlopenHandle) {
+      dlopenHandle = dlopen("libsensors.so", RTLD_LAZY);
+      if (!dlopenHandle)
+         goto dlfailure;
+
+      /* Clear any errors */
+      dlerror();
+
+      #define resolve(symbolname) do {                                      \
+         *(void **)(&sym_##symbolname) = dlsym(dlopenHandle, #symbolname);  \
+         if (!sym_##symbolname || dlerror() != NULL)                        \
+            goto dlfailure;                                                 \
+      } while(0)
+
+      resolve(sensors_init);
+      resolve(sensors_cleanup);
+      resolve(sensors_get_detected_chips);
+      resolve(sensors_snprintf_chip_name);
+      resolve(sensors_get_features);
+      resolve(sensors_get_subfeature);
+      resolve(sensors_get_value);
+
+      #undef resolve
+   }
+
+   return sym_sensors_init(input);
+
+dlfailure:
+   if (dlopenHandle) {
+      dlclose(dlopenHandle);
+      dlopenHandle = NULL;
+   }
+   return -1;
+}
+
+void LibSensors_cleanup(void) {
+   if (dlopenHandle) {
+      sym_sensors_cleanup();
+
+      dlclose(dlopenHandle);
+      dlopenHandle = NULL;
+   }
+}
+
+int LibSensors_getCPUTemperatures(CPUData* cpus, int cpuCount) {
+   if (!dlopenHandle)
+      return -ENOTSUP;
+
+   int tempCount = 0;
+
+   int n = 0;
+   for (const sensors_chip_name *chip = sym_sensors_get_detected_chips(NULL, &n); chip; chip = sym_sensors_get_detected_chips(NULL, &n)) {
+      char buffer[32];
+      sym_sensors_snprintf_chip_name(buffer, sizeof(buffer), chip);
+      if (!String_startsWith(buffer, "coretemp") && !String_startsWith(buffer, "cpu_thermal"))
+         continue;
+
+      int m = 0;
+      for (const sensors_feature *feature = sym_sensors_get_features(chip, &m); feature; feature = sym_sensors_get_features(chip, &m)) {
+         if (feature->type != SENSORS_FEATURE_TEMP)
+            continue;
+
+         if (feature->number > cpuCount)
+            continue;
+
+         const sensors_subfeature *sub_feature = sym_sensors_get_subfeature(chip, feature, SENSORS_SUBFEATURE_TEMP_INPUT);
+         if (sub_feature) {
+            double temp;
+            int r = sym_sensors_get_value(chip, sub_feature->number, &temp);
+            if (r != 0)
+               continue;
+
+            cpus[feature->number].temperature = temp;
+            tempCount++;
+         }
+      }
+   }
+
+   return tempCount;
+}
+
+#endif /* HAVE_SENSORS_SENSORS_H */