Dynamically load libsensors at runtime

CPUMeter.c

@@ -79,7 +79,7 @@ static void CPUMeter_updateValues(Meter* this, char* buffer, int size) {
       }
    }
 
-   #ifdef HAVE_LIBSENSORS
+   #ifdef HAVE_SENSORS_SENSORS_H
    if (this->pl->settings->showCPUTemperature) {
       double cpuTemperature = this->values[CPU_METER_TEMPERATURE];
       if (isnan(cpuTemperature))
@@ -150,7 +150,7 @@ static void CPUMeter_display(const Object* cast, RichString* out) {
       }
    }
 
-   #ifdef HAVE_LIBSENSORS
+   #ifdef HAVE_SENSORS_SENSORS_H
    if (this->pl->settings->showCPUTemperature) {
       char cpuTemperatureBuffer[10];
       double cpuTemperature = this->values[CPU_METER_TEMPERATURE];

DisplayOptionsPanel.c

@@ -116,8 +116,8 @@ DisplayOptionsPanel* DisplayOptionsPanel_new(Settings* settings, ScreenManager*
    Panel_add(super, (Object*) CheckItem_newByRef("Add guest time in CPU meter percentage", &(settings->accountGuestInCPUMeter)));
    Panel_add(super, (Object*) CheckItem_newByRef("Also show CPU percentage numerically", &(settings->showCPUUsage)));
    Panel_add(super, (Object*) CheckItem_newByRef("Also show CPU frequency", &(settings->showCPUFrequency)));
-   #ifdef HAVE_LIBSENSORS
+   #ifdef HAVE_SENSORS_SENSORS_H
-   Panel_add(super, (Object*) CheckItem_newByRef("Also show CPU temperature", &(settings->showCPUTemperature)));
+   Panel_add(super, (Object*) CheckItem_newByRef("Also show CPU temperature (requires libsensors)", &(settings->showCPUTemperature)));
    Panel_add(super, (Object*) CheckItem_newByRef("- Show temperature in degree Fahrenheit instead of Celsius", &(settings->degreeFahrenheit)));
    #endif
    Panel_add(super, (Object*) CheckItem_newByRef("Enable the mouse", &(settings->enableMouse)));

Makefile.am

@@ -126,6 +126,7 @@ myhtopheaders = \
 linux_platform_headers = \
 	linux/IOPriority.h \
 	linux/IOPriorityPanel.h \
+	linux/LibSensors.h \
 	linux/LinuxProcess.h \
 	linux/LinuxProcessList.h \
 	linux/Platform.h \
@@ -142,6 +143,7 @@ if HTOP_LINUX
 AM_LDFLAGS += -rdynamic
 myhtopplatsources = \
 	linux/IOPriorityPanel.c \
+	linux/LibSensors.c \
 	linux/LinuxProcess.c \
 	linux/LinuxProcessList.c \
 	linux/Platform.c \

Settings.c

@@ -183,7 +183,7 @@ static bool Settings_read(Settings* this, const char* fileName, int initialCpuCo
          this->showCPUUsage = atoi(option[1]);
       } else if (String_eq(option[0], "show_cpu_frequency")) {
          this->showCPUFrequency = atoi(option[1]);
-      #ifdef HAVE_LIBSENSORS
+      #ifdef HAVE_SENSORS_SENSORS_H
       } else if (String_eq(option[0], "show_cpu_temperature")) {
          this->showCPUTemperature = atoi(option[1]);
       } else if (String_eq(option[0], "degree_fahrenheit")) {
@@ -292,7 +292,7 @@ bool Settings_write(Settings* this) {
    fprintf(fd, "cpu_count_from_one=%d\n", (int) this->countCPUsFromOne);
    fprintf(fd, "show_cpu_usage=%d\n", (int) this->showCPUUsage);
    fprintf(fd, "show_cpu_frequency=%d\n", (int) this->showCPUFrequency);
-   #ifdef HAVE_LIBSENSORS
+   #ifdef HAVE_SENSORS_SENSORS_H
    fprintf(fd, "show_cpu_temperature=%d\n", (int) this->showCPUTemperature);
    fprintf(fd, "degree_fahrenheit=%d\n", (int) this->degreeFahrenheit);
    #endif
@@ -328,7 +328,7 @@ Settings* Settings_new(int initialCpuCount) {
    this->countCPUsFromOne = false;
    this->showCPUUsage = true;
    this->showCPUFrequency = false;
-   #ifdef HAVE_LIBSENSORS
+   #ifdef HAVE_SENSORS_SENSORS_H
    this->showCPUTemperature = false;
    this->degreeFahrenheit = false;
    #endif

Settings.h

@@ -38,7 +38,7 @@ typedef struct Settings_ {
    bool detailedCPUTime;
    bool showCPUUsage;
    bool showCPUFrequency;
-   #ifdef HAVE_LIBSENSORS
+   #ifdef HAVE_SENSORS_SENSORS_H
    bool showCPUTemperature;
    bool degreeFahrenheit;
    #endif

configure.ac

@@ -307,13 +307,11 @@ then
    ])
 fi
 
-AC_ARG_ENABLE(sensors, [AS_HELP_STRING([--enable-sensors], [enable libsensors support for reading temperature data.])],, enable_sensors="check")
+AC_ARG_ENABLE(sensors, [AS_HELP_STRING([--with-sensors], [Compile with libsensors support for reading temperature data. Only requires libsensors headers at compile time, at runtime libsensors is loaded via dlopen.])],, enable_sensors="check")
 if test "x$enable_sensors" = xyes; then
-   AC_CHECK_LIB([sensors], [sensors_get_value], [], [missing_libraries="$missing_libraries libsensors"])
    AC_CHECK_HEADERS([sensors/sensors.h], [], [missing_headers="$missing_headers $ac_header"])
 elif test "x$enable_sensors" = xcheck; then
    enable_sensors=yes
-   AC_CHECK_LIB([sensors], [sensors_get_value], [], [enable_sensors=no])
    AC_CHECK_HEADERS([sensors/sensors.h], [], [enable_sensors=no])
 fi
 

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 */

linux/LibSensors.h

@@ -0,0 +1,16 @@
+#ifndef HEADER_LibSensors
+#define HEADER_LibSensors
+
+#include "config.h" // IWYU pragma: keep
+
+#include <stdio.h>
+
+#include "LinuxProcessList.h"
+
+
+int LibSensors_init(FILE* input);
+void LibSensors_cleanup(void);
+
+int LibSensors_getCPUTemperatures(CPUData* cpus, int cpuCount);
+
+#endif /* HEADER_LibSensors */

linux/LinuxProcessList.c

@@ -53,8 +53,8 @@ in the source distribution for its full text.
 #include <sys/sysmacros.h>
 #endif
 
-#ifdef HAVE_LIBSENSORS
+#ifdef HAVE_SENSORS_SENSORS_H
-#include <sensors/sensors.h>
+#include "LibSensors.h"
 #endif
 
 
@@ -1794,41 +1794,7 @@ static void LinuxProcessList_scanCPUFrequency(LinuxProcessList* this) {
    scanCPUFreqencyFromCPUinfo(this);
 }
 
-#ifdef HAVE_LIBSENSORS
+#ifdef HAVE_SENSORS_SENSORS_H
-static int getCPUTemperatures(CPUData* cpus, int cpuCount) {
-   int tempCount = 0;
-
-   int n = 0;
-   for (const sensors_chip_name *chip = sensors_get_detected_chips(NULL, &n); chip; chip = sensors_get_detected_chips(NULL, &n)) {
-      char buffer[32];
-      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 = sensors_get_features(chip, &m); feature; feature = sensors_get_features(chip, &m)) {
-         if (feature->type != SENSORS_FEATURE_TEMP)
-            continue;
-
-         if (feature->number > cpuCount)
-            continue;
-
-         const sensors_subfeature *sub_feature = sensors_get_subfeature(chip, feature, SENSORS_SUBFEATURE_TEMP_INPUT);
-         if (sub_feature) {
-            double temp;
-            int r = sensors_get_value(chip, sub_feature->number, &temp);
-            if (r != 0)
-               continue;
-
-            cpus[feature->number].temperature = temp;
-            tempCount++;
-         }
-      }
-   }
-
-   return tempCount;
-}
-
 static void LinuxProcessList_scanCPUTemperature(LinuxProcessList* this) {
    const int cpuCount = this->super.cpuCount;
 
@@ -1836,10 +1802,10 @@ static void LinuxProcessList_scanCPUTemperature(LinuxProcessList* this) {
       this->cpus[i].temperature = NAN;
    }
 
-   int r = getCPUTemperatures(this->cpus, cpuCount);
+   int r = LibSensors_getCPUTemperatures(this->cpus, cpuCount);
 
    /* No temperature - nothing to do */
-   if (r == 0)
+   if (r <= 0)
       return;
 
    /* Only package temperature - copy to all cpus */
@@ -1878,7 +1844,7 @@ void ProcessList_goThroughEntries(ProcessList* super, bool pauseProcessUpdate) {
       LinuxProcessList_scanCPUFrequency(this);
    }
 
-   #ifdef HAVE_LIBSENSORS
+   #ifdef HAVE_SENSORS_SENSORS_H
    if (settings->showCPUTemperature)
       LinuxProcessList_scanCPUTemperature(this);
    #endif

linux/LinuxProcessList.h

@@ -48,7 +48,7 @@ typedef struct CPUData_ {
 
    double frequency;
 
-   #ifdef HAVE_LIBSENSORS
+   #ifdef HAVE_SENSORS_SENSORS_H
    double temperature;
    #endif
 } CPUData;

linux/Platform.c

@@ -61,10 +61,11 @@ in the source distribution for its full text.
 #include "zfs/ZfsArcStats.h"
 #include "zfs/ZfsCompressedArcMeter.h"
 
-#ifdef HAVE_LIBSENSORS
+#ifdef HAVE_SENSORS_SENSORS_H
-#include <sensors/sensors.h>
+#include "LibSensors.h"
 #endif
 
+
 ProcessField Platform_defaultFields[] = { PID, USER, PRIORITY, NICE, M_VIRT, M_RESIDENT, (int)M_SHARE, STATE, PERCENT_CPU, PERCENT_MEM, TIME, COMM, 0 };
 
 int Platform_numberOfFields = LAST_PROCESSFIELD;
@@ -119,14 +120,14 @@ void Platform_init(void) {
       exit(1);
    }
 
-#ifdef HAVE_LIBSENSORS
+#ifdef HAVE_SENSORS_SENSORS_H
-   sensors_init(NULL);
+   LibSensors_init(NULL);
 #endif
 }
 
 void Platform_done(void) {
-#ifdef HAVE_LIBSENSORS
+#ifdef HAVE_SENSORS_SENSORS_H
-   sensors_cleanup();
+   LibSensors_cleanup();
 #endif
 }
 
@@ -271,7 +272,7 @@ double Platform_setCPUValues(Meter* this, int cpu) {
 
    v[CPU_METER_FREQUENCY] = cpuData->frequency;
 
-#ifdef HAVE_LIBSENSORS
+#ifdef HAVE_SENSORS_SENSORS_H
    v[CPU_METER_TEMPERATURE] = cpuData->temperature;
 #else
    v[CPU_METER_TEMPERATURE] = NAN;