feat: add memory usage client

Makefile

@@ -4,7 +4,7 @@ BINARY_DIR = /usr/bin
 SYSTEMD_DIR = /etc/systemd/system
 
 DAEMON = daemon
-CLIENTS = dummy cpu_temp
+CLIENTS = dummy cpu_temp mem_usage
 
 SYSTEM_NAME = sibyl
 

clients/CMakeLists.txt

 add_subdirectory(cpu_temp)
 add_subdirectory(dummy)
+add_subdirectory(mem_usage)

clients/mem_usage/CMakeLists.txt

+add_executable(mem_usage
+    src/mem_usage.c
+)
+
+target_link_libraries(mem_usage
+    PRIVATE common
+)

clients/mem_usage/src/mem_usage.c

+#include "../../../common/include/measurement.h"
+#include "../../../common/include/userspace_comm.h"
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/sysinfo.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/sysinfo.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[]) {
+  if (argc < 3 || argc > 3) {
+    printf("Invalid arguments provided");
+    return EXIT_FAILURE;
+  }
+
+  userspace_send_handle_t userspace_send_handle;
+  if (create_userspace_send_handle(&userspace_send_handle) == -1) {
+    perror("Failed to open message queue");
+    return EXIT_FAILURE;
+  }
+
+  int id = atoi(argv[1]);
+  int sleep_ms = atoi(argv[2]);
+
+  printf("Started mem usage (id: %d, delay: %dms)\n", id, sleep_ms);
+
+  while (1) {
+    struct sysinfo meminfo;
+    sysinfo(&meminfo);
+
+    measurement_t measurement = {
+        .data.uint64 = meminfo.totalram - meminfo.freeram,
+        .datatype = UINT64,
+        .id = id,
+    };
+
+    if (send_userspace_message(&userspace_send_handle, measurement) == -1) {
+      if (errno == EIDRM || errno == EINVAL) {
+        printf("Message queue got closed\n");
+        break;
+      }
+      perror("Failed to send message");
+    }
+
+    usleep(sleep_ms * 1000);
+  }
+
+  destroy_userspace_send_handle(&userspace_send_handle);
+
+  return EXIT_SUCCESS;
+}

systemd/clients/sibyl-mem-usage.service

+[Unit]
+Description=Sibyl Client Memory Usage (incl. Caches & Buffers)
+Wants=sibyl-daemon.service
+After=sibyl-daemon.service
+
+[Service]
+ExecStart=/usr/bin/sibyl-mem-usage 3 250
+Restart=always
+
+[Install]
+WantedBy=multi-user.target