[common] cpuinfo: implement for linux by parsing /proc/cpuinfo

common/src/platform/linux/CMakeLists.txt

@@ -16,6 +16,7 @@ add_library(lg_common_platform_code STATIC
     time.c
     paths.c
     open.c
+    cpuinfo.c
 )
 
 if(ENABLE_BACKTRACE)

common/src/platform/linux/cpuinfo.c

@@ -0,0 +1,76 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2021 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "common/cpuinfo.h"
+#include "common/debug.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+bool lgCPUInfo(char * model, size_t modelSize, int * procs, int * cores)
+{
+  FILE * cpuinfo = fopen("/proc/cpuinfo", "r");
+  if (!cpuinfo)
+  {
+    DEBUG_ERROR("Failed to open /proc/cpuinfo: %s", strerror(errno));
+    return false;
+  }
+
+  if (procs)
+    *procs = 0;
+
+  if (cores)
+    *cores = 0;
+
+  char buffer[1024];
+  while (fgets(buffer, sizeof(buffer), cpuinfo))
+  {
+    if (procs && strncmp(buffer, "processor", 9) == 0)
+      ++*procs;
+    else if (model && strncmp(buffer, "model name", 10) == 0)
+    {
+      const char * name = strstr(buffer, ": ");
+      if (name)
+        name += 2;
+      snprintf(model, modelSize, "%s", name ? name : "Unknown");
+      model = NULL;
+    }
+    else if (cores && strncmp(buffer, "cpu cores", 9) == 0)
+    {
+      const char * num = strstr(buffer, ": ");
+      if (num)
+      {
+        *cores = atoi(num + 2);
+        cores = NULL;
+      }
+    }
+
+    // If a line is too long, skip it.
+    while (buffer[strlen(buffer) - 1] != '\n')
+      if (!fgets(buffer, sizeof(buffer), cpuinfo))
+        goto done;
+  }
+
+done:
+  fclose(cpuinfo);
+  return true;
+}