[common] linux: implement timers

common/src/platform/linux/CMakeLists.txt

@@ -11,6 +11,7 @@ add_library(lg_common_platform_code STATIC
     thread.c
     event.c
     ivshmem.c
+    time.c
 )
 
 if(ENABLE_BACKTRACE)
@@ -20,4 +21,5 @@ endif()
 target_link_libraries(lg_common_platform_code
 	lg_common
 	pthread
+	rt
 )

common/src/platform/linux/time.c

@@ -0,0 +1,109 @@
+/*
+Looking Glass - KVM FrameRelay (KVMFR) Client
+Copyright (C) 2020-2020 Max Sistemich <maximilian.sistemich@rwth-aachen.de>
+https://looking-glass.hostfission.com
+
+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/time.h"
+#include "common/debug.h"
+
+#include <errno.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+struct LGTimer
+{
+  LGTimerFn   fn;
+  void      * udata;
+  timer_t     id;
+  bool        running;
+};
+
+static void TimerProc(union sigval arg)
+{
+  LGTimer * timer = (LGTimer *)arg.sival_ptr;
+  if (!timer->fn(timer->udata))
+  {
+    if (timer_delete(timer->id))
+      DEBUG_ERROR("failed to destroy the timer: %s", strerror(errno));
+    timer->running = false;
+  }
+}
+
+bool lgCreateTimer(const unsigned int intervalMS, LGTimerFn fn,
+    void * udata, LGTimer ** result)
+{
+  LGTimer * ret = malloc(sizeof(LGTimer));
+
+  if (!ret)
+  {
+    DEBUG_ERROR("failed to malloc LGTimer struct");
+    return false;
+  }
+
+  ret->fn      = fn;
+  ret->udata   = udata;
+  ret->running = true;
+
+  struct sigevent sev =
+  {
+    .sigev_notify = SIGEV_THREAD,
+    .sigev_notify_function = &TimerProc,
+    .sigev_value.sival_ptr = ret,
+  };
+
+  if (timer_create(CLOCK_MONOTONIC, &sev, &ret->id))
+  {
+    DEBUG_ERROR("failed to create timer: %s", strerror(errno));
+    free(ret);
+    return false;
+  }
+
+  struct timespec interval =
+  {
+    .tv_sec = 0,
+    .tv_nsec = intervalMS * 1000 * 1000,
+  };
+  struct itimerspec spec =
+  {
+    .it_interval = interval,
+    .it_value = interval,
+  };
+
+  if (timer_settime(ret->id, 0, &spec, NULL))
+  {
+    DEBUG_ERROR("failed to set timer: %s", strerror(errno));
+    timer_delete(ret->id);
+    free(ret);
+    return false;
+  }
+
+  *result = ret;
+  return true;
+}
+
+void lgTimerDestroy(LGTimer * timer)
+{
+  if (timer->running)
+  {
+    if (timer_delete(timer->id))
+      DEBUG_ERROR("failed to destroy the timer: %s", strerror(errno));
+  }
+
+  free(timer);
+}