1 files changed, 66 insertions, 0 deletions
diff --git a/mcwrapper/alarm.py b/mcwrapper/alarm.py
new file mode 100644
index 0000000..de61741
--- /dev/null
+++ b/mcwrapper/alarm.py
@@ -0,0 +1,66 @@
+# vim: expandtab ft=python ts=4 sw=4 sts=4:
+import signal
+import time
+
+# Dict with alarms. Alarm is dictionary with initial time, alarm time and
+# handler
+__alarms__ = dict()
+__alarm_wait__ = None
+
+
+def __handler__(signum, frame):
+    if __alarm_wait__["arg"] is not None:
+        __alarm_wait__["handler"](__alarm_wait__["arg"])
+    else:
+        __alarm_wait__["handler"]()
+    if not __alarm_wait__["repeat"]:
+        __alarms__.pop(__alarm_wait__["name"])
+    else:
+        __alarm_wait__["time"] = __alarm_wait__["time"] + \
+            __alarm_wait__["timeout"]
+    __update__()
+
+
+def __update__():
+    lowest = None
+    lowest_time = None
+    now = time.time()
+    for name, al in __alarms__.items():
+        t = al["time"] + al["timeout"] - now
+        if lowest_time is None or lowest_time > t:
+            lowest_time = t
+            lowest = al
+    global __alarm_wait__
+    if lowest is not None:
+        if lowest_time < 1:
+            # Less then second is missed alarm. Fire handler.
+            __alarm_wait__ = lowest
+            __handler__(None, None)
+            return
+        __alarm_wait__ = lowest
+        signal.alarm(int(lowest_time))
+    elif __alarm_wait__ is not None:
+        signal.alarm(0)  # close any alarm
+        __alarm_wait__ = None
+
+
+def init():
+    signal.signal(signal.SIGALRM, __handler__)  # prepare alarm
+
+
+def set(name, t, handler, repeat=False, arg=None):
+    al = dict()
+    al["time"] = time.time()
+    al["handler"] = handler
+    al["timeout"] = t
+    al["repeat"] = repeat
+    al["arg"] = arg
+    al["name"] = name
+    __alarms__[name] = al
+    __update__()
+
+
+def unset(name):
+    if name in __update__:
+        __alarms__.pop(name)
+        __update__()