1 files changed, 142 insertions, 0 deletions
diff --git a/klippy/reactor.py b/klippy/reactor.py
new file mode 100644
index 000000000..e07c64402
--- /dev/null
+++ b/klippy/reactor.py
@@ -0,0 +1,142 @@
+# File descriptor and timer event helper
+#
+# Copyright (C) 2016  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+
+import select, time, math
+
+class ReactorTimer:
+    def __init__(self, callback, waketime):
+        self.callback = callback
+        self.waketime = waketime
+
+class ReactorFileHandler:
+    def __init__(self, fd, callback):
+        self.fd = fd
+        self.callback = callback
+    def fileno(self):
+        return self.fd
+
+class SelectReactor:
+    NOW = 0.
+    NEVER = 9999999999999999.
+    def __init__(self):
+        self._fds = []
+        self._timers = []
+        self._next_timer = self.NEVER
+        self._process = True
+    # Timers
+    def _note_time(self, t):
+        nexttime = t.waketime
+        if nexttime < self._next_timer:
+            self._next_timer = nexttime
+    def update_timer(self, t, nexttime):
+        t.waketime = nexttime
+        self._note_time(t)
+    def register_timer(self, callback, waketime = NEVER):
+        handler = ReactorTimer(callback, waketime)
+        timers = list(self._timers)
+        timers.append(handler)
+        self._timers = timers
+        self._note_time(handler)
+        return handler
+    def unregister_timer(self, handler):
+        timers = list(self._timers)
+        timers.pop(timers.index(handler))
+        self._timers = timers
+    def _check_timers(self, eventtime):
+        if eventtime < self._next_timer:
+            return min(1., max(.001, self._next_timer - eventtime))
+        self._next_timer = self.NEVER
+        for t in self._timers:
+            if eventtime >= t.waketime:
+                t.waketime = t.callback(eventtime)
+            self._note_time(t)
+        if eventtime >= self._next_timer:
+            return 0.
+        return min(1., max(.001, self._next_timer - time.time()))
+    # File descriptors
+    def register_fd(self, fd, callback):
+        handler = ReactorFileHandler(fd, callback)
+        self._fds.append(handler)
+        return handler
+    def unregister_fd(self, handler):
+        self._fds.pop(self._fds.index(handler))
+    # Main loop
+    def run(self):
+        self._process = True
+        eventtime = time.time()
+        while self._process:
+            timeout = self._check_timers(eventtime)
+            res = select.select(self._fds, [], [], timeout)
+            eventtime = time.time()
+            for fd in res[0]:
+                fd.callback(eventtime)
+    def end(self):
+        self._process = False
+
+class PollReactor(SelectReactor):
+    def __init__(self):
+        SelectReactor.__init__(self)
+        self._poll = select.poll()
+        self._fds = {}
+    # File descriptors
+    def register_fd(self, fd, callback):
+        handler = ReactorFileHandler(fd, callback)
+        fds = self._fds.copy()
+        fds[fd] = callback
+        self._fds = fds
+        self._poll.register(handler, select.POLLIN | select.POLLHUP)
+        return handler
+    def unregister_fd(self, handler):
+        self._poll.unregister(handler)
+        fds = self._fds.copy()
+        del fds[handler.fd]
+        self._fds = fds
+    # Main loop
+    def run(self):
+        self._process = True
+        eventtime = time.time()
+        while self._process:
+            timeout = int(math.ceil(self._check_timers(eventtime) * 1000.))
+            res = self._poll.poll(timeout)
+            eventtime = time.time()
+            for fd, event in res:
+                self._fds[fd](eventtime)
+
+class EPollReactor(SelectReactor):
+    def __init__(self):
+        SelectReactor.__init__(self)
+        self._epoll = select.epoll()
+        self._fds = {}
+    # File descriptors
+    def register_fd(self, fd, callback):
+        handler = ReactorFileHandler(fd, callback)
+        fds = self._fds.copy()
+        fds[fd] = callback
+        self._fds = fds
+        self._epoll.register(fd, select.EPOLLIN | select.EPOLLHUP)
+        return handler
+    def unregister_fd(self, handler):
+        self._epoll.unregister(handler.fd)
+        fds = self._fds.copy()
+        del fds[handler.fd]
+        self._fds = fds
+    # Main loop
+    def run(self):
+        self._process = True
+        eventtime = time.time()
+        while self._process:
+            timeout = self._check_timers(eventtime)
+            res = self._epoll.poll(timeout)
+            eventtime = time.time()
+            for fd, event in res:
+                self._fds[fd](eventtime)
+
+# Use the poll based reactor if it is available
+try:
+    select.poll
+    Reactor = PollReactor
+except:
+    Reactor = SelectReactor