def __init__(self, maxThreads, taskBufferSize=0,
taskTimeout=0):
self._mapTiles = modrana.m.get("mapTiles")
self._storeTiles = modrana.m.get("storeTiles")
# if task buffer size is set, start leaking
# old tile download requests from the bottom of the
# request stack once it becomes full, as we don't want
# the work queue to block and discarding old tile
# download requests is not an issue
leak = taskBufferSize >= 0
self._pool = LifoThreadPool(maxThreads,
name=constants.THREAD_POOL_AUTOMATIC_TILE_DOWNLOAD,
taskBufferSize=taskBufferSize,
leak=leak)
# in seconds, 0 == no task timeout
self._taskTimeout = taskTimeout
self._running = set()
self._runningLock = threading.RLock()
# due to GIL, we don't have a lock
# for the set of tile downloads
# in progress (hopefully)
self._imageSurface = self._mapTiles.cacheImageSurfaces
