class FrameManager:
def __init__(self, frames, hdd):
self._frames = frames
self._free_frames = frames
self._table = PaginationTable()
self._hdd = hdd
def update_free_frames(self):
self._free_frames = list(filter(lambda frame: not frame.is_in_use(), self._frames))
def map_page_to_frame(self, pcb):
print("Attempting to Assign Page for PCB ID: " + str(pcb._id))
pcb_pages = pcb.get_pages()
page = self.__not_used_page(pcb_pages)
#self._hdd.add_to_swap(page)
pages = self._hdd.find_page(page.get_index())
if pages:
page = pages[0]
return self.__update_page_and_frames(page)
def __update_page_and_frames(self,page):
policy_result = self.assign(page)
self.update_free_frames()
return policy_result
def get_frames_of_pcb(self,pcb):
self._frames
def __not_used_page(self,pcb_pages):
return FunctionsForLists.findFirst(lambda page: not page.has_been_used(), pcb_pages)
def free_frame_available(self):
return len(self._free_frames) > 0
def empty_youngest_frame(self):
youngest = min(self._frames, key=lambda x: x.get_life())
self._hdd.add_to_swap(youngest)
youngest.set_not_in_use()
def assign(self, page):
if self.free_frame_available():
policy_result = self._table.put_page(page, self._frames, self._free_frames)
print("Page successfuly assigned!")
return policy_result
else:
self.empty_youngest_frame()
self.update_free_frames()
print("A frame became empty!")
self.assign(page)
def get_frames(self):
return self._frames
class TableTest(unittest.TestCase):
# Arrange
def setUp(self):
self.frame1 = Frame(0, 0, 9)
self.frame2 = Frame(1, 10, 19)
self.frame3 = Frame(2, 20, 29)
self.frame4 = Frame(3, 30, 39)
self.frames = [self.frame1, self.frame2, self.frame3, self.frame4]
self.table = PaginationTable()
def test_whenIPutAPage_ThenItSavesAndFramesLifeIsIncreased(self):
page = Page(0, 0, 9, 10)
self.table.put_page(page, self.frames, self.frames)
self.assertEqual(self.frame1.get_life(), 0)
self.assertEqual(self.frame2.get_life(), 1)
self.assertEqual(self.frame3.get_life(), 1)
self.assertEqual(self.frame4.get_life(), 1)
def test_whenIPutTwoPages_ThenTheyAreSavedAndFramesLifeIsIncreased(self):
page1 = Page(0, 0, 9, 10)
page2 = Page(0, 0, 9, 10)
self.table.put_page(page1, self.frames, self.frames)
free_frames = [self.frame2, self.frame3, self.frame4]
self.table.put_page(page2, self.frames, free_frames)
self.assertEqual(self.frame1.get_life(), 1)
self.assertEqual(self.frame2.get_life(), 0)
self.assertEqual(self.frame3.get_life(), 2)
self.assertEqual(self.frame4.get_life(), 2)