def ask_for_resource(resource, process, res_class):
'''
1. process is blocked and added to resources awaiting processes list
2. resource planner is called
'''
if resource is not None:
logger.log("Process: " + process.name + " asked for resource " + resource.name)
resource.awaiting_processes.add(process)
process.awaiting_for_creation = None
resource.distribute()
else:
# there is no such resource created
logger.log("Process: " + process.name + " asked for resource that is not yet created")
kernel_data.ACTIVE_PROCESS.state = BLOCKED_STATE
logger.log(process.name + " now waits for resource " + str(res_class) +" to be created")
process.awaiting_for_creation = res_class
kernel.schedule()
def distribute(self):
''' Algorithm that distributes resource. (Resurso planuotojas) '''
logger.log("DISTRIBUTOR called on: " + self.name)
if self.free():
logger.log("GOT TRUE")
pr = self.awaiting_processes.get()
# if there are processes waiting for this resource
# give resource to them
if pr is not None:
pr.used_resources.add(self)
pr.make_ready()
self.awaiting_processes.remove(pr)
# lock_with_semaphore when asking_for_resoure
# if resource is guarded with semaphore create lock
if hasattr(self, 'sem'):
self.sem.v()
logger.log("LOCKED SEMAPHORE on " + self.name)
else:
kernel_data.ACTIVE_PROCESS.state = BLOCKED_STATE
self.awaiting_processes.add(kernel_data.ACTIVE_PROCESS)
logger.log("GOT FALSE")
kernel.schedule()
def distribute(self):
''' Algorithm that distributes resource. (Resurso planuotojas) '''
logger.log("DISTRIBUTOR called on: " + self.name)
if self.free():
logger.log("GOT TRUE")
pr = self.awaiting_processes.get()
# if there are processes waiting for this resource
# give resource to them
if pr is not None:
pr.used_resources.add(self)
pr.make_ready()
self.awaiting_processes.remove(pr)
# lock_with_semaphore when asking_for_resoure
# if resource is guarded with semaphore create lock
if hasattr(self, 'sem'):
self.sem.v()
logger.log("LOCKED SEMAPHORE on " + self.name)
else:
kernel_data.ACTIVE_PROCESS.state = BLOCKED_STATE
self.awaiting_processes.add(kernel_data.ACTIVE_PROCESS)
logger.log("GOT FALSE")
kernel.schedule()