#
# HTCondor Week 2015 Machine Policy Tutorial Example
#
# In this example startd policy configuration, we create
# a set of "suspendable slots" that will only run jobs tagged with the
# job classad attribute +IsSuspendableJob=True, and a set of
# "non-suspendable slots" that will only run non-suspendable jobs.
# The idea here is long running suspendable jobs can 'backfill' a
# machine by essentially checkpointing to RAM.
# So for example, on a 4-core server, 8 slots will be created.
# Non-suspendable jobs will run on slots 1-4, suspendable jobs on
# slots 5-8.  Whenever a non-suspendable job arrives, the startd
# will suspend (via SIGSTOP) one suspendable slot; likewise, when
# a non-suspendable job leaves, the startd will continue (via SIGCONT)
# one suspendable job.  
#

# Lie to HTCondor, to achieve 2 slots for each real slot
NUM_CPUS = $(DETECTED_CORES)*2

# There is no good way to tell HTCondor that the two slots should be treated
# as though they share the same real memory, so lie about how much
# memory we have.
MEMORY = $(DETECTED_MEMORY)*2

# Slots 1 through DETECTED_CORES are nonsuspendable and the rest are
# suspendable
IsSuspendableSlot = SlotID > $(DETECTED_CORES)

# If I am a suspendable slot, my corresponding nonsuspendable slot is
# my SlotID minus $(DETECTED_CORES)
NonSuspendableSlotState = eval(strcat("slot",SlotID-$(DETECTED_CORES),"_State"))

# The above expression looks at slotX_State, so we need to add
# State to the list of slot attributes to advertise
STARTD_SLOT_ATTRS = $(STARTD_SLOT_ATTRS) State

# For convenience, advertise these expressions in the machine ad.
STARTD_ATTRS = $(STARTD_ATTRS) IsSuspendableSlot NonSuspendableSlotState

MyNonSuspendableSlotIsIdle = \
     (NonSuspendableSlotState =!= "Claimed" && \
	  NonSuspendableSlotState =!= "Preempting")

#NonSuspendable slots are always willing to start jobs.
#Suspendable slots are only willing to start if the NonSuspendable slot is idle
START = \
	IsSuspendableSlot!=True && IsSuspendableJob=!=True || \
	IsSuspendableSlot && IsSuspendableJob==True && $(MyNonSuspendableSlotIsIdle)

# Suspend the suspendable slot if the other slot is busy.
SUSPEND = \
	IsSuspendableSlot && $(MyNonSuspendableSlotIsIdle)!=True
CONTINUE = ($(SUSPEND)) != True