Lock affected rows when assigning local IDs
Lock the targeted device when calculating the next heartbeat and crash
report local IDs. Lock the targeted crash report when calculating the
next log file local ID.
This change prevents race conditions that have occured previously.
Issue: HIC-251
Change-Id: I80a8498849e20769b0ab36afe68e6c20b3108c6d
diff --git a/crashreports/models.py b/crashreports/models.py
index f76c894..a405620 100644
--- a/crashreports/models.py
+++ b/crashreports/models.py
@@ -46,17 +46,19 @@
@transaction.atomic
def get_crashreport_key(self):
"""Get the next key for a crashreport and update the ID-counter."""
- ret = self.next_per_crashreport_key
- self.next_per_crashreport_key = self.next_per_crashreport_key + 1
- self.save()
+ device = Device.objects.select_for_update().get(id=self.id)
+ ret = device.next_per_crashreport_key
+ device.next_per_crashreport_key += 1
+ device.save()
return ret
@transaction.atomic
def get_heartbeat_key(self):
"""Get the next key for a heartbeat and update the ID-counter."""
- ret = self.next_per_heartbeat_key
- self.next_per_heartbeat_key = self.next_per_heartbeat_key + 1
- self.save()
+ device = Device.objects.select_for_update().get(id=self.id)
+ ret = device.next_per_heartbeat_key
+ device.next_per_heartbeat_key += 1
+ device.save()
return ret
@@ -118,9 +120,10 @@
@transaction.atomic
def get_logfile_key(self):
"""Get the next key for a log file and update the ID-counter."""
- ret = self.next_logfile_key
- self.next_logfile_key = self.next_logfile_key + 1
- self.save()
+ crashreport = Crashreport.objects.select_for_update().get(id=self.id)
+ ret = crashreport.next_logfile_key
+ crashreport.next_logfile_key += 1
+ crashreport.save()
return ret
def save(