0002228: Possible race condition with scheduler

View Revisions: Issue #2228

Summary	0002228: Possible race condition with scheduler

Revision	2014-11-23 20:01 by Chris Young
Additional Information	I'm not sure much can be done about this except to mitigate any problems (or insist events are always picked off a shared list). I've attached a possible fix for nsgif_animate but it may not be a full solution if the content object itself has been freed too. This also ties into 2227, as if nsgif_animate stops running long before the object is destroyed this issue would not have arisen.

Revision	2014-11-23 20:01 by Chris Young
Additional Information	I'm not sure much can be done about this except to mitigate any problems (or insist events are always picked off a shared list). I've attached a possible fix for nsgif_animate but it may not be a full solution if the content object itself has been freed too. This also ties into bug#2227, as if nsgif_animate stops running long before the object is destroyed this issue would not have arisen.

Revision	2014-11-23 20:01 by Chris Young
Description	When NetSurf deletes a scheduled event, there is the possibility that it is already "in transit" to be triggered before the delete takes effect. This will occur in the following circumstance: * The triggered event is sent to the main NetSurf loop using an external (eg. OS) timer, which includes details of the callback. * The event is deleted before NetSurf returns to the main loop to pick up messages from the timer. * The callback is then called but the pointer passed may no longer be valid = crash.

Revision	2014-12-01 14:15 by Vincent Sanders
Description	When NetSurf deletes a scheduled event, there is the possibility that it is already "in transit" to be triggered before the delete takes effect. This will occur in the following circumstance: * The triggered event is sent to the main NetSurf loop using an external (eg. OS) timer, which includes details of the callback. * The event is deleted before NetSurf returns to the main loop to pick up messages from the timer. * The callback is then called but the pointer passed may no longer be valid = crash.

Revision	2014-12-01 14:15 by Vincent Sanders
Additional Information	I'm not sure much can be done about this except to mitigate any problems (or insist events are always picked off a shared list). I've attached a possible fix for nsgif_animate but it may not be a full solution if the content object itself has been freed too. This also ties into bug#2227, as if nsgif_animate stops running long before the object is destroyed this issue would not have arisen.