Transparent (endpoint-preserving) restarts with identity transfer
are meant to exercise the crash recovery system only. After *real*
crashes, such restarts are useless at best and dangerous at worst,
because no state integrity can be guaranteed afterwards. Thus,
except after a controlled crash, it is best not to perform such
restarts at all. This patch changes SEF such that identity transfer
is successful only if the old process was the subject of a crash
induced through "service fi". As a result, testrelpol.sh should
continue to be able to use identity transfers for testing purposes,
but any real crash will be handled more appropriately.
This fixes#126.
Change-Id: Idc17ac7b3dfee05098529cb889ac835a0cd03ef0
- do not allow live update for request and protocol free states if
there are any worker threads that have pending or active work;
- destroy all worker threads before such live updates and recreate
them afterwards, because transferring (the contents of) the
thread stacks is not an option at this time;
- recreate worker threads in the new instance only if they were
shut down before the state transfer, by letting RS provide the
original preparation state as initialization information.
Change-Id: I846225f5b7281f19e69175485f2c88a4b4891dc2
The 'memory' service has holes in its data section, which causes
problems during state transfer. Since VM cannot handle page faults
during a multicomponent-with-VM live update, the state transfer must
ensure that no page faults occur during copying. Therefore, we now
query VM about the regions to copy, thus skipping holes. While the
solution is not ideal, it is sufficiently generic that it can be used
for the data section state transfer of all processes, and possibly
for state transfer of other regions in the future as well.
Change-Id: I2a71383a18643ebd36956c396fbd22c8fd137202
VM used to call sendrec to send a boot-time RS_INIT reply to RS, but
RS could run into a pagefault at the same time, thus spawning a
message to VM, resulting in a deadlock. We resolve this situation by
making VM acknowledge RS_INIT asynchronously at boot time, while
retaining the synchronous sendrec for subsequent RS_INIT responses.
Change-Id: I3cb72d7f8d6b9bfdc59a85958ada739c37fa3bde
