MessageRouter::disconnectAllTransportsLocked flow leads to erase while iterating transports vector

[jshslt]

MessageRouter::disconnectAllTransportsLocked uses a range-based for to iterate m_transports. this conflicts with the transport disconnect flow, which leads back to MessageRouter::onDisconnected and if still connected, an erase-remove on m_transports. This invalidates the outer iterator used by disconnectAllTransportsLocked, and can lead to segfault -

#0  0x76e6609c in alexaClientSDK::acl::MessageRouter::disconnectAllTransportsLocked (this=0xa4c7b8, reason=alexaClientSDK::acl::SERVER_ENDPOINT_CHANGED) at ../../../src/ACL/src/Transport/MessageRouter.cpp:177
#1  0x76e65834 in alexaClientSDK::acl::MessageRouter::setAVSEndpoint (this=0xa4c7b8, avsEndpoint=...) at ../../../src/ACL/src/Transport/MessageRouter.cpp:91
#2  0x0007a90c in AVS2Service::setEndpointLocked (this=0xad2140) at voiceservice_avs2.cxx:576
#3  0x0007b208 in AVS2Service::handleSetEndpointDirective (this=this@entry=0xad2140, directive=...) at voiceservice_avs2.cxx:881
#4  0x0007fc48 in AVS2Service::receive (this=0xad2140, msg=...) at voiceservice_avs2.cxx:791
#5  0x76e65cec in alexaClientSDK::acl::MessageRouter::__lambda9::operator() (__closure=0xb1b96c) at ../../../src/ACL/src/Transport/MessageRouter.cpp:158

our local solution was to set m_connectionStatus = ConnectionStatus::DISCONNECTED before iterating the transports and calling disconnect() on each.

[sanjayrd]

Thank you for pointing this out @jshslt. We plan on addressing this issue in either our 0.4.1 release, which we plan on being a patch update, or the 0.5 release, which should be a general improvements update. Both of these should be coming in the next few weeks.

[scotthea-amazon]

A fix for this has been pushed in version 0.4.1.