Problem with calling tx_free() when transaction is already aborted

[igchor]

Problem

In some cases, when we have complex object which holds several other objects (which allocate some memory) we can end up calling tx_free() inside of aborted transaction which will crash the application.

For example, if inside of a constructor of top level object we are constructing it's sub elements and construction of nth sub element fails (for example, because of out-of-memory), destructors of all already constructed objects will be called. If inside of those destructors we call free, application will crash.

This problem occurs for example inside segment_vector.

Solution

One solution would be to use no_abort flag for transactions. An abort would be done only in the outermost level. Inner transactions would not abort - only propagate appropriate exceptions.

[lukaszstolarczuk]

ref. #723 (support for no_abort)