Service request and forks

[joxoby]

There seems to be a problem when dealing with service request and forks:

Steps to reproduce

• Build and run test_service_request.cpp
• Run the executable test_service_request without arguments

Expected output

Load transport shared library BEFORE forking
Service executed: true
Service result: true
Service reply: true

Actual output

Load transport shared library BEFORE forking
Service executed: false
Service result: false
Service reply: false

Comments

If I run the executable test_service_request --random_arg to make it load the transport library after the fork, the output is:

Load transport shared library AFTER forking
Service executed: true
Service result: true
Service reply: true

The difference between both cases is that when loading the library before forking, the parent and the child share the same shared library in memory, which will make both processes share the same NodeShared singleton, and in turn, share use the same ZMQ context.

Possible solution

Create a NodeShared instance per process