State Model¶

To use the ecu.test code Library, it is important to understand the possible states and their transitions. The states are uninitialized, initialized, and running. Depending on the current state, different features are available. For example, a job must first be registered with ToolAccess.job("tool/myJob") before it can be called. Details about the available functions in the different states are illustrated in the state diagram below.

Transition Options¶

State changes can be carried out in two different ways:

Context Manager: When entering the context manager, the new state becomes active. Upon exiting, the ecu.test code Library automatically reverts to the previous state. This approach also ensures the connection to ecu.test is gracefully closed, even if exceptions occur.
Explicit Call: In this variant, the context manager is not used. Instead, the user calls ecutest.toolaccess.ToolAccess.init() or ecutest.toolaccess.ToolAccess.run(). In this case, the user must manually call ecutest.toolaccess.ToolAccess.stop() or ecutest.toolaccess.ToolAccess.deinit() to return to the previous state. This option offers more flexibility, e.g. for class-based tests.

Info

Even when you use the explicit transition variant (without the context manager), if an unexpected error (uncaught exception, forced termination, etc.) ends your Python process, ecu.test detects the dropped connection and automatically reverts its internal state to the initial state as if you had called ToolAccess.deinit(). This prevents ecu.test from remaining in an inconsistent state for subsequent sessions.

State diagram showing transitions between Uninitialized, Initialized and Running states — State model of the ecu.test *code* Library with the states and their transitions.¶

Examples¶

Below you will find short examples for both transition methods.

Context manager based transitions¶

from ecutest.toolaccess import ToolAccess

with ToolAccess().init() as ta:  # -> initialized
   job = ta.job("PORT/MyJob")
   with ta.run():               # -> running
      result = job(1, 2)
   # leaving run context -> initialized
# leaving init context -> uninitialized

Explicit transitions¶

from ecutest.toolaccess import ToolAccess

ta = ToolAccess()            # uninitialized
ta.init()                    # -> initialized
job = ta.job("PORT/MyJob")
ta.run()                     # -> running
result = job(1, 2)
ta.stop()                    # -> initialized
ta.deinit()                  # -> uninitialized