When idle shutdown triggered _stop_server(), it was creating a new event
loop and calling server.stop() on it, but the daemon thread was still
running loop.run_forever() on the original event loop. This left sockets
bound, causing "address already in use" on restart.
Fix by storing references to the server's event loop and thread, then
using call_soon_threadsafe(loop.stop) to signal the correct loop to exit.
The thread join ensures sockets are released before the next server starts.
Co-Authored-By: Claude Opus 4.5 <[email protected]>
Replace pause-on-idle with full server shutdown after IDLE_SHUTDOWN_SECONDS
(default 5 minutes). Next visitor gets a fresh simulation instance.
- Idle checker stops server and clears st.cache_resource
- init_session_state detects stopped server and recreates fresh state
- Clears instruments and history for clean restart
Configurable via IDLE_SHUTDOWN_SECONDS environment variable.
Co-Authored-By: Claude Opus 4.5 <[email protected]>
Replace module-level singleton with @st.cache_resource decorator.
This properly survives Streamlit reruns without losing the server
reference, preventing "port already in use" errors when refreshing
the browser in Docker.
The cache is tied to the Streamlit process lifecycle, so when the
process restarts, both the cache and daemon threads are cleared
together.
Co-Authored-By: Claude Opus 4.5 <[email protected]>
Check port availability before singleton state to detect orphan servers
from previous processes. When ports are in use but singleton is None,
wait up to 5 seconds for the orphan to shut down before failing with a
clear error message.
Co-Authored-By: Claude Opus 4.5 <[email protected]>
- Add reuse_address=True to TCP server start to allow quick rebind
after process restart (TIME_WAIT state)
- Add _is_server_responsive() check to verify server is actually
responding, not just trusting the is_running flag which can be stale
if the server thread died unexpectedly
Co-Authored-By: Claude Opus 4.5 <[email protected]>
When Streamlit refreshes/reruns, session state is lost but the old
simulation server thread keeps running on ports 5001-5003. This caused
"address already in use" errors when trying to start a new server.
Solution: Use a module-level singleton for the simulation server that
persists across Streamlit reruns. The get_or_create_server() function
checks if a server is already running before creating a new one.
Co-Authored-By: Claude Opus 4.5 <[email protected]>
- Update libgdk-pixbuf2.0-0 to libgdk-pixbuf-2.0-0 for Debian Trixie
- Remove bundled nginx container in favor of host nginx
- Use host networking for cloudflared to reach host nginx
- Expose streamlit on localhost:8080 for host nginx proxy
- Physics pauses after IDLE_PAUSE_SECONDS (default 30s) of inactivity
- Resumes instantly when someone views the dashboard
- No container restart needed - just pauses the simulation loop
- CPU usage drops to ~0% when paused
- IDLE_TIMEOUT_MINUTES env var (default 30 min)
- restart: no policy so container stays stopped
- Optional wakeup service for auto-restart
- Document three restart options in readme
- IDLE_TIMEOUT_MINUTES env var to configure shutdown after inactivity
- Background thread monitors activity and exits when timeout reached
- Activity tracked via simulation_display fragment (runs while page open)
- Set to 0 (default) to disable auto-shutdown
- Wrap simulation controls in form to prevent page reruns on change
- Fix TempCo test configs to use 2+ temperature points
- Add Installation, Quick Start, and usage examples to README
Redesign integration test architecture to eliminate async/sync deadlock:
- Run SimulationServer in dedicated background thread with own event loop
- Rewrite TempCo tests as fully synchronous (no @pytest.mark.asyncio)
- Add ServerThread fixture in tests/integration/conftest.py
- Fix Unicode encoding errors (replace deg, mu, +/- with ASCII)
- Optimize temperature points for faster settling (23C, 25C, 27C)
All 3 TempCo integration tests now passing in ~5 minutes total.
- Revert server to only send responses for non-empty strings
Per SCPI protocol: successful commands with no output send nothing
- Add TEMP:RAMP command support to thermal chamber simulator
- Fixes test_multiple_commands and test_physics_engine_integration
TCP server integration tests now passing (8/8).
TempCo integration tests still need work due to async/sync mixing.
Move synchronous test execution to thread pool executor to avoid
blocking the async event loop. This prevents deadlocks when sync
client code tries to communicate with async server in same loop.
Note: Integration tests still experiencing timeouts - needs further
investigation. Unit tests and TCP server communication are working.
- Always send a response (even empty) to prevent client timeouts
- Add pandas-stubs to dev dependencies for mypy type checking
- Server now sends newline-terminated response for all commands
This fixes the mypy CI failure. Integration test failures still need
investigation - likely due to event loop blocking when mixing sync/async.
- Fix import sorting in test_instruments.py (ruff I001)
- Install pandas-stubs for mypy type checking
- Add garbage collection cleanup to repository test fixtures
- Prevent Windows file locking errors in tempfile cleanup
All CI checks now passing: lint, type check, and all 244 tests.
- Use X | None syntax instead of Optional[X] (UP045)
- Sort imports in dashboard app (I001)
- Remove unnecessary UTF-8 encoding argument (UP012)
- Add 'from err' to exception re-raises (B904)
- Remove unused imports in integration tests (F401)
- Fix useless expression in test (B018)
- Cast **1.5 result to float in LDO model (mypy no-any-return)
- Use functools.partial instead of lambda in server (mypy misc)
InstrumentServer is a general-purpose SCPI-over-TCP server that can
host any device implementing the SCPIDevice protocol (process method).
Moving it from simulation/ to instruments/transport/ reflects this:
- simulation package now depends on instruments package
- InstrumentServer can host both virtual and real instrument adapters
- Added SCPIDevice Protocol for type-safe device registration
Test connection handling, multiple clients, instrument access across
all three virtual instruments, physics engine integration, and error
handling. Update pytest-asyncio config for v1.x compatibility.
Create SimulationServer that wires physics engine to all virtual
instruments and exposes them over TCP. Add 'serve' CLI command to
start the server with configurable ports and physics rate.
Create InstrumentServer class with asyncio for hosting virtual SCPI
instruments over TCP. Supports registering instruments on specific
ports with port-to-instrument mapping.
Comprehensive test coverage for MultimeterSim including MEAS:VOLT:DC,
MEAS:CURR:DC, CONF, and READ commands. Tests both standalone operation
and physics engine integration including temperature-dependent measurements.
Implement SCPI-based virtual DMM with DC voltage and current measurement.
Supports MEAS, CONF, and READ commands. Integrates with physics engine
for DUT output measurements.
Comprehensive test coverage for PowerSupplySim including VOLT, CURR,
OUTP, and MEAS commands. Tests both standalone operation and physics
engine integration.
Implement SCPI-based virtual power supply with voltage/current control
and output enable commands. Integrates with physics engine for DUT
input voltage simulation.
kschappellandClaude Opus 4.5