Hooked up simulation to BEsim

src/bedit_simulation/openmodelica.py

@@ -4,8 +4,10 @@ from __future__ import annotations
 
 import asyncio
 import os
+import signal
 import shlex
 import subprocess
+import time
 from collections.abc import Callable, Mapping, Sequence
 from dataclasses import dataclass
 from pathlib import Path
@@ -27,6 +29,10 @@ class OpenModelicaError(RuntimeError):
     """Raised when OMC cannot start or reports a failure."""
 
 
+class SimulationCancelledError(RuntimeError):
+    """Raised when a running compiled simulation is cancelled."""
+
+
 ProcessExecutor = Callable[
     [Sequence[str], Path, float | None, Mapping[str, str] | None],
     ProcessResult,
@@ -89,6 +95,58 @@ class OpenModelicaRunner:
         """Run OMC on an asyncio worker thread."""
         return await _run_on_worker(self._run, script, working_directory)
 
+    def _run_cancellable(self, script: Path, working_directory: Path, cancel_event: Event) -> ProcessResult:
+        command = (*self.command, str(script.resolve()))
+        return self._run_cancellable_process(command, working_directory, cancel_event)
+
+    def _run_cancellable_process(self, command: Sequence[str], working_directory: Path, cancel_event: Event) -> ProcessResult:
+        process_environment = None
+        if self.environment is not None:
+            process_environment = {**os.environ, **self.environment}
+        try:
+            process = subprocess.Popen(list(command), cwd=working_directory, env=process_environment, text=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE, start_new_session=os.name != "nt")
+        except OSError as exc:
+            raise OpenModelicaError(f"simulation executable could not start: {exc}") from exc
+        deadline = time.monotonic() + self.timeout if self.timeout is not None else None
+        while True:
+            if cancel_event.is_set():
+                _terminate_process(process)
+                try:
+                    stdout, stderr = process.communicate(timeout=5)
+                except subprocess.TimeoutExpired:
+                    _kill_process(process)
+                    stdout, stderr = process.communicate()
+                raise SimulationCancelledError("simulation was cancelled")
+            if deadline is not None and time.monotonic() >= deadline:
+                _kill_process(process)
+                process.communicate()
+                raise OpenModelicaError(f"simulation timed out after {self.timeout} seconds")
+            try:
+                stdout, stderr = process.communicate(timeout=0.05)
+                break
+            except subprocess.TimeoutExpired:
+                continue
+        result = ProcessResult(command=tuple(command), return_code=process.returncode, stdout=stdout, stderr=stderr)
+        if result.return_code != 0:
+            details = result.stderr.strip() or result.stdout.strip()
+            suffix = f": {details}" if details else ""
+            raise OpenModelicaError(f"simulation exited with status {result.return_code}{suffix}")
+        return result
+
+
+def _terminate_process(process: subprocess.Popen[str]) -> None:
+    if os.name == "nt":
+        process.terminate()
+    else:
+        os.killpg(process.pid, signal.SIGTERM)
+
+
+def _kill_process(process: subprocess.Popen[str]) -> None:
+    if os.name == "nt":
+        process.kill()
+    else:
+        os.killpg(process.pid, signal.SIGKILL)
+
 
 def _command_parts(command: str | Sequence[str]) -> tuple[str, ...]:
     if isinstance(command, str):
@@ -140,7 +198,7 @@ async def _run_on_worker(
     def invoke() -> None:
         try:
             results.append(operation(*args, **kwargs))
-        except BaseException as error:
+        except Exception as error:  # noqa: BLE001 - worker must relay operation failures
             errors.append(error)
         finally:
             finished.set()