Fix no-such-process error

src/_ert/forward_model_runner/forward_model_step.py

@@ -183,7 +183,7 @@ async def _run(self) -> "AsyncGenerator[Start | Exited | Running | None]":
                 stderr=stderr,
                 env=self._create_environment(),
             )
-            process = Process(proc.pid)
+
         except OSError as e:
             exited_message = self._handle_process_io_error_and_create_exited_message(
                 e, stderr
@@ -195,9 +195,9 @@ async def _run(self) -> "AsyncGenerator[Start | Exited | Running | None]":
         exit_code = None
 
         max_memory_usage = 0
-        fm_step_pids = {int(process.pid)}
+        fm_step_pids = {int(proc.pid)}
         while exit_code is None:
-            (memory_rss, cpu_seconds, oom_score) = _get_processtree_data(process)
+            (memory_rss, cpu_seconds, oom_score) = _get_processtree_data(proc.pid)
             max_memory_usage = max(memory_rss, max_memory_usage)
             yield Running(
                 self,
@@ -223,9 +223,11 @@ async def _run(self) -> "AsyncGenerator[Start | Exited | Running | None]":
                     yield potential_exited_msg
 
                     return
-                fm_step_pids |= {
-                    int(child.pid) for child in process.children(recursive=True)
-                }
+                with contextlib.suppress(NoSuchProcess):
+                    proccess = Process(proc.pid)
+                    fm_step_pids |= {
+                        int(child.pid) for child in proccess.children(recursive=True)
+                    }
 
         ensure_file_handles_closed([stdin, stdout, stderr])
         exited_message = self._create_exited_message_based_on_exit_code(
@@ -438,7 +440,7 @@ def ensure_file_handles_closed(file_handles: Sequence[io.TextIOWrapper | None])
 
 
 def _get_processtree_data(
-    process: Process,
+    pid: int,
 ) -> Tuple[int, float, Optional[int]]:
     """Obtain the oom_score (the Linux kernel uses this number to
     decide which process to kill first in out-of-memory siturations).
@@ -460,21 +462,19 @@ def _get_processtree_data(
     memory_rss = 0
     cpu_seconds = 0.0
     with contextlib.suppress(ValueError, FileNotFoundError):
-        oom_score = int(
-            Path(f"/proc/{process.pid}/oom_score").read_text(encoding="utf-8")
-        )
-    with (
-        contextlib.suppress(
-            ValueError, NoSuchProcess, AccessDenied, ZombieProcess, ProcessLookupError
-        ),
-        process.oneshot(),
+        oom_score = int(Path(f"/proc/{pid}/oom_score").read_text(encoding="utf-8"))
+    with contextlib.suppress(
+        ValueError, NoSuchProcess, AccessDenied, ZombieProcess, ProcessLookupError
     ):
-        memory_rss = process.memory_info().rss
-        cpu_seconds = process.cpu_times().user
+        process = Process(pid)
+        with process.oneshot():
+            memory_rss = process.memory_info().rss
+            cpu_seconds = process.cpu_times().user
 
     with contextlib.suppress(
         NoSuchProcess, AccessDenied, ZombieProcess, ProcessLookupError
     ):
+        process = Process(pid)
         for child in process.children(recursive=True):
             with contextlib.suppress(
                 ValueError,