Hard-restart SITL after mixed RX configuration

Author: xznhj8129

src/test/dualrx/dualrx_mixed_sitl_test.py

@@ -342,45 +342,46 @@ def configure_case(kind: str) -> list[str]:
     return commands
 
 
-def sitl_log_counts(sitl: SitlProcess) -> tuple[int, int]:
+def sitl_log_count(sitl: SitlProcess, marker: str) -> int:
     try:
         text = sitl.log_path.read_text(encoding="utf-8", errors="replace")
     except OSError:
-        return 0, 0
-    return text.count("[SYSTEM] Reset"), text.count("[SYSTEM] Init...")
+        return 0
+    return text.count(marker)
 
 
-def wait_for_sitl_reboot(
-    sitl: SitlProcess,
-    reset_count_before: int,
-    init_count_before: int,
-    timeout_s: float = 8.0,
-) -> None:
-    """Wait for CLI `save` to actually reset and finish re-execing SITL.
-
-    Waiting for the TCP port alone is insufficient: the pre-reset listener can
-    still accept a client while the delayed CLI reboot is pending, after which
-    systemReset() closes that just-opened MSP connection underneath the test.
-    """
+def wait_for_sitl_reset(sitl: SitlProcess, reset_count_before: int, timeout_s: float = 8.0) -> None:
+    """Wait until CLI `save` has persisted configuration and entered reset."""
     deadline = time.monotonic() + timeout_s
-    saw_reset = False
     last_reset_count = reset_count_before
-    last_init_count = init_count_before
     while time.monotonic() < deadline:
         sitl.check_alive()
-        last_reset_count, last_init_count = sitl_log_counts(sitl)
+        last_reset_count = sitl_log_count(sitl, "[SYSTEM] Reset")
         if last_reset_count > reset_count_before:
-            saw_reset = True
-        if saw_reset and last_init_count > init_count_before:
             return
         time.sleep(0.02)
     raise TestFailure(
-        "SITL did not complete CLI save/reboot cycle within "
-        f"{timeout_s:.1f}s (reset {reset_count_before}->{last_reset_count}, "
-        f"init {init_count_before}->{last_init_count})\n{sitl.tail_log(lines=80)}"
+        "SITL did not enter CLI save/reset cycle within "
+        f"{timeout_s:.1f}s (reset {reset_count_before}->{last_reset_count})\n"
+        f"{sitl.tail_log(lines=80)}"
     )
 
 
+def hard_restart_sitl_after_configuration(sitl: SitlProcess, reset_count_before: int) -> None:
+    """Replace SITL's in-process exec reboot with a clean harness restart.
+
+    The mixed serial layout opens UARTs lazily. During the exec-based reboot a
+    TCP listener can survive long enough for the new instance to hit EADDRINUSE,
+    leaving a receiver connected to the dying listener. Once `save` has reached
+    systemReset(), terminate that process completely and start a fresh one from
+    the saved EEPROM so every UART listener is recreated from a clean process.
+    """
+    wait_for_sitl_reset(sitl, reset_count_before)
+    sitl.stop()
+    time.sleep(0.05)
+    sitl.start()
+
+
 def run_case(kind: str, binary: Path, repo: Path, tcp_base: int, temp_dir: Path) -> None:
     eeprom = temp_dir / f"{kind}.bin"
     log_path = temp_dir / f"{kind}.log"
@@ -393,9 +394,9 @@ def run_case(kind: str, binary: Path, repo: Path, tcp_base: int, temp_dir: Path)
         msp_port = tcp_port(tcp_base, UART_MSP)
         wait_tcp("127.0.0.1", msp_port, 8.0, sitl)
         time.sleep(0.15)
-        reset_count, init_count = sitl_log_counts(sitl)
+        reset_count = sitl_log_count(sitl, "[SYSTEM] Reset")
         configure_cli("127.0.0.1", msp_port, configure_case(kind))
-        wait_for_sitl_reboot(sitl, reset_count, init_count)
+        hard_restart_sitl_after_configuration(sitl, reset_count)
         wait_tcp("127.0.0.1", msp_port, 8.0, sitl)
 
         msp = MspClient("127.0.0.1", msp_port, timeout_s=2.0)