feat: close unified_exec at end of turn (#8052)

codex-rs/core/tests/common/process.rs

@@ -0,0 +1,48 @@
+use anyhow::Context;
+use std::fs;
+use std::path::Path;
+use std::time::Duration;
+
+pub async fn wait_for_pid_file(path: &Path) -> anyhow::Result<String> {
+    let pid = tokio::time::timeout(Duration::from_secs(2), async {
+        loop {
+            if let Ok(contents) = fs::read_to_string(path) {
+                let trimmed = contents.trim();
+                if !trimmed.is_empty() {
+                    return trimmed.to_string();
+                }
+            }
+            tokio::time::sleep(Duration::from_millis(25)).await;
+        }
+    })
+    .await
+    .context("timed out waiting for pid file")?;
+
+    Ok(pid)
+}
+
+pub fn process_is_alive(pid: &str) -> anyhow::Result<bool> {
+    let status = std::process::Command::new("kill")
+        .args(["-0", pid])
+        .status()
+        .context("failed to probe process liveness with kill -0")?;
+    Ok(status.success())
+}
+
+async fn wait_for_process_exit_inner(pid: String) -> anyhow::Result<()> {
+    loop {
+        if !process_is_alive(&pid)? {
+            return Ok(());
+        }
+        tokio::time::sleep(Duration::from_millis(25)).await;
+    }
+}
+
+pub async fn wait_for_process_exit(pid: &str) -> anyhow::Result<()> {
+    let pid = pid.to_string();
+    tokio::time::timeout(Duration::from_secs(2), wait_for_process_exit_inner(pid))
+        .await
+        .context("timed out waiting for process to exit")??;
+
+    Ok(())
+}