src/server/worker_task.rs: implement and use status command

src/server/worker_task.rs

@@ -41,8 +41,38 @@ lazy_static! {
 }
 
 /// Test if the task is still running
-pub fn worker_is_active(upid: &UPID) -> bool {
+pub async fn worker_is_active(upid: &UPID) -> Result<bool, Error> {
+    if (upid.pid == *MY_PID) && (upid.pstart == *MY_PID_PSTART) {
+        return Ok(WORKER_TASK_LIST.lock().unwrap().contains_key(&upid.task_id));
+    }
 
+    if !procfs::check_process_running_pstart(upid.pid, upid.pstart).is_some() {
+        return Ok(false);
+    }
+
+    let socketname = format!(
+        "\0{}/proxmox-task-control-{}.sock", PROXMOX_BACKUP_VAR_RUN_DIR, upid.pid);
+
+    let cmd = json!({
+        "command": "status",
+        "upid": upid.to_string(),
+    });
+
+    let status = super::send_command(socketname, cmd).await?;
+
+    if let Some(active) = status.as_bool() {
+        Ok(active)
+    } else {
+        bail!("got unexpected result {:?} (expected bool)", status);
+    }
+}
+
+/// Test if the task is still running (fast but inaccurate implementation)
+///
+/// If the task is spanned from a different process, we simply return if
+/// that process is still running. This information is good enough to detect
+/// stale tasks...
+fn worker_is_active_local(upid: &UPID) -> bool {
     if (upid.pid == *MY_PID) && (upid.pstart == *MY_PID_PSTART) {
         WORKER_TASK_LIST.lock().unwrap().contains_key(&upid.task_id)
     } else {
@@ -60,11 +90,11 @@ pub fn create_task_control_socket() -> Result<(), Error> {
             .ok_or_else(|| format_err!("unable to parse parameters (expected json object)"))?;
         if param.keys().count() != 2 { bail!("wrong number of parameters"); }
 
-        let command = param.get("command")
+        let command = param["command"].as_str()
             .ok_or_else(|| format_err!("unable to parse parameters (missing command)"))?;
 
-        // this is the only command for now
-        if command != "abort-task" { bail!("got unknown command '{}'", command); }
+        // we have only two commands for now
+        if !(command == "abort-task" || command == "status") { bail!("got unknown command '{}'", command); }
 
         let upid_str = param["upid"].as_str()
             .ok_or_else(|| format_err!("unable to parse parameters (missing upid)"))?;
@@ -76,12 +106,24 @@ pub fn create_task_control_socket() -> Result<(), Error> {
         }
 
         let hash = WORKER_TASK_LIST.lock().unwrap();
-        if let Some(ref worker) = hash.get(&upid.task_id) {
-            worker.request_abort();
-        } else {
-            // assume task is already stopped
+
+        match command {
+            "abort-task" => {
+                if let Some(ref worker) = hash.get(&upid.task_id) {
+                    worker.request_abort();
+                } else {
+                    // assume task is already stopped
+                }
+                Ok(Value::Null)
+            }
+            "status" => {
+                let active = hash.contains_key(&upid.task_id);
+                Ok(active.into())
+            }
+            _ => {
+                bail!("got unknown command '{}'", command);
+            }
         }
-        Ok(Value::Null)
     })?;
 
     tokio::spawn(control_future);
@@ -97,7 +139,7 @@ pub fn abort_worker_async(upid: UPID) {
     });
 }
 
-pub fn abort_worker(upid: UPID) -> impl Future<Output = Result<(), Error>> {
+pub async fn abort_worker(upid: UPID) -> Result<(), Error> {
 
     let target_pid = upid.pid;
 
@@ -109,7 +151,7 @@ pub fn abort_worker(upid: UPID) -> impl Future<Output = Result<(), Error>> {
         "upid": upid.to_string(),
     });
 
-    super::send_command(socketname, cmd).map_ok(|_| ())
+    super::send_command(socketname, cmd).map_ok(|_| ()).await
 }
 
 fn parse_worker_status_line(line: &str) -> Result<(String, UPID, Option<(i64, String)>), Error> {
@@ -228,7 +270,7 @@ fn update_active_workers(new_upid: Option<&UPID>) -> Result<Vec<TaskListInfo>, E
                 Err(err) => bail!("unable to parse active worker status '{}' - {}", line, err),
                 Ok((upid_str, upid, state)) => {
 
-                    let running = worker_is_active(&upid);
+                    let running = worker_is_active_local(&upid);
 
                     if running {
                         active_list.push(TaskListInfo { upid, upid_str, state: None });