some cleanup work

examples/simple.rs

@@ -121,8 +121,8 @@ fn main() {
         }
         dc_chatlist_unref(chats);
 
-        *running.clone().write().unwrap() = false;
+        thread::sleep(duration);
-        println!("stopping threads");
+
         // let msglist = dc_get_chat_msgs(&ctx, chat_id, 0, 0);
         // for i in 0..dc_array_get_cnt(msglist) {
         //     let msg_id = dc_array_get_id(msglist, i);
@@ -133,6 +133,9 @@ fn main() {
         // }
         // dc_array_unref(msglist);
 
+        println!("stopping threads");
+
+        *running.clone().write().unwrap() = false;
         deltachat::dc_job::dc_interrupt_imap_idle(&ctx);
         deltachat::dc_job::dc_interrupt_smtp_idle(&ctx);
 

src/dc_job.rs

@@ -59,7 +59,33 @@ pub unsafe fn dc_perform_imap_jobs(context: &Context) {
 }
 
 unsafe fn dc_job_perform(context: &Context, thread: libc::c_int, probe_network: libc::c_int) {
-    let process_row = |row: &rusqlite::Row| {
+    let query = if probe_network == 0 {
+        // processing for first-try and after backoff-timeouts:
+        // process jobs in the order they were added.
+        "SELECT id, action, foreign_id, param, added_timestamp, desired_timestamp, tries \
+         FROM jobs WHERE thread=? AND desired_timestamp<=? ORDER BY action DESC, added_timestamp;"
+    } else {
+        // processing after call to dc_maybe_network():
+        // process _all_ pending jobs that failed before
+        // in the order of their backoff-times.
+        "SELECT id, action, foreign_id, param, added_timestamp, desired_timestamp, tries \
+         FROM jobs WHERE thread=? AND tries>0 ORDER BY desired_timestamp, action DESC;"
+    };
+
+    let params_no_probe = params![thread as i64, time()];
+    let params_probe = params![thread as i64];
+    let params: &[&dyn rusqlite::ToSql] = if probe_network == 0 {
+        params_no_probe
+    } else {
+        params_probe
+    };
+
+    let jobs: Vec<dc_job_t> = context
+        .sql
+        .query_map(
+            query,
+            params,
+            |row| {
                 let job = dc_job_t {
                     job_id: row.get(0)?,
                     action: row.get(1)?,
@@ -75,30 +101,12 @@ unsafe fn dc_job_perform(context: &Context, thread: libc::c_int, probe_network:
                 let packed: String = row.get(3)?;
                 dc_param_set_packed(job.param, to_cstring(packed).as_ptr());
                 Ok(job)
-    };
+            },
-
+            |jobs| {
-    let query = if probe_network == 0 {
-        "SELECT id, action, foreign_id, param, added_timestamp, desired_timestamp, tries \
-         FROM jobs WHERE thread=? AND desired_timestamp<=? ORDER BY action DESC, added_timestamp;"
-    } else {
-        "SELECT id, action, foreign_id, param, added_timestamp, desired_timestamp, tries \
-         FROM jobs WHERE thread=? AND tries>0 ORDER BY desired_timestamp, action DESC;"
-    };
-
-    let params_no_probe = params![thread as i64, time()];
-    let params_probe = params![thread as i64];
-    let params: &[&dyn rusqlite::ToSql] = if probe_network == 0 {
-        params_no_probe
-    } else {
-        params_probe
-    };
-
-    let jobs: Vec<dc_job_t> = context
-        .sql
-        .query_map(query, params, process_row, |jobs| {
                 jobs.collect::<Result<Vec<dc_job_t>, _>>()
                     .map_err(Into::into)
-        })
+            },
+        )
         .unwrap_or_default();
 
     for mut job in jobs {
@@ -111,49 +119,34 @@ unsafe fn dc_job_perform(context: &Context, thread: libc::c_int, probe_network:
             job.action,
         );
 
+        // some configuration jobs are "exclusive":
+        // - they are always executed in the imap-thread and the smtp-thread is suspended during execution
+        // - they may change the database handle change the database handle; we do not keep old pointers therefore
+        // - they can be re-executed one time AT_ONCE, but they are not save in the database for later execution
         if 900 == job.action || 910 == job.action {
             dc_job_kill_action(context, job.action);
             dc_jobthread_suspend(context, &context.sentbox_thread.clone().read().unwrap(), 1);
             dc_jobthread_suspend(context, &context.mvbox_thread.clone().read().unwrap(), 1);
             dc_suspend_smtp_thread(context, 1);
         }
+
         let mut tries = 0;
         while tries <= 1 {
+            // this can be modified by a job using dc_job_try_again_later()
             job.try_again = 0;
+
             match job.action {
-                5901 => {
+                5901 => dc_job_do_DC_JOB_SEND(context, &mut job),
-                    dc_job_do_DC_JOB_SEND(context, &mut job);
+                110 => dc_job_do_DC_JOB_DELETE_MSG_ON_IMAP(context, &mut job),
-                }
+                130 => dc_job_do_DC_JOB_MARKSEEN_MSG_ON_IMAP(context, &mut job),
-                110 => {
+                120 => dc_job_do_DC_JOB_MARKSEEN_MDN_ON_IMAP(context, &mut job),
-                    dc_job_do_DC_JOB_DELETE_MSG_ON_IMAP(context, &mut job);
+                200 => dc_job_do_DC_JOB_MOVE_MSG(context, &mut job),
-                }
+                5011 => dc_job_do_DC_JOB_SEND(context, &mut job),
-                130 => {
+                900 => dc_job_do_DC_JOB_CONFIGURE_IMAP(context, &mut job),
-                    dc_job_do_DC_JOB_MARKSEEN_MSG_ON_IMAP(context, &mut job);
+                910 => dc_job_do_DC_JOB_IMEX_IMAP(context, &mut job),
-                }
+                5005 => dc_job_do_DC_JOB_MAYBE_SEND_LOCATIONS(context, &mut job),
-                120 => {
+                5007 => dc_job_do_DC_JOB_MAYBE_SEND_LOC_ENDED(context, &mut job),
-                    dc_job_do_DC_JOB_MARKSEEN_MDN_ON_IMAP(context, &mut job);
+                105 => sql::housekeeping(context),
-                }
-                200 => {
-                    dc_job_do_DC_JOB_MOVE_MSG(context, &mut job);
-                }
-                5011 => {
-                    dc_job_do_DC_JOB_SEND(context, &mut job);
-                }
-                900 => {
-                    dc_job_do_DC_JOB_CONFIGURE_IMAP(context, &mut job);
-                }
-                910 => {
-                    dc_job_do_DC_JOB_IMEX_IMAP(context, &mut job);
-                }
-                5005 => {
-                    dc_job_do_DC_JOB_MAYBE_SEND_LOCATIONS(context, &mut job);
-                }
-                5007 => {
-                    dc_job_do_DC_JOB_MAYBE_SEND_LOC_ENDED(context, &mut job);
-                }
-                105 => {
-                    sql::housekeeping(context);
-                }
                 _ => {}
             }
             if job.try_again != -1 {
@@ -175,6 +168,7 @@ unsafe fn dc_job_perform(context: &Context, thread: libc::c_int, probe_network:
             dc_suspend_smtp_thread(context, 0);
             break;
         } else if job.try_again == 2 {
+            // just try over next loop unconditionally, the ui typically interrupts idle when the file (video) is ready
             info!(
                 context,
                 0,

src/dc_jobthread.rs

@@ -130,26 +130,26 @@ pub unsafe fn dc_jobthread_fetch(
  ******************************************************************************/
 
 unsafe fn connect_to_imap(context: &Context, jobthread: &dc_jobthread_t) -> libc::c_int {
-    let mut ret_connected: libc::c_int;
-
     if jobthread.imap.is_connected() {
-        ret_connected = 1;
+        return 1;
-    } else {
+    }
-        ret_connected = dc_connect_to_configured_imap(context, &jobthread.imap);
+
+    let mut ret_connected = dc_connect_to_configured_imap(context, &jobthread.imap);
+
     if !(0 == ret_connected) {
         if sql::get_config_int(context, &context.sql, "folders_configured", 0) < 3 {
             jobthread.imap.configure_folders(context, 0x1);
         }
-            let mvbox_name =
+
-                sql::get_config(context, &context.sql, jobthread.folder_config_name, None);
+        if let Some(mvbox_name) =
-            if let Some(name) = mvbox_name {
+            sql::get_config(context, &context.sql, jobthread.folder_config_name, None)
-                jobthread.imap.set_watch_folder(name);
+        {
+            jobthread.imap.set_watch_folder(mvbox_name);
         } else {
             jobthread.imap.disconnect(context);
             ret_connected = 0;
         }
     }
-    }
 
     ret_connected
 }

src/dc_msg.rs

@@ -428,6 +428,10 @@ pub unsafe fn dc_msg_get_timestamp(msg: *const dc_msg_t) -> i64 {
 }
 
 pub fn dc_msg_load_from_db<'a>(msg: *mut dc_msg_t<'a>, context: &'a Context, id: u32) -> bool {
+    if msg.is_null() {
+        return false;
+    }
+
     context.sql.query_row(
         "SELECT  \
          m.id,rfc724_mid,m.mime_in_reply_to,m.server_folder,m.server_uid,m.move_state,m.chat_id,  \