minor correction

[lttv.git] / ltt / branches / poly / doc / developer / lttvwindow_events_delivery.txt

diff --git a/ltt/branches/poly/doc/developer/lttvwindow_events_delivery.txt b/ltt/branches/poly/doc/developer/lttvwindow_events_delivery.txt
index e34ddf4e6baec2395d1539aec4dfcfd5a9125f6e..c7fe77d05298b3ee87f55ed0842027cdb4594118 100644 (file)
--- a/ltt/branches/poly/doc/developer/lttvwindow_events_delivery.txt
+++ b/ltt/branches/poly/doc/developer/lttvwindow_events_delivery.txt
@@ -141,8 +141,12 @@ Added to the lttvwindow API :
 
 
 void lttvwindow_events_request
 
 
 void lttvwindow_events_request

-( MainWindow                  *main_win,
-  EventsRequest                events_request);
+( Tab                  *tab,
+  const EventsRequest  *events_request);
+
+void lttvwindow_events_request_remove_all
+( Tab                *tab,
+  gconstpointer       viewer);

 
 
 Internal functions :
 
 
 Internal functions :


@@ -150,6 +154,85 @@ Internal functions :
 - lttvwindow_process_pending_requests
 
 
 - lttvwindow_process_pending_requests
 
 

+Events Requests Removal
+
+A new API function will be necessary to let viewers remove all event requests
+they have made previously. By allowing this, no more out of bound requests will
+be serviced : a viewer that sees its time interval changed before the first
+servicing is completed can clear its previous events requests and make a new
+one for the new interval needed, considering the finished chunks as completed
+area.
+
+It is also very useful for dealing with the viewer destruction case : the viewer
+just has to remove its events requests from the main window before it gets
+destroyed.
+
+
+Permitted GTK Events Between Chunks
+
+All GTK Events will be enabled between chunks. This is due to the fact that the
+background processing and a high priority request are seen as the same case.
+While a background processing is in progress, the whole graphical interface must
+be enabled.
+
+We needed to deal with the coherence of background processing and diverse GTK
+events anyway. This algorithm provides a generalized way to deal with any type
+of request and any GTK events.
+
+
+Background Computation Request
+
+The types of background computation that can be requested by a viewer : state
+computation (main window scope) or viewer specific background computation.
+
+A background computation request is asked via lttvwindow_events_request, with a
+priority field set with a low priority.
+
+In the case of a background computation with viewer pointer field set to NULL,
+if a lttvwindow_events_request_remove_all is done on the viewer pointer, it will
+not affect the state computation as no viewer pointer will have been passed in
+the initial request. This is the expected result. For the background processings
+that call viewer's hooks, they will be removed.
+
+
+A New "Redraw" Button
+
+It will be used to redraw the viewers entirely. It is useful to restart the
+servicing after a "stop" action.
+
+A New "Continue" Button
+
+It will tell the viewers to send requests for damaged areas. It is useful to
+complete the servicing after a "stop" action.
+
+
+
+Tab change
+
+If a tab change occurs, we still want to do background processing.
+Events requests must be stocked in a list located in the same scope than the
+traceset context. Right now, this is tab scope. All functions called from the
+request servicing function must _not_ use the current_tab concept, as it may
+change. The idle function must the take a tab, and not the main window, as
+parameter.
+
+If a tab is removed, its associated idle events requests servicing function must
+also be removed.
+
+It now looks a lot more useful to give a Tab* to the viewer instead of a
+MainWindow*, as all the information needed by the viewer is located at the tab
+level. It will diminish the dependance upon the current tab concept.
+
+
+
+Idle function (lttvwindow_process_pending_requests)
+
+The idle function must return FALSE to be removed from the idle functions when
+no more events requests are pending. Otherwise, it returns TRUE. It will service
+requests until there is no more request left.
+
+
+

 
 Implementation
 
 
 Implementation
 


@@ -166,25 +249,46 @@ each viewer through process traceset.
 
 - lttvwindow_events_request
 
 
 - lttvwindow_events_request
 

-It adds the EventsRequest struct to the array of time requests pending and
-registers a pending request for the next g_idle if none is registered.
+It adds the an EventsRequest struct to the array of time requests
+pending and registers a pending request for the next g_idle if none is
+registered. The viewer can access this structure during the read as its
+hook_data. Only the stop_flag can be changed by the viewer through the
+event hooks.
+
+typedef LttvEventsRequestPrio guint;

 
 typedef struct _EventsRequest {
 
 typedef struct _EventsRequest {

-  LttTime                     start_time,       /* Unset : { 0, 0 }       */
-  LttvTracesetContextPosition start_position,   /* Unset : num_traces = 0 */
-  LttTime                     end_time,         /* Unset : { 0, 0 }       */
-  guint                       num_events,       /* Unset : G_MAXUINT      */
-  LttvTracesetContextPosition end_position,     /* Unset : num_traces = 0 */
-  LttvHooksById              *before_traceset,  /* Unset : NULL           */
-  LttvHooksById              *before_trace,     /* Unset : NULL           */
-  LttvHooksById              *before_tracefile, /* Unset : NULL           */
-  LttvHooksById              *middle,           /* Unset : NULL           */
-  LttvHooksById              *after_tracefile,  /* Unset : NULL           */
-  LttvHooksById              *after_trace,      /* Unset : NULL           */
-  LttvHooksById              *after_traceset    /* Unset : NULL           */
+  gpointer                     viewer_data;
+  gboolean                     servicing;       /* service in progress: TRUE */ 
+  LttvEventsRequestPrio        prio;            /* Ev. Req. priority        */
+  LttTime                      start_time;      /* Unset : { 0, 0 }         */
+  LttvTracesetContextPosition *start_position;  /* Unset : num_traces = 0   */
+  gboolean                     stop_flag;       /* Continue:TRUE Stop:FALSE */
+  LttTime                      end_time;        /* Unset : { 0, 0 }         */
+  guint                        num_events;      /* Unset : G_MAXUINT        */
+  LttvTracesetContextPosition *end_position;    /* Unset : num_traces = 0   */
+  LttvHooks                   *before_traceset; /* Unset : NULL             */
+  LttvHooks                   *before_trace;    /* Unset : NULL             */
+  LttvHooks                   *before_tracefile;/* Unset : NULL             */
+  LttvHooks                   *event;           /* Unset : NULL             */
+  LttvHooksById               *event_by_id;     /* Unset : NULL             */
+  LttvHooks                   *after_tracefile; /* Unset : NULL             */
+  LttvHooks                   *after_trace;     /* Unset : NULL             */
+  LttvHooks                   *after_traceset;  /* Unset : NULL             */
+  LttvHooks                   *before_chunk;    /* Unset : NULL             */
+  LttvHooks                   *after_chunk      /* Unset : NULL             */

 } EventsRequest;
 
 
 } EventsRequest;
 
 

+
+- lttvwindow_events_request_remove_all
+
+It removes all the events requests from the pool that has their "viewer" field
+maching the viewer pointer given in argument.
+
+It calls the traceset/trace/tracefile end hooks for each request removed.
+
+

 - lttvwindow_process_pending_requests
 
 This internal function gets called by g_idle, taking care of the pending
 - lttvwindow_process_pending_requests
 
 This internal function gets called by g_idle, taking care of the pending


@@ -193,7 +297,18 @@ requests. It does it with the following algorithm organizing process traceset
 calls. Here is the detailed description of the way it works :
 
 
 calls. Here is the detailed description of the way it works :
 
 

-- Events Requests Servicing Algorithm
+
+- Revised Events Requests Servicing Algorithm (v2)
+
+The reads are splitted in chunks. After a chunk is over, we want to check if
+there is a GTK Event pending and execute it. It can add or remove events 
+requests from the event requests list. If it happens, we want to start over
+the algorithm from the beginning.
+
+Two levels of priority exists. High priority and low priority. High prio
+requests are serviced first, even if lower priority requests has lower start
+time or position.
+

 
 Data structures necessary :
 
 
 Data structures necessary :
 


@@ -206,60 +321,113 @@ list_in : empty
 list_out : many events requests
 
 
 list_out : many events requests
 
 

-While list_in !empty and list_out !empty
+A. While list_in !empty and list_out !empty and !GTK Event pending

   1. If list_in is empty (need a seek)
     1.1 Add requests to list_in
   1. If list_in is empty (need a seek)
     1.1 Add requests to list_in

-      1.1.1 Find all time requests with the lowest start time in list_out 
-            (ltime)
-      1.1.2 Find all position requests with the lowest position in list_out
-            (lpos)
-      1.1.3 If lpos.start time < ltime
+      1.1.1 Find all time requests with the highest priority and lowest start
+            time in list_out (ltime)
+      1.1.2 Find all position requests with the highest priority and lowest
+            position in list_out (lpos)
+      1.1.3 If lpos.prio > ltime.prio 
+                  || (lpos.prio == ltime.prio && lpos.start time < ltime)

         - Add lpos to list_in, remove them from list_out
         - Add lpos to list_in, remove them from list_out

-      1.1.4 Else, (lpos.start time >= ltime)
+      1.1.4 Else, (lpos.prio < ltime.prio 
+                        ||(lpos.prio == ltime.prio && lpos.start time >= ltime))

         - Add ltime to list_in, remove them from list_out
     1.2 Seek
       1.2.1 If first request in list_in is a time request
         - Add ltime to list_in, remove them from list_out
     1.2 Seek
       1.2.1 If first request in list_in is a time request

-        1.2.1.1 Seek to that time
+        - If first req in list_in start time != current time
+          - Seek to that time

       1.2.2 Else, the first request in list_in is a position request
       1.2.2 Else, the first request in list_in is a position request

-        1.2.2.1 Seek to that position
-    1.3 Call begin for all list_in members
-      (1.3.1 begin hooks called)
-      (1.3.2 middle hooks added)
+        - If first req in list_in pos != current pos
+          - If the position is the same than the saved state, restore state
+          - Else, seek to that position
+    1.3 Add hooks and call begin for all list_in members
+      1.3.1 If !servicing
+          - begin hooks called
+          - servicing = TRUE
+      1.3.2 call before_chunk
+      1.3.3 events hooks added

   2. Else, list_in is not empty, we continue a read
     2.1 For each req of list_out
     - if req.start time == current context time
       - Add to list_in, remove from list_out
   2. Else, list_in is not empty, we continue a read
     2.1 For each req of list_out
     - if req.start time == current context time
       - Add to list_in, remove from list_out

-      - Call begin
+      - If !servicing
+        - Call begin
+        - servicing = TRUE
+      - Call before_chunk
+      - events hooks added

     - if req.start position == current position
       - Add to list_in, remove from list_out
     - if req.start position == current position
       - Add to list_in, remove from list_out

-      - Call begin
+      - If !servicing
+        - Call begin
+        - servicing = TRUE
+      - Call before_chunk
+      - events hooks added

 
   3. Find end criterions
     3.1 End time
       3.1.1 Find lowest end time in list_in
 
   3. Find end criterions
     3.1 End time
       3.1.1 Find lowest end time in list_in

-      3.1.2 Find lowest start time in list_out
+      3.1.2 Find lowest start time in list_out (>= than current time*)
+                                * To eliminate lower prio requests

       3.1.3 Use lowest of both as end time
     3.2 Number of events
       3.2.1 Find lowest number of events in list_in
       3.1.3 Use lowest of both as end time
     3.2 Number of events
       3.2.1 Find lowest number of events in list_in

+      3.2.2 Use min(CHUNK_NUM_EVENTS, min num events in list_in) as num_events

     3.3 End position
       3.3.1 Find lowest end position in list_in
     3.3 End position
       3.3.1 Find lowest end position in list_in

-      3.3.2 Find lowest start position in list_out
+      3.3.2 Find lowest start position in list_out (>= than current
+                                                    position)

       3.3.3 Use lowest of both as end position
 
   4. Call process traceset middle
     4.1 Call process traceset middle (Use end criterion found in 3)
       3.3.3 Use lowest of both as end position
 
   4. Call process traceset middle
     4.1 Call process traceset middle (Use end criterion found in 3)

+      * note : end criterion can also be viewer's hook returning TRUE

   5. After process traceset middle
   5. After process traceset middle

+    - if current context time > traceset.end time
+      - For each req in list_in
+        - Call end for req
+        - Remove events hooks for req
+        - remove req from list_in

     5.1 For each req in list_in
           - req.num -= count
           - if req.num == 0
             - Call end for req
     5.1 For each req in list_in
           - req.num -= count
           - if req.num == 0
             - Call end for req

+            - Remove events hooks for req

             - remove req from list_in
           - if current context time > req.end time
             - Call end for req
             - remove req from list_in
           - if current context time > req.end time
             - Call end for req

+            - Remove events hooks for req

             - remove req from list_in
           - if req.end pos == current pos
             - Call end for req
             - remove req from list_in
           - if req.end pos == current pos
             - Call end for req

+            - Remove events hooks for req
+            - remove req from list_in
+          - if req.stop_flag == TRUE
+            - Call end for req
+            - Remove events hooks for req

             - remove req from list_in
             - remove req from list_in

+          - if exists one events requests in list_out that has
+                  higher priority and time != current time
+            - Use current position as start position for req
+            - Remove start time from req
+            - Call after_chunk for req
+            - Remove event hooks for req
+            - Put req back in list_out, remove from list_in
+            - Save current state into saved_state.
+
+B. When interrupted
+  1. for each request in list_in
+    1.1. Use current postition as start position
+    1.2. Remove start time
+    1.3. Call after_chunk
+    1.4. Remove event hooks
+    1.5. Put it back in list_out
+  2. Save current state into saved_state.
+    2.1 Free old saved state.
+    2.2 save current state.
+
+

 
 
 
 
 
 


@@ -269,16 +437,31 @@ If the criterion is reached, event is out of boundaries and we return.
 Current time >= End time
 Event count > Number of events
 Current position >= End position
 Current time >= End time
 Event count > Number of events
 Current position >= End position

+Last hook list called returned TRUE

 
 The >= for position is necessary to make ensure consistency between start time
 requests and positions requests that happens to be at the exact same start time
 and position.
 
 
 The >= for position is necessary to make ensure consistency between start time
 requests and positions requests that happens to be at the exact same start time
 and position.
 

+We only keep one saved state in memory. If, for example, a low priority
+servicing is interrupted, a high priority is serviced, then the low priority
+will use the saved state to start back where it was instead of seeking to the
+time. In the very specific case where a low priority servicing is interrupted,
+and then a high priority servicing on top of it is also interrupted, well, the
+low priority will loose its state and will have to seek back. It should not
+occur often. The solution to it would be to save one state per priority.
+
+
+
+

 
 
 Weaknesses
 
 
 
 Weaknesses
 

-- None (nearly?) :)
+- There is a possibility that we must use seek if more than one interruption
+  occurs, i.e. low priority interrupted by addition of high priority, and then
+  high priority interrupted. The seek will be necessary for the low priority.
+  It could be a good idea to keep one saved_state per priority ?

 
 
 Strengths
 
 
 Strengths


@@ -289,3 +472,6 @@ Strengths
 
 - Solves all the weaknesses idenfied in the actual boundaryless traceset
 reading.
 
 - Solves all the weaknesses idenfied in the actual boundaryless traceset
 reading.

+
+- Background processing available.
+