Reworking scheduler

TODO.FACTOR.txt

@@ -1,52 +1,26 @@
-- unix i/o: problems with passing f to syscalls
 - if a primitive throws an error, :c doesn't show the call frame there
 - "benchmark/help": without a yield UI runs out of memory
-- x11 title bars are funny
+
 + httpd:
   - outliners don't work
   - browser responder doesn't work
   - fix remaining HTML stream issues
   - update for file style prop becoming presented <file>
 
-- fix this:
-
-  [ 1 2 3 4 5 6 7 8 9 10 10 10 10 10 10 10 10 10 10 11 11 11 113 ] .
-[ 1 2 3 4 5 6 7 8 9 10 10 10 10 10 10 10 10 10 10 11 11 11 113 
-]
-
-- code walker & exceptions -- test and debug problems
-- another i/o bug: on factorcode eventually all i/o times out
-  - bug in pound?
-- factorcode httpd started using 99% CPU, but still received connections;
-  closing read-fds solved it
-- if the listener is running a command when the image is saved, it
-  restores to an unresponsive gadget
-- fix top level window positioning
-- services do not launch if factor not running
-- rollover is not updated on window focus changes
-- amd64 crash
-- x86 bootstrap intermittent crash
-- get factor running on mac intel
-- constant branch folding
-- cocoa: starting the UI with +foo switches opens them as files
-+ refactor style stack code so that nested styles are handled at a lower-level
-  - with-style & with-stream-style
-    - in HTML, we can nest div tags, etc
-  - prettyprinter's highlighting of non-leaves looks bad
-  - better line spacing in ui and html - related issue
-
-+ fix compiled gc check
-  - there was a performance hit, investigate
-  - float boxing and overflow checks need a gc check too
-
 + io:
 
+- unix i/o: problems with passing f to syscalls
+- factorcode httpd started using 99% CPU, but still received connections;
+  closing read-fds solved it
 - gdb triggers 'mutliple i/o ops on port' error
 - better i/o scheduler - eg, yield in a loop starves i/o
 - "localhost" 50 <client> won't fail
 
 + help:
 
+- refactor style stack code so that nested styles are handled at a lower-level
+  - with-style & with-stream-style
+    - in HTML, we can nest div tags, etc
 - automatically update help graph when adding/removing articles/words
 - help search:
   - edit distance algorithm
@@ -55,6 +29,15 @@
 
 + ui:
 
+- x11 title bars are funny
+- cocoa: starting the UI with +foo switches opens them as files
+- if the listener is running a command when the image is saved, it
+  restores to an unresponsive gadget
+- fix top level window positioning
+- services do not launch if factor not running
+- prettyprinter's highlighting of non-leaves doesn't really work
+- better line spacing in ui and html - related issue
+- rollover is not updated on window focus changes
 - fix listener scroll to
 - { } H{ } [ ] tabular-output -- excess newline
 - multiple listener-run-files is broken
@@ -72,8 +55,6 @@
   - only do clipping for certain gadgets
   - use glRect
   - use complex numbers instead of arrays for co-ordinates
-  - decrease minimum growable size from 50 to 4 or something, to reduce
-    memory consumption of a gadget with one child
   - use vertex arrays
   - use display lists
 - reimplement tab completion
@@ -85,6 +66,12 @@
 
 + compiler/ffi:
 
+- fix compiled gc check
+  - there was a performance hit, investigate
+  - float boxing and overflow checks need a gc check too
+- amd64 crash
+- get factor running on mac intel
+- constant branch folding
 - type inference at branch merge points
 - free up r11, r12 as a vreg on ppc
 - float= on powerpc doesn't consider nans equal
@@ -104,6 +91,13 @@
 
 + misc:
 
+- fix this:
+
+  [ 1 2 3 4 5 6 7 8 9 10 10 10 10 10 10 10 10 10 10 11 11 11 113 ] .
+[ 1 2 3 4 5 6 7 8 9 10 10 10 10 10 10 10 10 10 10 11 11 11 113 
+]
+
+- code walker & exceptions -- test and debug problems
 - slice: if sequence or seq start is changed, abstraction violation
 - make 3.4 bits>double an error
 - break: perhaps use current stdio to run break listener

doc/handbook/dataflow.facts

@@ -157,7 +157,7 @@ ARTICLE: "threads" "Multitasking"
 { $subsection run-queue }
 { $subsection sleep-queue }
 { $subsection schedule-thread }
-{ $subsection next-thread } ;
+{ $subsection idle-thread } ;
 
 ARTICLE: "continuations-internals" "Continuation implementation details"
 "A continuation is simply a tuple holding the contents of the four stacks:"

library/bootstrap/boot-stage2.factor

@@ -40,9 +40,6 @@ parser sequences sequences-internals words ;
         "Not every word compiles, by design." print
         terpri flush
 
-        "Building online help search index..." print flush
-        index-help
-
         "Initializing native I/O..." print flush
         "native-io" get [ init-io ] when
         
@@ -61,6 +58,9 @@ parser sequences sequences-internals words ;
         ] when
     ] when
         
+    "Building online help search index..." print flush
+    index-help
+    
     [
         boot
         run-user-init

library/threads.factor

@@ -19,16 +19,23 @@ namespaces queues sequences vectors ;
 : sleep-time ( sorted-queue -- ms )
     dup empty? [ drop 1000 ] [ peek first millis [-] ] if ;
 
-DEFER: next-thread
-
-: do-sleep ( -- continuation )
-    sleep-queue* dup sleep-time dup zero?
-    [ drop pop second ] [ nip io-multiplex next-thread ] if ;
-
-: next-thread ( -- continuation )
-    run-queue dup queue-empty? [ drop do-sleep ] [ deque ] if ;
-
-: stop ( -- ) next-thread continue ;
+! DEFER: next-thread
+! 
+! : do-sleep ( -- continuation )
+!     sleep-queue* dup sleep-time dup zero?
+!     [ drop pop second ] [ nip io-multiplex next-thread ] if ;
+! 
+! : next-thread ( -- continuation )
+!     run-queue dup queue-empty? [ drop do-sleep ] [ deque ] if ;
+! 
+! : stop ( -- ) next-thread continue ;
+!
+! : init-threads ( -- )
+!     global [
+!         <queue> \ run-queue set
+!         V{ } clone \ sleep-queue set
+!     ] bind ;
+: stop ( -- ) run-queue deque continue ;
 
 : yield ( -- ) [ schedule-thread stop ] callcc0 ;
 
@@ -44,8 +51,18 @@ DEFER: next-thread
         try stop
     ] callcc0 drop ;
 
+: (idle-thread) ( fast? -- )
+    #! If fast, then we don't sleep, just select()
+    sleep-queue* dup sleep-time dup zero?
+    [ drop pop second schedule-thread ]
+    [ nip 0 ? io-multiplex ] if ;
+
+: idle-thread ( -- )
+    #! This thread is always running.
+    #! If run queue is not empty, we don't sleep.
+    run-queue queue-empty? (idle-thread) yield idle-thread ;
+
 : init-threads ( -- )
-    global [
-        <queue> \ run-queue set
-        V{ } clone \ sleep-queue set
-    ] bind ;
+    <queue> \ run-queue set-global
+    V{ } clone \ sleep-queue set-global
+    [ idle-thread ] in-thread ;

library/threads.facts

@@ -20,10 +20,6 @@ HELP: sleep-time "( vector -- ms )"
 { $values { "vector" "a sorted sleep queue" } { "ms" "a non-negative integer" } }
 { $description "Outputs the time until the next sleeping thread is scheduled to wake up, or -1 if there are no sleeping threads. The input must be a sorted sleep queue output by " { $link sleep-queue* } "." } ;
 
-HELP: next-thread "( -- continuation )"
-{ $values { "continuation" "a continuation" } }
-{ $description "Outputs the next runnable thread. If there are no runnable threads, waits for a sleeping thread to wake up." } ;
-
 HELP: stop "( -- )"
 { $description "Stops the current thread." } ;
 

library/unix/io.factor

@@ -116,7 +116,7 @@ GENERIC: task-container ( task -- vector )
 
 : handle-fd ( task -- )
     dup io-task-port touch-port dup do-io-task
-    [ pop-callback continue ] [ drop ] if ;
+    [ pop-callback schedule-thread ] [ drop ] if ;
 
 : timeout? ( port -- ? )
     port-cutoff dup zero? not swap millis < and ;
@@ -125,7 +125,7 @@ GENERIC: task-container ( task -- vector )
     [
         nip dup io-task-port timeout? [
             dup io-task-port "Timeout" swap report-error
-            nip pop-callback continue
+            nip pop-callback schedule-thread
         ] [
             tuck io-task-fd swap bit-nth
             [ handle-fd ] [ drop ] if