Linux inotify support work in progress

extra/io/unix/linux/linux.factor

@@ -1,15 +1,136 @@
 ! Copyright (C) 2008 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
+USING: kernel io.backend io.monitor io.monitor.private io.files
+io.buffers io.nonblocking io.unix.backend io.unix.select
+io.unix.launcher unix.linux.inotify assocs namespaces threads
+continuations init math alien.c-types alien ;
 IN: io.unix.linux
-USING: io.backend io.unix.backend io.unix.launcher io.unix.select
-namespaces kernel assocs unix.process init ;
 
 TUPLE: linux-io ;
 
 INSTANCE: linux-io unix-io
 
+TUPLE: linux-monitor path wd callback ;
+
+: <linux-monitor> ( path wd -- monitor )
+    f (monitor) {
+        set-linux-monitor-path
+        set-linux-monitor-wd
+        set-delegate
+    } linux-monitor construct ;
+
+TUPLE: inotify watches ;
+
+: wd>path ( wd -- path )
+    inotify get-global inotify-watches at linux-monitor-path ;
+
+: <inotify> ( -- port )
+    H{ } clone
+    inotify_init dup io-error inotify <buffered-port>
+    { set-inotify-watches set-delegate } inotify construct ;
+
+: inotify-fd inotify get-global port-handle ;
+
+: watches inotify get-global inotify-watches ;
+
+: (add-watch) ( path mask -- wd )
+    inotify-fd -rot inotify_add_watch dup io-error ;
+
+: check-existing ( wd -- )
+    watches key? [
+        "Cannot open multiple monitors for the same file" throw
+    ] when ;
+
+: add-watch ( path mask -- monitor )
+    dupd (add-watch)
+    dup check-existing
+    [ <linux-monitor> dup ] keep watches set-at ;
+
+: remove-watch ( monitor -- )
+    dup linux-monitor-wd watches delete-at
+    linux-monitor-wd inotify-fd swap inotify_rm_watch io-error ;
+
+M: linux-io <monitor> ( path recursive? -- monitor )
+    drop IN_CHANGE_EVENTS add-watch ;
+
+: notify-callback ( assoc monitor -- )
+    linux-monitor-callback dup
+    [ schedule-thread-with ] [ 2drop ] if ;
+
+M: linux-io fill-queue ( monitor -- assoc )
+    dup linux-monitor-callback [
+        "Cannot wait for changes on the same file from multiple threads" throw
+    ] when
+    [ swap set-linux-monitor-callback stop ] callcc1
+    swap check-monitor ;
+
+M: linux-monitor dispose ( monitor -- )
+    dup check-monitor
+    t over set-monitor-closed?
+    H{ } over notify-callback
+    remove-watch ;
+
+: ?flag ( n mask symbol -- n )
+    pick rot bitand 0 > [ , ] [ drop ] if ;
+
+: parse-action ( mask -- changed )
+    [
+        IN_CREATE +add-file+ ?flag
+        IN_DELETE +remove-file+ ?flag
+        IN_DELETE_SELF +remove-file+ ?flag
+        IN_MODIFY +modify-file+ ?flag
+        IN_ATTRIB +modify-file+ ?flag
+        IN_MOVED_FROM +rename-file+ ?flag
+        IN_MOVED_TO +rename-file+ ?flag
+        IN_MOVE_SELF +rename-file+ ?flag
+        drop
+    ] { } make ;
+
+: parse-file-notify ( buffer -- changed path )
+    {
+        inotify-event-wd
+        inotify-event-name
+        inotify-event-mask
+    } get-slots
+    parse-action -rot alien>char-string >r wd>path r> path+ ;
+
+: events-exhausted? ( i buffer -- ? )
+    buffer-fill >= ;
+
+: inotify-event@ ( i buffer -- alien )
+    buffer-ptr <displaced-alien> ;
+
+: next-event ( i buffer -- i buffer )
+    2dup inotify-event@
+    inotify-event-len "inotify-event" heap-size +
+    swap >r + r> ;
+
+: parse-file-notifications ( i buffer -- )
+    2dup events-exhausted? [ 2drop ] [
+        2dup inotify-event@ parse-file-notify changed-file
+        next-event parse-file-notifications
+    ] if ;
+
+: read-notifications ( port -- )
+    dup refill drop
+    0 over parse-file-notifications
+    0 swap buffer-reset ;
+
+TUPLE: inotify-task ;
+
+: <inotify-task> ( port -- task )
+    f inotify-task <input-task> ;
+
+: init-inotify ( mx -- )
+    <inotify>
+    dup inotify set-global
+    <inotify-task> swap register-io-task ;
+
+M: inotify-task do-io-task ( task -- )
+    io-task-port read-notifications f ;
+
 M: linux-io init-io ( -- )
-    <select-mx> mx set-global ;
+    <select-mx> mx set-global ; ! init-inotify ;
 
 T{ linux-io } set-io-backend
 

extra/unix/linux/inotify/inotify.factor

@@ -1,6 +1,6 @@
 ! Copyright (C) 2008 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: alien.syntax ;
+USING: alien.syntax math math.bitfields ;
 IN: unix.linux.inotify
 
 C-STRUCT: inotify-event
@@ -8,7 +8,7 @@ C-STRUCT: inotify-event
     { "uint" "mask" }    ! watch mask
     { "uint" "cookie" }  ! cookie to synchronize two events
     { "uint" "len" }     ! length (including nulls) of name
-    { "char[1]" "name" } ! stub for possible name
+    { "char[0]" "name" } ! stub for possible name
     ;
 
 : IN_ACCESS HEX: 1 ; inline         ! File was accessed
@@ -37,6 +37,13 @@ C-STRUCT: inotify-event
 : IN_ISDIR HEX: 40000000 ; inline      ! event occurred against dir
 : IN_ONESHOT HEX: 80000000 ; inline    ! only send event once
 
+: IN_CHANGE_EVENTS
+    {
+        IN_MODIFY IN_ATTRIB IN_MOVED_FROM
+        IN_MOVED_TO IN_DELETE IN_CREATE IN_DELETE_SELF
+        IN_MOVE_SELF
+    } flags ; foldable
+
 : IN_ALL_EVENTS
     {
         IN_ACCESS IN_MODIFY IN_ATTRIB IN_CLOSE_WRITE
@@ -45,6 +52,6 @@ C-STRUCT: inotify-event
         IN_MOVE_SELF
     } flags ; foldable
 
-FUNCTION: int inotify_init ( void ) ;
-FUNCTION: int inotify_add_watch ( int fd, char* name, u32 mask  ) ;
-FUNCTION: int inotify_rm_watch ( int fd, u32 wd ) ;
+FUNCTION: int inotify_init ( ) ;
+FUNCTION: int inotify_add_watch ( int fd, char* name, uint mask  ) ;
+FUNCTION: int inotify_rm_watch ( int fd, uint wd ) ;

vm/os-linux.h

@@ -1,3 +1,5 @@
+#include <sys/syscall.h>
+
 #define UNKNOWN_TYPE_P(file) ((file)->d_type == DT_UNKNOWN)
 #define DIRECTORY_P(file) ((file)->d_type == DT_DIR)