set timer [after 50 set z timeout]
    vwait z
    after cancel $timer
    set z
} -cleanup {
    close $f
} -result [list {del calling recursive} {del deleted notcalled} \
	       {del deleted myself} {del after recursive}]
test io-50.6 {testing handler deletion vs reentrant calls} -constraints {testchannelevent testservicemode} -setup {
    file delete $path(test1)
} -body {
    set f [open $path(test1) w]
    close $f
    proc first {f} {
	variable u
	variable z
	variable done
	if {"$u" == "toplevel"} {
	    lappend z "first called"
	    set u first
	    set timer [after 50 lappend z timeout]
	    vwait z
	    after cancel $timer
	    lappend z "first after toplevel"
	    set done 1
	} else {
	    lappend z "first called not toplevel"
	}
    }
    proc second {f} {
	variable u
	variable z

	} else {
	    lappend z "second called, cannot happen!"
	    testchannelevent $f removeall
	}
    }
    set z ""
    set u toplevel
    set done 0
    testservicemode 0
    set f [open $path(test1) r]
    testchannelevent $f add readable [namespace code [list second $f]]
    testchannelevent $f add readable [namespace code [list first $f]]
    testservicemode 1
    update
    if {!$done} {
	set $timer2 [after 200 lappend done timeout]
	vwait done
	after cancel timer2
    }
    set z
} -cleanup {
    close $f
} -result [list {first called} {first called not toplevel} \
	{second called, first time} {second called, second time} \
	{first after toplevel}]

test io-51.1 {Test old socket deletion on Macintosh} {socket} {
    set x 0
    set result ""
    proc accept {s a p} {
	variable x
	variable wait
	fconfigure $s -blocking off