- The class THREAD is used to create, initialize - and destroy threads and to pass commands to these - threads. It is designed in a way to create threads - lazyly such that thread definitions can be included - in the modules directory of the aolserver and - therefore be part of the aolserver blueprints. - When an instance of THREAD is created (e.g. t1), - an init-command is provided. e.g.: + The class THREAD is used to create, initialize + and destroy threads and to pass commands to these + threads. It is designed in a way to create threads + lazyly such that thread definitions can be included + in the modules directory of the AOLserver and + therefore be part of the AOLserver blueprints. + When an instance of THREAD is created (e.g. t1), + an init-command is provided. e.g.:
- ::xotcl::THREAD create t1 {
- Class Counter -parameter {{value 1}}
- Counter instproc ++ {} {my incr value}
- Counter c1
- Counter c2
- }
+ ::xotcl::THREAD create t1 {
+ Class create Counter -parameter {{value 1}}
+ Counter instproc ++ {} {my incr value}
+ Counter create c1
+ Counter create c2
+ }
- Commands are sent to the thread via the
- "do" method, which returns the result of the
- command evaluated in the specified thread.
- When the first command is sent to a
- non-initialized thread, such as
+ Commands are sent to the thread via the
+ "do" method, which returns the result of the
+ command evaluated in the specified thread.
+ When the first command is sent to a
+ non-initialized thread, such as
- set x [t1 do c1 ++] + set x [t1 do c1 ++]- the actual thread is created and the thread - ID is remembered in a tsv array. When a - THREAD object is destroyed, the associated - thread is terminated as well. + the actual thread is created and the thread + ID is remembered in a tsv array. When a + THREAD object is destroyed, the associated + thread is terminated as well. - Notice that according to the aol-server behavior it - is possible to create **persistent threads** - (when the thread object is created during + Notice that according to the aol-server behavior it + is possible to create **persistent threads** + (when the thread object is created during startup and provided to all request threads - through the blueprint, or to create **volatile - threads** that are created during a request - and which are deleted when the thread cleanup - is called after some timeout. Volatile threads can - shared as well (when different request-threads - create the same-named thread objects) and can - be used for caching proposes. Flushing the cache - can be done in the thread's exitHandler. + through the blueprint), or to create **volatile + threads** that are created during a request + and which are deleted when the thread cleanup + is called after some timeout. Volatile threads can + shared as well (when different request-threads + create the same-named thread objects) and can + be used for caching proposes. Flushing the cache + can be done in the thread's exitHandler. - The Proxy class can be used to simplify - the interaction with a thread and to - hide the fact, that certain classes/objects - are part of a thread. The following command - creates a Proxy for an object c1 in thread t1. - After this, c1 can be used like an local object. + The Proxy class can be used to simplify + the interaction with a thread and to + hide the fact, that certain classes/objects + are part of a thread. The following command + creates a Proxy for an object c1 in thread t1. + After this, c1 can be used like an local object.
- ::xotcl::THREAD::Proxy c1 -attach t1 - set x [c1 ++] + ::xotcl::THREAD::Proxy c1 -attach t1 + set x [c1 ++]The Proxy forwards all commands to the attached thread except the methods attatch, filter, detachAll and destroy. The attach method can be used to reattach a proxy instance to a different thread, such as
- c1 attach t2 + c1 attach t2- A proxy can be (temporarily) detachted from a thread via + A proxy can be (temporarily) detachted from a thread via
- c1 filter "" + c1 filter ""Later forwarding to the thread can be re-enabled via
- c1 filter forward + c1 filter forwardWhen a proxy is attached to a thread and receives a destroy command, both the proxy @@ -93,12 +93,16 @@ ::Serializer exportObjects { ::xotcl::THREAD ::xotcl::THREAD::Client - ::xotcl::THREAD::Proxy } +# ::xotcl::THREAD::Proxy ################## main thread support ################## Class create ::xotcl::THREAD \ - -parameter {{persistent 0} {lightweight 0}} + -parameter { + {persistent 0} + {lightweight 0} + {exithandler {ns_log notice "EXITHANDLER of slave thread SELF [pid]"}} + } ::xotcl::THREAD instproc check_blueprint {} { if {![[self class] exists __blueprint_checked]} { @@ -127,10 +131,10 @@ } append initcmd { ns_thread name SELF - ::xotcl::Object setExitHandler { - #my log "EXITHANDLER of slave thread SELF [pid]" - } } + append initcmd [subst { + ::xotcl::Object setExitHandler [list [my exithandler]] + }] regsub -all SELF $initcmd [self] initcmd append initcmd \n\ [list set ::xotcl::currentScript [info script]] \n\ @@ -202,19 +206,19 @@ } nsv_set [self class] [self] $tid if {[my persistent]} { - my log "--created new persistent [self class] as $tid pid=[pid]" + my log "--created new persistent [self class] as $tid pid=[pid]" } else { - my log "--created new [self class] as $tid pid=[pid]" + my log "--created new [self class] as $tid pid=[pid]" } #my log "--THREAD DO send [self] epoch = [ns_ictl epoch]" if {[my lightweight]} { } elseif {![ns_ictl epoch]} { - #ns_log notice "--THREAD send [self] no epoch" - # We are during initialization. For some unknown reasons, XOTcl - # is not available in newly created threads, so we have to care - # for full initialization, including xotcl blueprint. - _ns_savenamespaces - set initcmd [ns_ictl get] + #ns_log notice "--THREAD send [self] no epoch" + # We are during initialization. For some unknown reasons, XOTcl + # is not available in newly created threads, so we have to care + # for full initialization, including xotcl blueprint. + _ns_savenamespaces + set initcmd [ns_ictl get] } append initcmd [my set initcmd] #ns_log notice "INIT $initcmd" @@ -231,9 +235,9 @@ if {![my exists tid]} { # this is the first call if {![my persistent] && ![my exists recreate]} { - # for a shared thread, we do ref-counting through preseve - my log "must preserve for sharing request-thread [pid]" + # for a shared thread, we do ref-counting through preserve set tid [nsv_get [self class] [self]] + my log "THREAD::PRESERVE must preserve for sharing request-thread [pid] tid $tid" ::thread::preserve $tid } my set tid $tid @@ -249,18 +253,18 @@ # create a sample persistent thread that can be acessed # via request threads #::xotcl::THREAD create t0 { -# Class Counter -parameter {{value 1}} +# Class create Counter -parameter {{value 1}} # Counter instproc ++ {} {my incr value} # -# Counter c1 -# Counter c2 +# Counter create c1 +# Counter create c2 #} -persistent 1 # ################## forwarding proxy ################## -# Class ::xotcl::THREAD::Proxy -parameter {attach} +# Class create ::xotcl::THREAD::Proxy -parameter {attach} # ::xotcl::THREAD::Proxy configure \ -# -instproc forward args { + # -instproc forward args { # set cp [self calledproc] # if { $cp eq "attach" # || $cp eq "filter" @@ -284,7 +288,7 @@ # sample Thread client routine, calls a same named object in the server thread # a thread client should be created in an connection thread dynamically to # avoid name clashes in the blueprint. - + Class create ::xotcl::THREAD::Client -parameter {server {serverobj [self]}} ::xotcl::THREAD::Client instproc do args { [my server] do [my serverobj] {*}$args