[boost-users][bind, signal] how to
Hello, I've got the following design: several functors ("Tasks"), when executed, "delegate" to a shared Processor object that performs some coordination between the tasks. The Processor runs the tasks at some stage, and wants to be notified by the task when it's over. However, I wouldn't like them to "know" each other. I even wouldn't like the Processor making assumptions about exact Task's "connection point" signature/name. For this purpose I want the Task to pass its "connection point" as a generic functor - so that the Processor would execute it to subscribe. However, I haven't managed to bind signal::connect. I'd appreciate any idea about what's wrong in the following schematic code: (In the real code the life-time of the objects is managed by means of shared/weak pointers, which are omitted here for the sake of simplicity!) //task.hpp class Task { public: typedef signal<void (void)> CompletionEvent; void operator ()() { // forward the execution to the processor; (*processor)(bind(&Task::run, this), bind(&CompetionEvent::connect, &done_, _1)); // this bind dosen't compile! } private: void run(); Processor *processor_; signal<void(void)> done_; }; // processor.hpp class Processor { public: void operator ()(boost::function<void(void)> task, boost::function<void(boost::function<void(void)>)> completionNotifier) { // this way I'd like to call signal::connect(bind(&Processor::taskDone, this)); completionNotifier(bind(&Processor::taskDone, this)); } private: void taskDone(); }; Thank you!
On Wed, July 16, 2008 13:18, Igor R wrote:
//task.hpp class Task { public: typedef signal<void (void)> CompletionEvent; void operator ()() { // forward the execution to the processor; (*processor)(bind(&Task::run, this), bind(&CompetionEvent::connect, &done_, _1)); // this bind dosen't compile!
This is too obvious to be the real answer, but the first thing that I see on the line you say doesn't compile is a typo in the class name. -- David Dyer-Bennet, dd-b@dd-b.net; http://dd-b.net/ Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ Photos: http://dd-b.net/photography/gallery/ Dragaera: http://dragaera.info
If I am able to understand your problem correctly sounds like you want to use active object pattern. http://en.wikipedia.org/wiki/Active_Object http://www.cs.wustl.edu/~schmidt/PDF/Act-Obj.pdf ACE has support for that not sure if boost has it. -----Original Message----- From: boost-users-bounces@lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Igor R Sent: Wednesday, July 16, 2008 2:18 PM To: boost-users@lists.boost.org Subject: [Boost-users] [boost-users][bind, signal] how to Hello, I've got the following design: several functors ("Tasks"), when executed, "delegate" to a shared Processor object that performs some coordination between the tasks. The Processor runs the tasks at some stage, and wants to be notified by the task when it's over. However, I wouldn't like them to "know" each other. I even wouldn't like the Processor making assumptions about exact Task's "connection point" signature/name. For this purpose I want the Task to pass its "connection point" as a generic functor - so that the Processor would execute it to subscribe. However, I haven't managed to bind signal::connect. I'd appreciate any idea about what's wrong in the following schematic code: (In the real code the life-time of the objects is managed by means of shared/weak pointers, which are omitted here for the sake of simplicity!) //task.hpp class Task { public: typedef signal<void (void)> CompletionEvent; void operator ()() { // forward the execution to the processor; (*processor)(bind(&Task::run, this), bind(&CompetionEvent::connect, &done_, _1)); // this bind dosen't compile! } private: void run(); Processor *processor_; signal<void(void)> done_; }; // processor.hpp class Processor { public: void operator ()(boost::function<void(void)> task, boost::function<void(boost::function<void(void)>)> completionNotifier) { // this way I'd like to call signal::connect(bind(&Processor::taskDone, this)); completionNotifier(bind(&Processor::taskDone, this)); } private: void taskDone(); }; Thank you! _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - This message is intended only for the personal and confidential use of the designated recipient(s) named above. If you are not the intended recipient of this message you are hereby notified that any review, dissemination, distribution or copying of this message is strictly prohibited. This communication is for information purposes only and should not be regarded as an offer to sell or as a solicitation of an offer to buy any financial product, an official confirmation of any transaction, or as an official statement of Lehman Brothers. Email transmission cannot be guaranteed to be secure or error-free. Therefore, we do not represent that this information is complete or accurate and it should not be relied upon as such. All information is subject to change without notice. -------- IRS Circular 230 Disclosure: Please be advised that any discussion of U.S. tax matters contained within this communication (including any attachments) is not intended or written to be used and cannot be used for the purpose of (i) avoiding U.S. tax related penalties or (ii) promoting, marketing or recommending to another party any transaction or matter addressed herein.
AMDG Igor R wrote:
Hello,
I've got the following design: several functors ("Tasks"), when executed, "delegate" to a shared Processor object that performs some coordination between the tasks. The Processor runs the tasks at some stage, and wants to be notified by the task when it's over. However, I wouldn't like them to "know" each other. I even wouldn't like the Processor making assumptions about exact Task's "connection point" signature/name. For this purpose I want the Task to pass its "connection point" as a generic functor - so that the Processor would execute it to subscribe. However, I haven't managed to bind signal::connect. I'd appreciate any idea about what's wrong in the following schematic code: (In the real code the life-time of the objects is managed by means of shared/weak pointers, which are omitted here for the sake of simplicity!)
Can't you pass a boost::signal rather than a boost::function that connects to the signal? Otherwise, try making a function object (untested): struct connect { typedef void result_type; template<class Signal, class F> void operator()(Signal& signal, const F& f) { signal.connect(f); } } ... boost::bind(connect(), boost::ref(done_), _1) In Christ, Steven Watanabe
Otherwise, try making a function object (untested):
struct connect { typedef void result_type; template<class Signal, class F> void operator()(Signal& signal, const F& f) { signal.connect(f); } } ... boost::bind(connect(), boost::ref(done_), _1)
Great, it compiles! Thanks a lot.
participants (4)
-
David Dyer-Bennet -
Igor R -
Khandelwal, Amit -
Steven Watanabe