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digitalmars.D.learn - flush MessageBox

reply "Chris" <wendlec tcd.ie> writes:
Is there a way to flush a thread's message box other than 
aborting the thread? MailBox is private:

https://github.com/D-Programming-Language/phobos/blob/master/std/concurrency.d#L1778
Aug 20 2015
parent reply "John Colvin" <john.loughran.colvin gmail.com> writes:
On Thursday, 20 August 2015 at 15:25:57 UTC, Chris wrote:
 Is there a way to flush a thread's message box other than 
 aborting the thread? MailBox is private:

 https://github.com/D-Programming-Language/phobos/blob/master/std/concurrency.d#L1778
flush from inside the thread? You could call receiveTimeout with a 0 timer in a loop until it returns false.
Aug 20 2015
parent reply "Chris" <wendlec tcd.ie> writes:
On Thursday, 20 August 2015 at 15:57:47 UTC, John Colvin wrote:
 On Thursday, 20 August 2015 at 15:25:57 UTC, Chris wrote:
 Is there a way to flush a thread's message box other than 
 aborting the thread? MailBox is private:

 https://github.com/D-Programming-Language/phobos/blob/master/std/concurrency.d#L1778
flush from inside the thread? You could call receiveTimeout with a 0 timer in a loop until it returns false.
Yes, from inside the thread. I have a worker thread (with receiveTimeout) that is started when the program starts and sits there waiting for input. I naively thought this was a great idea, until I noticed that when input comes fast the mailbox grows and the bloody thread won't stop until all the items in the mailbox are processed. I was looking for something like `if (abort) { mailbox.flush(); }`
Aug 21 2015
parent reply "John Colvin" <john.loughran.colvin gmail.com> writes:
On Friday, 21 August 2015 at 10:43:22 UTC, Chris wrote:
 On Thursday, 20 August 2015 at 15:57:47 UTC, John Colvin wrote:
 On Thursday, 20 August 2015 at 15:25:57 UTC, Chris wrote:
 Is there a way to flush a thread's message box other than 
 aborting the thread? MailBox is private:

 https://github.com/D-Programming-Language/phobos/blob/master/std/concurrency.d#L1778
flush from inside the thread? You could call receiveTimeout with a 0 timer in a loop until it returns false.
Yes, from inside the thread. I have a worker thread (with receiveTimeout) that is started when the program starts and sits there waiting for input. I naively thought this was a great idea, until I noticed that when input comes fast the mailbox grows and the bloody thread won't stop until all the items in the mailbox are processed. I was looking for something like `if (abort) { mailbox.flush(); }`
void flushMailbox() { bool r; do { r = receiveTimeout(Duration.zero, (Variant _){}); } while(r); } You could optimise that to more efficiently deal with the actual types you're receiving, instead of making a Variant every time, but it's probably not worth it. The compiler might even optimise it away anyway.
Aug 21 2015
parent reply "Chris" <wendlec tcd.ie> writes:
On Friday, 21 August 2015 at 12:59:09 UTC, John Colvin wrote:
 On Friday, 21 August 2015 at 10:43:22 UTC, Chris wrote:
 On Thursday, 20 August 2015 at 15:57:47 UTC, John Colvin wrote:
 On Thursday, 20 August 2015 at 15:25:57 UTC, Chris wrote:
 Is there a way to flush a thread's message box other than 
 aborting the thread? MailBox is private:

 https://github.com/D-Programming-Language/phobos/blob/master/std/concurrency.d#L1778
flush from inside the thread? You could call receiveTimeout with a 0 timer in a loop until it returns false.
Yes, from inside the thread. I have a worker thread (with receiveTimeout) that is started when the program starts and sits there waiting for input. I naively thought this was a great idea, until I noticed that when input comes fast the mailbox grows and the bloody thread won't stop until all the items in the mailbox are processed. I was looking for something like `if (abort) { mailbox.flush(); }`
void flushMailbox() { bool r; do { r = receiveTimeout(Duration.zero, (Variant _){}); } while(r); } You could optimise that to more efficiently deal with the actual types you're receiving, instead of making a Variant every time, but it's probably not worth it. The compiler might even optimise it away anyway.
Wouldn't it be easier to have a library function that can empty the mailbox immediately? It's a waste of time to have all items in the mailbox crash against a wall, before you can go on as in [ item1 // cancel item2 ===> do nothing return; item3 ===> do nothing return; ] In parts I find std.concurrency lacking. Simple things sometimes need workarounds.
Aug 21 2015
next sibling parent "Chris" <wendlec tcd.ie> writes:
On Friday, 21 August 2015 at 14:35:53 UTC, Chris wrote:
 On Friday, 21 August 2015 at 12:59:09 UTC, John Colvin wrote:
 On Friday, 21 August 2015 at 10:43:22 UTC, Chris wrote:
 On Thursday, 20 August 2015 at 15:57:47 UTC, John Colvin 
 wrote:
 On Thursday, 20 August 2015 at 15:25:57 UTC, Chris wrote:
 Is there a way to flush a thread's message box other than 
 aborting the thread? MailBox is private:

 https://github.com/D-Programming-Language/phobos/blob/master/std/concurrency.d#L1778
flush from inside the thread? You could call receiveTimeout with a 0 timer in a loop until it returns false.
Yes, from inside the thread. I have a worker thread (with receiveTimeout) that is started when the program starts and sits there waiting for input. I naively thought this was a great idea, until I noticed that when input comes fast the mailbox grows and the bloody thread won't stop until all the items in the mailbox are processed. I was looking for something like `if (abort) { mailbox.flush(); }`
void flushMailbox() { bool r; do { r = receiveTimeout(Duration.zero, (Variant _){}); } while(r); }
Thanks by the way. This does the trick.
Aug 21 2015
prev sibling parent reply "John Colvin" <john.loughran.colvin gmail.com> writes:
On Friday, 21 August 2015 at 14:35:53 UTC, Chris wrote:
 On Friday, 21 August 2015 at 12:59:09 UTC, John Colvin wrote:
 [...]
Wouldn't it be easier to have a library function that can empty the mailbox immediately? It's a waste of time to have all items in the mailbox crash against a wall, before you can go on as in [ item1 // cancel item2 ===> do nothing return; item3 ===> do nothing return; ] In parts I find std.concurrency lacking. Simple things sometimes need workarounds.
yes, it would be better. Please file an enhancement request: https://issues.dlang.org
Aug 21 2015
parent "Chris" <wendlec tcd.ie> writes:
On Friday, 21 August 2015 at 17:05:56 UTC, John Colvin wrote:
 On Friday, 21 August 2015 at 14:35:53 UTC, Chris wrote:
 On Friday, 21 August 2015 at 12:59:09 UTC, John Colvin wrote:
 [...]
Wouldn't it be easier to have a library function that can empty the mailbox immediately? It's a waste of time to have all items in the mailbox crash against a wall, before you can go on as in [ item1 // cancel item2 ===> do nothing return; item3 ===> do nothing return; ] In parts I find std.concurrency lacking. Simple things sometimes need workarounds.
yes, it would be better. Please file an enhancement request: https://issues.dlang.org
Done. https://issues.dlang.org/show_bug.cgi?id=14953
Aug 24 2015