question about getting input when searching

[Cesar Contreras]

Geschrieben von:/Posted by: Cesar Contreras at 12 August 2004 01:48:02:

I'm working on getting winboard or user input when searching, to force a move or to quit, because my current public version receibe the message only when the search finish. Current public version does the next:
main() {
do {
gets(message);
...
...
// Process message
...
...
} while (message!="quit");
}
I have now a private version that creates a thread to receibe input, and all i do is to ask in the search function if is there any new message to process.
But my problem it's that now the main function uses too much CPU time polling a function to see if there is a new message:
main()
{
create_threat_for_input();
do {
// Next line is the problem, the program waste valuable time polling
// for a message instead of bloking until getting a message.
while(is_there_a_message()==false) {};
messaje=last_message();
...
...
// Process message
...
...
} while (message!="quit");
}
I now can poll for input during search, and it seems to work ok, now i can force a move or quit while searching, but at the cost of wasting time when not in search. Now my program waste CPU time when it's not calculating!!. I have seen other engines, and those don't waste time when waiting for input. I'm missing something.
I'm looking for an alternative, something like a way to block the main thread until getting a message, or trigering an event.
Any help is apreciated.
Thanks in advance.

[Pham]

Geschrieben von:/Posted by: Pham at 12. August 2004 06:08:
Als Antwort auf:/In reply to: question about getting input when searching geschrieben von:/posted by: Cesar Contreras at 12 August 2004 01:48:02:

I think your problem concerns with priority of threads.
You may try one of follows:
- Set priority of thread for getting messages lower.
- Do the opposite thing: use the loop in main function to send/receive message and create a new thread for computing moves (I do like this for my program).
Pham

I'm working on getting winboard or user input when searching, to force a move or to quit, because my current public version receibe the message only when the search finish. Current public version does the next:
main() {
do {
gets(message);
...
...
// Process message
...
...
} while (message!="quit");
}
I have now a private version that creates a thread to receibe input, and all i do is to ask in the search function if is there any new message to process.
But my problem it's that now the main function uses too much CPU time polling a function to see if there is a new message:
main()
{
create_threat_for_input();
do {
// Next line is the problem, the program waste valuable time polling
// for a message instead of bloking until getting a message.
while(is_there_a_message()==false) {};
messaje=last_message();
...
...
// Process message
...
...
} while (message!="quit");
}
I now can poll for input during search, and it seems to work ok, now i can force a move or quit while searching, but at the cost of wasting time when not in search. Now my program waste CPU time when it's not calculating!!. I have seen other engines, and those don't waste time when waiting for input. I'm missing something.
I'm looking for an alternative, something like a way to block the main thread until getting a message, or trigering an event.
Any help is apreciated.
Thanks in advance.

[Leo Dijksman]

Geschrieben von:/Posted by: Leo Dijksman at 12 August 2004 06:43:16:
Als Antwort auf:/In reply to: question about getting input when searching geschrieben von:/posted by: Cesar Contreras at 12 August 2004 01:48:02:

I'm working on getting winboard or user input when searching, to force a move or to quit, because my current public version receibe the message only when the search finish. Current public version does the next:
main() {
do {
gets(message);
...
...
// Process message
...
...
} while (message!="quit");
}
I have now a private version that creates a thread to receibe input, and all i do is to ask in the search function if is there any new message to process.
But my problem it's that now the main function uses too much CPU time polling a function to see if there is a new message:
main()
{
create_threat_for_input();
do {
// Next line is the problem, the program waste valuable time polling
// for a message instead of bloking until getting a message.
while(is_there_a_message()==false) {};
messaje=last_message();
...
...
// Process message
...
...
} while (message!="quit");
}
I now can poll for input during search, and it seems to work ok, now i can force a move or quit while searching, but at the cost of wasting time when not in search. Now my program waste CPU time when it's not calculating!!. I have seen other engines, and those don't waste time when waiting for input. I'm missing something.
I'm looking for an alternative, something like a way to block the main thread until getting a message, or trigering an event.
Any help is apreciated.
Thanks in advance.

Have you read the message below?
Maby it helps.
Leo.


message

[Volker Boehm]

Geschrieben von:/Posted by: Volker Boehm at 12 August 2004 08:04:57:
Als Antwort auf:/In reply to: question about getting input when searching geschrieben von:/posted by: Cesar Contreras at 12 August 2004 01:48:02:

I'm working on getting winboard or user input when searching, to force a move or to quit, because my current public version receibe the message only when the search finish. Current public version does the next:
main() {
do {
gets(message);
...
...
// Process message
...
...
} while (message!="quit");
}
I have now a private version that creates a thread to receibe input, and all i do is to ask in the search function if is there any new message to process.
But my problem it's that now the main function uses too much CPU time polling a function to see if there is a new message:
main()
{
create_threat_for_input();
do {
// Next line is the problem, the program waste valuable time polling
// for a message instead of bloking until getting a message.
while(is_there_a_message()==false) {};
messaje=last_message();
...
...
// Process message
...
...
} while (message!="quit");
}
I now can poll for input during search, and it seems to work ok, now i can force a move or quit while searching, but at the cost of wasting time when not in search. Now my program waste CPU time when it's not calculating!!. I have seen other engines, and those don't waste time when waiting for input. I'm missing something.
I'm looking for an alternative, something like a way to block the main thread until getting a message, or trigering an event.
Any help is apreciated.
Thanks in advance.

Hi,
one thread, the thread for input is a thread that blocks until a message arrives. If it is a message for the main thread than set a "there_is_a_message" flag, I called it "stop".
Now while searching you can poll for the stop flag. Just test it seldom. I test it the beginning of negamax (or search or alphabeta however you call it) and not in quiescense.
Thus
Negamax (aplpha, beta, depth)
{
if stop() return;
...
}
Set the same stop flag if you run out of time, then you have only one if for every pre-frontier node. That does not take time at all.
Greetings Volker

[Anthony Cozzie]

Geschrieben von:/Posted by: Anthony Cozzie at 12 August 2004 15:06:52:
Als Antwort auf:/In reply to: question about getting input when searching geschrieben von:/posted by: Cesar Contreras at 12 August 2004 01:48:02:

I'm working on getting winboard or user input when searching, to force a move or to quit, because my current public version receibe the message only when the search finish. Current public version does the next:
main() {
do {
gets(message);
...
...
// Process message
...
...
} while (message!="quit");
}
I have now a private version that creates a thread to receibe input, and all i do is to ask in the search function if is there any new message to process.
But my problem it's that now the main function uses too much CPU time polling a function to see if there is a new message:
main()
{
create_threat_for_input();
do {
// Next line is the problem, the program waste valuable time polling
// for a message instead of bloking until getting a message.
while(is_there_a_message()==false) {};
messaje=last_message();
...
...
// Process message
...
...
} while (message!="quit");
}
I now can poll for input during search, and it seems to work ok, now i can force a move or quit while searching, but at the cost of wasting time when not in search. Now my program waste CPU time when it's not calculating!!. I have seen other engines, and those don't waste time when waiting for input. I'm missing something.
I'm looking for an alternative, something like a way to block the main thread until getting a message, or trigering an event.
Any help is apreciated.
Thanks in advance.

You need synchronization. Lookup online about mutexes and events. Those can cause a thread to block.
anthony

[Cesar Contreras]

Geschrieben von:/Posted by: Cesar Contreras at 12 August 2004 22:37:08:
Als Antwort auf:/In reply to: question about getting input when searching geschrieben von:/posted by: Cesar Contreras at 12 August 2004 01:48:02:

I'm working on getting winboard or user input when searching, to force a move or to quit, because my current public version receibe the message only when the search finish. Current public version does the next:
main() {
do {
gets(message);
...
...
// Process message
...
...
} while (message!="quit");
}
I have now a private version that creates a thread to receibe input, and all i do is to ask in the search function if is there any new message to process.
But my problem it's that now the main function uses too much CPU time polling a function to see if there is a new message:
main()
{
create_threat_for_input();
do {
// Next line is the problem, the program waste valuable time polling
// for a message instead of bloking until getting a message.
while(is_there_a_message()==false) {};
messaje=last_message();
...
...
// Process message
...
...
} while (message!="quit");
}
I now can poll for input during search, and it seems to work ok, now i can force a move or quit while searching, but at the cost of wasting time when not in search. Now my program waste CPU time when it's not calculating!!. I have seen other engines, and those don't waste time when waiting for input. I'm missing something.
I'm looking for an alternative, something like a way to block the main thread until getting a message, or trigering an event.
Any help is apreciated.
Thanks in advance.