Search found 17077 matches

by bob
Mon Feb 01, 2021 1:47 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Proportion of time for fixed depth vs. quiescent search
Replies: 6
Views: 1422

Re: Proportion of time for fixed depth vs. quiescent search

easy enough. Don't "give" it an amount of time to use and fix the depth based on that. Instead, start the search and stop when time runs out...
by bob
Fri Dec 18, 2020 4:50 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Asynchronous tablebase lookups
Replies: 9
Views: 2092

Re: Asynchronous tablebase lookups

This is not a new idea. Same thing occurs in a cluster chess engine where you distribute the transposition across all nodes. Latency is high compared to local memory. There are several papers around on cluster chess engines. You might give 'em a whirl to see what has been done in the past. The bigge...
by bob
Mon Dec 14, 2020 3:12 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Position Causes Stockfish and Komodo To Crash
Replies: 135
Views: 18224

Re: Position Causes Stockfish and Komodo To Crash

Someone recently wasted their time writing up 20 paragraphs showing how they could "exploit" Stockfish into crashing.... If you send a chess engine garbage, you should expect garbage. If you don't know it is garbage, then maybe a GUI should be doing it for you. The above has been affirmed many time...
by bob
Thu Nov 12, 2020 3:39 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Killing zombies (POSIX)
Replies: 16
Views: 3139

Re: Killing zombies (POSIX)

I am not sure why your example fails. IE when the parent dies, the kernel should change the PPID to 1, which lets "init" take over as the parent, where it will absorb those SIGCHLD signals and wait() to get their status and dismiss 'em. Of course, you do have to make sure the processes terminate, ot...
by bob
Mon Nov 09, 2020 5:17 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Killing zombies (POSIX)
Replies: 16
Views: 3139

Re: Killing zombies (POSIX)

The most elegant solution to this is to do the following: (1) I assume you use either fork() or to spawn new processes. Either works. (2) in the code that does the fork (the one where fork returns pid of child you need to catch the signal SIGCHLD. When a process terminates in unix/linux/etc, the O/S...
by bob
Tue Oct 06, 2020 12:39 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Performance loss when removing unused function
Replies: 11
Views: 2948

Re: Performance loss when removing unused function

You might check out your compilers many alignment optimization options...
by bob
Sun Jul 19, 2020 2:57 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Data structure choice for TT
Replies: 35
Views: 15788

Re: Data structure choice for TT

This is a bit confusing using normal terminology. "age" refers to the search that an entry is stored. IE it advances once for each real move played on the board. The idea is to let you recognize entries that come from the previous search (which might be great for the current search or completely use...
by bob
Sun Jul 19, 2020 2:46 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Mind your language
Replies: 16
Views: 5305

Re: Mind your language

In 1969/1970 PL/1 was "the up and coming language" with bits of Algol, FORTRAN and COBOL included. And then in the 80's it was ADA. There is always going to be the next great language that turns out to be "not so great". C is 50 years old. That much history can't be completely wrong.
by bob
Sun Jul 12, 2020 1:34 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Idea for ID/transposition table
Replies: 7
Views: 3010

Re: Idea for ID/transposition table

Probably would work, but you won't have a PV for the best move at that point. Would be sort of an odd circumstance as to how this might happen, however. There's a moderately good chance that the PV can be recreated by following the stored best move from the hash for as far as it goes, which optimal...
by bob
Sat Jul 11, 2020 2:53 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Idea for ID/transposition table
Replies: 7
Views: 3010

Re: Idea for ID/transposition table

Probably would work, but you won't have a PV for the best move at that point.

Would be sort of an odd circumstance as to how this might happen, however.