Re:New Concurrent Hash Maps for C++
by vardump on Wednesday February 03, 2016 @12:07AM
(#11024822)
Yeah, I was talking about spinlocks.
You're right that context switches would dominate std::mutex. For some reason I was thinking std::mutex uses spinlocks, even though I knew better. Too much kernel side coding lately - context switches are often not possible there, so mutexes are often not possible as potential synchronization mechanisms.
Re:New Concurrent Hash Maps for C++
by gpderetta on Friday February 05, 2016 @12:56PM
(#11043221)
You might still be right. The implementation of std::mutex is unspecified, and real world implementations will probably spin a bit before going into the kernel, so for your test case with a tiny critical section it might behave like a spinlock.
You're right that context switches would dominate std::mutex. For some reason I was thinking std::mutex uses spinlocks, even though I knew better. Too much kernel side coding lately - context switches are often not possible there, so mutexes are often not possible as potential synchronization mechanisms.