Why define threadId()? about concurrentqueue HOT 3 CLOSED

Sorry for the delay, I accidentally broke all incoming traffic (including emails, like those from GitHub) to my server :-{

There's two reasons. First, std::this_thread::get_id() is very slow on certain key platforms, like Windows (orders of magnitude slower than calling GetCurrentThreadId()). Second, the type of the object returned is implementation defined. I need a thread ID that I can use inside a special-purpose lock-free hash internally, and for that I need some sort of numeric/pointer type with a defined maximum size.

Also, ideally I need two invalid thread ID values; std::thread_id has just one. This is currently only used in code that is disabled (because it causes problems for some people), but eventually I'd like to enable that code, and for that I need a second invalid thread ID.

I only use std::thread_id on iOS because there's no better way to get a thread ID, and even then it's reinterpreted as a numeric type (this relies on platform-specific implementation details, but is better than not having support for iOS at all, and these details are at least unlikely to change).

from concurrentqueue.

Thanks for the reply. I was just curious.

On Wed, 30 Mar 2016 at 16:28 Cameron [email protected] wrote:

Sorry for the delay, I accidentally broke all incoming traffic (including
emails, like those from GitHub) to my server :-{

There's two reasons. First, std::thread::this_thread::get_id() is very
slow on certain key platforms, like Windows (orders of magnitude slower
than calling GetCurrentThreadId()). Second, the type of the object
returned is implementation defined. I need a thread ID that I can use
inside a special-purpose lock-free hash internally, and for that I need
some sort of numeric/pointer type with a defined maximum size.

I only use std::thread_id on iOS because there's no better way to get a
thread ID, and even then it's reinterpreted as a numeric type (this relies
on platform-specific implementation details, but is better than not having
support for iOS at all, and these details are at least unlikely to change).

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#43 (comment)

from concurrentqueue.

No problem :-)

from concurrentqueue.