On Sat, 31 Dec 2011 23:28:09 +0100, dsimcha <[email protected]> wrote:
I have a plan to avoid the GC lock for most small (<1 page) GC
allocations. I hope to have a pull request within a week or two, in
time for the next release. There's one detail I need clarified by Sean,
Walter or someone who designed the D GC.
Currently small allocations are handled by popping a block off a free
list, if a block is available. I plan to make each page owned by a
single thread, and make the free lists thread-local. The array of free
lists (one for each power of two size) is stored in the Gcx struct. The
easiest way to make this array thread-local is to move it out of the Gcx
struct and make it global. Is there any reason why >1 instance of Gcx
would exist (maybe as an implementation detail of shared libraries,
etc.)? If not, what's to point of having the Gcx struct instead of just
making its variables global?
Not for shared libraries.
You should probably wrap multiple TLS variables in a struct and put only
a reference into TLS to reduce the expense of thread local access.
