This is the mail archive of the mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Go patch committed: Multiplex goroutines onto OS threads

This patch changes the Go library to multiplex goroutines onto operating
system threads.  Previously, each new goroutine ran in a separate
thread.  That is inefficient for programs with lots of goroutines.  This
patch changes the library such that it runs a certain numbers of
threads, and lets each thread switch between goroutines.  This is how
the master Go library works, and this patch brings in code from the
master Go library, adjusted for use by gccgo.

After this it will be appropriate to adjust the channel implementation
to use the one in the master Go library, as that one works with the
scheduler.  The current gccgo channel implementation still uses mutexes
and condition variables.  It will be more efficient to hook into the
scheduler directly.

This implementation relies on the functions getcontext, setcontext, and
makecontext.  If there are systems which don't have those, getcontext
and setcontext can be replaced by setjmp and longjmp, but there is no
obvious replacement for makecontext.  I think that will have to be
implemented using processor-specific code, as it needs to set the stack
pointer to point to a new stack, and I don't know how to do that in a
portable processor-independent manner without using makecontext.

Bootstrapped and ran Go testsuite on x86_64-unknown-linux-gnu.  Tested
both with and without -fsplit-stack support.  Committed to mainline.


Attachment: foo.patch.bz2
Description: patch

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]