(Thanks to ken and rsc for pointing this out)
rsc:
ken pointed out that there's a race in the new
one-lock-per-channel code. the issue is that
if one goroutine has gone to sleep doing
select {
case <-c1:
case <-c2:
}
and then two more goroutines try to send
on c1 and c2 simultaneously, the way that
the code makes sure only one wins is the
selgen field manipulation in dequeue:
// if sgp is stale, ignore it
if(sgp->selgen != sgp->g->selgen) {
//prints("INVALID PSEUDOG POINTER\n");
freesg(c, sgp);
goto loop;
}
// invalidate any others
sgp->g->selgen++;
but because the global lock is gone both
goroutines will be fiddling with sgp->g->selgen
at the same time.
This results in a 7% slowdown in the single threaded case for a
ping-pong microbenchmark.
Since the cas predominantly succeeds, adding a simple check first
didn't make any difference.
R=rsc
CC=golang-dev
https://golang.org/cl/180068
The change to assign.go is because the gcc testsuite fails to
handle .* in a normal way: it matches against the entire
compiler output, not just a single line.
assign.go:15:6: error: incompatible types in assignment (implicit assignment of 'sync.Mutex' hidden field 'key')
assign.go:19:6: error: incompatible types in assignment (implicit assignment of 'sync.Mutex' hidden field 'key')
assign.go:23:6: error: incompatible types in assignment (implicit assignment of 'sync.Mutex' hidden field 'key')
assign.go:27:6: error: incompatible types in assignment (implicit assignment of 'sync.Mutex' hidden field 'key')
chan/perm.go:14:5: error: incompatible types in assignment
chan/perm.go:15:5: error: incompatible types in assignment
chan/perm.go:16:6: error: incompatible types in assignment
chan/perm.go:17:6: error: incompatible types in assignment
chan/perm.go:24:7: error: invalid send on receive-only channel
chan/perm.go:25:12: error: invalid send on receive-only channel
chan/perm.go:31:4: error: invalid receive on send-only channel
chan/perm.go:32:9: error: invalid receive on send-only channel
chan/perm.go:38:2: error: invalid send on receive-only channel
chan/perm.go:42:2: error: invalid receive on send-only channel
initializerr.go:14:17: error: reference to undefined variable 'X'
initializerr.go:14:19: error: mixture of field and value initializers
initializerr.go:15:26: error: duplicate value for field 'Y'
initializerr.go:16:10: error: too many values in struct composite literal
initializerr.go:18:19: error: index expression is not integer constant
initializerr.go:17:11: error: too many elements in composite literal
R=rsc
DELTA=12 (0 added, 0 deleted, 12 changed)
OCL=29657
CL=29665
- don't need *struct
- don't need item/rat both
- closures make the inner slaves easier
- delete some old BUG comments
powser2 is left mostly alone, for variety.
R=rsc
DELTA=134 (2 added, 20 deleted, 112 changed)
OCL=24579
CL=24581
recognize methods for a variable whose type is a named type
which is a pointer type. Add bug117 to test this case.
R=r
DELTA=24 (22 added, 0 deleted, 2 changed)
OCL=18547
CL=18554
current spec forbids it:
The type specified by the type name is called ``receiver
base type''. The receiver base type must be a type
declared in the current file, and it must not be a pointer
type.
R=r
DELTA=2 (0 added, 0 deleted, 2 changed)
OCL=18527
CL=18541
* 1. all statements and declarations are terminated by semicolons
* 2. semicolons can be omitted at top level.
* 3. semicolons can be omitted before and after the closing ) or }
* on a list of statements or declarations.
/home/rsc/bin/addsemi and then diff+tweak.
R=r,gri
OCL=16620
CL=16643
