Brad Fitzpatrick [Fri, 2 Aug 2013 17:19:52 +0000 (10:19 -0700)]
misc/dist: don't ship cmd/api
cmd/api is a tool to prevent the Go developers from breaking
the Go 1 API promise. It has no utility to end users and
doesn't run on arbitrary packages (it's always been full of
hacks for its bespoke type checker to work on the standard
library)
Robert's in-progress rewrite depends on the go.tools repo for
go/types, so we won't be able to ship this tool later
anyway. Just remove it from binary distributions.
A future change to run.bash can conditionally build & run
cmd/api, perhaps automatically fetching go/types if
necessary. I assume people don't want to vendor go/types into
a private gopath just for cmd/api.
Russ Cox [Fri, 2 Aug 2013 00:07:01 +0000 (20:07 -0400)]
runtime: disable preemption during software fp routines
It's okay to preempt at ordinary function calls because
compilers arrange that there are no live registers to save
on entry to the function call.
The software floating point routines are function calls
masquerading as individual machine instructions. They are
expected to keep all the registers intact. In particular,
they are expected not to clobber all the floating point
registers.
The floating point registers are kept per-M, because they
are not live at non-preemptive goroutine scheduling events,
and so keeping them per-M reduces the number of 132-byte
register blocks we are keeping in memory.
Because they are per-M, allowing the goroutine to be
rescheduled during software floating point simulation
would mean some other goroutine could overwrite the registers
or perhaps the goroutine would continue running on a different
M entirely.
Disallow preemption during the software floating point
routines to make sure that a function full of floating point
instructions has the same floating point registers throughout
its execution.
R=golang-dev, dave
CC=golang-dev
https://golang.org/cl/12298043
Scott Ferguson [Thu, 1 Aug 2013 22:52:56 +0000 (15:52 -0700)]
net/url: prepend slash to path in String()
Previously if a path was set manually without a leading /, String()
would not insert the slash when writing its output. This would lead
to situations where a URL that should be http://www.google.com/search
is output as http://www.google.comsearch
Pieter Droogendijk [Thu, 1 Aug 2013 22:20:01 +0000 (15:20 -0700)]
compress/flate: Fixed two panics on bad data
I used just enough of the data provided by Matt in Issue 5915 to trigger
issue 5915. As luck would have it, using slightly less of it triggered
issue 5962.
Russ Cox [Thu, 1 Aug 2013 16:58:27 +0000 (12:58 -0400)]
cmd/ld: report pclntab, funcdata sizes in 6l -v output
Also move chatty recent additions to -v -v.
For what it's worth:
$ go build -o /dev/null -ldflags -v cmd/go
...
0.87 pclntab=1110836 bytes, funcdata total 69700 bytes
...
$
This broke the ELF builds last time because I tried to dedup
the funcdata in case the same funcdata was pointed at by
multiple functions. That doesn't currently happen, so I've
removed that test.
If we start doing bitmap coalescing we'll need to figure out
how to measure the size more carefully, but I think at that
point the bitmaps will be an extra indirection away from the
funcdata anyway, so the dedup I used before wouldn't help.
Dmitriy Vyukov [Thu, 1 Aug 2013 15:28:38 +0000 (19:28 +0400)]
runtime: print "created by" for running goroutines in traceback
This allows to at least determine goroutine "identity".
Now it looks like:
goroutine 12 [running]:
goroutine running on other thread; stack unavailable
created by testing.RunTests
src/pkg/testing/testing.go:440 +0x88e
Dmitriy Vyukov [Thu, 1 Aug 2013 14:25:36 +0000 (18:25 +0400)]
runtime: make new tests shorter in short mode
We see timeouts in these tests on some platforms,
but not on the others. The hypothesis is that
the problematic platforms are slow uniprocessors.
Stack traces do not suggest that the process
is completely hang, and it is able to schedule
the alarm goroutine. And if it actually hangs,
we still will be able to detect that.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/12253043
1) Explain a[i] and a[i:j] where a is of type *A as
shortcut for (*a)[i] and (*a)[i:j], respectively.
2) Together with 1), because len() of nil slices is
well defined, there's no need to special case nil
operands anymore.
3) The result of indexing or slicing a constant string
is always a non-constant byte or string value.
4) The result of slicing an untyped string is a value
of type string.
5) If the operand of a valid slice a[i:j] is nil (i, j
must be 0 for it to be valid - this already follows
from the in-range rules), the result is a nil slice.
Fixes #4913.
Fixes #5951.
R=r, rsc, iant, ken
CC=golang-dev
https://golang.org/cl/12198043
Russ Cox [Thu, 1 Aug 2013 04:16:31 +0000 (00:16 -0400)]
runtime: fix arm preemption
Preemption during the software floating point code
could cause m (R9) to change, so that when the
original registers were restored at the end of the
floating point handler, the changed and correct m
would be replaced by the old and incorrect m.
««« original CL description
spec: clarify index and selector expressions
1) Explain a[i] and a[i:j] where a is of type *A as
shortcut for (*a)[i] and (*a)[i:j], respectively.
2) Together with 1), because len() of nil slices is
well defined, there's no need to special case nil
operands anymore.
3) The result of indexing or slicing a constant string
is always a non-constant byte or string value.
4) The result of slicing an untyped string is a value
of type string.
5) If the operand of a valid slice a[i:j] is nil (i, j
must be 0 for it to be valid - this already follows
from the in-range rules), the result is a nil slice.
Fixes #4913.
Fixes #5951.
R=rsc, r, iant, ken
CC=golang-dev
https://golang.org/cl/11884043
»»»
Robert Griesemer [Wed, 31 Jul 2013 20:40:01 +0000 (13:40 -0700)]
spec: clarify index and selector expressions
1) Explain a[i] and a[i:j] where a is of type *A as
shortcut for (*a)[i] and (*a)[i:j], respectively.
2) Together with 1), because len() of nil slices is
well defined, there's no need to special case nil
operands anymore.
3) The result of indexing or slicing a constant string
is always a non-constant byte or string value.
4) The result of slicing an untyped string is a value
of type string.
5) If the operand of a valid slice a[i:j] is nil (i, j
must be 0 for it to be valid - this already follows
from the in-range rules), the result is a nil slice.
Fixes #4913.
Fixes #5951.
R=rsc, r, iant, ken
CC=golang-dev
https://golang.org/cl/11884043
This patch introduces specialized functions for initial
and final permutations, and precomputes the output of the
third permutation on the S-box elements.
benchmark old ns/op new ns/op delta
BenchmarkEncrypt 3581 1226 -65.76%
BenchmarkDecrypt 3590 1224 -65.91%
benchmark old MB/s new MB/s speedup
BenchmarkEncrypt 2.23 6.52 2.92x
BenchmarkDecrypt 2.23 6.53 2.93x
runtime: better debug output for inconsistent Note
Update #5139.
Double wakeup on Note was reported several times,
but no reliable reproducer.
There also was a strange report about weird value of epoll fd.
Maybe it's corruption of global data...
runtime: do not park sysmon thread if any goroutines are running
Sysmon thread parks if no goroutines are running (runtime.sched.npidle ==
runtime.gomaxprocs).
Currently it's unparked when a goroutine enters syscall, it was enough
to retake P's from blocking syscalls.
But it's not enough for reliable goroutine preemption. We need to ensure that
sysmon runs if any goroutines are running.
Submitted with some unrelated changes that were not intended to go in.
««« original CL description
runtime: do not park sysmon thread if any goroutines are running
Sysmon thread parks if no goroutines are running (runtime.sched.npidle == runtime.gomaxprocs).
Currently it's unparked when a goroutine enters syscall, it was enough
to retake P's from blocking syscalls.
But it's not enough for reliable goroutine preemption. We need to ensure that
sysmon runs if any goroutines are running.
cmd/gc: record argument size for all indirect function calls
This is required to properly unwind reflect.methodValueCall/makeFuncStub.
Fixes #5954.
Stats for 'go install std':
61849 total INSTCALL
24655 currently have ArgSize metadata
27278 have ArgSize metadata with this change
godoc size before: 11351888, after: 11364288
runtime: do not park sysmon thread if any goroutines are running
Sysmon thread parks if no goroutines are running (runtime.sched.npidle == runtime.gomaxprocs).
Currently it's unparked when a goroutine enters syscall, it was enough
to retake P's from blocking syscalls.
But it's not enough for reliable goroutine preemption. We need to ensure that
sysmon runs if any goroutines are running.
Rob Pike [Wed, 31 Jul 2013 05:09:13 +0000 (15:09 +1000)]
text/template/parse: print TextNodes using %s not %q
This means that printing a Node will produce output that can be used as valid input.
It won't be exactly the same - some spacing may be different - but it will mean the same.
Rob Pike [Wed, 31 Jul 2013 05:00:08 +0000 (15:00 +1000)]
fmt: treat \r\n as \n in Scan
When scanning input and "white space" is permitted, a carriage return
followed immediately by a newline (\r\n) is treated exactly the same
as a plain newline (\n). I hope this makes it work better on Windows.
We do it everywhere, not just on Windows, since why not?
Keith Randall [Wed, 31 Jul 2013 04:39:57 +0000 (21:39 -0700)]
runtime: optimize some hash lookups.
When comparing strings, check these (in order):
- length mismatch => not equal
- string pointer equal => equal
- if length is short:
- memeq on body
- if length is long:
- compare first&last few bytes, if different => not equal
- save entry as a possible match
- after checking every entry, if there is only one possible
match, use memeq on that entry. Otherwise, fallback to hash.
benchmark old ns/op new ns/op delta
BenchmarkSameLengthMap 43 4 -89.77%
cmd/go: send timed out test SIGQUIT before SIGKILL
There is a chance that the SIGQUIT will make the test process
dump its stacks as part of exiting, which would be nice for
finding out what it is doing.
Right now the builders are occasionally timing out running
the runtime test. I hope this will give us some information
about the state of the runtime.
R=golang-dev, dave
CC=golang-dev
https://golang.org/cl/12041051
runtime: cut struct Hmap back to 48-byte allocation
struct Hmap is the header for a map value.
CL 8377046 made flags a uint32 so that it could be updated atomically,
but that bumped the struct to 56 bytes, which allocates as 64 bytes (on amd64).
hash0 is initialized from runtime.fastrand1, which returns a uint32,
so the top 32 bits were always zero anyway. Declare it as a uint32
to reclaim 4 bytes and bring the Hmap size back down to a 48-byte allocation.
The current failure is:
fatal error: runtime: stack split during syscall
goroutine 2 [stack split]:
_si2v(0xb6ebaebc, 0x3b9aca00)
/usr/local/go/src/pkg/runtime/vlrt_arm.c:628 fp=0xb6ebae9c
runtime.timediv(0xf8475800, 0xd, 0x3b9aca00, 0xb6ebaef4)
/usr/local/go/src/pkg/runtime/runtime.c:424 +0x1c fp=0xb6ebaed4
Just adding textflag 7 causes the following error:
notetsleep: nosplit stack overflow
128 assumed on entry to notetsleep
96 after notetsleep uses 32
60 after runtime.futexsleep uses 36
4 after runtime.timediv uses 56
-4 after _si2v uses 8
runtime: fix openbsd build
notetsleep: nosplit stack overflow
120 assumed on entry to notetsleep
96 after notetsleep uses 24
88 on entry to runtime.semasleep
32 after runtime.semasleep uses 56
24 on entry to runtime.nanotime
-8 after runtime.nanotime uses 32
Nanotime seems to be using only 24 bytes of stack space.
Unless I am missing something.
runtime: fix freebsd build
notetsleep: nosplit stack overflow
120 assumed on entry to notetsleep
80 after notetsleep uses 40
72 on entry to runtime.futexsleep
16 after runtime.futexsleep uses 56
8 on entry to runtime.printf
-16 after runtime.printf uses 24
runtime: do not split stacks in syscall status
Split stack checks (morestack) corrupt g->sched,
but g->sched must be preserved consistent for GC/traceback.
The change implements runtime.notetsleepg function,
which does entersyscall/exitsyscall and is carefully arranged
to not call any split functions in between.