See golang.org/s/go13nacl for design overview.
This CL is the mostly mechanical changes from rsc's Go 1.2 based NaCl branch, specifically 39cb35750369 to 500771b477cf from https://code.google.com/r/rsc-go13nacl. This CL does not include working NaCl support, there are probably two or three more large merges to come.
CL 15750044 is not included as it involves more invasive changes to the linker which will need to be merged separately.
The exact change lists included are
15050047: syscall: support for Native Client
15360044: syscall: unzip implementation for Native Client
15370044: syscall: Native Client SRPC implementation
15400047: cmd/dist, cmd/go, go/build, test: support for Native Client
15410048: runtime: support for Native Client
15410049: syscall: file descriptor table for Native Client
15410050: syscall: in-memory file system for Native Client
15440048: all: update +build lines for Native Client port
15540045: cmd/6g, cmd/8g, cmd/gc: support for Native Client
15570045: os: support for Native Client
15680044: crypto/..., hash/crc32, reflect, sync/atomic: support for amd64p32
15690044: net: support for Native Client
15690048: runtime: support for fake time like on Go Playground
15690051: build: disable various tests on Native Client
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/68150047
IsNil isn't quite the same as == nil, as this snippet shows:
// http://play.golang.org/p/huomslDZgw
package main
import "fmt"
import "reflect"
func main() {
var i interface{}
v := reflect.ValueOf(i)
fmt.Println(v.IsValid(), i == nil)
fmt.Println(v.IsNil())
}
The fact that IsNil panics if you call it with an untyped nil
was not apparent. Verbiage added for clarity.
LGTM=rsc
R=rsc
CC=golang-codereviews
https://golang.org/cl/65480043
Reflect used to communicate to the runtime using interface words,
which is bad for precise GC because sometimes iwords hold a pointer
and sometimes they don't. This change rewrites channel and select
operations to always pass pointers to the runtime.
reflect.Select gets somewhat more expensive, as we now do an allocation
per receive case instead of one allocation whose size is the max of
all the received types. This seems unavoidable to get preciseness
(unless we move the allocation into selectgo, which is a much bigger
change).
Fixes#6490
R=golang-codereviews, dvyukov, rsc
CC=golang-codereviews
https://golang.org/cl/52900043
Give proper types to the argument/return areas
allocated for reflect calls. Avoid use of iword to
manipulate receivers, which may or may not be pointers.
Update #6490
R=rsc
CC=golang-codereviews
https://golang.org/cl/52110044
Needed for precise gc and copying stacks.
reflect.Value now takes 4 words instead of 3.
Still to do:
- un-iword-ify channel ops.
- un-iword-ify method receivers.
R=golang-dev, iant, rsc, khr
CC=golang-dev
https://golang.org/cl/43040043
gccgo has problems using reflect.Call with functions that take and
return structs with no members. Prior to fixing that problem there, I
thought it sensible to add some tests of this situation.
Update #6761
First contribution to Go, apologies in advance if I'm doing it wrong.
R=golang-dev, dave, minux.ma, iant, khr, bradfitz
CC=golang-dev
https://golang.org/cl/26570046
and methodValueCall directly. Instead, we inline their behavior
inside of reflect.call.
This change is required because otherwise we have a situation where
reflect.callXX calls makeFuncStub, neither of which knows the
layout of the args passed between them. That's bad for
precise gc & stack copying.
Fixes#6619.
R=golang-dev, dvyukov, rsc, iant, khr
CC=golang-dev
https://golang.org/cl/26970044
This change is part of the plan to get rid of all vararg C calls
which are a pain for getting exact stack scanning.
We allocate a chunk of zero memory to return a pointer to when a
map access doesn't find the key. This is simpler than returning nil
and fixing things up in the caller. Linker magic allocates a single
zero memory area that is shared by all (non-reflect-generated) map
types.
Passing things by reference gets rid of some copies, so it speeds
up code with big keys/values.
benchmark old ns/op new ns/op delta
BenchmarkBigKeyMap 34 31 -8.48%
BenchmarkBigValMap 37 30 -18.62%
BenchmarkSmallKeyMap 26 23 -11.28%
R=golang-dev, dvyukov, khr, rsc
CC=golang-dev
https://golang.org/cl/14794043
Failure occurred when using reflect.Call to pass a func value
following a non-pointer value.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/14186043
The argument slice was kept hidden from the garbage collector
by destroying its referent in an unsafe.Pointer to uintptr
conversion. This change preserves the unsafe.Pointer referent
and only performs an unsafe.Pointer to uintptr conversions
within expressions that construct new unsafe.Pointer values.
R=golang-dev, khr, rsc
CC=golang-dev
https://golang.org/cl/14008043
Bug #1:
Issue 5406 identified an interesting case:
defer iface.M()
may end up calling a wrapper that copies an indirect receiver
from the iface value and then calls the real M method. That's
two calls down, not just one, and so recover() == nil always
in the real M method, even during a panic.
[For the purposes of this entire discussion, a wrapper's
implementation is a function containing an ordinary call, not
the optimized tail call form that is somtimes possible. The
tail call does not create a second frame, so it is already
handled correctly.]
Fix this bug by introducing g->panicwrap, which counts the
number of bytes on current stack segment that are due to
wrapper calls that should not count against the recover
check. All wrapper functions must now adjust g->panicwrap up
on entry and back down on exit. This adds slightly to their
expense; on the x86 it is a single instruction at entry and
exit; on the ARM it is three. However, the alternative is to
make a call to recover depend on being able to walk the stack,
which I very much want to avoid. We have enough problems
walking the stack for garbage collection and profiling.
Also, if performance is critical in a specific case, it is already
faster to use a pointer receiver and avoid this kind of wrapper
entirely.
Bug #2:
The old code, which did not consider the possibility of two
calls, already contained a check to see if the call had split
its stack and so the panic-created segment was one behind the
current segment. In the wrapper case, both of the two calls
might split their stacks, so the panic-created segment can be
two behind the current segment.
Fix this by propagating the Stktop.panic flag forward during
stack splits instead of looking backward during recover.
Fixes#5406.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/13367052
But keep their case for ease of searching.
They were added recently. We don't want them part of go1.2's API.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/13569044
DeepEqual caches addresses of compared values
each time it visits addressable values. This is
more expensive than actually comparing them in
the common case of large slices of bytes or integers.
Also add a fast path for slices with identical
underlying array.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13000044
pointer. An example that triggers the bad behavior on a 64bit
machine http://play.golang.org/p/GrNFakAYLN
rv1 := reflect.ValueOf(complex128(0))
rt := rv1.Type()
rv2 := rv1.Convert(rt)
rv3 := reflect.New(rt).Elem()
rv3.Set(rv2)
Running the code fails with the following:
panic: reflect: internal error: storeIword of 16-byte value
I've tested on a 64bit machine and verified this fixes the panic. I
haven't tested on a 32bit machine so I haven't verified the other
cases, but they follow logically.
R=golang-dev, r, iant
CC=golang-dev
https://golang.org/cl/12805045
Update #5000
Should reduce the flakiness a little. Malloc counting is important
to general testing but not to the build dashboard, which uses -short.
R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/12866047
See issue 4949 for a full explanation.
Allocs go from 1 to zero in the non-addressable case.
Fixes#4949.
BenchmarkInterfaceBig 90 14 -84.01%
BenchmarkInterfaceSmall 14 14 +0.00%
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/12646043
you do reflect.call with too big an argument list.
Not worth the hassle.
Fixes#6023Fixes#6033
R=golang-dev, bradfitz, dave
CC=golang-dev
https://golang.org/cl/12485043
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
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/12163043
It changes an exported API, and breaks the build.
««« original CL description
reflect: use unsafe.Pointer in StringHeader and SliceHeader
Relates to issue 5193.
R=r
CC=golang-dev
https://golang.org/cl/8363045
»»»
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/8357051
