Use typedmemmove, typedslicecopy, and adjust reflect.call
to execute the necessary write barriers.
Found with GODEBUG=wbshadow=2 mode.
Eventually that will run automatically, but right now
it still detects other missing write barriers.
Change-Id: Iec5b5b0c1be5589295e28e5228e37f1a92e07742
Reviewed-on: https://go-review.googlesource.com/2312
Reviewed-by: Keith Randall <khr@golang.org>
These depend on storing arbitrary integer values using
pointer atomics, and we can't support that anymore.
Change-Id: I8cadd6d462c3eebdbe7078f43fe7c779fa8f52b3
Reviewed-on: https://go-review.googlesource.com/2311
Reviewed-by: Rick Hudson <rlh@golang.org>
A side effect of this change is that when assertI2T writes to the
memory for the T being extracted, it can use typedmemmove
for write barriers.
There are other ways we could have done this, but this one
finishes a TODO in package runtime.
Found with GODEBUG=wbshadow=2 mode.
Eventually that will run automatically, but right now
it still detects other missing write barriers.
Change-Id: Icbc8aabfd8a9b1f00be2e421af0e3b29fa54d01e
Reviewed-on: https://go-review.googlesource.com/2279
Reviewed-by: Keith Randall <khr@golang.org>
Found with GODEBUG=wbshadow=2 mode.
Eventually that will run automatically, but right now
it still detects other missing write barriers.
Change-Id: I1320d5340a9e421c779f24f3b170e33974e56e4f
Reviewed-on: https://go-review.googlesource.com/2278
Reviewed-by: Rick Hudson <rlh@golang.org>
Found with GODEBUG=wbshadow=2 mode.
Eventually that will run automatically, but right now
it still detects other missing write barriers.
Change-Id: Iea83d693480c2f3008b4e80d55821acff65970a6
Reviewed-on: https://go-review.googlesource.com/2277
Reviewed-by: Keith Randall <khr@golang.org>
Preparation for replacing many memmove calls in runtime
with typedmemmove, which is a clearer description of what
the routine is doing.
For the same reason, rename writebarriercopy to typedslicecopy.
Change-Id: I6f23bef2c2215509fefba175b16908f76dc7538c
Reviewed-on: https://go-review.googlesource.com/2276
Reviewed-by: Rick Hudson <rlh@golang.org>
Add write barrier to atomic operations manipulating pointers.
In general an atomic write of a pointer word may indicate racy accesses,
so there is no strictly safe way to attempt to keep the shadow copy
in sync with the real one. Instead, mark the shadow copy as not used.
Redirect sync/atomic pointer routines back to the runtime ones,
so that there is only one copy of the write barrier and shadow logic.
In time we might consider doing this for most of the sync/atomic
functions, but for now only the pointer routines need that treatment.
Found with GODEBUG=wbshadow=1 mode.
Eventually that will run automatically, but right now
it still detects other missing write barriers.
Change-Id: I852936b9a111a6cb9079cfaf6bd78b43016c0242
Reviewed-on: https://go-review.googlesource.com/2066
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
The Gobuf.g goroutine pointer is almost always updated by assembly code.
In one of the few places it is updated by Go code - func save - it must be
treated as a uintptr to avoid a write barrier being emitted at a bad time.
Instead of figuring out how to emit the write barriers missing in the
assembly manipulation, change the type of the field to uintptr, so that
it does not require write barriers at all.
Goroutine structs are published in the allg list and never freed.
That will keep the goroutine structs from being collected.
There is never a time that Gobuf.g's contain the only references
to a goroutine: the publishing of the goroutine in allg comes first.
Goroutine pointers are also kept in non-GC-visible places like TLS,
so I can't see them ever moving. If we did want to start moving data
in the GC, we'd need to allocate the goroutine structs from an
alternate arena. This CL doesn't make that problem any worse.
Found with GODEBUG=wbshadow=1 mode.
Eventually that will run automatically, but right now
it still detects other missing write barriers.
Change-Id: I85f91312ec3e0ef69ead0fff1a560b0cfb095e1a
Reviewed-on: https://go-review.googlesource.com/2065
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Found with GODEBUG=wbshadow=1 mode.
Eventually that will run automatically, but right now
it still detects other missing write barriers.
Change-Id: Ic8624401d7c8225a935f719f96f2675c6f5c0d7c
Reviewed-on: https://go-review.googlesource.com/2064
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
This is the detection code. It works well enough that I know of
a handful of missing write barriers. However, those are subtle
enough that I'll address them in separate followup CLs.
GODEBUG=wbshadow=1 checks for a write that bypassed the
write barrier at the next write barrier of the same word.
If a bug can be detected in this mode it is typically easy to
understand, since the crash says quite clearly what kind of
word has missed a write barrier.
GODEBUG=wbshadow=2 adds a check of the write barrier
shadow copy during garbage collection. Bugs detected at
garbage collection can be difficult to understand, because
there is no context for what the found word means.
Typically you have to reproduce the problem with allocfreetrace=1
in order to understand the type of the badly updated word.
Change-Id: If863837308e7c50d96b5bdc7d65af4969bf53a6e
Reviewed-on: https://go-review.googlesource.com/2061
Reviewed-by: Austin Clements <austin@google.com>
When constants were declared using unexported constants,
the type information was lost when those constants were filtered out.
This CL propagates the type information of unexported constants
so that it is available for display.
This is a follow-up to CL 144110044, which fixed this problem
specifically for _ constants.
Updates #5397.
Change-Id: I3f0c767a4007d88169a5634ab2870deea4e6a740
Reviewed-on: https://go-review.googlesource.com/2091
Reviewed-by: Robert Griesemer <gri@golang.org>
Noticed while investigating the speed of the runtime tests, as part
of debugging while Plan 9's runtime tests are timing out on GCE.
Change-Id: I95f5a3d967a0b45ec1ebf10067e193f51db84e26
Reviewed-on: https://go-review.googlesource.com/2283
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The existing go code document did not link to the GOPATH documentation.
This will link to it, in hopes of making it more discoverable.
Change-Id: Ie4ded2fdce08f412e4acbcc93acdd76f5791b84a
Reviewed-on: https://go-review.googlesource.com/2265
Reviewed-by: Andrew Gerrand <adg@golang.org>
This reverts commit ab0535ae3f.
I think it will remain useful to distinguish code that must
run on a system stack from code that can run on either stack,
even if that distinction is no
longer based on the implementation language.
That is, I expect to add a //go:systemstack comment that,
in terms of the old implementation, tells the compiler,
to pretend this function was written in C.
Change-Id: I33d2ebb2f99ae12496484c6ec8ed07233d693275
Reviewed-on: https://go-review.googlesource.com/2275
Reviewed-by: Russ Cox <rsc@golang.org>
This CL splits the (ever growing) list of ca cert locations by major unix
platforms (darwin, windows and plan9 are already handled seperately).
Although it is clear the unix variants cannot manage to agree on some standard
locations, we can avoid to some extent an artificial ranking of priority
amongst the supported GOOSs.
* Split certFiles definition by GOOS
* Include NetBSD ca cert location
Fixes#9285
Change-Id: I6df2a3fddf3866e71033e01fce43c31e51b48a9e
Reviewed-on: https://go-review.googlesource.com/2208
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
This ensures that changing an image.YCbCr's Y values can't change its
chroma values, even after re-slicing up to capacity.
Change-Id: Icb626561522e336a3220e10f456c95330ae7db9e
Reviewed-on: https://go-review.googlesource.com/2209
Reviewed-by: Rob Pike <r@golang.org>
Previously, we ended up passing two compiled objects for the package
being tested when linking the test executable. Somewhat by luck, this
worked most of the time but occasionally it did not. This changes the
linking code to not pass two objects for the same ImportPath and to
always pass the object for the test version of the package and removes
some unecessary nil checks.
Change-Id: I7bbd3fc708f14672ee2cc6aed3397421fceb8a38
Reviewed-on: https://go-review.googlesource.com/1840
Reviewed-by: Ian Lance Taylor <iant@golang.org>
liblink used to encode both SETEQ BP and SETEQ CH as 0f 94 c5,
however, SETEQ BP should have used a REX prefix.
Fixes#8545.
Change-Id: Ie59c990cdd0ec506cffe4318e9ad1b48db5e57dd
Reviewed-on: https://go-review.googlesource.com/2270
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
This CL adds missing ipv4-mapped ipv6 address test cases to TestParseIP.
Change-Id: I3144d2a88d409bd515cf52f8711d407bfa81ed68
Reviewed-on: https://go-review.googlesource.com/2205
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Shell out to `uname -r` this time, so that the test will compile
even if the platform doesn't have syscall.Sysctl.
Change-Id: I3a19ab5d820bdb94586a97f4507b3837d7040525
Reviewed-on: https://go-review.googlesource.com/2271
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The test program requires static constructor, which in turn needs
external linking to work, but external linking never works on 10.6.
This should fix the darwin-{386,amd64} builders.
Change-Id: I714fdd3e35f9a7e5f5659cf26367feec9412444f
Reviewed-on: https://go-review.googlesource.com/2235
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Mostly I need to tickle the builders, since I'm working on the
dashboard builders right now.
Change-Id: I833fc22bc942758a58791ed038634cdd812f5411
Reviewed-on: https://go-review.googlesource.com/2261
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
If the user provided a key but no value via -ldflag -X,
another linker flag was used as the value.
Placing the user's flags at the end avoids this problem.
It also provides the user the opportunity to
override existing linker flags.
Fixes#8810.
Change-Id: I96f4190713dc9a9c29142e56658446fba7fb6bc8
Reviewed-on: https://go-review.googlesource.com/2242
Reviewed-by: Minux Ma <minux@golang.org>
Remove use of itod on posix systems and replace with call to itoa.
Build and use same itoa function on all systems.
Fix infinite recursion in iota function for the case -1<<63.
Change-Id: I89d7e742383c5c4aeef8780501c78a3e1af87a6f
Reviewed-on: https://go-review.googlesource.com/2213
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Updated the issue tracker link the compiler prints out
when asking for a bug report after an internal error.
Change-Id: I092b118130f131c6344d9d058bea4ad6379032b8
Reviewed-on: https://go-review.googlesource.com/2218
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Our definition of struct timespec used to cause problems with
certain versions of mingw-rt. However, as it turns out, we don't
actually need those definitions and prototypes, so remove them.
Fixes#9472.
Change-Id: Ie0880f0d58be112625140f73d0bed71f98b7cf05
Reviewed-on: https://go-review.googlesource.com/2236
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Preventing returning io.EOF on non-connection oriented sockets is
already applied to Unix variants. This CL applies it to Windows.
Update #4856.
Change-Id: I82071d40f617e2962d0540b9d1d6a10ea4cdb2ec
Reviewed-on: https://go-review.googlesource.com/2203
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
There is no reason to have the redundant test case TestDNSThreadLimt
because TestLookupIPDeadline does cover what we need to test with
-dnsflood flag and more.
Also this CL moves TestLookupIPDeadline into lookup_test.go to avoid
abusing to control the order of test case execution by using file name.
Change-Id: Ib417d7d3411c59d9352c03c996704d584368dc62
Reviewed-on: https://go-review.googlesource.com/2204
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Fixes build on plan9 and windows.
Change-Id: Ic9b02c641ab84e4f6d8149de71b9eb495e3343b2
Reviewed-on: https://go-review.googlesource.com/2233
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
I missed this one in golang.org/cl/2232 and only tested the patch
on openbsd/amd64.
Change-Id: I4ff437ae0bfc61c989896c01904b6d33f9bdf0ec
Reviewed-on: https://go-review.googlesource.com/2234
Reviewed-by: Minux Ma <minux@golang.org>
This is a genuine bug exposed by our test for issue 9456: our wrapper
for pthread_create is not initialized until we initialize cgo itself,
but it is possible that a static constructor could call pthread_create,
and in that case, it will be calling a nil function pointer.
Fix that by also initializing the sys_pthread_create function pointer
inside our pthread_create wrapper function, and use a pthread_once to
make sure it is only initialized once.
Fix build for openbsd.
Change-Id: Ica4da2c21fcaec186fdd3379128ef46f0e767ed7
Reviewed-on: https://go-review.googlesource.com/2232
Reviewed-by: David Crawshaw <crawshaw@golang.org>
%lL will prepend the current directory to the filename, which is not
what we want here (as the file name is already absolute).
Fixes#9150.
Change-Id: I4c9386be6baf421393b92d9401a264b4692986d0
Reviewed-on: https://go-review.googlesource.com/2231
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Some libraries, for example, OpenBLAS, create work threads in a global constructor.
If we're doing cpu profiling, it's possible that SIGPROF might come to some of the
worker threads before we make our first cgo call. Cgocallback used to terminate the
process when that happens, but it's better to miss a couple profiling signals than
to abort in this case.
Fixes#9456.
Change-Id: I112b8e1a6e10e6cc8ac695a4b518c0f577309b6b
Reviewed-on: https://go-review.googlesource.com/2141
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Avoid the decimal lookup in digits array and compute the decimal character value directly.
Reduce calls to 64bit division on 32bit plattforms by splitting conversion into smaller blocks.
Convert value to uintptr type when it can be represented by uintptr.
on darwin/386
benchmark old ns/op new ns/op delta
BenchmarkFormatInt 8352 7466 -10.61%
BenchmarkAppendInt 4281 3401 -20.56%
BenchmarkFormatUint 2785 2251 -19.17%
BenchmarkAppendUint 1770 1223 -30.90%
on darwin/amd64
benchmark old ns/op new ns/op delta
BenchmarkFormatInt 5531 5492 -0.71%
BenchmarkAppendInt 2435 2295 -5.75%
BenchmarkFormatUint 1628 1569 -3.62%
BenchmarkAppendUint 726 750 +3.31%
Change-Id: Ifca281cbdd62ab7d7bd4b077a96da99eb12cf209
Reviewed-on: https://go-review.googlesource.com/2105
Reviewed-by: Robert Griesemer <gri@golang.org>
