Michael Anthony Knyszek [Wed, 18 Mar 2020 15:09:40 +0000 (15:09 +0000)]
runtime: ensure minTriggerRatio never exceeds maxTriggerRatio
Currently, the capping logic for the GC trigger ratio is such that if
gcpercent is low, we may end up setting the trigger ratio far too high,
breaking the promise of SetGCPercent and GOGC has a trade-off knob (we
won't start a GC early enough, and we will use more memory).
This change modifies the capping logic for the trigger ratio by scaling
the minTriggerRatio with gcpercent the same way we scale
maxTriggerRatio.
This makes all modern public keys in the standard library implement a
common interface (below) that can be used by applications for better
type safety and allows for checking that public (and private keys via
Public()) are equivalent.
interface {
Equal(crypto.PublicKey) bool
}
Equality for ECDSA keys is complicated, we take a strict interpretation
that works for all secure applications (the ones not using the
unfortunate non-constant time CurveParams implementation) and fails
closed otherwise.
Tests in separate files to make them x_tests and avoid an import loop
with crypto/x509.
Re-landing of CL 223754. Dropped the test that was assuming named curves
are not implemented by CurveParams, because it's not true for all
curves, and anyway is not a property we need to test. There is still a
test to check that different curves make keys not Equal.
Xiangdong Ji [Thu, 5 Dec 2019 03:22:34 +0000 (03:22 +0000)]
runtime: fix threshold calculation of TestPhysicalMemoryUtilization
Variable 'procs' used to calculate the threshold of overuse in
TestPhysicalMemoryUtilization should be updated if GOMAXPROCS
gets changed, otherwise the threshold could be a large number,
making the test meaningless.
Change-Id: I876cbf11457529f56bae77af1e35f4538a721f95
Reviewed-on: https://go-review.googlesource.com/c/go/+/210297
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
Rob Pike [Wed, 25 Mar 2020 22:32:27 +0000 (09:32 +1100)]
scan: for style, adjust code for bad scan read counts
Make the code more consistent with the rest of the file.
Should have caught this in review of CL 225357.
Change-Id: I12824cb436539c31604684e043ebb7587cc92471
Reviewed-on: https://go-review.googlesource.com/c/go/+/225557 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Michael Anthony Knyszek [Wed, 25 Mar 2020 16:41:20 +0000 (16:41 +0000)]
runtime: prevent preemption while timer is in timerModifying
Currently if a goroutine is preempted while owning a timer in the
timerModifying state, it could self-deadlock. When the goroutine is
preempted and calls into the scheduler, it could call checkTimers. If
checkTimers encounters the timerModifying timer and calls runtimer on
it, then runtimer will spin, waiting for that timer to leave the
timerModifying state, which it never will.
So far we got lucky that for the most part that there were no preemption
points while timerModifying is happening, however CL 221077 seems to
have introduced one, leading to sporadic self-deadlocks.
This change disables preemption explicitly while a goroutines holds a
timer in timerModifying. Since only checkTimers (and thus runtimer) is
called from the scheduler, this is sufficient to prevent
preemption-based self-deadlocks.
Fixes #38070.
Updates #37894.
Change-Id: Idbfac310889c92773023733ff7e2ff87e9896f0c
Reviewed-on: https://go-review.googlesource.com/c/go/+/225497
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Bryan C. Mills [Fri, 20 Mar 2020 19:15:35 +0000 (15:15 -0400)]
cmd/api: make NewWatcher populate its own package and import metadata
This partially undoes the optimizations of CL 177597, but makes up
some of the difference by caching the package list and import metadata
and making the initial calls concurrently, including in TestMain.
That reduces the critical path from two sequential 'go list'
invocations to just one (run many times concurrently), and eliminates
the need for assumptions about the consistency of the 'std' dependency
graph across platforms (and hard-coded special cases for packages that
violate those assumptions).
In the process, this simplifies and fixes TestBenchmark (which has
been silently broken since CL 164623).
This increases 'time go tool dist test api' on my workstation from
0m8.4s / 0m13.8s / 0m1.7s to 0m10.5s / 0m23.1s / 0m5.1s,
compared to 0m12.4s / 0m23.2s / 0m4.7s before CL 177597.
(That is, this change retains about half of the wall-time speedup, but
almost none of the user-time speedup.)
Tested manually using 'go test -race -bench=. cmd/api'.
Fixes #37951
Change-Id: Icd537e035e725e1ee7c41d97da5c6651233b927e
Reviewed-on: https://go-review.googlesource.com/c/go/+/224619
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Alexander Rakoczy <alex@golang.org>
fanzha02 [Wed, 25 Mar 2020 03:11:24 +0000 (11:11 +0800)]
cmd/link/internal/arm64: increase the function alignment to 16
On arm64, a function's address is 16 bytes aligned, and
the assembler aligns the size of function symbol to 16 bytes,
so to keep the consistent, this patch changes the function
alignment in the linker to 16 bytes.
cmd/internal/obj/arm64: add support of PCALIGN directive
Recently, we get requirements of instructions and functions alignment
from the gVisor project. To fit the alignment requirement of interrupt
table, they require an instruction's address to be aligned 128 bytes
and a function's entry address to be aligned 2K bytes. Thus we add
support for PCALIGN directive first. Below is a discussion about this
topic. https://groups.google.com/forum/m/#!topic/golang-dev/RPj90l5x86I
Functions in Go are aligned to 16 bytes on arm64, thus now we only
support 8 and 16 bytes alignment.
This patch adds support for PCALIGN directive. This directive can be
used within Go asm to align instruction by padding NOOP directives.
This patch also adds a test to verify the correnctness of the PCALIGN
directive. The test is contributed by Fannie Zhang <Fannie.Zhang@arm.com>.
Bryan C. Mills [Tue, 24 Mar 2020 20:18:02 +0000 (16:18 -0400)]
test: make runindir tests pass regardless of whether module mode is in use
The "runindir" tests used "go run", but relied on relative imports
(which are not supported by "go run" in module mode). Instead, such
tests must use fully-qualified imports, which require either a go.mod
file (in module mode) or that the package be in an appropriate
subdirectory of GOPATH/src (in GOPATH mode).
To set up such a directory, we use yet another copy of the same
overlayDir function currently found in the misc subdirectory of this
repository.
Fixes #33912
Updates #30228
Change-Id: If3d7ea2f7942ba496d98aaaf24a90bcdcf4df9f7
Reviewed-on: https://go-review.googlesource.com/c/go/+/225205 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Joel Sing [Mon, 9 Mar 2020 16:31:22 +0000 (03:31 +1100)]
cmd/compile: fold constants into immediate instructions on riscv64
Where possible, fold constants into versions of instructions that take
an immediate. This avoids the need to allocate a register and load the
immediate into it.
Change-Id: If911ca41235e218490679aed2ce5f48bf807a2b3
Reviewed-on: https://go-review.googlesource.com/c/go/+/222639
Run-TryBot: Joel Sing <joel@sing.id.au>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
Lynn Boger [Tue, 17 Mar 2020 13:24:47 +0000 (09:24 -0400)]
cmd/internal/obj/ppc64: fix PCALIGN on ppc64le
This fixes a potential issue with the previous implementation
of PCALIGN on ppc64. Previously PCALIGN was processed inside of
asmout and indicated the padding size by setting the value in
the optab, changing it back after the alignment instructions
were added. Now PCALIGN is processed outside of asmout, and optab
is not changed.
Ian Lance Taylor [Tue, 24 Mar 2020 04:11:01 +0000 (21:11 -0700)]
internal/poll: assume we have CancelIoEX on Windows
As of the Go 1.11 release we require at least Windows 7, so CancelIoEx
is always available. This lets us simplify the code to not require
dedicated threads to handle I/O requests.
Fixes #37956
Change-Id: If1dc4ac4acb61c43e4f2a9f26f225869050262a5
Reviewed-on: https://go-review.googlesource.com/c/go/+/225060
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Dan Scales [Fri, 20 Mar 2020 16:31:20 +0000 (09:31 -0700)]
runtime: fix code so defer record is not added to g0 defer list during panic
newdefer() actually adds the new defer to the current g's defer chain. That
happens even if we are on the system stack, in which case the g will be the g0
stack. For open-coded defers, we call newdefer() (only during panic processing)
while on the system stack, so the new defer is unintentionally added to the
g0._defer defer list. The code later correctly adds the defer to the user g's
defer list.
The g0._defer list is never used. However, that pointer on the g0._defer list can
keep a defer struct alive that is intended to be garbage-collected (smaller defers
use a defer pool, but larger-sized defer records are just GC'ed). freedefer() does
not zero out pointers when it intends that a defer become garbage-collected. So,
we can have the pointers in a defer that is held alive by g0._defer become invalid
(in particular d.link). This is the cause of the bad pointer bug in this issue
The fix is to change newdefer (only used in two places) to not add the new defer
to the gp._defer list. We just do it after the call with the correct gp pointer.
(As mentioned above, this code was already there after the newdefer in
addOneOpenDeferFrame.) That ensures that defers will be correctly
garbage-collected and eliminate the bad pointer.
This fix definitely fixes the original repro. I added a test and tried hard to
reproduce the bug (based on the original repro code), but awasn't actually able to
cause the bug. However, the test is still an interesting mix of heap-allocated,
stack-allocated, and open-coded defers.
Fixes #37688
Change-Id: I1a481b9d9e9b9ba4e8726ef718a1f4512a2d6faf
Reviewed-on: https://go-review.googlesource.com/c/go/+/224581
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
Ian Lance Taylor [Tue, 24 Mar 2020 03:42:29 +0000 (20:42 -0700)]
runtime: always use GetQueuedCompletionStatusEx on Windows
We used to fall back to GetQueuedCompletionStatus if
GetQueuedCompletionStatus was not available, but as of Go 1.11 we
require Windows 7 or later, so GetQueuedCompletionStatusEx is always
available.
Fixes #37957
Change-Id: I7d8d49a92ab7b1f5afdc54a442f696aaf4a5168e
Reviewed-on: https://go-review.googlesource.com/c/go/+/225059
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
nao20010128nao [Sat, 21 Mar 2020 06:52:58 +0000 (06:52 +0000)]
syscall/js: make wasm_exec.js compatible with Webpack
In Webpack, require("fs") will always be empty. This behavior throws an error: "fs.writeSync is not function". It happens when you did "fmt.Println".
This PR avoids such problem and use polyfill in wasm_exec.js on Webpack.
Dan Scales [Wed, 11 Mar 2020 19:08:03 +0000 (12:08 -0700)]
cmd/go: define a build tag for any GOEXPERIMENT which is enabled.
For each experiment that has been enabled in the toolchain, define a build tag
with the same name (but prefixed by "goexperiment.") which can be used for
compiling alternative files for the experiment. This allows changes for the
experiment, like extra struct fields in the runtime, without affecting the base
non-experiment code at all.
I use this capability in my CL for static lock ranking
(https://go-review.googlesource.com/c/go/+/207619), so that static lock ranking
can be fully enabled as a GOEXPERIMENT, but there is no overhead in the runtime
when the experiment is not enabled.
I added a test in cmd/go/testdata/scripts to make sure the build tags are being
defined properly. In order to implement the test, I needed to provide environment
variable GOEXPSTRING to the test scripts (with its value set from
objabi.Expstring(), so that it can determine the experiments baked into the
toolchain.
I filed https://github.com/golang/go/issues/37937 to make a builder with
GOEXPERIMENT set to 'staticlockranking'. This builder will ensure another variant
of GOEXPERIMENT is being tested regularly for this change, as well as checking
static lock ranking in the runtime.
Change-Id: Ieb4b86107238febd105558c1e639d30cfe57ab5c
Reviewed-on: https://go-review.googlesource.com/c/go/+/222925
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Jay Conrod <jayconrod@google.com> Reviewed-by: Bryan C. Mills <bcmills@google.com>
This makes all modern public keys in the standard library implement a
common interface (below) that can be used by applications for better
type safety and allows for checking that public (and private keys via
Public()) are equivalent.
interface {
Equal(crypto.PublicKey) bool
}
Equality for ECDSA keys is complicated, we take a strict interpretation
that works for all secure applications (the ones not using the
unfortunate non-constant time CurveParams implementation) and fails
closed otherwise.
Tests in separate files to make them x_tests and avoid an import loop
with crypto/x509.
Giovanni Bajo [Mon, 23 Mar 2020 08:21:44 +0000 (09:21 +0100)]
cmd/compile: fold LEAQ with constant scale into LEA
Discovered this after rebasing CL196679 (use poset bounds in prove).
Some tests fail with that CL applied:
codegen/smallintiface.go:11: linux/amd64/: opcode not found: "^LEAQ\\truntime.staticuint64s\\+8\\(SB\\)"
codegen/smallintiface.go:16: linux/amd64/: opcode not found: "^LEAQ\\truntime.staticuint64s\\+2024\\(SB\\)"
codegen/smallintiface.go:21: linux/amd64/: opcode not found: "^LEAQ\\truntime.staticuint64s\\+24\\(SB\\)"
The only difference in prove SSA dumps is that a single Lsh64x64
op with constant shift (<< 3) is marked as bounded. This triggers
a different rule matching sequence in lower, which manages to generate
worse code for the above testcases.
This CL fixes the above test after CL196679 is applied. Right now,
these rules never trigger (this CL passes toolstash -cmp), so I can't
write a test.
Change-Id: I353f1c79c1875cac1da82cd8afa1e05e42684f1c
Reviewed-on: https://go-review.googlesource.com/c/go/+/224877
Run-TryBot: Giovanni Bajo <rasky@develer.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
Roland Shoemaker [Fri, 20 Mar 2020 20:28:43 +0000 (20:28 +0000)]
crypto/x509: add RevocationList and CreateRevocationList
The existing Certificate.CreateCRL method generates non-conformant CRLs and
as such cannot be used for implementations that require standards
compliance. This change implements a new top level method, CreateCRL, which
generates compliant CRLs, and offers an extensible API if any
extensions/fields need to be supported in the future.
Here is an example Issuer/CRL generated using this change:
-----BEGIN CERTIFICATE-----
MIIBNjCB3aADAgECAgEWMAoGCCqGSM49BAMCMBIxEDAOBgNVBAMTB3Rlc3Rpbmcw
IhgPMDAwMTAxMDEwMDAwMDBaGA8wMDAxMDEwMTAwMDAwMFowEjEQMA4GA1UEAxMH
dGVzdGluZzBZMBMGByqGSM49AgEGCCqGSM49AwEHA0IABLHrudbSM36sn1VBrmm/
OfQTyEsI4tIUV1VmneOKHL9ENBGCiec4GhQm2SGnDT/sZy2bB3c3yozh/roS6cZJ
UZqjIDAeMA4GA1UdDwEB/wQEAwIBAjAMBgNVHQ4EBQQDAQIDMAoGCCqGSM49BAMC
A0gAMEUCIQCoAYN6CGZPgd5Sw5a1rd5VexciT5MCxTfXj+ZfJNfoiAIgQVCTB8AE
Nm2xset7+HOgtQYlKNw/rGd8cFcv5Y9aUzo=
-----END CERTIFICATE-----
-----BEGIN X509 CRL-----
MIHWMH0CAQEwCgYIKoZIzj0EAwIwEjEQMA4GA1UEAxMHdGVzdGluZxgPMDAwMTAx
MDIwMDAwMDBaGA8wMDAxMDEwMzAwMDAwMFowFjAUAgECGA8wMDAxMDEwMTAxMDAw
MFqgHjAcMA4GA1UdIwQHMAWAAwECAzAKBgNVHRQEAwIBBTAKBggqhkjOPQQDAgNJ
ADBGAiEAjqfj/IG4ys5WkjrbTNpDbr+saHGO/NujLJotlLL9KzgCIQDm8VZPzj0f
NYEQgAW4nsiUzlvEUCoHMw0141VCZXv67A==
-----END X509 CRL-----
Michael Anthony Knyszek [Mon, 27 Jan 2020 20:41:38 +0000 (20:41 +0000)]
runtime: use OnesCount64 to count allocated objects in a span
This change modifies the implementation of (*mspan).countAlloc by
using OnesCount64 (which on many systems is intrinsified). It does so by
using an unsafe pointer cast, but in this case we don't care about
endianness because we're just counting bits set.
This change means we no longer need the popcnt table which was redundant
in the runtime anyway. We can also simplify the logic here significantly
by observing that mark bits allocations are always 8-byte aligned, so we
don't need to handle any edge-cases due to the fact that OnesCount64
operates on 64 bits at a time: all irrelevant bits will be zero.
Overall, this implementation is significantly faster than the old one on
amd64, and should be similarly faster (or better!) on other systems
which support the intrinsic. On systems which do not, it should be
roughly the same performance because OnesCount64 is implemented using a
table in the general case.
Michael Anthony Knyszek [Wed, 18 Mar 2020 18:46:04 +0000 (18:46 +0000)]
runtime: add countAlloc benchmark
This change adds a small microbenchmark for (*mspan).countAlloc, which
we're about to replace. Admittedly this isn't a critical piece of code,
but the benchmark was useful in understanding the performance change.
Michael Anthony Knyszek [Fri, 20 Mar 2020 19:08:13 +0000 (19:08 +0000)]
cmd/compile: panic if trying to alias an intrinsic with no definitions
Currently if we try to alias an intrinsic which hasn't been defined for
any architecture (such as by accidentally creating the alias before the
intrinsic is created with addF), then we'll just silently not apply any
intrinsics to those aliases.
Catch this particular case by panicking in alias if we try to apply the
alias and it did nothing.
Change-Id: I98e75fc3f7206b08fc9267cedb8db3e109ec4f5d
Reviewed-on: https://go-review.googlesource.com/c/go/+/224637
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
Michael Anthony Knyszek [Fri, 20 Mar 2020 15:26:46 +0000 (15:26 +0000)]
cmd/compile: declare runtime bit func aliases after math/bits intrinsics
Currently runtime/internal/sys bit-manipulation functions are aliased to
math/bits functions, which are intrinsified. Unfortunately these aliases
are declared before the intrinsified versions are generated, resulting
in the generic version of the code being copied over.
This change moves the aliases for bit operations in runtime/internal/sys
after the addF calls to generate those intrinsics in SSA, so that the
intrinsified SSA representation of those functions actually get copied
over.
This should improve the overall performance of the runtime (especially
the page allocator) since these bit operations will actually be
intrinsified now.
Matthew Dempsky [Thu, 12 Mar 2020 19:14:02 +0000 (12:14 -0700)]
cmd/compile: skip generating args_stackmap for "pulled" funcs
In golang.org/cl/171464, we cleaned up generation of .stkobj linker
symbols, but we couldn't figure out why a similar cleanup to
.args_stackmap linker symbols caused problems.
The issue is that we only need/want to generate .args_stackmap for
functions that are implemented in assembly in the same package. When
"pulling" a function from another package via //go:linkname, we can
safely skip emitting .args_stackmap, because compiling that package
will have generated it, if necessary.
Fixes #31615.
Change-Id: If8680aa7dd5b4e8f268b6b032d746f1b8536c867
Reviewed-on: https://go-review.googlesource.com/c/go/+/223238
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com> Reviewed-by: Keith Randall <khr@golang.org>
Andy Pan [Sun, 22 Mar 2020 06:22:41 +0000 (06:22 +0000)]
runtime: correct the system-call name of kevent in comment
Change-Id: Ib1f4a6f7e36d28eff39f597df5c4703bf62654a4
GitHub-Last-Rev: 15ea1b9fa846737bd5d30b7b98d8933f9992e5c7
GitHub-Pull-Request: golang/go#37994
Reviewed-on: https://go-review.googlesource.com/c/go/+/224590
Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Ben Schwartz [Mon, 10 Jun 2019 16:29:23 +0000 (12:29 -0400)]
runtime: speed up receive on empty closed channel
Currently, nonblocking receive on an open channel is about
700 times faster than nonblocking receive on a closed channel.
This change makes closed channels equally fast.
Fixes #32529. Includes a correction based on #36714.
Giovanni Bajo [Sun, 22 Mar 2020 08:28:21 +0000 (09:28 +0100)]
build: force all Windows batch files to CRLF
Batch files should use CRLF endings. LF endings mostly
work but in some situations they cause random errors like
goto commands failing for mysterious reasons. See
golang.org/issue/37791 for more information.
Next CL triggered one of such bug (a label was not being
recognized), so prepare for it by converting to CRLF.
This CL also touches all existing batch files to force git
to update the line endings (unfortunately, changing
.gitattributes only has effect next time the file is checked
out or modified).
Fixes #37791
Updates #9281
Change-Id: I6f9a114351cb7ac9881914400aa210c930eb8cc1
Reviewed-on: https://go-review.googlesource.com/c/go/+/96495
Run-TryBot: Giovanni Bajo <rasky@develer.com> Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Alex Brainman [Sun, 16 Feb 2020 01:01:02 +0000 (12:01 +1100)]
runtime: ignore error returned by PowerRegisterSuspendResumeNotification
It appears that PowerRegisterSuspendResumeNotification is not supported
when running inside Docker - see issues #35447, #36557 and #37149.
Our current code relies on error number to determine Docker environment.
But we already saw PowerRegisterSuspendResumeNotification return
ERROR_FILE_NOT_FOUND, ERROR_INVALID_PARAMETERS and ERROR_ACCESS_DENIED
(see issues above). So this approach is not sustainable.
Just ignore PowerRegisterSuspendResumeNotification returned error.
Fixes #37149
Change-Id: I2beba9d45cdb8c1efac5e974e747827a6261915a
Reviewed-on: https://go-review.googlesource.com/c/go/+/219657
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Austin Clements [Fri, 20 Mar 2020 15:37:54 +0000 (11:37 -0400)]
runtime: use divRoundUp
There are a handful of places where the runtime wants to round up the
result of a division. We just introduced a helper to do this. This CL
replaces all of the hand-coded round-ups (that I could find) with this
helper.
Austin Clements [Wed, 26 Feb 2020 20:12:33 +0000 (15:12 -0500)]
runtime: fix rounding in materializeGCProg
materializeGCProg allocates a temporary buffer for unrolling a GC
program. Unfortunately, when computing the size of the buffer, it
rounds *down* the number of bytes needed to store bitmap before
rounding up the number of pages needed to store those bytes. The fact
that it rounds up to pages usually mitigates the rounding down, but
the type from #37470 exists right on the boundary where this doesn't
work:
On 64-bit, this GC bitmap is exactly 8 KiB of zeros, followed by three
one bits. Hence, this needs 8193 bytes of storage, but the current
math in materializeGCProg rounds *down* the three one bits to 8192
bytes. Since this is exactly pageSize, the next step of rounding up to
the page size doesn't mitigate this error, and materializeGCProg
allocates a buffer that is one byte too small. runGCProg then writes
one byte past the end of this buffer, causing either a segfault (if
you're lucky!) or memory corruption.
Ian Lance Taylor [Thu, 23 Jan 2020 23:02:43 +0000 (15:02 -0800)]
runtime/race: test that close synchronizes with read
Add a test to ensure that the race detector sees that closing a
channel synchronizes with a read from that channel.
This test case failed when CL 181543 was in the tree.
CL 181543 was reverted in CL 216158; this adds a test to make
sure that we don't re-introduce the problem at a later date.
For #32529
For #36714
Change-Id: I5a40f744c67c3f8191d6ad822710c180880a7375
Reviewed-on: https://go-review.googlesource.com/c/go/+/216099
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Ian Lance Taylor [Thu, 19 Mar 2020 21:29:23 +0000 (14:29 -0700)]
net: merge common Unix/Windows methods
When we added the internal/poll package, the Unix and Windows implementations
of several netFD methods became exactly the same, except for using a
different name for the string passed to wrapSyscallError.
One case is not an exact duplicate: we slightly tweak the implementation
of (*netFD).shutdown on Windows to wrap the error.
Change-Id: I3d87a317d5468ff8f1958d86f6189ea1ba697e9a
Reviewed-on: https://go-review.googlesource.com/c/go/+/224140
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Tobias Klauser [Thu, 19 Mar 2020 21:33:40 +0000 (22:33 +0100)]
crypto/x509: bump minimum macOS version to 10.11
The minimum macOS supported version is 10.11 as of Go 1.14, see #23011.
Thus, bump macosx-version-min to 10.11
While at it, drop __MAC_OS_X_VERSION_MAX_ALLOWED as suggested by
Filippo:
In general, I can see why we'd want to tell the libraries which
minimum version we target so they drop compatibility with older
versions. No idea why we'd specify a max version, unless it's to make
sure we don't use APIs added after that version, but then it would
have to be 1011 not 1015.
Let's try dropping that define and see if anything blows up? ¯\_(ツ)_/¯
Changkun Ou [Fri, 28 Feb 2020 20:53:38 +0000 (21:53 +0100)]
testing: fix data race between parallel subtests
This CL fixes a race condition if there are two subtests, and
one finishing but the other is panicking.
Fixes #37551
Change-Id: Ic33963eb338aec228964b95f7c34a0d207b91e00
Reviewed-on: https://go-review.googlesource.com/c/go/+/221322
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Tim Möhlmann [Fri, 10 Jan 2020 10:06:53 +0000 (12:06 +0200)]
database/sql: add method Err on sql.Row
The Row.Err method is intended to assist wrapping sql.DB.
Because sql.Row is a struct with private fields,
a wrapper in an existing code base cannot easily provide users
with a different implementation without large rewrites.
Adding this method allows query level errors to be handled
centrally.
Fixes #35804
Change-Id: I94e6329de89a7ee1284ce9ef76af4363d2d081f9
Reviewed-on: https://go-review.googlesource.com/c/go/+/214317 Reviewed-by: Daniel Theophanes <kardianos@gmail.com>
Run-TryBot: Daniel Theophanes <kardianos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Kyle Nusbaum [Wed, 18 Mar 2020 19:17:50 +0000 (19:17 +0000)]
context: prevent creation of invalid contexts
This commit makes it impossible to create derived contexts with nil parents.
Previously it was possible to create derived contexts with nil parents, and
invalid contexts could propogate through the program. Eventually this can
cause a panic downstream, which is difficult to trace back to the source
of the error.
Although `WithCancel` and `WithDeadline` already panic if `parent` is `nil`, this adds explicit checks to give a useful message in the panic.
Fixes #37908
Change-Id: I70fd01f6539c1b0da0e775fc5457e32e7075e52c
GitHub-Last-Rev: 1b7dadd7db9ba42952644ad5e9a49591d6a5191f
GitHub-Pull-Request: golang/go#37898
Reviewed-on: https://go-review.googlesource.com/c/go/+/223777
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Michael Anthony Knyszek [Mon, 17 Jun 2019 19:03:09 +0000 (19:03 +0000)]
runtime: don't hold worldsema across mark phase
This change makes it so that worldsema isn't held across the mark phase.
This means that various operations like ReadMemStats may now stop the
world during the mark phase, reducing latency on such operations.
Only three such operations are still no longer allowed to occur during
marking: GOMAXPROCS, StartTrace, and StopTrace.
For the former it's because any change to GOMAXPROCS impacts GC mark
background worker scheduling and the details there are tricky.
For the latter two it's because tracing needs to observe consistent GC
start and GC end events, and if StartTrace or StopTrace may stop the
world during marking, then it's possible for it to see a GC end event
without a start or GC start event without an end, respectively.
To ensure that GOMAXPROCS and StartTrace/StopTrace cannot proceed until
marking is complete, the runtime now holds a new semaphore, gcsema,
across the mark phase just like it used to with worldsema.
This change is being landed once more after being reverted in the Go
1.14 release cycle, since CL 215157 allows it to have a positive
effect on system performance.
For the benchmark BenchmarkReadMemStatsLatency in the runtime, which
measures ReadMemStats latencies while the GC is exercised, the tail of
these latencies reduced dramatically on an 8-core machine:
name old 50%tile-ns new 50%tile-ns delta
ReadMemStatsLatency-8 4.40M ±74% 0.12M ± 2% -97.35% (p=0.008 n=5+5)
name old 90%tile-ns new 90%tile-ns delta
ReadMemStatsLatency-8 102M ± 6% 0M ±14% -99.79% (p=0.008 n=5+5)
name old 99%tile-ns new 99%tile-ns delta
ReadMemStatsLatency-8 147M ±18% 4M ±57% -97.43% (p=0.008 n=5+5)
Michael Anthony Knyszek [Wed, 19 Feb 2020 20:54:25 +0000 (20:54 +0000)]
runtime: add ReadMemStats latency benchmark
This change adds a benchmark to the runtime which measures ReadMemStats
latencies. It generates allocations with lots of pointers to keep the GC
busy while hitting ReadMemStats and measuring the time it takes to
complete.
Michael Anthony Knyszek [Thu, 16 Jan 2020 21:39:42 +0000 (21:39 +0000)]
runtime: preempt dedicated background mark workers for STW
Currently, dedicated background mark workers are essentially always
non-preemptible.
This change makes it so that dedicated background mark workers park if
their preemption flag is set and someone is trying to STW, allowing them
to do so.
This change prepares us for allowing a STW to happen (and happen
promptly) during GC marking in a follow-up change.
Jay Conrod [Mon, 10 Feb 2020 19:42:02 +0000 (14:42 -0500)]
cmd/go/internal/modfetch/zip_sum_test: remove dead versions
* gitlab.com/yumeko/MumbleEmu: the go-import tag now points to
gitlab.com/yumeko/mumbleemu, but the module path hasn't changed
in go.mod.
* github.com/openshift/api: tag v3.9.0 was deleted.
* github.com/AlexStocks/log4go: tag v1.0.5 was deleted.
* github.com/belogik/goes: repository is no longer available.
* llvm.org/llvm: server times out and disconnects after 30-40 mins.
Also, fix a typo in an error message.
With these versions removed, zip_sum_test passes.
Updates #35290
Change-Id: Id3bdb8675a5582f88a6ff4c12dd7d1abe31aa56f
Reviewed-on: https://go-review.googlesource.com/c/go/+/218917
Run-TryBot: Jay Conrod <jayconrod@google.com> Reviewed-by: Bryan C. Mills <bcmills@google.com>
Cherry Zhang [Tue, 17 Mar 2020 00:08:00 +0000 (20:08 -0400)]
runtime: don't send preemption signal if there is a signal pending
If multiple threads call preemptone to preempt the same M, it may
send many signals to the same M such that it hardly make
progress, causing live-lock problem. Only send a signal if there
isn't already one pending.
Bryan C. Mills [Tue, 17 Mar 2020 19:17:22 +0000 (15:17 -0400)]
cmd/go: add a missing curly-brace in the 'stale' command format string
The missing brace made the 'stale' command a no-op in the non-error case.
Fix the 'short' skip in install_cross_gobin (it was backward) and
update it to no longer check staleness of a not-necessarily-stale
target and to no longer expect to be able to install into GOROOT/pkg.
(This was missed in #30316 because that part of the test was
erroneously skipped in non-short mode.)
Change-Id: I6a276fec5fa5e5da3fe0daf0c2b5086116ed7c1a
Reviewed-on: https://go-review.googlesource.com/c/go/+/223747
Run-TryBot: Bryan C. Mills <bcmills@google.com> Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Daniel Theophanes [Fri, 26 Apr 2019 21:45:46 +0000 (14:45 -0700)]
database/sql: process all Session Resets synchronously
Adds a new interface, driver.ConnectionValidator, to allow
drivers to signal they should not be used again,
separatly from the session resetter interface.
This is done now that the session reset is done
after the connection is put into the connection pool.
Previous behavior attempted to run Session Resets
in a background worker. This implementation had two
problems: untested performance gains for additional
complexity, and failures when the pool size
exceeded the connection reset channel buffer size.
Rodolfo Carvalho [Tue, 17 Mar 2020 10:41:45 +0000 (10:41 +0000)]
testing: use "exit code" in documentation consistently
The documentation for m.Run says it returns an "exit code" to pass to
os.Exit. The argument to os.Exit is named "code".
While "exit code", "exit status" and "exit status code" are all valid ways
to refer to the same concept, prefer to stick to one form for consistency
and to avoid confusing users.
Change-Id: If76ee3fab5cc99c79e05ac1a4e413790a9c93d60
GitHub-Last-Rev: 85a081d2f03c2cf9e8e519916986c59c86aebf57
GitHub-Pull-Request: golang/go#37899
Reviewed-on: https://go-review.googlesource.com/c/go/+/223778 Reviewed-by: Gabriel Aszalos <gabriel.aszalos@gmail.com> Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Gabriel Aszalos <gabriel.aszalos@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Bryan C. Mills [Tue, 17 Mar 2020 14:50:40 +0000 (10:50 -0400)]
cmd/go: replace TestCgoDependsOnSyscall with a simpler script test
The existing test attempted to remove '_race' binaries from
GOROOT/pkg, which could not only fail if GOROOT is read-only, but also
interfere with other tests run in parallel.
Updates #30316
Updates #37573
Updates #17751
Change-Id: Id7e2286ab67f8333baf4d52244b7f4476aa93a46
Reviewed-on: https://go-review.googlesource.com/c/go/+/223745
Run-TryBot: Bryan C. Mills <bcmills@google.com> Reviewed-by: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Changkun Ou [Sun, 16 Feb 2020 13:42:29 +0000 (14:42 +0100)]
testing: do not require os.Exit in TestMain
If TestMain reports a wrong exit code to os.Exit, the test will be
exited with exist code inconsist with test results.
This CL eliminates the requirement of calling os.Exit in TestMain.
Now, m.Run records the execution status of its test, the outer
main func will call os.Exit with that exit code if TestMain does
not call os.Exit.
If TestMain does not call m.Run, the outer main func remain calls
os.Exit(0) as before.
Fixes #34129
Change-Id: I9598023e03b0a6260f0217f34df41c231c7d6489
Reviewed-on: https://go-review.googlesource.com/c/go/+/219639 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Ian Lance Taylor [Fri, 24 Jan 2020 04:38:20 +0000 (20:38 -0800)]
runtime: add goroutines returned by poller to local run queue
In Go 1.13, when the network poller found a list of ready goroutines,
they were added to the global run queue. The timer goroutine would
typically sleep in a futex with a timeout, and when the timeout
expired the timer goroutine would either be handed off to an idle P
or added to the global run queue. The effect was that on a busy system
with no idle P's goroutines waiting for timeouts and goroutines waiting
for the network would start at the same priority.
That changed on tip with the new timer code. Now timer functions are
invoked directly from a P, and it happens that the functions used
by time.Sleep and time.After and time.Ticker add the newly ready
goroutines to the local run queue. When a P looks for work it will
prefer goroutines on the local run queue; in fact it will only
occasionally look at the global run queue, and even when it does it
will just pull one goroutine off. So on a busy system with both active
timers and active network connections the system can noticeably prefer
to run goroutines waiting for timers rather than goroutines waiting
for the network.
This CL undoes that change by, when possible, adding goroutines
waiting for the network to the local run queue of the P that checked.
This doesn't affect network poller checks done by sysmon, but it
does affect network poller checks done as each P enters the scheduler.
This CL also makes injecting a list into either the local or global run
queue more efficient, using bulk operations rather than individual ones.
Change-Id: I85a66ad74e4fc3b458256fb7ab395d06f0d2ffac
Reviewed-on: https://go-review.googlesource.com/c/go/+/216198 Reviewed-by: Michael Knyszek <mknyszek@google.com>