CL 570555 replaced a loop which added empty
color.RGBA elements with a call to clear.
color.Palette is a slice of interfaces, so using
clear results in a slice of nil elements, rather
than what we previously had which was empty
color.RGBA elements. This could cause a panic when
attempting to re-encode a GIF which had an
extended color palette because of the weird
transparency hack.
This was discovered by OSS-Fuzz. I've added a test
case using their reproducer in order to prevent
future regressions.
Change-Id: I00a89257d90b6cca68672173eecdaa0a24f18d9c
Reviewed-on: https://go-review.googlesource.com/c/go/+/577555
Reviewed-by: Nigel Tao <nigeltao@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Roland Shoemaker <roland@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
For #61060
Change-Id: I13cd73b4062cb7bd248d2a4afae06dfa29ac0203
Reviewed-on: https://go-review.googlesource.com/c/go/+/577955
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Commit-Queue: Ian Lance Taylor <iant@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Depending on the query, a RawBytes can contain memory owned by the
driver or by database/sql:
If the driver provides the column as a []byte,
RawBytes aliases that []byte.
If the driver provides the column as any other type,
RawBytes contains memory allocated by database/sql.
Prior to this CL, Rows.Scan will reuse existing capacity in a
RawBytes to permit a single allocation to be reused across rows.
When a RawBytes is reused across queries, this can result
in database/sql writing to driver-owned memory.
Add a buffer to Rows to store RawBytes data, and reuse this
buffer across calls to Rows.Scan.
Fixes#65201
Change-Id: Iac640174c7afa97eeb39496f47dec202501b2483
Reviewed-on: https://go-review.googlesource.com/c/go/+/557917
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Document that links to symbols in the standard library can be
written as "[foo]", without the actual link.
For #64169.
Change-Id: I9d8a33e85df70037320a169d55a2bb4a8a981ebf
Reviewed-on: https://go-review.googlesource.com/c/go/+/577915
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
This test has been OOMing on 32-bit platforms for a bit. I suspect the
very high allocation rate is causing the program to outrun the GC in
some corner-case scenarios, especially on 32-bit Windows.
I don't have a strong grasp of what's going on yet, but lowering the
memory footprint should help with the flakiness. This shouldn't
represent a loss in test coverage, since we're still allocating and
assisting plenty (tracing the latter is a strong reason this test
exists).
For #66624.
Change-Id: Idd832cfc5cde04701386919df4490f201c71130a
Reviewed-on: https://go-review.googlesource.com/c/go/+/577475
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
The existing implementation of traceMap is a hash map with a fixed
bucket table size which scales poorly with the number of elements added
to the map. After a few thousands elements are in the map, it tends to
fall over.
Furthermore, cleaning up the trace map is currently non-preemptible,
without very good reason.
This change replaces the traceMap implementation with a simple
append-only concurrent hash-trie. The data structure is incredibly
simple and does not suffer at all from the same scaling issues.
Because the traceMap no longer has a lock, and the traceRegionAlloc it
embeds is not thread-safe, we have to push that lock down. While we're
here, this change also makes the fast path for the traceRegionAlloc
lock-free. This may not be inherently faster due to contention on the
atomic add, but it creates an easy path to sharding the main allocation
buffer to reduce contention in the future. (We might want to also
consider a fully thread-local allocator that covers both string and
stack tables. The only reason a thread-local allocator isn't feasible
right now is because each of these has their own region, but we could
certainly group all them together.)
Change-Id: I8c06d42825c326061a1b8569e322afc4bc2a513a
Reviewed-on: https://go-review.googlesource.com/c/go/+/570035
Reviewed-by: Carlos Amedee <carlos@golang.org>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
TryBot-Bypass: Michael Knyszek <mknyszek@google.com>
Reviewed-by: David Chase <drchase@google.com>
Currently lots of functions require systemstack because the trace buffer
might get flushed, but that will already switch to the systemstack for
the most critical bits (grabbing trace.lock). That means a lot of this
code is non-preemptible when it doesn't need to be. We've seen this
cause problems at scale, when dumping very large numbers of stacks at
once, for example.
This is a re-land of CL 572095 which was reverted in CL 577376. This
re-land includes a fix of the test that broke on the longtest builders.
Change-Id: Ia8d7cbe3aaa8398cf4a1818bac66c3415a399348
Cq-Include-Trybots: luci.golang.try:gotip-linux-amd64-longtest
Reviewed-on: https://go-review.googlesource.com/c/go/+/577377
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Change-Id: I28baf375502ccf3b0dfcc8250650e914ac7bae78
Reviewed-on: https://go-review.googlesource.com/c/go/+/577835
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Jes Cok <xigua67damn@gmail.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
This is covered by the existing tests under gotypesalias=1.
Change-Id: Ia17f35fe580b745fa4bdaf4689dfe9c2ed6ebc5b
Reviewed-on: https://go-review.googlesource.com/c/go/+/577735
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Auto-Submit: Alan Donovan <adonovan@google.com>
This change reenables the legacy three-phase resolution
(non-alias typenames, aliases, the rest) even when
GODEBUG=gotypesalias=1. Unfortunately the existing test case
for #50259 causes the simpler logic to fail.
Updates #50259
Updates #65294
Change-Id: Ibfaf8146e46760718673a916a9b220a9d678409a
Reviewed-on: https://go-review.googlesource.com/c/go/+/577616
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Flag flip to enable stack slot merging by default when optimizing.
Please see the earlier CL for details on what this is doing.
Updates #62737.
Updates #65532.
Updates #65495.
Change-Id: I8e30d553e74ace43d418f883199721f05320d3d7
Reviewed-on: https://go-review.googlesource.com/c/go/+/576681
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
It is possible to have situations where a given ir.Name is
non-address-taken at the source level, but whose address is
materialized in order to accommodate the needs of arch-dependent
memory ops. The issue here is that the SymAddr op will show up as
touching a variable of interest, but the subsequent memory op will
not. This is generally not an issue for computing whether something is
live across a call, but it is problematic for collecting the more
fine-grained live interval info that drives stack slot merging.
As an example, consider this Go code:
package p
type T struct {
x [10]int
f float64
}
func ABC(i, j int) int {
var t T
t.x[i&3] = j
return t.x[j&3]
}
On amd64 the code sequences we'll see for accesses to "t" might look like
v10 = VarDef <mem> {t} v1
v5 = MOVOstoreconst <mem> {t} [val=0,off=0] v2 v10
v23 = LEAQ <*T> {t} [8] v2 : DI
v12 = DUFFZERO <mem> [80] v23 v5
v14 = ANDQconst <int> [3] v7 : AX
v19 = MOVQstoreidx8 <mem> {t} v2 v14 v8 v12
v22 = ANDQconst <int> [3] v8 : BX
v24 = MOVQloadidx8 <int> {t} v2 v22 v19 : AX
v25 = MakeResult <int,mem> v24 v19 : <>
Note that the the loads and stores (ex: v19, v24) all refer directly
to "t", which means that regular live analysis will work fine for
identifying variable lifetimes. The DUFFZERO is (in effect) an
indirect write, but since there are accesses immediately after it we
wind up with the same live intervals.
Now the same code with GOARCH=ppc64:
v10 = VarDef <mem> {t} v1
v20 = MOVDaddr <*T> {t} v2 : R20
v12 = LoweredZero <mem> [88] v20 v10
v3 = CLRLSLDI <int> [212543] v7 : R5
v15 = MOVDaddr <*T> {t} v2 : R6
v19 = MOVDstoreidx <mem> v15 v3 v8 v12
v29 = CLRLSLDI <int> [212543] v8 : R4
v24 = MOVDloadidx <int> v15 v29 v19 : R3
v25 = MakeResult <int,mem> v24 v19 : <>
Here instead of memory ops that refer directly to the symbol, we take
the address of "t" (ex: v15) and then pass the address to memory ops
(where the ops themselves no longer refer to the symbol).
This patch enhances the stack slot merging liveness analysis to handle
cases like the PPC64 one above. We add a new phase in candidate
selection that collects more precise use information for merge
candidates, and screens out candidates that are too difficult to
analyze. The phase make a forward pass over each basic block looking
for instructions of the form vK := SymAddr(N) where N is a raw
candidate. It then creates an entry in a map with key vK and value
holding name and the vK use count. As the walk continues, we check for
uses of of vK: when we see one, record it in a side table as an
upwards exposed use of N. At each vK use we also decrement the use
count in the map entry, and if we hit zero, remove the map entry. If
we hit the end of the basic block and we still have map entries, this
implies that the address in question "escapes" the block -- at that
point to be conservative we just evict the name in question from the
candidate set.
Although this CL fixes the issues that forced a revert of the original
merging CL, this CL doesn't enable stack slot merging by default; a
subsequent CL will do that.
Updates #62737.
Updates #65532.
Updates #65495.
Change-Id: Id41d359a677767a8e7ac1e962ae23f7becb4031f
Reviewed-on: https://go-review.googlesource.com/c/go/+/576735
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
For -gcflags=-d=mergelocalstrace=1 (which reports estimated savings
from stack slot merging), emit separate values for pointerful vs
non-pointerful variables, for a bit more detail.
Updates #62737.
Updates #65532.
Updates #65495.
Change-Id: I9dd27d2a254036448c85c13d189d1ed36157c9d7
Reviewed-on: https://go-review.googlesource.com/c/go/+/576680
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
[This is a partial roll-forward of CL 553055, the main change here
is that the stack slot overlap operation is flagged off by default
(can be enabled by hand with -gcflags=-d=mergelocals=1) ]
Preliminary compiler support for merging/overlapping stack slots of
local variables whose access patterns are disjoint.
This patch includes changes in AllocFrame to do the actual
merging/overlapping based on information returned from a new
liveness.MergeLocals helper. The MergeLocals helper identifies
candidates by looking for sets of AUTO variables that either A) have
the same size and GC shape (if types contain pointers), or B) have the
same size (but potentially different types as long as those types have
no pointers). Variables must be greater than (3*types.PtrSize) in size
to be considered for merging.
After forming candidates, MergeLocals collects variables into "can be
overlapped" equivalence classes or partitions; this process is driven
by an additional liveness analysis pass. Ideally it would be nice to
move the existing stackmap liveness pass up before AllocFrame
and "widen" it to include merge candidates so that we can do just a
single liveness as opposed to two passes, however this may be difficult
given that the merge-locals liveness has to take into account
writes corresponding to dead stores.
This patch also required a change to the way ssa.OpVarDef pseudo-ops
are generated; prior to this point they would only be created for
variables whose type included pointers; if stack slot merging is
enabled then the ssagen code creates OpVarDef ops for all auto vars
that are merge candidates.
Note that some temporaries created late in the compilation process
(e.g. during ssa backend) are difficult to reason about, especially in
cases where we take the address of a temp and pass it to the runtime.
For the time being we mark most of the vars created post-ssagen as
"not a merge candidate".
Stack slot merging for locals/autos is enabled by default if "-N" is
not in effect, and can be disabled via "-gcflags=-d=mergelocals=0".
Fixmes/todos/restrictions:
- try lowering size restrictions
- re-evaluate the various skips that happen in SSA-created autotmps
Updates #62737.
Updates #65532.
Updates #65495.
Change-Id: Ifda26bc48cde5667de245c8a9671b3f0a30bb45d
Reviewed-on: https://go-review.googlesource.com/c/go/+/575415
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
This change makes it possible for the runtime to preempt the zeroing of
large objects that contain pointers. It turns out this is fairly
straightforward with allocation headers, since we can just temporarily
tell the GC that there's nothing to scan for a large object with a
single pointer write (as opposed to trying to zero a whole bunch of
bits, as we would've had to do once upon a time).
Fixes#31222.
Change-Id: I10d0dcfa3938c383282a3eb485a6f00070d07bd2
Reviewed-on: https://go-review.googlesource.com/c/go/+/577495
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
This change removes the allocheaders, deleting all the old code and
merging mbitmap_allocheaders.go back into mbitmap.go.
This change also deletes the SetType benchmarks which were already
broken in the new GOEXPERIMENT (it's harder to set up than before). We
weren't really watching these benchmarks at all, and they don't provide
additional test coverage.
Change-Id: I135497201c3259087c5cd3722ed3fbe24791d25d
Reviewed-on: https://go-review.googlesource.com/c/go/+/567200
Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
The previous CL, CL 570257, made it so that STW time no longer
overlapped with other CPU time tracking. However, what we lost was
insight into the CPU time spent _stopping_ the world, which can be just
as important. There's pretty much no easy way to measure this
indirectly, so this CL implements a direct measurement: whenever a P
enters _Pgcstop, it writes down what time it did so. stopTheWorld then
accumulates all the time deltas between when it finished stopping the
world and each P's stop time into a total additional pause time. The GC
pause cases then accumulate this number into the metrics.
This should cause minimal additional overhead in stopping the world. GC
STWs already take on the order of 10s to 100s of microseconds. Even for
100 Ps, the extra `nanotime` call per P is only 1500ns of additional CPU
time. This is likely to be much less in actual pause latency, since it
all happens concurrently.
Change-Id: Icf190ffea469cd35ebaf0b2587bf6358648c8554
Reviewed-on: https://go-review.googlesource.com/c/go/+/574215
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Nicolas Hillegeer <aktau@google.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Currently the GC CPU pause time metrics start measuring before the STW
is complete. This results in a slightly less accurate measurement and
creates some overlap with other timings (for example, the idle time of
idle Ps) that will cause double-counting.
This CL adds a field to worldStop to track the point at which the world
actually stopped and uses that as the basis for the GC CPU pause time
metrics, basically eliminating this overlap.
Note that this will cause Ps in _Pgcstop before the world is fully
stopped to be counted as user time. A follow-up CL will fix this
discrepancy.
Change-Id: I287731f08415ffd97d327f582ddf7e5d2248a6f5
Reviewed-on: https://go-review.googlesource.com/c/go/+/570258
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Nicolas Hillegeer <aktau@google.com>
This change fixes a possible race with updating metrics and reading
them. The update is intended to be protected by the world being stopped,
but here, it clearly isn't.
Fixing this lets us lower the thresholds in the metrics tests by an
order of magnitude, because the only thing we have to worry about now is
floating point error (the tests were previously written assuming the
floating point error was much higher than it actually was; that turns
out not to be the case, and this bug was the problem instead). However,
this still isn't that tight of a bound; we still want to catch any and
all problems of exactness. For this purpose, this CL adds a test to
check the source-of-truth (in uint64 nanoseconds) that ensures the
totals exactly match.
This means we unfortunately have to take another time measurement, but
for now let's prioritize correctness. A few additional nanoseconds of
STW time won't be terribly noticable.
Fixes#66212.
Change-Id: Id02c66e8a43c13b1f70e9b268b8a84cc72293bfd
Reviewed-on: https://go-review.googlesource.com/c/go/+/570257
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Nicolas Hillegeer <aktau@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Pull in CL 576895:
ec05fdcd http2: don't retry the first request on a connection on GOAWAY error
For #66668.
Fixes#60636.
Change-Id: I9903607e3d432a5db0325da82eb7f4b378fbddde
Reviewed-on: https://go-review.googlesource.com/c/go/+/576976
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Rather than requiring that HTTP/1 and HTTP/2 servers behave identically
when a misbehaving handler writes too many bytes, check only that both
behave reasonably.
In particular, allow the handler to defer detection of a write overrun
until flush time, and permit the HTTP/2 handler to reset the stream
rather than requring it to return a truncated body as HTTP/1 must.
For #56019
Change-Id: I0838e550c4fc202dcbb8bf39ce0fa4a367ca7e71
Reviewed-on: https://go-review.googlesource.com/c/go/+/577415
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
This was missed in CL 571055.
Change-Id: I58d6469c9ea323943e9c230a54fba8f7ec705d47
Reviewed-on: https://go-review.googlesource.com/c/go/+/573515
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Currently we use stwprocs as the multiplier for the STW CPU time
computation, but this isn't the same as GOMAXPROCS, which is used for
the total time in the CPU metrics. The two numbers need to be
comparable, so this change switches to using maxprocs to make it so.
Change-Id: I423e3c441d05b1bd656353368cb323289661e302
Reviewed-on: https://go-review.googlesource.com/c/go/+/570256
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Nicolas Hillegeer <aktau@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Currently this is done manually in two places. Replace these manual
updates with a method that also forces the caller to be mindful that the
number will be multiplied (and that it needs to be). This will make
follow-up changes simpler too.
Change-Id: I81ea844b47a40ff3470d23214b4b2fb5b71a4abe
Reviewed-on: https://go-review.googlesource.com/c/go/+/570255
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Change-Id: I940c63c3040035e507428798d50060cfd0d04e16
GitHub-Last-Rev: e27484cd43
GitHub-Pull-Request: golang/go#66706
Reviewed-on: https://go-review.googlesource.com/c/go/+/577055
Reviewed-by: Than McIntosh <thanm@google.com>
Auto-Submit: Ian Lance Taylor <iant@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Than McIntosh <thanm@google.com>
Ensure that the immediate for a RORI or RORIW instruction are within range,
adding test coverage. Also use a consistent "immediate out of range" error
for both rotations and shifts.
Change-Id: Id687d7c6e028786f607e9519bbb64dab62b6cf3d
Reviewed-on: https://go-review.googlesource.com/c/go/+/572735
Reviewed-by: M Zhuo <mengzhuo1203@gmail.com>
Run-TryBot: Joel Sing <joel@sing.id.au>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Pull in CL 576756:
b67a0f05 http2: send correct LastStreamID in stream-caused GOAWAY
It comes with newer x/crypto and x/sys requirements via CL 576516.
For #65051.
Fixes#66668.
Change-Id: Ib6df49b779ff5ea56966ae3de443e87ac7f4ec4f
Cq-Include-Trybots: luci.golang.try:gotip-linux-amd64-longtest
Reviewed-on: https://go-review.googlesource.com/c/go/+/576679
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Reviewed-by: Damien Neil <dneil@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Pull in CL 576155:
ba872109 http2: close connections when receiving too many headers
Fixes CVE-2023-45288.
Fixes#65051.
Change-Id: I3f4e3d565189b4ed552935fe1d96f94ebac86d48
Reviewed-on: https://go-review.googlesource.com/c/go/+/576295
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Unalias memoizes the result of removing Alias constructors.
When Unalias is called too soon on a type in a cycle,
the initial value of the alias, Invalid, gets latched by
the memoization, causing it to appear Invalid forever.
This change disables memoization of Invalid, and adds
a regression test.
Fixes#66704
Updates #65294
Change-Id: I479fe14c88c802504a69f177869f091656489cd4
Reviewed-on: https://go-review.googlesource.com/c/go/+/576975
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Robert Findley <rfindley@google.com>
Auto-Submit: Alan Donovan <adonovan@google.com>
Currently lots of functions require systemstack because the trace buffer
might get flushed, but that will already switch to the systemstack for
the most critical bits (grabbing trace.lock). That means a lot of this
code is non-preemptible when it doesn't need to be. We've seen this
cause problems at scale, when dumping very large numbers of stacks at
once, for example.
Change-Id: I88340091a3c43f0513b5601ef5199c946aa56ed7
Reviewed-on: https://go-review.googlesource.com/c/go/+/572095
Auto-Submit: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Chase <drchase@google.com>
Currently, the execution tracer may attempt to take a stack trace of a
goroutine whose stack it does not own. For example, if the goroutine is
in _Grunnable or _Gwaiting. This is easily fixed in all cases by simply
moving the emission of GoStop and GoBlock events to before the
casgstatus happens. The goroutine status is what is used to signal stack
ownership, and the GC may shrink a goroutine's stack if it can acquire
the scan bit.
Although this is easily fixed, the interaction here is very subtle,
because stack ownership is only implicit in the goroutine's scan status.
To make this invariant more maintainable and less error-prone in the
future, this change adds a GODEBUG setting that checks, at the point of
taking a stack trace, whether the caller owns the goroutine. This check
is not quite perfect because there's no way for the stack tracing code
to know that the _Gscan bit was acquired by the caller, so for
simplicity it assumes that it was the caller that acquired the scan bit.
In all other cases however, we can check for ownership precisely. At the
very least, this check is sufficient to catch the issue this change is
fixing.
To make sure this debug check doesn't bitrot, it's always enabled during
trace testing. This new mode has actually caught a few other issues
already, so this change fixes them.
One issue that this debug mode caught was that it's not safe to take a
stack trace of a _Gwaiting goroutine that's being unparked.
Another much bigger issue this debug mode caught was the fact that the
execution tracer could try to take a stack trace of a G that was in
_Gwaiting solely to avoid a deadlock in the GC. The execution tracer
already has a partial list of these cases since they're modeled as the
goroutine just executing as normal in the tracer, but this change takes
the list and makes it more formal. In this specific case, we now prevent
the GC from shrinking the stacks of goroutines in this state if tracing
is enabled. The stack traces from these scenarios are too useful to
discard, but there is indeed a race here between the tracer and any
attempt to shrink the stack by the GC.
Change-Id: I019850dabc8cede202fd6dcc0a4b1f16764209fb
Cq-Include-Trybots: luci.golang.try:gotip-linux-amd64-longtest,gotip-linux-amd64-longtest-race
Reviewed-on: https://go-review.googlesource.com/c/go/+/573155
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
This change adds a new event, GoStatusStack, which is like GoStatus but
also carries a stack ID. The purpose of this event is to emit stacks in
more places, in particular for goroutines that may never emit a
stack-bearing event in a whole generation.
This CL targets one specific case: goroutines that were blocked or in a
syscall the entire generation. This particular case is handled at the
point that we scribble down the goroutine's status before the generation
transition. That way, when we're finishing up the generation and
emitting events for any goroutines we scribbled down, we have an
accurate stack for those goroutines ready to go, and we emit a
GoStatusStack instead of a GoStatus event. There's a small drawback with
the way we scribble down the stack though: we immediately register it in
the stack table instead of tracking the PCs. This means that if a
goroutine does run and emit a trace event in between when we scribbled
down its stack and the end of the generation, we will have recorded a
stack that never actually gets referenced in the trace. This case should
be rare.
There are two remaining cases where we could emit stacks for goroutines
but we don't.
One is goroutines that get unblocked but either never run, or run and
never block within a generation. We could take a stack trace at the
point of unblocking the goroutine, if we're emitting a GoStatus event
for it, but unfortunately we don't own the stack at that point. We could
obtain ownership by grabbing its _Gscan bit, but that seems a little
risky, since we could hold up the goroutine emitting the event for a
while. Something to consider for the future.
The other remaining case is a goroutine that was runnable when tracing
started and began running, but then ran until the end of the generation
without getting preempted or blocking. The main issue here is that
although the goroutine will have a GoStatus event, it'll only have a
GoStart event for it which doesn't emit a stack trace. This case is
rare, but still certainly possible. I believe the only way to resolve it
is to emit a GoStatusStack event instead of a GoStatus event for a
goroutine that we're emitting GoStart for. This case is a bit easier
than the last one because at the point of emitting GoStart, we have
ownership of the goroutine's stack.
We may consider dealing with these in the future, but for now, this CL
captures a fairly large class of goroutines, so is worth it on its own.
Fixes#65634.
Change-Id: Ief3b6df5848b426e7ee6794e98dc7ef5f37ab2d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/567076
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
When go tool <toolname> is run, increment the
go/subcommand:tool-<toolname> counter instead of just
go/subcommand:tool. go/subcommand:tool will be incremented
if go tool is run without a tool argument to list the
available tools.
Change-Id: I22b888fada1441389315a79f417c72b3f74070f8
Reviewed-on: https://go-review.googlesource.com/c/go/+/571802
Reviewed-by: Alan Donovan <adonovan@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Sam Thanawalla <samthanawalla@google.com>
TestFS now returns a structured error built with errors.Join to allow to
inspect errors using errors.Is and errors.As.
All errors are now wrapped using fmt.Errorf and %w.
Fixes#63675.
Change-Id: I8fc3363f8ae70085af4afdb84c16be9ca70d7731
Reviewed-on: https://go-review.googlesource.com/c/go/+/537015
Reviewed-by: Bryan Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
This CL changes the compiler's type import/export logic
to create and preserve materialized Alias types
when GODEBUG=gotypesaliases=1.
In conjunction with CL 574717, it allows the x/tools
tests to pass with GODEBUG=gotypesaliases=1.
Updates #65294
Updates #64581Fixes#66550
Change-Id: I70b9279f4e0ae7a1f95ad153c4e6909a878915a4
Reviewed-on: https://go-review.googlesource.com/c/go/+/574737
Auto-Submit: Alan Donovan <adonovan@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Robert Findley <rfindley@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Beyond the required file move and refactor to use the testing package,
a number of changes were made to get the fuzzing working properly.
First, add more logs to see what is going on.
Second, some option combinations set Comma to the null character,
which simply never worked at all. I suspect the author meant to leave
the comma character as the default instead.
This was spotted thanks to the added logging.
Third, the round-trip DeepEqual check did not work at all
when any comments were involved, as the writer does not support them.
Fourth and last, massage the first and second parsed records before
comparing them with DeepEqual, as the nature of Reader and Writer
causes empty quoted records and CRLF sequences to change.
With all the changes above, the fuzzing function appears to work
normally on my laptop now. I fuzzed for a solid five minutes and
could no longer encounter any errors or panics.
Change-Id: Ie27f65f66099bdaa076343cee18b480803d2e4d3
Reviewed-on: https://go-review.googlesource.com/c/go/+/576375
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Joseph Tsai <joetsai@digital-static.net>
Reviewed-by: Ian Lance Taylor <iant@google.com>
slices.SortFunc requires a three-way comparison and we need an
efficient strings.Compare to perform three-way string comparisons.
This new implementation adds bytealg.CompareString as a wrapper of
runtime_cmpstring and changes Compare to use bytealg.CompareString.
The new implementation of Compare with runtime_cmpstring is about
28% faster than the previous one.
Fixes#61725
│ /tmp/gobench-sort-cmp.txt │ /tmp/gobench-sort-strings.txt │
│ sec/op │ sec/op vs base │
SortFuncStruct/Size16-48 918.8n ± 1% 726.6n ± 0% -20.92% (p=0.000 n=10)
SortFuncStruct/Size32-48 2.666µ ± 1% 2.003µ ± 1% -24.85% (p=0.000 n=10)
SortFuncStruct/Size64-48 1.934µ ± 1% 1.331µ ± 1% -31.22% (p=0.000 n=10)
SortFuncStruct/Size128-48 3.560µ ± 1% 2.423µ ± 0% -31.94% (p=0.000 n=10)
SortFuncStruct/Size512-48 13.019µ ± 0% 9.071µ ± 0% -30.33% (p=0.000 n=10)
SortFuncStruct/Size1024-48 25.61µ ± 0% 17.75µ ± 0% -30.70% (p=0.000 n=10)
geomean 4.217µ 3.018µ -28.44%
Change-Id: I2513b6f8c1b9b273ef2d23f0a86f691e2d097eb6
Reviewed-on: https://go-review.googlesource.com/c/go/+/532195
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Ian Lance Taylor <iant@golang.org>
Reviewed-by: qiu laidongfeng2 <2645477756@qq.com>
Reviewed-by: Keith Randall <khr@google.com>
The method comment of TCPConn.SetKeepAlivePeriod had become
obsolete and inaccurate since CL 565495 and CL 570077 were merged.
For #65817
Change-Id: Ide99b2949676d452a505ba6fd634088f05c9df44
Reviewed-on: https://go-review.googlesource.com/c/go/+/576435
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
Any normal float32 constant can be generated by this instruction;
use xxspltidp when possible. This prefixed instruction is much
faster than the two instruction load sequence from the
float32/float64 constant pool.
Change-Id: Id751d9ffdae71463adbde66427b986f0b2ef74c2
Reviewed-on: https://go-review.googlesource.com/c/go/+/575555
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Paul Murphy <murp@ibm.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
In CL575777 I forgot to remove the key from the "sync.Map".
This did not cause the test to fail due to the lack of an associated
testcase. Now delete the key correctly and add the testcase.
Change-Id: I26f770966a828caa02f1766675756b67894dc195
GitHub-Last-Rev: a351ce095b
GitHub-Pull-Request: golang/go#66675
Reviewed-on: https://go-review.googlesource.com/c/go/+/576395
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: qiu laidongfeng2 <2645477756@qq.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Change-Id: I0ee85161846c13d938213ef04d3a34f690a93e48
Reviewed-on: https://go-review.googlesource.com/c/go/+/553435
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@golang.org>
The comment contains a dead link to a OpenJDK bug ID 7073588
this change fixes the link.
Change-Id: Ib9b10362c707507e59bb6f340d52a0025f65e292
GitHub-Last-Rev: 37af15b947
GitHub-Pull-Request: golang/go#66669
Reviewed-on: https://go-review.googlesource.com/c/go/+/576335
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Change-Id: Idfe9cf2f2e4750d6673455f98deef2efc2d292a6
Reviewed-on: https://go-review.googlesource.com/c/go/+/539837
Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Ian Lance Taylor <iant@golang.org>
Change-Id: Iad58155f29a101fb72768b170c0c2c9d76b6041a
Reviewed-on: https://go-review.googlesource.com/c/go/+/539357
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
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Reviewed-by: qiu laidongfeng2 <2645477756@qq.com>
Run-TryBot: shuang cui <imcusg@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Many tools (especially in the IDE) rely on type information
being computed even for packages that have some type errors.
Previously, there were two early (error) exits in checkFiles
that violated this invariant, one related to FakeImportC
and one related to a too-new Config.GoVersion.
(The FakeImportC one is rarely encountered in practice,
but the GoVersion one, which was recently downgraded from
a panic by CL 507975, was a source of crashes
due to incomplete type information.)
This change moves both of those errors out of checkFiles
so that they report localized errors and don't obstruct
type checking. A test exercises the errors, and that
type annotations are produced.
Also, we restructure and document checkFiles to make clear
that it is never supposed to stop early.
Updates #66525
Change-Id: I9c6210e30bbf619f32a21157f17864b09cfb5cf2
Reviewed-on: https://go-review.googlesource.com/c/go/+/574495
Reviewed-by: Tim King <taking@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
