In issue 50113, we see that a thread blocked in a system call can result
in a hang of AllThreadsSyscall. To resolve this, we must send a signal
to these threads to knock them out of the system call long enough to run
the per-thread syscall.
Stepping back, if we need to send signals anyway, it should be possible
to implement this entire mechanism on top of signals. This CL does so,
vastly simplifying the mechanism, both as a direct result of
newly-unnecessary code as well as some ancillary simplifications to make
things simpler to follow.
Major changes:
* The rest of the mechanism is moved to os_linux.go, with fields in mOS
instead of m itself.
* 'Fixup' fields and functions are renamed to 'perThreadSyscall' so they
are more precise about their purpose.
* Rather than getting passed a closure, doAllThreadsSyscall takes the
syscall number and arguments. This avoids a lot of hairy behavior:
* The closure may potentially only be live in fields in the M,
hidden from the GC. Not necessary with no closure.
* The need to loan out the race context. A direct RawSyscall6 call
does not require any race context.
* The closure previously conditionally panicked in strange
locations, like a signal handler. Now we simply throw.
* All manual fixup synchronization with mPark, sysmon, templateThread,
sigqueue, etc is gone. The core approach is much simpler:
doAllThreadsSyscall sends a signal to every thread in allm, which
executes the system call from the signal handler. We use (SIGRTMIN +
1), aka SIGSETXID, the same signal used by glibc for this purpose. As
such, we are careful to only handle this signal on non-cgo binaries.
Synchronization with thread creation is a key part of this CL. The
comment near the top of doAllThreadsSyscall describes the required
synchronization semantics and how they are achieved.
Note that current use of allocmLock protects the state mutations of allm
that are also protected by sched.lock. allocmLock is used instead of
sched.lock simply to avoid holding sched.lock for so long.
Fixes#50113
Change-Id: Ic7ea856dc66cf711731540a54996e08fc986ce84
Reviewed-on: https://go-review.googlesource.com/c/go/+/383434
Reviewed-by: Austin Clements <austin@google.com>
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Add a generic syscall package for use by the runtime. Eventually we'd
like to clean up system calls in the runtime to use more code generation
and be moved out of the main runtime package.
The implementations of the assembly functions are based on copies of
syscall.RawSyscall6, modified slightly for more consistency between
arches. e.g., renamed trap to num, always set syscall num register
first.
For now, this package is just the bare minimum needed for
doAllThreadsSyscall to make an arbitrary syscall.
For #51087.
For #50113.
Change-Id: Ibecb5e6303279ce15286759e1cd6a2ddc52f7c72
Reviewed-on: https://go-review.googlesource.com/c/go/+/383999
Trust: Michael Pratt <mpratt@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
syscall_runtime_doAllThreadsSyscall is only used on Linux. In
preparation of a follow-up CL that will modify the function to use other
Linux-only functions, move it to os_linux.go with no changes.
For #50113.
Change-Id: I348b6130038603aa0a917be1f1debbca5a5a073f
Reviewed-on: https://go-review.googlesource.com/c/go/+/383996
Trust: Michael Pratt <mpratt@google.com>
Reviewed-by: Andrew G. Morgan <agm@google.com>
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
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Add tests that verify consistent behavior of go/types and types2 with
respect to potentially ambiguous type parameter lists.
For #49482
Change-Id: I3386d4fa3eb91f2a8ea0987372ca40a6962de886
Reviewed-on: https://go-review.googlesource.com/c/go/+/385756
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This is a port of CL 370774 to go/parser and go/printer. It is adjusted
for the slightly different factoring of parameter list parsing and
printing in go/parser and go/printer.
For #49482
Change-Id: I1c5b1facddbfcb7f7b2be356c817fc7e608223f1
Reviewed-on: https://go-review.googlesource.com/c/go/+/385575
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
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Reviewed-by: Matthew Dempsky <mdempsky@google.com>
When line number saturates, we can end up getting non-monotonic
position info, because the start of the next line after line=lineMax,col=2
is line=lineMax,col=1.
Instead, if line==lineMax, make the column always 0 (no column info).
If the line number is wrong, having column info probably isn't that helpful.
Fixes#51193
Change-Id: If3d90472691b1f6163654f3505e2cb98467f2383
Reviewed-on: https://go-review.googlesource.com/c/go/+/385795
Trust: Keith Randall <khr@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
Pointer comparison is lowered to the following on RISCV64
(EqPtr x y) => (SEQZ (SUB <x.Type> x y))
The difference of two pointers (the SUB) should not be pointer
type. Otherwise it can cause the GC to find a bad pointer.
Should fix#51101.
Change-Id: I7e73c2155c36ff403c032981a9aa9cccbfdf0f64
Reviewed-on: https://go-review.googlesource.com/c/go/+/385655
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Previously, TestNotTemporaryRead issued the Read on the Accept side of
the connection, and Closed the Dial side. It appears that on some
platforms, Dial may return before the connection has been Accepted,
and if that connection is immediately closed with no bytes written and
SO_LINGER set to 0, the connection may no longer even exist by the
time Accept returns, causing Accept to block indefinitely until the
Listener is closed.
If we were to just swap the directions, we would have an analogous
problem: Accept could accept the connection and close it before the
client even finishes dialing, causing Dial (instead of Read) to return
the ECONNRESET error.
Here, we take a middle path: we Accept and Dial the connection
concurrently, but wait until both the Accept and the Dial have
returned (indicating that the connection is completely established and
won't vanish from the accept queue) before resetting the connection.
Fixes#29685
Updates #25289
Change-Id: Ida06f70f7205fffcdafa3df78bd56184e6cec760
Reviewed-on: https://go-review.googlesource.com/c/go/+/385314
Trust: Bryan Mills <bcmills@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Compiler errors now (as of 1.18) might start with a tab character,
for errors which take multiple lines to report. e.g.:
/Users/khr/gowork/tmp1.go:3:15: x redeclared in this block
/Users/khr/gowork/tmp1.go:3:8: other declaration of x
This CL makes error lines starting with a tab character
eligible for replacing absolute paths with relative ones.
Fixes#51177
Change-Id: Ic9e9c610a1aa1e21e9f19e6a9bd05c73b5a14e4a
Reviewed-on: https://go-review.googlesource.com/c/go/+/385755
Trust: Keith Randall <khr@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Trust: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gopher Robot <gobot@golang.org>
When we receive an error writing the first byte of a request to a
reused connection, we retry the request on a new connection. Remove
a flaky path which could cause the request to not be retried if
persistConn.roundTrip reads the error caused by closing the connection
before it reads the write error that caused the connection to be
closed.
Fixes#30938.
Change-Id: Iafd99e3239cd9dba4a4c9ddd950a877ca9815e59
Reviewed-on: https://go-review.googlesource.com/c/go/+/379554
Trust: Bryan Mills <bcmills@google.com>
Trust: Damien Neil <dneil@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
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This is a follow up to CL 385494. In early patch sets of that CL,
renamed type parameters were substituted in arguments, which meant that
they could leak into the inference results. However, we subsequently
realized that we could instead substitute in the signature parameters.
In this case it is not possible for the substituted type parameters to
appear in the resulting type arguments, so there is no need to
un-substitute.
Change-Id: I4da45b0b8d7ad809d0ddfa7061ae5f6f07895540
Reviewed-on: https://go-review.googlesource.com/c/go/+/385574
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
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Reviewed-by: Robert Griesemer <gri@golang.org>
The (temporary) highlights will make it easier to review the spec
in formatted form as opposed to html text.
Added a missing rule about the use of adjusted core types for
constraint type inference.
Adjusted rule for invalid embedding of interface types.
Change-Id: Ie573068d2307b66c937e803c486724175415b9c6
Reviewed-on: https://go-review.googlesource.com/c/go/+/385535
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Type inference uses type parameter pointer identity to keep track of the
correspondence between type parameters and type arguments. However, this
technique can misidentify type parameters that are used in explicit type
arguments or function arguments, as in the recursive instantiation
below:
func f[P *Q, Q any](p P, q Q) {
f[P]
}
In this example, the fact that the P used in the instantation f[P] has
the same pointer identity as the P we are trying to solve for via
unification is coincidental: there is nothing special about recursive
calls that should cause them to conflate the identity of type arguments
with type parameters. To put it another way: any such self-recursive
call is equivalent to a mutually recursive call, which does not run into
any problems of type parameter identity. For example, the following code
is equivalent to the code above.
func f[P interface{*Q}, Q any](p P, q Q) {
f2[P]
}
func f2[P interface{*Q}, Q any](p P, q Q) {
f[P]
}
We can turn the first example into the second example by renaming type
parameters in the original signature to give them a new identity. This
CL does this for self-recursive instantiations.
Fixes#51158Fixes#48656
Updates #48619
Change-Id: I54fe37f2a79c9d98950cf6a3602335db2896dc24
Reviewed-on: https://go-review.googlesource.com/c/go/+/385494
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Change-Id: Ie949f2131845f9f9292caff798f6933648779122
Reviewed-on: https://go-review.googlesource.com/c/go/+/385434
Trust: Ian Lance Taylor <iant@golang.org>
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Reviewed-by: Than McIntosh <thanm@google.com>
This change adds tests that use a type parameter's core type during
function argument type inference, not just during constraint type
inference.
Also, fix a typo in a comment.
For #50755.
Change-Id: I0c3196bdce5338341e0b6dfd7c63efb2e43ace25
Reviewed-on: https://go-review.googlesource.com/c/go/+/385376
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
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Reviewed-by: Robert Findley <rfindley@google.com>
NOTE: Should this change cause problems, the new functionality
can be disabled by setting the flag enableCoreTypeUnification
in unify.go to false.
In the code
func f1[M1 map[K1]int, K1 comparable](m1 M1) {}
func f2[M2 map[K2]int, K2 comparable](m2 M2) {
f1(m2)
}
type inference attempts to unify the types of m1 and m2. This leads
to the unification attempt of M1 and M2. The result is that the type
argument for M1 is inferred to be M2. Since there is no furter function
argument to use, constraint type inference attempts to infer the type
for K1 which is still missing. Constraint type inference (inferB in
the trace below) compares the inferred type for M1 (i.e., M2) against
map[K1]int. M2 is bound to f2, not f1; with the existing algorithm
that means M2 is simply a named type without further information.
Unification fails and with that type inference, and the type checker
reports an error.
-- inferA [M1₁, K1₂] ➞ []
M1₁ ≡ M2₃
. M1₁ ➞ M2₃
-- inferB [M1₁, K1₂] ➞ [M2₃, <nil>]
M1₁ ➞ M2₃
M1₁ ≡ map[K1₂]int
. M2₃ ≡ map[K1₂]int
. M2₃ ≢ map[K1₂]int
M1₁ ≢ map[K1₂]int
=> inferB [M1₁, K1₂] ➞ []
=> inferA [M1₁, K1₂] ➞ []
With this change, when attempting to unify M2 with map[K1]int,
rather than failing, the unifier now considers the core type of
M2 which is map[K2]int. This leads to the unification of K1 and
K2; so type inference successfully infers M2 for M1 and K2 for K1.
-- inferA [M1₁, K1₂] ➞ []
M1₁ ≡ M2₃
. M1₁ ➞ M2₃
-- inferB [M1₁, K1₂] ➞ [M2₃, <nil>]
M1₁ ➞ M2₃
M1₁ ≡ map[K1₂]int
. M2₃ ≡ map[K1₂]int
. . core M2₃ ≡ map[K1₂]int
. . map[K2₄]int ≡ map[K1₂]int
. . . K2₄ ≡ K1₂
. . . . K1₂ ➞ K2₄
. . . int ≡ int
=> inferB [M1₁, K1₂] ➞ [M2₃, K2₄]
=> inferA [M1₁, K1₂] ➞ [M2₃, K2₄]
The fix for this issue was provided by Rob Findley in CL 380375;
this change is a copy of that fix with some additional changes:
- Constraint type inference doesn't simply use a type parameter's
core type. Instead, if the type parameter type set consists of
a single, possibly named type, it uses that type. Factor out the
existing code into a new function adjCoreType. This change is not
strictly needed but makes it easier to think about the code.
- Tracing code is added for debugging type inference. All tracing
code is guarded with the flag traceEnabled which is set to false
by default.
- The change to the unification algorithm is guarded with the flag
enableCoreTypeUnification.
- The sprintf function has a new type switch case for lists of
type parameters. This is used for tracing output (and was also
missing for a panic that was printing type parameter lists).
Fixes#50755.
Change-Id: Ie50c8f4540fcd446a71b07e2b451a95339b530ce
Reviewed-on: https://go-review.googlesource.com/c/go/+/385354
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
We used to only accept up to 512 bytes in a DNS packet, per RFC 1035.
Increase the size we accept to 1232 bytes, per https://dnsflagday.net/2020/,
and advertise that larger limit in a EDNS(0) OPT record.
Fixes#6464Fixes#21160Fixes#44135Fixes#51127
Change-Id: I496a294e9a8015de4161cbc1825b0dc5b4e9f5d8
Reviewed-on: https://go-review.googlesource.com/c/go/+/385035
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
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Reviewed-by: Matthew Dempsky <mdempsky@google.com>
If an invalid array length is just an identifier, mention
"array length" so that it's clear this is an invalid array
declaration and not a (invalid) generic type declaration.
Fixes#51145.
Change-Id: I8878cbb6c7b1277fc0a9a014712ec8d55499c5c7
Reviewed-on: https://go-review.googlesource.com/c/go/+/385255
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
With the switch to the register ABI, we now generate wrapper
functions for go statements in many cases. A new goroutine's start
PC now points to the wrapper function. This does not affect
execution, but the runtime tracer uses the start PC and the
function name as the name/label of that goroutine. If the start
function is a named function, using the name of the wrapper loses
that information. Furthur, the tracer's goroutine view groups
goroutines by start PC. For multiple go statements with the same
callee, they are grouped together. With the wrappers, which is
context-dependent as it is a closure, they are no longer grouped.
This CL fixes the problem by providing the underlying unwrapped
PC for tracing. The compiler emits metadata to link the unwrapped
PC to the wrapper function. And the runtime reads that metadata
and record that unwrapped PC for tracing.
(This doesn't work for shared buildmode. Unfortunate.)
TODO: is there a way to test?
Fixes#50622.
Change-Id: Iaa20e1b544111c0255eb0fc04427aab7a5e3b877
Reviewed-on: https://go-review.googlesource.com/c/go/+/384158
Trust: Cherry Mui <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
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This test has failed on four different builders in the past month.
Moreover, because every Go program depends on "runtime", it is likely
to be run any time a user runs 'go test all' in their own program.
Since the test is known to be flaky, let's skip it to avoid
introducing testing noise until someone has time to investigate. It
seems like we have enough samples in the builder logs to at least
start with.
For #50979
Change-Id: I9748a82fbb97d4ed95d6f474427e5aa6ecdb023d
Reviewed-on: https://go-review.googlesource.com/c/go/+/385154
Trust: Bryan Mills <bcmills@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
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Add modload.InitWorkfile to runVet so that the vet command recognizes
and uses the workspace.
Fixes#51072
Change-Id: Ia6727eff9b80eb33627f5ae23e4d72cde581e75f
Reviewed-on: https://go-review.googlesource.com/c/go/+/385176
Trust: Michael Matloob <matloob@golang.org>
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This change moves the relevant prose of the section on type parameters
into the section on type parameter lists and eliminates the former.
With this change, the section on types now exclusively describes all
Go composite types.
User-defined named types (defined types and type parameters) are
described with their declarations.
Change-Id: I3e421cd236e8801d31a4a81ff1e5ec9933e3ed20
Reviewed-on: https://go-review.googlesource.com/c/go/+/385037
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Also, fixed several closing header tags and removed a duplicate "the".
(Thanks to @hopehook and Hossein Zolfi for pointing these out.)
Change-Id: I85a40ba44b8570a578bce8d211dcc5ea3901fb1e
Reviewed-on: https://go-review.googlesource.com/c/go/+/385036
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Add comparable to the list of predeclared types.
Fixesgolang/go#51141.
Change-Id: I4a2d4e7e5680e115de9bca03b6c8ad454551cb82
Reviewed-on: https://go-review.googlesource.com/c/go/+/385114
Trust: Jonathan Amsterdam <jba@google.com>
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The outcome of type inference depends critically on when function
argument type inference stops processing arguments. Describe this
and explain an example with some detail.
Also: In the section on the built-in function delete, refer to the
value rather than the type of the second argument, as it may be an
untyped constant.
Change-Id: Ice7fbb33f985afe082380b8d37eaf763238a3818
Reviewed-on: https://go-review.googlesource.com/c/go/+/385034
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: I6de236442f213ab4b4f19ec881add4923d8bfd8d
Reviewed-on: https://go-review.googlesource.com/c/go/+/385054
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Kevin Burke <kevin@burke.dev>
A basic interface is a classical Go interface containing only
methods or embedding basic interfaces.
Use this to simplify rule about what interfaces may be used
where. The term "basic interface" will also be useful when
talking about various interfaces in general.
Fix rule restricting union terms: as it was written it also
excluded interface terms with non-empty method sets due to
embedded non-interface types with methods.
Split the large section on interfaces into three smaller
pieces by introducing section titles.
Change-Id: I142a4d5609eb48aaa0f7800b5b85c1d6c0703fcb
Reviewed-on: https://go-review.googlesource.com/c/go/+/384994
Trust: Robert Griesemer <gri@golang.org>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
This makes the prose easier to read while being just as precise.
Change-Id: Ie46c6c5042f419de9fdeb1c75bb72b5a40c37073
Reviewed-on: https://go-review.googlesource.com/c/go/+/384774
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
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TryBot-Result: Gopher Robot <gobot@golang.org>
If register assignment fails, revert back the value to stack
Change-Id: I6f65092461ad4d793206a679a5fef1b560b387f0
Reviewed-on: https://go-review.googlesource.com/c/go/+/384455
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
This change only shuffles sections for better organization; there
are no other changes except title and link adjustments.
Until now, the sections on underlying types and method sets were
immediately following the introduction of types. As it becomes
necessary to introduce the notion of a core type more centrally,
the natural place is immediately following the section on underlying
types. All together, these sections, immediately after the introduction
of types, would distract from purpose of the section on types, which
is to introduce the various types that Go offers.
The more natural place for the definition of underlying, core, and
specific types is the section on properties of types and values.
To accomplish this, the section on the structure of interfaces is
split into a section on core types and one on specific types, and
the various sections are reorganized appropriately.
The new organization of the section on types now simply introduces
all Go types as follows:
- boolean types
- numeric types
- string types
- array types
- slice types
- struct types
- pointer types
- function types
- interface types
- map types
- channel types
- type parameters
The new organization of the section on properties of types and values
is as follows:
- underlying types
- core types
- specific types
- type identity
- assignability
- representability
- method sets
Change-Id: I59e4d47571da9d4c89d47d777f5353fb1c5843e6
Reviewed-on: https://go-review.googlesource.com/c/go/+/384623
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
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Includes a few minor cosmetic changes.
Change-Id: I6c307d958b47d83671142688630ea7835168439f
Reviewed-on: https://go-review.googlesource.com/c/go/+/384622
Trust: Robert Griesemer <gri@golang.org>
Run-TryBot: Robert Griesemer <gri@golang.org>
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Reviewed-by: Ian Lance Taylor <iant@golang.org>
In workspace mode, if a user lists a package or patternthat's inside a
module that's not listed in go.work, mention that the package or pattern
is outside the modules listed in go.work so the user has a better idea
of how to fix the issue.
(Question: it's valid in those flows to add a pattern that points into
the module cache. Should we expand the error to say "package outside
modules listed in go.work file or contained in module cache"? That seems
clunky (and is the uncommon case) which is why I didn't do so in this
case, but it's possible)
Fixes#49632
Change-Id: I3f0ea1b2f566d52a8079b58593fcc5cc095e7a41
Reviewed-on: https://go-review.googlesource.com/c/go/+/384236
Trust: Michael Matloob <matloob@golang.org>
Run-TryBot: Michael Matloob <matloob@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
If something goes horribly wrong with the assumptions surrounding a
piController, its internal error state might accumulate in an unbounded
manner. In practice this means unexpected Inf and NaN values.
Avoid this by identifying cases where the error overflows and resetting
controller state.
In the scavenger, this case is much more likely. All that has to happen
is the proportional relationship between sleep time and estimated CPU
usage has to break down. Unfortunately because we're just measuring
monotonic time for all this, there are lots of ways it could happen,
especially in an oversubscribed system. In these cases, just fall back
on a conservative pace for scavenging and try to wait out the issue.
In the pacer I'm pretty sure this is impossible. Because we wire the
output of the controller to the input, the response is very directly
correlated, so it's impossible for the controller's core assumption to
break down.
While we're in the pacer, add more detail about why that controller is
even there, as well as its purpose.
Finally, let's be proactive about other sources of overflow, namely
overflow from a very large input value. This change adds a check after
the first few operations to detect overflow issues from the input,
specifically the multiplication.
No tests for the pacer because I was unable to actually break the
pacer's controller under a fuzzer, and no tests for the scavenger because
it is not really in a testable state.
However:
* This change includes a fuzz test for the piController.
* I broke out the scavenger code locally and fuzz tested it, confirming
that the patch eliminates the original failure mode.
* I tested that on a local heap-spike test, the scavenger continues
operating as expected under normal conditions.
Fixes#51061.
Change-Id: I02a01d2dbf0eb9d2a8a8e7274d4165c2b6a3415a
Reviewed-on: https://go-review.googlesource.com/c/go/+/383954
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
The "block" helpers in TestBlockProfile previously slept for an
arbitrary duration and assumed that that duration was long enough for
the parent goroutine to have registered as blocking. However —
especially on slow or overloaded builders — the current arbitrary
duration is sometimes not quite long enough.
Rather than increasing the duration to a different arbitrary value
(which would make the test slower but not actually eliminate the
possibility of flakes!), we can use the runtime's own accounting to
detect when the goroutine is actually blocked: we obtain a goroutine
dump from the runtime, and assume that blocking has been registered in
the profile only if the runtime shows the test goroutine in the
appropriate blocked state.
That not only makes the test more reliable, but also makes it
significantly lower-latency when run on a fast machine.
Fixes#6999Fixes#37844
Change-Id: I465ed2afd406fd2b621419e1f06925f283525f25
Reviewed-on: https://go-review.googlesource.com/c/go/+/384534
Trust: Bryan Mills <bcmills@google.com>
Trust: Benny Siegert <bsiegert@gmail.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The regexp code assumes it can recurse over the structure of
a regexp safely. Go's growable stacks make that reasonable
for all plausible regexps, but implausible ones can reach the
“infinite recursion?” stack limit.
This CL limits the depth of any parsed regexp to 1000.
That is, the depth of the parse tree is required to be ≤ 1000.
Regexps that require deeper parse trees will return ErrInternalError.
A future CL will change the error to ErrInvalidDepth,
but using ErrInternalError for now avoids introducing new API
in point releases when this is backported.
Fixes#51112.
Change-Id: I97d2cd82195946eb43a4ea8561f5b95f91fb14c5
Reviewed-on: https://go-review.googlesource.com/c/go/+/384616
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
These TODOs were originally removed in CL 368794.
Updates #47694
Change-Id: I39d5c0ce5f96adbbc466585a5831f721057dbed5
Reviewed-on: https://go-review.googlesource.com/c/go/+/384619
Trust: Carlos Amedee <carlos@golang.org>
Run-TryBot: Carlos Amedee <carlos@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
There was an off-by-one error in the time histogram buckets calculation
that caused the linear sub-buckets distances to be off by 2x.
The fix was trivial, but in writing tests I realized there was a much
simpler way to express the calculation for the histogram buckets, and
took the opportunity to do that here. The new bucket calculation also
fixes the bug.
Fixes#50732.
Change-Id: Idae89986de1c415ee4e148f778e0e101ca003ade
Reviewed-on: https://go-review.googlesource.com/c/go/+/380094
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com>
Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
This is a pure rename of the respective Go functions/methods
with corresponding adjustments to error messages and tests.
A couple of comments were manually rephrased.
With this change, the implementation and error messages match
the latest spec.
No functionality change.
Change-Id: Iaa92a08b64756356fb2c5abdaca5c943c9105c96
Reviewed-on: https://go-review.googlesource.com/c/go/+/384618
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
The latter is subject to kern.maxfilelimit restrictions on darwin which
are not reflected in the return value. This makes it difficult to
reliably restore the default after the test is complete. RLIMIT_CPU
should hopefully sidestep this problem.
Updates #40564.
Change-Id: Ifb33c7d46f2708130cef366dc245c643a2d5e465
Reviewed-on: https://go-review.googlesource.com/c/go/+/383234
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>
Trust: Bryan Mills <bcmills@google.com>
For #49735.
Change-Id: Ib7343061dca0e8d848e0719d39be0393d7cfad93
Reviewed-on: https://go-review.googlesource.com/c/go/+/384615
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
Fixes#51110.
Change-Id: I11370417f1ef435b05dfab18eeabc2c3c1b7b8a1
Reviewed-on: https://go-review.googlesource.com/c/go/+/384674
Trust: Robert Griesemer <gri@golang.org>
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Dan Scales <danscales@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Add corresponding rules and a couple of examples.
Fixes#50202.
Change-Id: I4287b5e2d0fd29a0c871795e07f1bb529c9c6004
Reviewed-on: https://go-review.googlesource.com/c/go/+/384240
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This change in terminology prevents potential confusion
that migth be caused by associating "structural type"
with "structural typing"; the two are not connected.
Also, adjusted introductory paragraph of section on
constraint type inference: type inference goes in both
directions, from type parameter to core type and vice
versa. The previous description was not quite accurate.
Change-Id: If4ca300f525eea660f68486302619aa6ad5dbc2c
Reviewed-on: https://go-review.googlesource.com/c/go/+/384238
Trust: Robert Griesemer <gri@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
AES-196 does not exist, but AES-192 does.
Signed-off-by: Eric Lagergren <eric@ericlagergren.com>
Change-Id: I8c9ac67735e99e5b2ee7fb9824029c1164221153
Reviewed-on: https://go-review.googlesource.com/c/go/+/384374
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Cherry Mui <cherryyz@google.com>
For #47694.
Change-Id: I5f6850e171f574a5342671778df854dc68a5148f
Reviewed-on: https://go-review.googlesource.com/c/go/+/384554
Trust: Carlos Amedee <carlos@golang.org>
Run-TryBot: Carlos Amedee <carlos@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Alex Rakoczy <alex@golang.org>
Trust: Alex Rakoczy <alex@golang.org>
Run-TryBot: Alex Rakoczy <alex@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
