The old code was recording the current table output offset,
so the table from the next function would be used instead of
the runtime realizing that there was no table at all.
Add debug constant in runtime to check this for every function
at startup. It's too expensive to do that by default, but we can
do the last five functions. The end of the table is usually where
the C symbols end up, so that's where the problems typically are.
Fixes#10747.
Fixes#11396.
Change-Id: I13592e78017969fc22979fa902e19e1b151d41b1
Reviewed-on: https://go-review.googlesource.com/11657
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
Currently we fail to reset the live heap accounting state before the
checkmark mark and before the gctrace=2 extra mark. As a result, if
either are enabled, at the end of GC it thinks there are 0 bytes of
live heap, which causes the GC controller to initiate a new GC
immediately, regardless of the true heap size.
Fix this by factoring this state reset into a function and calling it
before all three possible marks.
This function should be merged with gcResetGState, but doing so
requires some additional cleanup, so it will wait for after the
freeze. Filed #11427 for this cleanup.
Fixes#10492.
Change-Id: Ibe46348916fc8368fac6f086e142815c970a6f4d
Reviewed-on: https://go-review.googlesource.com/11561
Reviewed-by: Russ Cox <rsc@golang.org>
Memory for stacks is manually managed by the runtime and, currently
(with one exception) we free stack spans immediately when the last
stack on a span is freed. However, the garbage collector assumes that
spans can never transition from non-free to free during scan or mark.
This disagreement makes it possible for the garbage collector to mark
uninitialized objects and is blocking us from re-enabling the bad
pointer test in the garbage collector (issue #9880).
For example, the following sequence will result in marking an
uninitialized object:
1. scanobject loads a pointer slot out of the object it's scanning.
This happens to be one of the special pointers from the heap into a
stack. Call the pointer p and suppose it points into X's stack.
2. X, running on another thread, grows its stack and frees its old
stack.
3. The old stack happens to be large or was the last stack in its
span, so X frees this span, setting it to state _MSpanFree.
4. The span gets reused as a heap span.
5. scanobject calls heapBitsForObject, which loads the span containing
p, which is now in state _MSpanInUse, but doesn't necessarily have
an object at p. The not-object at p gets marked, and at this point
all sorts of things can go wrong.
We already have a partial solution to this. When shrinking a stack, we
put the old stack on a queue to be freed at the end of garbage
collection. This was done to address exactly this problem, but wasn't
a complete solution.
This commit generalizes this solution to both shrinking and growing
stacks. For stacks that fit in the stack pool, we simply don't free
the span, even if its reference count reaches zero. It's fine to reuse
the span for other stacks, and this enables that. At the end of GC, we
sweep for cached stack spans with a zero reference count and free
them. For larger stacks, we simply queue the stack span to be freed at
the end of GC. Ideally, we would reuse these large stack spans the way
we can small stack spans, but that's a more invasive change that will
have to wait until after the freeze.
Fixes#11267.
Change-Id: Ib7f2c5da4845cc0268e8dc098b08465116972a71
Reviewed-on: https://go-review.googlesource.com/11502
Reviewed-by: Russ Cox <rsc@golang.org>
We don't use this state. _GCoff means we're sweeping in the
background. This makes it clear in the next commit that _GCoff and
only _GCoff means sweeping.
Change-Id: I416324a829ba0be3794a6cf3cf1655114cb6e47c
Reviewed-on: https://go-review.googlesource.com/11501
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Currently the runtime fails to clear a G's stack barriers in gfput if
the G's stack allocation is _FixedStack bytes. This causes the runtime
to panic if the following sequence of events happens:
1) The runtime installs stack barriers on a G.
2) The G exits by calling runtime.Goexit. Since this does not
necessarily return through the stack barriers installed on the G,
there may still be untriggered stack barriers left on the G's stack
in recorded in g.stkbar.
3) The runtime calls gfput to add the exiting G to the free pool. If
the G's stack allocation is _FixedStack bytes, we fail to clear
g.stkbar.
4) A new G starts and allocates the G that was just added to the free
pool.
5) The new G begins to execute and overwrites the stack slots that had
stack barriers in them.
6) The garbage collector enters mark termination, attempts to remove
stack barriers from the new G, and finds that they've been
overwritten.
Fix this by clearing the stack barriers in gfput in the case where it
reuses the stack.
Fixes#11256.
Change-Id: I377c44258900e6bcc2d4b3451845814a8eeb2bcf
Reviewed-on: https://go-review.googlesource.com/11461
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Russ Cox <rsc@golang.org>
Also improve the documentation. A prior fix in this release
changed the properties for empty strings and slices, incorrectly.
Previous behavior is now restored and better documented.
Add lots of tests.
The behavior is that when using a string-like format (%s %q %x %X)
a byte slice is equivalent to a string, and printed as a unit. The padding
applies to the entire object. (The space and sharp flags apply
elementwise.)
Fixes#11422.
Fixes#10430.
Change-Id: I758f0521caf71630437e43990ec6d6c9a92655e3
Reviewed-on: https://go-review.googlesource.com/11600
Reviewed-by: Russ Cox <rsc@golang.org>
TestTransportAndServerSharedBodyRace got flaky after
issue #9662 was fixed by https://golang.org/cl/11412, which made
servers hang up on clients when a Handler stopped reading its body
early.
This test was affected by a race between the the two goroutines in the
test both only reading part of the request, which was an unnecessary
detail for what the test was trying to test (concurrent Read/Close
races on an *http.body)
Also remove an unused remnant from an old test from which this one was
derived. And make the test not deadlock when it fails. (which was why
the test was showing up as 2m timeouts on the dashboard)
Fixes#11418
Change-Id: Ic83d18aef7e09a9cd56ac15e22ebed75713026cb
Reviewed-on: https://go-review.googlesource.com/11610
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
These benchmarks demonstrate that
the nilcheckelim pass is roughly O(n^2):
BenchmarkNilCheckDeep1 2000000 741 ns/op 1.35 MB/s
BenchmarkNilCheckDeep10 1000000 2237 ns/op 4.47 MB/s
BenchmarkNilCheckDeep100 20000 60713 ns/op 1.65 MB/s
BenchmarkNilCheckDeep1000 200 7925198 ns/op 0.13 MB/s
BenchmarkNilCheckDeep10000 1 1220104252 ns/op 0.01 MB/s
Profiling suggests that building the
dominator tree is also O(n^2),
and before size factors take over,
considerably more expensive than nilcheckelim.
Change-Id: If966b38ec52243a25f355dab871300d29db02e16
Reviewed-on: https://go-review.googlesource.com/11520
Reviewed-by: Keith Randall <khr@golang.org>
The correct way to compare gc.Types is Eqtype,
rather than pointer equality.
Introduce an Equal method for ssa.Type to allow
us to use it.
In the cse pass, use a type's string to build
the coarse partition, and then use Type.Equal
during refinement.
This lets the cse pass do a better job.
In the ~20% of the standard library that SSA
can compile, the number of common subexpressions
recognized by the cse pass increases from
27,550 to 32,199 (+17%). The number of nil checks
eliminated increases from 75 to 115 (+50%).
Change-Id: I0bdbfcf613ca6bc2ec987eb19b6b1217b51f3008
Reviewed-on: https://go-review.googlesource.com/11451
Reviewed-by: Keith Randall <khr@golang.org>
It looks like the test for whether symbols contain subsymbols is wrong.
In particular, symbols in C libraries are mistakenly considered container
symbols.
Fix the test so only symbols which actually have a subsymbol
are excluded from the symtab. When linking cgo programs the list
of containers is small, something like:
container _/home/khr/sandbox/symtab/misc/cgo/test(.text)<74>
container _/home/khr/sandbox/symtab/misc/cgo/test/issue8828(.text)<75>
container _/home/khr/sandbox/symtab/misc/cgo/test/issue9026(.text)<76>
container runtime/cgo(.text)<77>
I'm not sure this is the right fix. In particular I can't reproduce
the original problem. Anyone have a repro they can try and see if
this fix works?
Fixes#10747Fixes#11396
Change-Id: Id8b016389d33348b4a791fdcba0f9db8ae71ebf3
Reviewed-on: https://go-review.googlesource.com/11652
Reviewed-by: Russ Cox <rsc@golang.org>
Invalid UTF-8 triggers an error when marshaling but, previously, not
when unmarshaling. This means that ASN.1 structures were not
round-tripping.
This change makes invalid UTF-8 in a string marked as UTF-8 to be an
error when Unmarshaling.
Fixes#11126.
Change-Id: Ic37be84d21dc5c03983525e244d955a8b1e1ff14
Reviewed-on: https://go-review.googlesource.com/11056
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
The time package does normalisation of times: for example day zero is
converted to the last day of the previous month and the 31st of February
is moved into March etc. This makes the ASN.1 parsing a little
worryingly lax.
This change causes the parser to reserialise parsed times to ensure that
they round-trip correctly and thus were not normalised.
Fixes#11134.
Change-Id: I3988bb95153a7b33d64ab861fbe51b1a34a359e9
Reviewed-on: https://go-review.googlesource.com/11094
Run-TryBot: Adam Langley <agl@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Stack can move during callback, so libcall struct cannot be stored on stack.
asmstdcall updates return values and errno in libcall struct parameter, but
these could be at different location when callback returns.
Store these in m, so they are not affected by GC.
Fixes#10406
Change-Id: Id01c9d2b4b44530494e6d9e9e1c875261ce477cd
Reviewed-on: https://go-review.googlesource.com/10370
Reviewed-by: Russ Cox <rsc@golang.org>
git sets read-only flag on all its repo files on Windows.
os.Remove cannot delete these files.
Fixes windows build
Change-Id: Icaf72470456b88a1c26295caecd4e0d3dc22a1b6
Reviewed-on: https://go-review.googlesource.com/11602
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
The race occurs rarely, but by putting some delays and more reads/writes
of prePendingDial/postPendingDial in the handlePendingDial function I
could reproduce it.
Fixes#11136
Change-Id: I8da9e66c88fbda049eaaaaffa2717264ef327768
Reviewed-on: https://go-review.googlesource.com/11250
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
AFAIK, the documentation does not explicitly state whether
variables can store a callable entity or not. I believe the
current implementation in text/template assumes they cannot
though. The call builtin function is supposed to be used for
this purpose.
Template "{{0|$}}" should generate an error at runtime,
instead of a panic.
Similarly, template "{{0|(nil)}}" should not generate
a panic.
This CL aborts the sanitization process for a given pipeline
when no identifier can be derived from the selected node.
It happens with malformed pipelines.
We now have the following errors:
{{ 0 | $ }}
template: foo:1:10: executing "foo" at <$>: can't give argument to non-function $
{{ 0 | (nil) }}
template: foo:1:11: executing "foo" at <nil>: nil is not a command
Fixes#11118Fixes#11356
Change-Id: Idae52f806849f4c9ab7aca1b4bb4b59a74723d0e
Reviewed-on: https://go-review.googlesource.com/10823
Reviewed-by: Rob Pike <r@golang.org>
Partial revert of cl/10284 to get -buildmode=c-archive working for
darwin/arm.
Manually tested with iostest.bash while builder is offline.
Change-Id: I98e4e209765666e320e680e11151fce59e2afde9
Reviewed-on: https://go-review.googlesource.com/11306
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Change createCmd, downloadCmd, tagSyncCmd, tagSyncDefault to allow
multiple commands.
When using the vendoring experiment, fetch git submodules in `go get`,
and update them in `go get -u`.
This is a reincarnation of https://codereview.appspot.com/142180043.
For #7764.
Change-Id: I8248efb851130620ef762a765ab8716af430572a
Reviewed-on: https://go-review.googlesource.com/9815
Reviewed-by: Russ Cox <rsc@golang.org>
cmd/go sometimes returns relative path in the error message
(see shortPath function). Account for that during
TestFileLineInErrorMessages.
Fixes#11355
Change-Id: Ica79359eab48d669d307449fdd458764895fab2c
Reviewed-on: https://go-review.googlesource.com/11475
Reviewed-by: Russ Cox <rsc@golang.org>
- Let runOutput return the error message
- When `git config ...` returns empty buffer, it means the config key is
correct, but there is no corresponding value.
- Return the correct error when the url of remote origin is not found.
- Update error message
Fixes: #10922
Change-Id: I3f8880f6717a4f079b840d1249174378d36bca1b
Reviewed-on: https://go-review.googlesource.com/10475
Reviewed-by: Russ Cox <rsc@golang.org>
Linux allows to have a peer IP address on IP interface over ethernet
link encapsulation, though it only installs a static route with the peer
address as an on-link nexthop.
Fixes#11338.
Change-Id: Ie2583737e4c7cec39baabb89dd732463d3f10a61
Reviewed-on: https://go-review.googlesource.com/11352
Reviewed-by: Russ Cox <rsc@golang.org>
Also add a couple more errors, such as modulo with a zero divisor.
Change-Id: If24c95477f7ae86cf4aef5b3460e9ec249ea5ae2
Reviewed-on: https://go-review.googlesource.com/11535
Reviewed-by: Russ Cox <rsc@golang.org>
Currently, to write out the bitmap of a slice of a type with a GCprog,
we construct a new GCprog that executes the underlying type's GCprog
to write out the bitmap once and then repeats those bits n more times.
This results in n+1 repetitions of the bitmap, which is one more
repetition than it should be. This corrupts the bitmap of the heap
following the slice and may write past the mapped bitmap memory and
segfault.
Fix this by repeating the bitmap only n-1 more times.
Fixes#11430.
Change-Id: Ic24854363bffc5a755b66f257339f9309ada3aa5
Reviewed-on: https://go-review.googlesource.com/11570
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
A comment in waitgroup.go describes the following scenario
as the reason to have dynamically created semaphores:
// G1: Add(1)
// G1: go G2()
// G1: Wait() // Context switch after Unlock() and before Semacquire().
// G2: Done() // Release semaphore: sema == 1, waiters == 0. G1 doesn't run yet.
// G3: Wait() // Finds counter == 0, waiters == 0, doesn't block.
// G3: Add(1) // Makes counter == 1, waiters == 0.
// G3: go G4()
// G3: Wait() // G1 still hasn't run, G3 finds sema == 1, unblocked! Bug.
However, the scenario is incorrect:
G3: Add(1) happens concurrently with G1: Wait(),
and so there is no reasonable behavior of the program
(G1: Wait() may or may not wait for G3: Add(1) which
can't be the intended behavior).
With this conclusion we can:
1. Remove dynamic allocation of semaphores.
2. Remove the mutex entirely and instead pack counter and waiters
into single uint64.
This makes the logic significantly simpler, both Add and Wait
do only a single atomic RMW to update the state.
benchmark old ns/op new ns/op delta
BenchmarkWaitGroupUncontended 30.6 32.7 +6.86%
BenchmarkWaitGroupActuallyWait 722 595 -17.59%
BenchmarkWaitGroupActuallyWait-2 396 319 -19.44%
BenchmarkWaitGroupActuallyWait-4 224 183 -18.30%
BenchmarkWaitGroupActuallyWait-8 134 106 -20.90%
benchmark old allocs new allocs delta
BenchmarkWaitGroupActuallyWait 2 1 -50.00%
benchmark old bytes new bytes delta
BenchmarkWaitGroupActuallyWait 48 16 -66.67%
Change-Id: I28911f3243aa16544e99ac8f1f5af31944c7ea3a
Reviewed-on: https://go-review.googlesource.com/4117
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
This commit fixes a cosmetic defect whereby quick.Check reports that
the provided function returns too many values when it may, in fact,
return too few:
func f() {}
func TestFoo(t *testing.T) {
if err := quick.Check(f, nil); err != nil {
t.Fatal(err)
}
}
// yields
// $ go test -v foo_test.go
// === RUN TestFoo
// --- FAIL: TestFoo (0.00s)
// foo_test.go:76: function returns more than one value.
Change-Id: Ia209ff5b57375b30f8db425454e80798908e8ff4
Reviewed-on: https://go-review.googlesource.com/11281
Reviewed-by: Russ Cox <rsc@golang.org>
Not sure if I'm on time for 1.5; Unicode 8 just got released.
Straighforward upgrade. Only changed maketables.go to prevent it from adding
the Cherokee upper and lower case mappings. This change causes the caseOrbit
table to NOT change. Added tests to verify that the relevant functions still
produce the correct result, even for Cherokee.
Fixes#11309
Change-Id: I42850f5b3399bde125b002efc78eff96dbd86a08
Reviewed-on: https://go-review.googlesource.com/11286
Reviewed-by: Russ Cox <rsc@golang.org>
Removes the remains of the old C based stepflt implementation.
Also removed goto usage.
Change-Id: Ida4742c49000fae4fea4649f28afde630ce4c577
Reviewed-on: https://go-review.googlesource.com/9600
Reviewed-by: Russ Cox <rsc@golang.org>
The new inlined code for append assumed that it could pass the
desired new cap to growslice, not the number of new elements.
But growslice still interpreted the argument as the number of new elements,
making it always grow by >2x (more precisely, 2x+1 rounded up
to the next malloc block size). At the time, I had intended to change
the other callers to use the new cap as well, but it's too late for that.
Instead, introduce growslice_n for the old callers and keep growslice
for the inlined (common case) caller.
Fixes#11403.
Filed #11419 to merge them.
Change-Id: I1338b1e5b352f3be4e43641f44b652ef7195251b
Reviewed-on: https://go-review.googlesource.com/11541
Reviewed-by: Austin Clements <austin@google.com>
Includes a new net/http test too.
Fixes#11202
Change-Id: I61edc594f4de8eb6780b8dfa221269dd482e8f35
Reviewed-on: https://go-review.googlesource.com/11492
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Russ Cox <rsc@golang.org>
All other exported errors in net/http are commented. This change adds
documentation to ErrNoCookie and ErrNoLocation to explain where they are
returned, and why.
Change-Id: I21fa0d070dd35256681ad0714000f238477d4af1
Reviewed-on: https://go-review.googlesource.com/11044
Reviewed-by: Russ Cox <rsc@golang.org>
This adds a GC bitmap test of a type with many pointer bits and a
large scalar tail, such as the one in issue #11286. This test would
have failed prior to the fix in a8ae93f. This test is a more direct
version of the test introduced in that commit (which was distilled
from the failing test in the issue).
Change-Id: I2e716cd1000b49bde237f5da6d857e8983fe7e7a
Reviewed-on: https://go-review.googlesource.com/11423
Reviewed-by: Russ Cox <rsc@golang.org>
Currently we test bitmap repetitions constructed by the compiler (for
small arrays) and repetitions performed by GC programs (large arrays
and reflect-constructed arrays), but we don't test dynamic repetitions
performed by the runtime for slice backing stores. Add tests that
parallel the array tests using slices.
Change-Id: If4425941a33cc5b20178dd819a7371e347e47585
Reviewed-on: https://go-review.googlesource.com/11422
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
The consecutive calls to Head would sometimes get different
connections depending on if the readLoop had finished executing
and placed its connection on the idle list or not. This change
ensures that readLoop completes before we make our second connection.
Fixes#11250
Change-Id: Ibdbc4d3d0aba0162452f6dec5928355a37dda70a
Reviewed-on: https://go-review.googlesource.com/11170
Reviewed-by: Russ Cox <rsc@golang.org>
