Currently for 2-word blocks we set the flag to clear the flag. Makes no sense.
In particular on 32-bits we call memclr always.
R=golang-codereviews, dave, iant
CC=golang-codereviews, khr, rsc
https://golang.org/cl/41170044
The test prints an excessive \n when /dev/null is not present.
R=golang-codereviews, bradfitz, dave
CC=golang-codereviews
https://golang.org/cl/54890043
What was happenning is as follows:
Each writer goroutine always triggers GC during its scheduling quntum.
After GC goroutines are shuffled so that the timer goroutine is always second in the queue.
This repeats infinitely, causing timer goroutine starvation.
Fixes#7126.
R=golang-codereviews, shanemhansen, khr, khr
CC=golang-codereviews
https://golang.org/cl/53080043
It's pretty distracting to use expvar with the output of both
the top-level map and map values jumping around randomly.
Also fixes a potential race where multiple clients trying to
increment a map int or float key at the same time could lose
updates.
R=golang-codereviews, couchmoney
CC=golang-codereviews
https://golang.org/cl/54320043
Use testing.AllocsPerRun now that it exists, instead of doing it by hand.
Fixes#6076
R=golang-codereviews, alex.brainman
CC=golang-codereviews
https://golang.org/cl/53810043
Vararg C calls present a problem for the GC because the
argument types are not derivable from the signature. Remove
them by passing pointers to channel elements instead of the
channel elements directly.
R=golang-codereviews, gobot, rsc, dvyukov
CC=golang-codereviews
https://golang.org/cl/53430043
The compiler change is an ugly hack.
We can do better.
««« original CL description
syscall: mark arguments to Syscall as noescape
Heap arguments to "async" syscalls will break when/if we have moving GC anyway.
With this change is must not break until moving GC, because a user must
reference the object in Go to preserve liveness. Otherwise the code is broken already.
Reduces number of leaked params from 125 to 36 on linux.
R=golang-codereviews, mikioh.mikioh, bradfitz
CC=cshapiro, golang-codereviews, khr, rsc
https://golang.org/cl/45930043
»»»
R=golang-codereviews, r
CC=bradfitz, dvyukov, golang-codereviews
https://golang.org/cl/53870043
Recent crashes on 386 Darwin appear to be caused by this system call
smashing the stack. Phenomenology shows that allocating more data
here addresses the probem.
The guess is that since the actual system call is getdirentries64, 64 is
what we should allocate.
Should fix the darwin/386 build.
R=rsc
CC=golang-codereviews
https://golang.org/cl/53840043
Heap arguments to "async" syscalls will break when/if we have moving GC anyway.
With this change is must not break until moving GC, because a user must
reference the object in Go to preserve liveness. Otherwise the code is broken already.
Reduces number of leaked params from 125 to 36 on linux.
R=golang-codereviews, mikioh.mikioh, bradfitz
CC=cshapiro, golang-codereviews, khr, rsc
https://golang.org/cl/45930043
decrypt: reduced the number of copy calls from 2n to 1.
encrypt: reduced the number of copy calls from n to 1.
Encryption is straight-forward: use dst instead of tmp when
xoring the block with the iv.
Decryption now loops backwards through the blocks abusing the
fact that the previous block's ciphertext (src) is the iv. This
means we don't need to copy the iv every time, in addition to
using dst instead of tmp like encryption.
R=golang-codereviews, agl, mikioh.mikioh
CC=golang-codereviews
https://golang.org/cl/50900043
Falsely claimed an old, no longer true condition that the first argument
must be a pointer.
Fixes#6697
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/53480043
Update #5001
This test is flakey on linux servers and fails otherwise good builds. Mikio has some proposals to fix the test, but they require additional plumbing.
In the meantime, disable this test in -short mode so it will run during the full net test suite, but not during builder ci.
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/53410043
No changes, just rearrangement. The tests were in need of a little
housekeeping.
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/53400043
Matches Darwin and the BSDs. This means leveldb-go, kv,
Camlistore, etc can stop defining these structs on Linux by
hand.
Update #7059
R=golang-codereviews, dave, iant
CC=golang-codereviews
https://golang.org/cl/53350043
Reflect used to communicate to the runtime using interface words,
which is bad for precise GC because sometimes iwords hold a pointer
and sometimes they don't. This change rewrites channel and select
operations to always pass pointers to the runtime.
reflect.Select gets somewhat more expensive, as we now do an allocation
per receive case instead of one allocation whose size is the max of
all the received types. This seems unavoidable to get preciseness
(unless we move the allocation into selectgo, which is a much bigger
change).
Fixes#6490
R=golang-codereviews, dvyukov, rsc
CC=golang-codereviews
https://golang.org/cl/52900043
Status codes 204, 304, and 1xx don't allow bodies. We already
had a function for this, but we were hard-coding just 304
(StatusNotModified) in a few places. Use the function
instead, and flesh out tests for all codes.
Fixes#6685
R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/53290044
Apparently this is expensive on Windows.
Fixes#7020
R=golang-codereviews, alex.brainman, mattn.jp, dvyukov
CC=golang-codereviews
https://golang.org/cl/52840043
We forgot to include the width of "0x" when computing the crossover
from internal buffer to allocated buffer.
Also add a helper function to the test for formatting large zero-padded
test strings.
Fixes#6777.
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/50820043
This CL makes the bitmaps a little more precise about variables
that have their address taken but for which the address does not
escape to the heap, so that the variables are kept in the stack frame
rather than allocated on the heap.
The code before this CL handled these variables by treating every
return statement as using every such variable and depending on
liveness analysis to essentially treat the variable as live during the
entire function. That approach has false positives and (worse) false
negatives. That is, it's both sloppy and buggy:
func f(b1, b2 bool) { // x live here! (sloppy)
if b2 {
print(0) // x live here! (sloppy)
return
}
var z **int
x := new(int)
*x = 42
z = &x
print(**z) // x live here (conservative)
if b2 {
print(1) // x live here (conservative)
return
}
for {
print(**z) // x not live here (buggy)
}
}
The first two liveness annotations (marked sloppy) are clearly
wrong: x cannot be live if it has not yet been declared.
The last liveness annotation (marked buggy) is also wrong:
x is live here as *z, but because there is no return statement
reachable from this point in the code, the analysis treats x as dead.
This CL changes the liveness calculation to mark such variables
live exactly at points in the code reachable from the variable
declaration. This keeps the conservative decisions but fixes
the sloppy and buggy ones.
The CL also detects ambiguously live variables, those that are
being marked live but may not actually have been initialized,
such as in this example:
func f(b1 bool) {
var z **int
if b1 {
x := new(int)
*x = 42
z = &x
} else {
y := new(int)
*y = 54
z = &y
}
print(**z) // x, y live here (conservative)
}
Since the print statement is reachable from the declaration of x,
x must conservatively be marked live. The same goes for y.
Although both x and y are marked live at the print statement,
clearly only one of them has been initialized. They are both
"ambiguously live".
These ambiguously live variables cause problems for garbage
collection: the collector cannot ignore them but also cannot
depend on them to be initialized to valid pointer values.
Ambiguously live variables do not come up too often in real code,
but recent changes to the way map and interface runtime functions
are invoked has created a large number of ambiguously live
compiler-generated temporary variables. The next CL will adjust
the analysis to understand these temporaries better, to make
ambiguously live variables fairly rare.
Once ambiguously live variables are rare enough, another CL will
introduce code at the beginning of a function to zero those
slots on the stack. At that point the garbage collector and the
stack copying routines will be able to depend on the guarantee that
if a slot is marked as live in a liveness bitmap, it is initialized.
R=khr
CC=golang-codereviews, iant
https://golang.org/cl/51810043
Example of output:
goroutine 4 [sleep for 3 min]:
time.Sleep(0x34630b8a000)
src/pkg/runtime/time.goc:31 +0x31
main.func·002()
block.go:16 +0x2c
created by main.main
block.go:17 +0x33
Full program and output are here:
http://play.golang.org/p/NEZdADI3TdFixes#6809.
R=golang-codereviews, khr, kamil.kisiel, bradfitz, rsc
CC=golang-codereviews
https://golang.org/cl/50420043
Use lock-free fixed-size ring for work queues
instead of an unbounded mutex-protected array.
The ring has single producer and multiple consumers.
If the ring overflows, work is put onto global queue.
benchmark old ns/op new ns/op delta
BenchmarkMatmult 7 5 -18.12%
BenchmarkMatmult-4 2 2 -18.98%
BenchmarkMatmult-16 1 0 -12.84%
BenchmarkCreateGoroutines 105 88 -16.10%
BenchmarkCreateGoroutines-4 376 219 -41.76%
BenchmarkCreateGoroutines-16 241 174 -27.80%
BenchmarkCreateGoroutinesParallel 103 87 -14.66%
BenchmarkCreateGoroutinesParallel-4 169 143 -15.38%
BenchmarkCreateGoroutinesParallel-16 158 151 -4.43%
R=golang-codereviews, rsc
CC=ddetlefs, devon.odell, golang-codereviews
https://golang.org/cl/46170044
Give proper types to the argument/return areas
allocated for reflect calls. Avoid use of iword to
manipulate receivers, which may or may not be pointers.
Update #6490
R=rsc
CC=golang-codereviews
https://golang.org/cl/52110044
Replace the pack command, a C program, with a clean reimplementation in Go.
It does not need to reproduce the full feature set and it is no longer used by
the build chain, but has a role in looking inside archives created by the build
chain directly.
Since it's not in C, it is no longer build by dist, so remove it from cmd/dist and
make it a "tool" in cmd/go terminology.
Fixes#2705
R=rsc, dave, minux.ma, josharian
CC=golang-codereviews
https://golang.org/cl/52310044
Previously, filenames containing special characters could:
1) Escape the <a> tag, with a file called something like: ">foo
2) Break the links in the index by prematurely ending the path portion
of the url, with a file called: foo?bar
In order to avoid a forbidden dependency on the html package, I'm
using htmlReplacer from net/http/server.go, which is equivalent to
html.EscapeString.
This change also expands fakeFile.Readdir to better emulate
os.File.Readdir.
R=golang-codereviews, rsc, gobot, bradfitz, josharian, mikioh.mikioh
CC=golang-codereviews
https://golang.org/cl/37440043
Map iteration previously started from a random bucket, but walked each
bucket from the beginning. Now, iteration always starts from the first
bucket and walks each bucket starting at a random offset. For
performance, the random offset is selected at the start of iteration
and reused for each bucket.
Iteration over a map with 8 or fewer elements--a single bucket--will
now be non-deterministic. There will now be only 8 different possible
map iterations.
Significant benchmark changes, on my OS X laptop (rough but consistent):
benchmark old ns/op new ns/op delta
BenchmarkMapIter 128 121 -5.47%
BenchmarkMapIterEmpty 4.26 4.45 +4.46%
BenchmarkNewEmptyMap 114 111 -2.63%
Fixes#6719.
R=khr, bradfitz
CC=golang-codereviews
https://golang.org/cl/47370043
Still work to do. See http://golang.org/issue/7125
««« original CL description
net/http/cookiejar: document format of domain in PublicSuffix
Document what values a PublicSuffixList must accept as
a domain in a call to PublicSuffix.
R=bradfitz, nigeltao
CC=golang-codereviews
https://golang.org/cl/47560044
»»»
R=golang-codereviews, minux.ma
CC=golang-codereviews
https://golang.org/cl/51770044
