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Author SHA1 Message Date
Brad Fitzpatrick
34c58065e5 runtime: rename os1_linux.go to os_linux.go
Change-Id: I938f61763c3256a876d62aeb54ef8c25cc4fc90e
Reviewed-on: https://go-review.googlesource.com/21567
Reviewed-by: Minux Ma <minux@golang.org>
2016-04-06 03:55:38 +00:00
Brad Fitzpatrick
5103fbfdb2 runtime: merge os_linux.go into os1_linux.go
Change-Id: I791c47014fe69e8529c7b2f0b9a554e47902d46c
Reviewed-on: https://go-review.googlesource.com/21566
Reviewed-by: Minux Ma <minux@golang.org>
2016-04-06 03:54:47 +00:00
David Symonds
6f2a8810b0 expvar: Ensure strings are written as valid JSON.
Change-Id: I5147dbf4e85cf42cd1f32c57861e4c16d9dbd049
Reviewed-on: https://go-review.googlesource.com/21529
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-04-06 03:52:39 +00:00
Brad Fitzpatrick
870d997ab4 net/http: keep request context during Client redirects
Change-Id: I25c51280ba55120ffeaf08222f5ac5d471632d89
Reviewed-on: https://go-review.googlesource.com/21535
Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-06 03:20:35 +00:00
Josh Bleecher Snyder
fda831ed3f cmd/compile: encapsulate reads of gc.Type.Funarg
Changes generated with eg and then manually
checked and in some cases simplified.

Passes toolstash -cmp.

Change-Id: I2119f37f003368ce1884d2863b406d6ffbfe38c7
Reviewed-on: https://go-review.googlesource.com/21563
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-04-06 02:49:18 +00:00
Brad Fitzpatrick
e0307c25be net/http: document that Handlers shouldn't mutate Request
Also, don't read from the Request.Headers in the http Server code once
ServeHTTP has started. This is partially redundant with documenting
that handlers shouldn't mutate request, but: the space is free due to
bool packing, it's faster to do the checks once instead of N times in
writeChunk, and it's a little nicer to code which previously didn't
play by the unwritten rules. But I'm not going to fix all the cases.

Fixes #14940

Change-Id: I612a8826b41c8682b59515081c590c512ee6949e
Reviewed-on: https://go-review.googlesource.com/21530
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-04-06 02:40:49 +00:00
Brad Fitzpatrick
8556c76f88 runtime: minor Windows cleanup
Change-Id: I9a8081ef1109469e9577c642156aa635188d8954
Reviewed-on: https://go-review.googlesource.com/21538
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
2016-04-06 02:23:29 +00:00
Brad Fitzpatrick
cb284313f7 net/http, net/http/httputil: start with capitals in deprecation sentences
Fixes #15139

Change-Id: I73111137907e612af871b77ccf166572bf78c840
Reviewed-on: https://go-review.googlesource.com/21544
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-04-06 00:17:51 +00:00
Matthew Dempsky
5ba797bd18 cmd/compile: move a lot of declarations outside of go.go
go.go is currently a grab bag of various unrelated type and variable
declarations. Move a bunch of them into other more relevant source
files.

There are still more that can be moved, but these were the low hanging
fruit with obvious homes.

No code/comment changes. Just shuffling stuff around.

Change-Id: I43dbe1a5b8b707709c1a3a034c693d38b8465063
Reviewed-on: https://go-review.googlesource.com/21561
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-05 21:38:15 +00:00
Matthew Dempsky
cca4ddb497 cmd/compile: add comments explaining how declarations/scopes work
Change-Id: I301760b015eb69ff12eee53473fdbf5e9f168413
Reviewed-on: https://go-review.googlesource.com/21542
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
2016-04-05 21:04:11 +00:00
Brad Fitzpatrick
d7c699d993 crypto/rsa, crypto/ecdsa: fail earlier on zero parameters
Change-Id: Ia6ed49d5ef3a256a55e6d4eaa1b4d9f0fc447013
Reviewed-on: https://go-review.googlesource.com/21560
Reviewed-by: Robert Griesemer <gri@golang.org>
2016-04-05 21:03:20 +00:00
Marcel van Lohuizen
7e0d66020c testing: improve output
This introduces a few changes
- Skipped benchmarks now print a SKIP line, also if there was
no output
- The benchmark name is only printed if there the benchmark
was not skipped or did not fail in the probe phase.

It also fixes a bug of doubling a skip message in chatty mode in
absense of a failure.

The chatty flag is now passed in the common struct to allow
for testing of the printed messages.

Fixes #14799

Change-Id: Ia8eb140c2e5bb467e66b8ef20a2f98f5d95415d5
Reviewed-on: https://go-review.googlesource.com/21504
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-05 20:38:41 +00:00
Josh Bleecher Snyder
5e1b7bdecf cmd/compile: pull ssa OAPPEND expression handing into its own function
Pure code movement.

Change-Id: Ia07ee0b0041c931b08adf090f262a6f74a6fdb01
Reviewed-on: https://go-review.googlesource.com/21546
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-05 20:31:38 +00:00
Josh Bleecher Snyder
7735dfb67c cmd/compile: give TLS relocations a name when dumping assembly
Before:

	...
	0x00d0 ff ff ff e8 00 00 00 00 e9 23 ff ff ff cc cc cc  .........#......
	rel 5+4 t=14 +0
	rel 82+4 t=13 runtime.writeBarrier+0
	...

After:

	...
	0x00d0 ff ff ff e8 00 00 00 00 e9 23 ff ff ff cc cc cc  .........#......
	rel 5+4 t=14 TLS+0
	rel 82+4 t=13 runtime.writeBarrier+0
	...

Change-Id: Ibdaf694581b5fd5fb87fa8ce6a792f3eb4493622
Reviewed-on: https://go-review.googlesource.com/21545
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-05 20:21:25 +00:00
Joe Tsai
260ea68999 os: deprecate os.SEEK_SET, os.SEEK_CUR, and os.SEEK_END
CL/19862 introduced the same set of constants to the io package.
We should steer users away from the os.SEEK* versions and towards
the io.Seek* versions.

Updates #6885

Change-Id: I96ec5be3ec3439e1295c937159dadaf1ebfb2737
Reviewed-on: https://go-review.googlesource.com/21540
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-05 19:59:50 +00:00
Robert Griesemer
f79b50b8d5 go/importer: match predeclared type list with gc's list in binary exporter
I think we had this code before but it may have gone lost somehow.

Change-Id: Ifde490e686de0d2bfe907cbe19c9197f24f5fa8e
Reviewed-on: https://go-review.googlesource.com/21537
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-04-05 18:23:31 +00:00
David Chase
d8c815d8b5 cmd/compile: note escape of parts of closured-capture vars
Missed a case for closure calls (OCALLFUNC && indirect) in
esc.go:esccall.

Cleanup to runtime code for windows to more thoroughly hide
a technical escape.  Also made code pickier about failing
to late non-optional kernel32.dll.

Fixes #14409.

Change-Id: Ie75486a2c8626c4583224e02e4872c2875f7bca5
Reviewed-on: https://go-review.googlesource.com/20102
Run-TryBot: David Chase <drchase@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-05 18:10:09 +00:00
Robert Griesemer
eb876dd83c crypto/dsa: eliminate invalid PublicKey early
For PublicKey.P == 0, Verify will fail. Don't even try.

Change-Id: I1009f2b3dead8d0041626c946633acb10086d8c8
Reviewed-on: https://go-review.googlesource.com/21533
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-05 17:41:47 +00:00
Brad Fitzpatrick
b9531d31ac doc: add httptest.ResponseRecorder note to go1.7.txt notes
Fixes #14928

Change-Id: Id772eb623815cb2bb3e49de68a916762345a9dc1
Reviewed-on: https://go-review.googlesource.com/21531
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-05 16:05:16 +00:00
Dmitry Vyukov
475d113b53 runtime: don't burn CPU unnecessarily
Two GC-related functions, scang and casgstatus, wait in an active spin loop.
Active spinning is never a good idea in user-space. Once we wait several
times more than the expected wait time, something unexpected is happenning
(e.g. the thread we are waiting for is descheduled or handling a page fault)
and we need to yield to OS scheduler. Moreover, the expected wait time is
very high for these functions: scang wait time can be tens of milliseconds,
casgstatus can be hundreds of microseconds. It does not make sense to spin
even for that time.

go install -a std profile on a 4-core machine shows that 11% of time is spent
in the active spin in scang:

  6.12%    compile  compile                [.] runtime.scang
  3.27%    compile  compile                [.] runtime.readgstatus
  1.72%    compile  compile                [.] runtime/internal/atomic.Load

The active spin also increases tail latency in the case of the slightest
oversubscription: GC goroutines spend whole quantum in the loop instead of
executing user code.

Here is scang wait time histogram during go install -a std:

13707.0000 - 1815442.7667 [   118]: ∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎...
1815442.7667 - 3617178.5333 [     9]: ∎∎∎∎∎∎∎∎∎
3617178.5333 - 5418914.3000 [    11]: ∎∎∎∎∎∎∎∎∎∎∎
5418914.3000 - 7220650.0667 [     5]: ∎∎∎∎∎
7220650.0667 - 9022385.8333 [    12]: ∎∎∎∎∎∎∎∎∎∎∎∎
9022385.8333 - 10824121.6000 [    13]: ∎∎∎∎∎∎∎∎∎∎∎∎∎
10824121.6000 - 12625857.3667 [    15]: ∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
12625857.3667 - 14427593.1333 [    18]: ∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
14427593.1333 - 16229328.9000 [    18]: ∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
16229328.9000 - 18031064.6667 [    32]: ∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
18031064.6667 - 19832800.4333 [    28]: ∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
19832800.4333 - 21634536.2000 [     6]: ∎∎∎∎∎∎
21634536.2000 - 23436271.9667 [    15]: ∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
23436271.9667 - 25238007.7333 [    11]: ∎∎∎∎∎∎∎∎∎∎∎
25238007.7333 - 27039743.5000 [    27]: ∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
27039743.5000 - 28841479.2667 [    20]: ∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
28841479.2667 - 30643215.0333 [    10]: ∎∎∎∎∎∎∎∎∎∎
30643215.0333 - 32444950.8000 [     7]: ∎∎∎∎∎∎∎
32444950.8000 - 34246686.5667 [     4]: ∎∎∎∎
34246686.5667 - 36048422.3333 [     4]: ∎∎∎∎
36048422.3333 - 37850158.1000 [     1]: ∎
37850158.1000 - 39651893.8667 [     5]: ∎∎∎∎∎
39651893.8667 - 41453629.6333 [     2]: ∎∎
41453629.6333 - 43255365.4000 [     2]: ∎∎
43255365.4000 - 45057101.1667 [     2]: ∎∎
45057101.1667 - 46858836.9333 [     1]: ∎
46858836.9333 - 48660572.7000 [     2]: ∎∎
48660572.7000 - 50462308.4667 [     3]: ∎∎∎
50462308.4667 - 52264044.2333 [     2]: ∎∎
52264044.2333 - 54065780.0000 [     2]: ∎∎

and the zoomed-in first part:

13707.0000 - 19916.7667 [     2]: ∎∎
19916.7667 - 26126.5333 [     2]: ∎∎
26126.5333 - 32336.3000 [     9]: ∎∎∎∎∎∎∎∎∎
32336.3000 - 38546.0667 [     8]: ∎∎∎∎∎∎∎∎
38546.0667 - 44755.8333 [    12]: ∎∎∎∎∎∎∎∎∎∎∎∎
44755.8333 - 50965.6000 [    10]: ∎∎∎∎∎∎∎∎∎∎
50965.6000 - 57175.3667 [     5]: ∎∎∎∎∎
57175.3667 - 63385.1333 [     6]: ∎∎∎∎∎∎
63385.1333 - 69594.9000 [     5]: ∎∎∎∎∎
69594.9000 - 75804.6667 [     6]: ∎∎∎∎∎∎
75804.6667 - 82014.4333 [     6]: ∎∎∎∎∎∎
82014.4333 - 88224.2000 [     4]: ∎∎∎∎
88224.2000 - 94433.9667 [     1]: ∎
94433.9667 - 100643.7333 [     1]: ∎
100643.7333 - 106853.5000 [     2]: ∎∎
106853.5000 - 113063.2667 [     0]:
113063.2667 - 119273.0333 [     2]: ∎∎
119273.0333 - 125482.8000 [     2]: ∎∎
125482.8000 - 131692.5667 [     1]: ∎
131692.5667 - 137902.3333 [     1]: ∎
137902.3333 - 144112.1000 [     0]:
144112.1000 - 150321.8667 [     2]: ∎∎
150321.8667 - 156531.6333 [     1]: ∎
156531.6333 - 162741.4000 [     1]: ∎
162741.4000 - 168951.1667 [     0]:
168951.1667 - 175160.9333 [     0]:
175160.9333 - 181370.7000 [     1]: ∎
181370.7000 - 187580.4667 [     1]: ∎
187580.4667 - 193790.2333 [     2]: ∎∎
193790.2333 - 200000.0000 [     0]:

Here is casgstatus wait time histogram:

  631.0000 -  5276.6333 [     3]: ∎∎∎
 5276.6333 -  9922.2667 [     5]: ∎∎∎∎∎
 9922.2667 - 14567.9000 [     2]: ∎∎
14567.9000 - 19213.5333 [     6]: ∎∎∎∎∎∎
19213.5333 - 23859.1667 [     5]: ∎∎∎∎∎
23859.1667 - 28504.8000 [     6]: ∎∎∎∎∎∎
28504.8000 - 33150.4333 [     6]: ∎∎∎∎∎∎
33150.4333 - 37796.0667 [     2]: ∎∎
37796.0667 - 42441.7000 [     1]: ∎
42441.7000 - 47087.3333 [     3]: ∎∎∎
47087.3333 - 51732.9667 [     0]:
51732.9667 - 56378.6000 [     1]: ∎
56378.6000 - 61024.2333 [     0]:
61024.2333 - 65669.8667 [     0]:
65669.8667 - 70315.5000 [     0]:
70315.5000 - 74961.1333 [     1]: ∎
74961.1333 - 79606.7667 [     0]:
79606.7667 - 84252.4000 [     0]:
84252.4000 - 88898.0333 [     0]:
88898.0333 - 93543.6667 [     0]:
93543.6667 - 98189.3000 [     0]:
98189.3000 - 102834.9333 [     0]:
102834.9333 - 107480.5667 [     1]: ∎
107480.5667 - 112126.2000 [     0]:
112126.2000 - 116771.8333 [     0]:
116771.8333 - 121417.4667 [     0]:
121417.4667 - 126063.1000 [     0]:
126063.1000 - 130708.7333 [     0]:
130708.7333 - 135354.3667 [     0]:
135354.3667 - 140000.0000 [     1]: ∎

Ideally we eliminate the waiting by switching to async
state machine for GC, but for now just yield to OS scheduler
after a reasonable wait time.

To choose yielding parameters I've measured
golang.org/x/benchmarks/http tail latencies with different yield
delays and oversubscription levels.

With no oversubscription (to the degree possible):

scang yield delay = 1, casgstatus yield delay = 1
Latency-50   1.41ms ±15%  1.41ms ± 5%    ~     (p=0.611 n=13+12)
Latency-95   5.21ms ± 2%  5.15ms ± 2%  -1.15%  (p=0.012 n=13+13)
Latency-99   7.16ms ± 2%  7.05ms ± 2%  -1.54%  (p=0.002 n=13+13)
Latency-999  10.7ms ± 9%  10.2ms ±10%  -5.46%  (p=0.004 n=12+13)

scang yield delay = 5000, casgstatus yield delay = 3000
Latency-50   1.41ms ±15%  1.41ms ± 8%    ~     (p=0.511 n=13+13)
Latency-95   5.21ms ± 2%  5.14ms ± 2%  -1.23%  (p=0.006 n=13+13)
Latency-99   7.16ms ± 2%  7.02ms ± 2%  -1.94%  (p=0.000 n=13+13)
Latency-999  10.7ms ± 9%  10.1ms ± 8%  -6.14%  (p=0.000 n=12+13)

scang yield delay = 10000, casgstatus yield delay = 5000
Latency-50   1.41ms ±15%  1.45ms ± 6%    ~     (p=0.724 n=13+13)
Latency-95   5.21ms ± 2%  5.18ms ± 1%    ~     (p=0.287 n=13+13)
Latency-99   7.16ms ± 2%  7.05ms ± 2%  -1.64%  (p=0.002 n=13+13)
Latency-999  10.7ms ± 9%  10.0ms ± 5%  -6.72%  (p=0.000 n=12+13)

scang yield delay = 30000, casgstatus yield delay = 10000
Latency-50   1.41ms ±15%  1.51ms ± 7%  +6.57%  (p=0.002 n=13+13)
Latency-95   5.21ms ± 2%  5.21ms ± 2%    ~     (p=0.960 n=13+13)
Latency-99   7.16ms ± 2%  7.06ms ± 2%  -1.50%  (p=0.012 n=13+13)
Latency-999  10.7ms ± 9%  10.0ms ± 6%  -6.49%  (p=0.000 n=12+13)

scang yield delay = 100000, casgstatus yield delay = 50000
Latency-50   1.41ms ±15%  1.53ms ± 6%  +8.48%  (p=0.000 n=13+12)
Latency-95   5.21ms ± 2%  5.23ms ± 2%    ~     (p=0.287 n=13+13)
Latency-99   7.16ms ± 2%  7.08ms ± 2%  -1.21%  (p=0.004 n=13+13)
Latency-999  10.7ms ± 9%   9.9ms ± 3%  -7.99%  (p=0.000 n=12+12)

scang yield delay = 200000, casgstatus yield delay = 100000
Latency-50   1.41ms ±15%  1.47ms ± 5%    ~     (p=0.072 n=13+13)
Latency-95   5.21ms ± 2%  5.17ms ± 2%    ~     (p=0.091 n=13+13)
Latency-99   7.16ms ± 2%  7.02ms ± 2%  -1.99%  (p=0.000 n=13+13)
Latency-999  10.7ms ± 9%   9.9ms ± 5%  -7.86%  (p=0.000 n=12+13)

With slight oversubscription (another instance of http benchmark
was running in background with reduced GOMAXPROCS):

scang yield delay = 1, casgstatus yield delay = 1
Latency-50    840µs ± 3%   804µs ± 3%  -4.37%  (p=0.000 n=15+18)
Latency-95   6.52ms ± 4%  6.03ms ± 4%  -7.51%  (p=0.000 n=18+18)
Latency-99   10.8ms ± 7%  10.0ms ± 4%  -7.33%  (p=0.000 n=18+14)
Latency-999  18.0ms ± 9%  16.8ms ± 7%  -6.84%  (p=0.000 n=18+18)

scang yield delay = 5000, casgstatus yield delay = 3000
Latency-50    840µs ± 3%   809µs ± 3%  -3.71%  (p=0.000 n=15+17)
Latency-95   6.52ms ± 4%  6.11ms ± 4%  -6.29%  (p=0.000 n=18+18)
Latency-99   10.8ms ± 7%   9.9ms ± 6%  -7.55%  (p=0.000 n=18+18)
Latency-999  18.0ms ± 9%  16.5ms ±11%  -8.49%  (p=0.000 n=18+18)

scang yield delay = 10000, casgstatus yield delay = 5000
Latency-50    840µs ± 3%   823µs ± 5%  -2.06%  (p=0.002 n=15+18)
Latency-95   6.52ms ± 4%  6.32ms ± 3%  -3.05%  (p=0.000 n=18+18)
Latency-99   10.8ms ± 7%  10.2ms ± 4%  -5.22%  (p=0.000 n=18+18)
Latency-999  18.0ms ± 9%  16.7ms ±10%  -7.09%  (p=0.000 n=18+18)

scang yield delay = 30000, casgstatus yield delay = 10000
Latency-50    840µs ± 3%   836µs ± 5%    ~     (p=0.442 n=15+18)
Latency-95   6.52ms ± 4%  6.39ms ± 3%  -2.00%  (p=0.000 n=18+18)
Latency-99   10.8ms ± 7%  10.2ms ± 6%  -5.15%  (p=0.000 n=18+17)
Latency-999  18.0ms ± 9%  16.6ms ± 8%  -7.48%  (p=0.000 n=18+18)

scang yield delay = 100000, casgstatus yield delay = 50000
Latency-50    840µs ± 3%   836µs ± 6%    ~     (p=0.401 n=15+18)
Latency-95   6.52ms ± 4%  6.40ms ± 4%  -1.79%  (p=0.010 n=18+18)
Latency-99   10.8ms ± 7%  10.2ms ± 5%  -4.95%  (p=0.000 n=18+18)
Latency-999  18.0ms ± 9%  16.5ms ±14%  -8.17%  (p=0.000 n=18+18)

scang yield delay = 200000, casgstatus yield delay = 100000
Latency-50    840µs ± 3%   828µs ± 2%  -1.49%  (p=0.001 n=15+17)
Latency-95   6.52ms ± 4%  6.38ms ± 4%  -2.04%  (p=0.001 n=18+18)
Latency-99   10.8ms ± 7%  10.2ms ± 4%  -4.77%  (p=0.000 n=18+18)
Latency-999  18.0ms ± 9%  16.9ms ± 9%  -6.23%  (p=0.000 n=18+18)

With significant oversubscription (background http benchmark
was running with full GOMAXPROCS):

scang yield delay = 1, casgstatus yield delay = 1
Latency-50   1.32ms ±12%  1.30ms ±13%    ~     (p=0.454 n=14+14)
Latency-95   16.3ms ±10%  15.3ms ± 7%  -6.29%  (p=0.001 n=14+14)
Latency-99   29.4ms ±10%  27.9ms ± 5%  -5.04%  (p=0.001 n=14+12)
Latency-999  49.9ms ±19%  45.9ms ± 5%  -8.00%  (p=0.008 n=14+13)

scang yield delay = 5000, casgstatus yield delay = 3000
Latency-50   1.32ms ±12%  1.29ms ± 9%    ~     (p=0.227 n=14+14)
Latency-95   16.3ms ±10%  15.4ms ± 5%  -5.27%  (p=0.002 n=14+14)
Latency-99   29.4ms ±10%  27.9ms ± 6%  -5.16%  (p=0.001 n=14+14)
Latency-999  49.9ms ±19%  46.8ms ± 8%  -6.21%  (p=0.050 n=14+14)

scang yield delay = 10000, casgstatus yield delay = 5000
Latency-50   1.32ms ±12%  1.35ms ± 9%     ~     (p=0.401 n=14+14)
Latency-95   16.3ms ±10%  15.0ms ± 4%   -7.67%  (p=0.000 n=14+14)
Latency-99   29.4ms ±10%  27.4ms ± 5%   -6.98%  (p=0.000 n=14+14)
Latency-999  49.9ms ±19%  44.7ms ± 5%  -10.56%  (p=0.000 n=14+11)

scang yield delay = 30000, casgstatus yield delay = 10000
Latency-50   1.32ms ±12%  1.36ms ±10%     ~     (p=0.246 n=14+14)
Latency-95   16.3ms ±10%  14.9ms ± 5%   -8.31%  (p=0.000 n=14+14)
Latency-99   29.4ms ±10%  27.4ms ± 7%   -6.70%  (p=0.000 n=14+14)
Latency-999  49.9ms ±19%  44.9ms ±15%  -10.13%  (p=0.003 n=14+14)

scang yield delay = 100000, casgstatus yield delay = 50000
Latency-50   1.32ms ±12%  1.41ms ± 9%  +6.37%  (p=0.008 n=14+13)
Latency-95   16.3ms ±10%  15.1ms ± 8%  -7.45%  (p=0.000 n=14+14)
Latency-99   29.4ms ±10%  27.5ms ±12%  -6.67%  (p=0.002 n=14+14)
Latency-999  49.9ms ±19%  45.9ms ±16%  -8.06%  (p=0.019 n=14+14)

scang yield delay = 200000, casgstatus yield delay = 100000
Latency-50   1.32ms ±12%  1.42ms ±10%   +7.21%  (p=0.003 n=14+14)
Latency-95   16.3ms ±10%  15.0ms ± 7%   -7.59%  (p=0.000 n=14+14)
Latency-99   29.4ms ±10%  27.3ms ± 8%   -7.20%  (p=0.000 n=14+14)
Latency-999  49.9ms ±19%  44.8ms ± 8%  -10.21%  (p=0.001 n=14+13)

All numbers are on 8 cores and with GOGC=10 (http benchmark has
tiny heap, few goroutines and low allocation rate, so by default
GC barely affects tail latency).

10us/5us yield delays seem to provide a reasonable compromise
and give 5-10% tail latency reduction. That's what used in this change.

go install -a std results on 4 core machine:

name      old time/op  new time/op  delta
Time       8.39s ± 2%   7.94s ± 2%  -5.34%  (p=0.000 n=47+49)
UserTime   24.6s ± 2%   22.9s ± 2%  -6.76%  (p=0.000 n=49+49)
SysTime    1.77s ± 9%   1.89s ±11%  +7.00%  (p=0.000 n=49+49)
CpuLoad    315ns ± 2%   313ns ± 1%  -0.59%  (p=0.000 n=49+48) # %CPU
MaxRSS    97.1ms ± 4%  97.5ms ± 9%    ~     (p=0.838 n=46+49) # bytes

Update #14396
Update #14189

Change-Id: I3f4109bf8f7fd79b39c466576690a778232055a2
Reviewed-on: https://go-review.googlesource.com/21503
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
2016-04-05 15:52:03 +00:00
Dmitry Vyukov
3b246fa863 runtime: sleep less when we can do work
Usleep(100) in runqgrab negatively affects latency and throughput
of parallel application. We are sleeping instead of doing useful work.
This is effect is particularly visible on windows where minimal
sleep duration is 1-15ms.

Reduce sleep from 100us to 3us and use osyield on windows.
Sync chan send/recv takes ~50ns, so 3us gives us ~50x overshoot.

benchmark                    old ns/op     new ns/op     delta
BenchmarkChanSync-12         216           217           +0.46%
BenchmarkChanSyncWork-12     27213         25816         -5.13%

CPU consumption goes up from 106% to 108% in the first case,
and from 107% to 125% in the second case.

Test case from #14790 on windows:

BenchmarkDefaultResolution-8  4583372   29720    -99.35%
Benchmark1ms-8                992056    30701    -96.91%

99-th latency percentile for HTTP request serving is improved by up to 15%
(see http://golang.org/cl/20835 for details).

The following benchmarks are from the change that originally added this sleep
(see https://golang.org/s/go15gomaxprocs):

name        old time/op  new time/op  delta
Chain       22.6µs ± 2%  22.7µs ± 6%    ~      (p=0.905 n=9+10)
ChainBuf    22.4µs ± 3%  22.5µs ± 4%    ~      (p=0.780 n=9+10)
Chain-2     23.5µs ± 4%  24.9µs ± 1%  +5.66%   (p=0.000 n=10+9)
ChainBuf-2  23.7µs ± 1%  24.4µs ± 1%  +3.31%   (p=0.000 n=9+10)
Chain-4     24.2µs ± 2%  25.1µs ± 3%  +3.70%   (p=0.000 n=9+10)
ChainBuf-4  24.4µs ± 5%  25.0µs ± 2%  +2.37%  (p=0.023 n=10+10)
Powser       2.37s ± 1%   2.37s ± 1%    ~       (p=0.423 n=8+9)
Powser-2     2.48s ± 2%   2.57s ± 2%  +3.74%   (p=0.000 n=10+9)
Powser-4     2.66s ± 1%   2.75s ± 1%  +3.40%  (p=0.000 n=10+10)
Sieve        13.3s ± 2%   13.3s ± 2%    ~      (p=1.000 n=10+9)
Sieve-2      7.00s ± 2%   7.44s ±16%    ~      (p=0.408 n=8+10)
Sieve-4      4.13s ±21%   3.85s ±22%    ~       (p=0.113 n=9+9)

Fixes #14790

Change-Id: Ie7c6a1c4f9c8eb2f5d65ab127a3845386d6f8b5d
Reviewed-on: https://go-review.googlesource.com/20835
Reviewed-by: Austin Clements <austin@google.com>
2016-04-05 15:32:06 +00:00
Ilya Tocar
036d09d5bf cmd/compile/internal/amd64: Use 32-bit operands for byte operations
We already generate ADDL for byte operations, reflect this in code.
This also allows inc/dec for +-1 operation, which are 1-byte shorter,
and enables lea for 3-operand addition/subtraction.

Change-Id: Ibfdfee50667ca4cd3c28f72e3dece0c6d114d3ae
Reviewed-on: https://go-review.googlesource.com/21251
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-05 15:15:19 +00:00
Augusto Roman
ffbd31e9f7 encoding/json: allow non-string type keys for (un-)marshal
This CL allows JSON-encoding & -decoding maps whose keys are types that
implement encoding.TextMarshaler / TextUnmarshaler.

During encode, the map keys are marshaled upfront so that they can be
sorted.

Fixes #12146

Change-Id: I43809750a7ad82a3603662f095c7baf75fd172da
Reviewed-on: https://go-review.googlesource.com/20356
Run-TryBot: Caleb Spare <cespare@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-05 15:08:04 +00:00
Eric Lagergren
acefcb732c io: define SeekStart, SeekCurrent, SeekEnd constants for use with Seeker
Fixes #6885

Change-Id: I6907958186f6a2427da1ad2f6c20bd5d7bf7a3f9
Reviewed-on: https://go-review.googlesource.com/19862
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-05 14:07:04 +00:00
Alexandru Moșoi
1747788c56 cmd/compile: add a pass to print bound checks
Since BCE happens over several passes (opt, loopbce, prove)
it's easy to regress especially with rewriting.

The pass is only activated with special debug flag.

Change-Id: I46205982e7a2751156db8e875d69af6138068f59
Reviewed-on: https://go-review.googlesource.com/21510
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
2016-04-05 12:46:59 +00:00
Brad Fitzpatrick
3bbede0c51 net/http: zero pad Response status codes to three digits
Go 1.6's HTTP/1.x Transport started enforcing that responses have 3
status digits, per the spec, but we could still write out invalid
status codes ourselves if the called
ResponseWriter.WriteHeader(0). That is bogus anyway, since the minimum
status code is 1xx, but be a little bit less bogus (and consistent)
and zero pad our responses.

Change-Id: I6883901fd95073cb72f6b74035cabf1a79c35e1c
Reviewed-on: https://go-review.googlesource.com/19130
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-04-05 05:57:00 +00:00
Dave Cheney
7208a2cd78 cmd/compile/internal/ssa: hide gen packge from ./make.bash
Fixes #15122

Change-Id: Ie2c802d78aea731e25bf4b193b3c2e4c884e0573
Reviewed-on: https://go-review.googlesource.com/21524
Run-TryBot: Dave Cheney <dave@cheney.net>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-05 05:53:15 +00:00
David Symonds
e8f01e5cae expvar: document that the Var interface's String method should return a valid JSON value.
Change-Id: If4e740f3dbef4053355542eebdd899b3099d872c
Reviewed-on: https://go-review.googlesource.com/21525
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-04-05 05:50:56 +00:00
Paul Marks
869e576517 net: wait for cancelation goroutine before returning from connect.
This fixes a race which made it possible to cancel a connection after
returning from net.Dial.

Fixes #15035
Fixes #15078

Change-Id: Iec6215009538362f7ad9f408a33549f3e94d1606
Reviewed-on: https://go-review.googlesource.com/21497
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-05 05:12:22 +00:00
Alex Brainman
bbbd572c10 cmd/go: leave directory before removing it in TestSharedLibName
Fixes #15124

Change-Id: I55fe4c2957370f3fb417c3df54f99fb085a5dada
Reviewed-on: https://go-review.googlesource.com/21522
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-05 04:45:47 +00:00
Alex Brainman
31f2bb4ba2 debug/gosym: do not forget to close test binay file handle in TestPCLine
Fixes #15121

Change-Id: I651521743c56244c55eda5762905889d7e06887a
Reviewed-on: https://go-review.googlesource.com/21521
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-05 04:43:44 +00:00
Alex Brainman
ffeae198d0 runtime: leave directory before removing it in TestDLLPreloadMitigation
Fixes #15120

Change-Id: I1d9a192ac163826bad8b46e8c0b0b9e218e69570
Reviewed-on: https://go-review.googlesource.com/21520
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-05 04:32:49 +00:00
Brad Fitzpatrick
c1c7547f6a net/http: add Request.Context and Request.WithContext
Currently only used by the client. The server is not yet wired up.  A
TODO remains to document how it works server-side, once implemented.

Updates #14660

Change-Id: I27c2e74198872b2720995fa8271d91de200e23d5
Reviewed-on: https://go-review.googlesource.com/21496
Reviewed-by: Andrew Gerrand <adg@golang.org>
2016-04-05 03:14:38 +00:00
Alex Brainman
fcac88098b runtime: remove race out of BenchmarkChanToSyscallPing1ms
Fixes #15119

Change-Id: I31445bf282a5e2a160ff4e66c5a592b989a5798f
Reviewed-on: https://go-review.googlesource.com/21448
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-05 00:52:40 +00:00
Hiroshi Ioka
c4dda7e5a8 path/filepath: normalize output of EvalSymlinks on windows
Current implementation uses GetShortPathName and GetLongPathName
to get a normalized path. That approach sometimes fails because
user can disable short path name anytime. This CL provides
an alternative approach suggested by MSDN.

https://msdn.microsoft.com/en-us/library/windows/desktop/aa364989(v=vs.85).aspx

Fixes #13980

Change-Id: Icf4afe4c9c4b507fc110c1483bf8db2c3f606b0a
Reviewed-on: https://go-review.googlesource.com/20860
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-05 00:39:25 +00:00
Brad Fitzpatrick
9db7ef5614 context: add the context package from golang.org/x/net/context
This copies the golang.org/x/net/context package to the standard library.

It is imported from the x/net repo's git rev 1d9fd3b8333e (the most
recent modified to x/net/context as of 2016-03-07).

The corresponding change to x/net/context is in https://golang.org/cl/20347

Updates #14660

Change-Id: Ida14b1b7e115194d6218d9ac614548b9f41641cc
Reviewed-on: https://go-review.googlesource.com/20346
Reviewed-by: Sameer Ajmani <sameer@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-05 00:08:50 +00:00
Matthew Dempsky
0c71e293b5 cmd/compile: minor cleanup to import loading
Briefly document what the importfoo functions do.

Get rid of importsym's unused result parameter.

Get rid of the redundant calls to importsym(s, OTYPE)
after we've already called pkgtype(s).

Passes toolstash -cmp.

Change-Id: I4c057358144044f5356e4dec68907ec85f1fe806
Reviewed-on: https://go-review.googlesource.com/21498
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-04 23:47:25 +00:00
Mikio Hara
86e7a5b92a net: factor out fdMutex-related methods on netFD
Also updates documentation.

Change-Id: Idb0fc0feed61407f7f07eab81ce82b55ffde5040
Reviewed-on: https://go-review.googlesource.com/21446
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-04 22:31:06 +00:00
Mikio Hara
2ae749c13f net: rename TestSelfConnect to TestTCPSelfConnect
Alos moves TestTCPSelfConnect into tcpsock_test.go

Change-Id: I3e1cbd029594ecb36a67f42bc3ecdbc7176a95dc
Reviewed-on: https://go-review.googlesource.com/21447
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-04 22:21:26 +00:00
Shahar Kohanim
bc94282306 cmd/link: grow rdBuf lazily
Counting the final buffer size usually doesn't result in the buffer growing,
so assume that it doesn't need to grow and only grow if necessary.

name       old secs    new secs    delta
LinkCmdGo   0.49 ± 4%   0.48 ± 3%  -1.31%   (p=0.000 n=95+95)

name       old MaxRSS  new MaxRSS  delta
LinkCmdGo   122k ± 4%   121k ± 5%    ~     (p=0.065 n=96+100)

Change-Id: I85e7f5688a61ef5ef2b1b7afe56507e71c5bd5b1
Reviewed-on: https://go-review.googlesource.com/21509
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Shahar Kohanim <skohanim@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-04-04 21:22:44 +00:00
Robert Griesemer
a9ea36afbb cmd/compile: export inlined function bodies
Completed implementation for exporting inlined functions
using the new binary export format. This change passes
(export GO_GCFLAGS=-newexport; make all.bash) but for
gc's builtin_test.go which we need to adjust before enabling
this code by default.

For a high-level description of the export format see the
comment at the top of bexport.go.

Major changes:

1) The export format for the platform independent export data
   changed: When we export inlined function bodies, additional
   objects (other functions, types, etc.) that are referred to
   by the function bodies will need to be exported. While this
   doesn't affect the platform-independent portion directly, it
   adds more objects to the exportlist while we are exporting.
   Instead of trying to sort the objects into groups, just export
   objects as they appear in the export list. This is slightly
   less compact (one extra byte per object), but it is simpler
   and much more flexible.

2) The export format contains now three sections: 1) The plat-
   form independent objects, 2) the objects pulled in for export
   via inlined function bodies, and 3) the inlined function bodies.

3) Completed the exporting and importing code for inlined function
   bodies. The format is completely compiler-specific and easily
   changeable w/o affecting other tools. There is still quite a
   bit of room for denser encoding. This can happen at any time
   in the future.

This change contains also the adjustments for go/internal/gcimporter,
necessary because of the export format change 1) mentioned above.

For #13241.

Change-Id: I86bca0bd984b12ccf13d0d30892e6e25f6d04ed5
Reviewed-on: https://go-review.googlesource.com/21172
Run-TryBot: Robert Griesemer <gri@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-04 19:22:24 +00:00
Matthew Dempsky
38e11d05b9 cmd/compile: use *byte for pointer to string memory
Change-Id: I14cff013ef4920d33b5ead0c75d51681bb4f635a
Reviewed-on: https://go-review.googlesource.com/21337
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-04-04 18:19:51 +00:00
Marcel van Lohuizen
8bc9c57b18 testing: unflake TestBRun
by only testing the lower bound of memalloc

Fixes #15063

Change-Id: Iab2fdd75e9ce98c641bfbce57f142fa47176772d
Reviewed-on: https://go-review.googlesource.com/21507
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
2016-04-04 17:37:58 +00:00
Alexandru Moșoi
060501dc0e cmd/compile: constant fold modulo
Fixes #15079

Change-Id: Ib4dd9eab322da39234008e040100e75cb58761b3
Reviewed-on: https://go-review.googlesource.com/21501
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-04 16:58:17 +00:00
Alexandru Moșoi
68325b56e7 cmd/compile: fold IsInBounds of modulo.
In b we only need the division by 0 check.

func b(i uint, v []byte) byte {
    return v[i%uint(len(v))]
}

Updates #15079.

Change-Id: Ic7491e677dd57cd6ba577efbce576dbb6e023cbd
Reviewed-on: https://go-review.googlesource.com/21502
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Ahmed Waheed <oneofone@gmail.com>
2016-04-04 16:06:34 +00:00
Austin Clements
61f56e925e runtime: fix pagesInUse accounting
When we grow the heap, we create a temporary "in use" span for the
memory acquired from the OS and then free that span to link it into
the heap. Hence, we (1) increase pagesInUse when we make the temporary
span so that (2) freeing the span will correctly decrease it.

However, currently step (1) increases pagesInUse by the number of
pages requested from the heap, while step (2) decreases it by the
number of pages requested from the OS (the size of the temporary
span). These aren't necessarily the same, since we round up the number
of pages we request from the OS, so steps 1 and 2 don't necessarily
cancel out like they're supposed to. Over time, this can add up and
cause pagesInUse to underflow and wrap around to 2^64. The garbage
collector computes the sweep ratio from this, so if this happens, the
sweep ratio becomes effectively infinite, causing the first allocation
on each P in a sweep cycle to sweep the entire heap. This makes
sweeping effectively STW.

Fix this by increasing pagesInUse in step 1 by the number of pages
requested from the OS, so that the two steps correctly cancel out. We
add a test that checks that the running total matches the actual state
of the heap.

Fixes #15022. For 1.6.x.

Change-Id: Iefd9d6abe37d0d447cbdbdf9941662e4f18eeffc
Reviewed-on: https://go-review.googlesource.com/21280
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2016-04-04 15:33:26 +00:00
David Crawshaw
2d5688952d cmd/link: keep types together when dynamic linking
To refer to types and names by offsets, we want to keep the symbols in
the same sections. Do this by making all types .relro for now.

Once name offsets are further along, name data can move out of relro.

Change-Id: I1cbd2e914bd180cdf25c4aeb13d9c1c734febe69
Reviewed-on: https://go-review.googlesource.com/21394
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-04 15:30:40 +00:00
Caio Marcelo de Oliveira Filho
74c0fea9e8 go/types: better error when assigning to struct field in map
Identify this assignment case and instead of the more general error

    prog.go:6: cannot assign to students["sally"].age (value of type int)

produce

    prog.go:6: cannot directly assign to struct field students["sally"].age in map

that explains why the assignment is not possible. Used ExprString
instead of String of operand since the type of the field is not relevant
to the error.

Updates #13779.

Change-Id: I581251145ae6336ddd181b9ddd77f657c51b5aff
Reviewed-on: https://go-review.googlesource.com/21463
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-04 15:10:48 +00:00
Caio Marcelo de Oliveira Filho
f229e46783 cmd/compile: better error when assigning to struct field in map
Identify this assignment case and instead of the more general error

    prog.go:6: cannot assign to students["sally"].age

produce

    prog.go:6: cannot directly assign to struct field students["sally"].age in map

that explains why the assignment is not possible.

Fixes #13779.

Change-Id: I90c10b445f907834fc1735aa66e44a0f447aa74f
Reviewed-on: https://go-review.googlesource.com/21462
Reviewed-by: David Chase <drchase@google.com>
2016-04-04 14:07:47 +00:00
Alex Brainman
1f5b1b2b66 runtime: change osyield to use Windows SwitchToThread
It appears that windows osyield is just 15ms sleep on my computer
(see benchmarks below). Replace NtWaitForSingleObject in osyield
with SwitchToThread (as suggested by Dmitry).

Also add issue #14790 related benchmarks, so we can track perfomance
changes in CL 20834 and CL 20835 and beyond.

Update #14790

benchmark                             old ns/op     new ns/op     delta
BenchmarkChanToSyscallPing1ms         1953200       1953000       -0.01%
BenchmarkChanToSyscallPing15ms        31562904      31248400      -1.00%
BenchmarkSyscallToSyscallPing1ms      5247          4202          -19.92%
BenchmarkSyscallToSyscallPing15ms     5260          4374          -16.84%
BenchmarkChanToChanPing1ms            474           494           +4.22%
BenchmarkChanToChanPing15ms           468           489           +4.49%
BenchmarkOsYield1ms                   980018        75.5          -99.99%
BenchmarkOsYield15ms                  15625200      75.8          -100.00%

Change-Id: I1b4cc7caca784e2548ee3c846ca07ef152ebedce
Reviewed-on: https://go-review.googlesource.com/21294
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-04-04 10:05:05 +00:00