Previous CLs (CL/54970, CL55231, and CL/55237) re-implemented tar.Writer
entirely using specialized methods (writeUSTARHeader, writePAXHeader,
and writeGNUHeader) allowing tar.Writer to entirely side-step the broken
and buggy logic in writeHeader.
Since writeHeader and writePAXHeaderLegacy is now dead-code,
we can delete them.
One minor change is that we call Writer.Flush at the start of WriteHeader.
This used to be performed by writeHeader, but doing so in WriteHeader
ensures each of the specialized methods can benefit from its effect.
Fixes#17665Fixes#12594
Change-Id: Iff2ef8e7310d40ac5484d2f8852fc5df25201426
Reviewed-on: https://go-review.googlesource.com/55550
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Rather than going through writeHeader, which attempts to handle all formats,
implement writeGNUHeader, which only has an understanding of the GNU format.
Currently, the implementation is nearly identical to writeUSTARHeader, except:
* formatNumeric is used instead of formatOctal
* the GNU magic value is used
This is kept as a separate method since it makes more logical sense
when we add support for sparse files, long filenames, and atime/ctime fields,
which do not affect USTAR.
Updates #12594
Change-Id: I76efc0b39dc649efc22646dfc9867a7c165f34a8
Reviewed-on: https://go-review.googlesource.com/55237
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
This avoids the never triggered capacity checks in newarray.
Change-Id: Ib72b204adcb9e3fd3ab963defe0cd40e22d5d492
Reviewed-on: https://go-review.googlesource.com/54731
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Remove goto and use helper functions in ParseUint to create errors.
Change-Id: I1c4677ae1b9980db79065a9f8ca1f2c470249505
Reviewed-on: https://go-review.googlesource.com/55135
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Instead of printing Atoi as function name for test failures
print the actual function name and arguments tested.
Add a base field to the parseUint64BaseTests for consistency with
the parseInt64BaseTests tests.
Change-Id: Ib9891bdb87b62672b4216625212acfe6474c70fc
Reviewed-on: https://go-review.googlesource.com/55136
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
This makes sure that its argument is marked live on entry.
We need its arg to be live so defers of KeepAlive get
scanned correctly by the GC.
Fixes#21402
Change-Id: I906813e433d0e9726ca46483723303338da5b4d7
Reviewed-on: https://go-review.googlesource.com/55150
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Currently go fmt formats all files sequentially.
That's a shame. Parallelize it over files.
Reduces time of go fmt ./... in std lib
from ~6.1s to ~0.9s.
Reduces time of go fmt github.com/google/syzkaller/...
from ~5.2s to ~1.8s.
Change-Id: I3d27fc25326106b2a4781e13506a25c12d5bcdc5
Reviewed-on: https://go-review.googlesource.com/45491
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Also, unexport Machoadddynlib
n=`go test -c crypto/x509 && otool -l x509.test | grep libSystem | wc -l`
Before this CL, n = 3.
After this CL, n = 1.
on my environment.
Change-Id: Ic7b8157435cc85086404860dc6c84eb0aecc5d19
Reviewed-on: https://go-review.googlesource.com/44771
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Avelino <t@avelino.xxx>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Fixes#21435
Change-Id: I5f8d93a45b84a871ceea881ecb1a38a37e96006c
Reviewed-on: https://go-review.googlesource.com/55263
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Change some configurations to enable the feature. Also add the test.
This CL doesn't include internal linking support which is tentatively
disabled due to #18968. We could do that another day.
Fixes#21220
Change-Id: I601d2d78446d36332acc70be0d5b9461ac635208
Reviewed-on: https://go-review.googlesource.com/54790
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The parser mistakenly assumed it could always fold \r\n into \n, which
is not true since a \r\n inside a quoted fields has no special meaning
and should be kept as is.
Fix this by not folding \r\n to \n inside quotes fields.
Fixes#21201
Change-Id: Ifebc302e49cf63e0a027ee90f088dbc050a2b7a6
Reviewed-on: https://go-review.googlesource.com/52810
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
* Remove an unnecessary type conversion
* Make golint happier about consistent receiver names
* Make golint happier about a foo_bar var name
Change-Id: I5223808109f6f8b69ed4be76de82faf2478c6a2e
Reviewed-on: https://go-review.googlesource.com/54530
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Tom Bergan <tombergan@google.com>
The old comment for the example
type PtrMutex *Mutex
talked about the method set of the base type of PtrMutex.
It's more direct and clearer to talk about the underlying
type of PtrMutex for this specific example.
Also removed link inside pre-formatted region of text.
Fixes#20900.
Change-Id: Ie37340e53670e34ebe13e780ba8ccb1bba67795c
Reviewed-on: https://go-review.googlesource.com/55070
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This change replaces the current runtime capabilities check for ppc64x with the
new internal/cpu package. It also adds support for the new POWER9 ISA and
capabilities.
Updates #15403
Change-Id: I5b64a79e782f8da3603e5529600434f602986292
Reviewed-on: https://go-review.googlesource.com/53830
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Since test files don't exceed 10KiB, print the full context of the diff,
including bytes that are equal.
Also, fix the labels for got and want; they were backwards before.
Change-Id: Ibac022e5f988d26812c3f75b643cae8b95603fc9
Reviewed-on: https://go-review.googlesource.com/55151
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Rather than going through writeHeader, which attempts to handle all formats,
implement writePAXHeader, which only has an understanding of the PAX format.
In PAX, the USTAR header is filled out in a best-effort manner.
Thus, we change logic of formatString and formatOctal to try their best to
output something (possibly truncated) in the event of an error.
The new implementation of PAX headers causes several tests to fail.
An investigation into the new output reveals that the new behavior is correct,
while the tests had actually locked in incorrect behavior before.
A dump of the differences is listed below (-before, +after):
<< writer-big.tar >>
This change is due to fact that we changed the Header.Devminor to force the
tar.Writer to choose the GNU format over the PAX one.
The ability to control the output is an open issue (see #18710).
- 00000150 00 30 30 30 30 30 30 30 00 00 00 00 00 00 00 00 |.0000000........|
+ 00000150 00 ff ff ff ff ff ff ff ff 00 00 00 00 00 00 00 |................|
<< writer-big-long.tar>>
The previous logic generated the GNU magic values for a PAX file.
The new logic correctly uses the USTAR magic values.
- 00000100 00 75 73 74 61 72 20 20 00 00 00 00 00 00 00 00 |.ustar ........|
- 00000500 00 75 73 74 61 72 20 20 00 67 75 69 6c 6c 61 75 |.ustar .guillau|
+ 00000100 00 75 73 74 61 72 00 30 30 00 00 00 00 00 00 00 |.ustar.00.......|
+ 00000500 00 75 73 74 61 72 00 30 30 67 75 69 6c 6c 61 75 |.ustar.00guillau|
The previous logic tried to use the specified timestmap in the PAX headers file,
but this is problematic as this timestamp can overflow, defeating the point
of using PAX, which is intended to extend tar.
The new logic uses the zero timestamp similar to what GNU and BSD tar do.
- 00000080 30 30 30 30 32 33 32 00 31 32 33 33 32 37 37 30 |0000232.12332770|
+ 00000080 30 30 30 30 32 35 36 00 30 30 30 30 30 30 30 30 |0000256.00000000|
The previous logic populated the devminor and devmajor fields.
The new logic leaves them zeroed just like what GNU and BSD tar do.
- 00000140 00 00 00 00 00 00 00 00 00 30 30 30 30 30 30 30 |.........0000000|
- 00000150 00 30 30 30 30 30 30 30 00 00 00 00 00 00 00 00 |.0000000........|
+ 00000140 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
+ 00000150 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
The previous logic uses PAX headers, but fails to add a record for the size.
The new logic does properly add a record for the size.
- 00000290 31 36 67 69 67 2e 74 78 74 0a 00 00 00 00 00 00 |16gig.txt.......|
- 000002a0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
+ 00000290 31 36 67 69 67 2e 74 78 74 0a 32 30 20 73 69 7a |16gig.txt.20 siz|
+ 000002a0 65 3d 31 37 31 37 39 38 36 39 31 38 34 0a 00 00 |e=17179869184...|
The previous logic encoded the size as a base-256 field,
which is only valid in GNU, but the previous PAX headers implies this should
be a PAX file. This result in a strange hybrid that is neither GNU nor PAX.
The new logic uses PAX headers to store the size.
- 00000470 37 35 30 00 30 30 30 31 37 35 30 00 80 00 00 00 |750.0001750.....|
- 00000480 00 00 00 04 00 00 00 00 31 32 33 33 32 37 37 30 |........12332770|
+ 00000470 37 35 30 00 30 30 30 31 37 35 30 00 30 30 30 30 |750.0001750.0000|
+ 00000480 30 30 30 30 30 30 30 00 31 32 33 33 32 37 37 30 |0000000.12332770|
<< ustar.issue12594.tar >>
The previous logic used the specified timestamp for the PAX headers file.
The new logic just uses the zero timestmap.
- 00000080 30 30 30 30 32 33 31 00 31 32 31 30 34 34 30 32 |0000231.12104402|
+ 00000080 30 30 30 30 32 33 31 00 30 30 30 30 30 30 30 30 |0000231.00000000|
The previous logic populated the devminor and devmajor fields.
The new logic leaves them zeroed just like what GNU and BSD tar do.
- 00000140 00 00 00 00 00 00 00 00 00 30 30 30 30 30 30 30 |.........0000000|
- 00000150 00 30 30 30 30 30 30 30 00 00 00 00 00 00 00 00 |.0000000........|
+ 00000140 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
+ 00000150 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
Change-Id: I33419eb1124951968e9d5a10d50027e03133c811
Reviewed-on: https://go-review.googlesource.com/55231
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Just like https://golang.org/cl/34783
Given cgo.go:
1 package main
2
3 /*
4 long double x = 0;
5 */
6 import "C"
7
8 func main() {
9 _ = C.x
10 _ = C.x
11 }
Before:
./cgo.go:10:6: unexpected: 16-byte float type - long double
After:
./cgo.go:9:6: unexpected: 16-byte float type - long double
The above test case is not portable. So it is tested on only amd64.
Change-Id: If0b84cf73d381a22e2ada71c8e9a6e6ec77ffd2e
Reviewed-on: https://go-review.googlesource.com/54950
Reviewed-by: Ian Lance Taylor <iant@golang.org>
We might want to replace some linker's feature by debug/macho in future.
This CL gathers information of required constants.
Change-Id: Iea14abdb32709a4f5404a17874f9c925d29ba999
Reviewed-on: https://go-review.googlesource.com/55252
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Fixes#21414
Change-Id: Idff6e269ae32b33253067c9f32cac25256eb7f1c
Reviewed-on: https://go-review.googlesource.com/55251
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The tests for error scenarios were done by manually checking
error strings. Improved them by checking the actual error type
instead of just the string.
Printing the actual error in case of failure instead of a
generic string.
Also added a new scenario with both an invalid byte and an
invalid length string to verify that the length is checked first
before doing any computation.
Change-Id: Ic2a19a6d6058912632d597590186ee2d8348cb45
Reviewed-on: https://go-review.googlesource.com/55256
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Errors returned by Reader contain the line where the Reader originally
encountered the error. This can be suboptimal since that line does not
always correspond with the line the current record/field started at.
This can easily happen with LazyQuotes as seen in #19019, but also
happens for example when a quoted fields has no closing quote and
the parser hits EOF before it finds another quote.
When this happens finding the erroneous field can be somewhat
complicated and time consuming, and in most cases it would be better to
report the line where the record started.
This change updates Reader to keep track of the line on which a record
begins and uses it for errors instead of the current line, making it
easier to find errors.
Although a user-visible change, this should have no impact on existing
code, since most users don't explicitly work with the line in the error
and probably already expect the new behaviour.
Updates #19019
Change-Id: Ic9bc70fad2651c69435d614d537e7a9266819b05
Reviewed-on: https://go-review.googlesource.com/52830
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
No semantic change, just clarifying a bit by choosing better words
in a couple of places.
Change-Id: I4496062ee7909baf83d4d22d25e13ef93b358b4b
Reviewed-on: https://go-review.googlesource.com/55255
Reviewed-by: Ian Lance Taylor <iant@golang.org>
All the BSDs and Solaris support the utimensat syscall, but Darwin
doesn't. Account for that by adding the //sys lines not to
syscall_bsd.go but the individual OS's syscall_*.go files and implement
utimensat on Darwin as just returning ENOSYS, such that UtimesNano will
fall back to use utimes as it currently does unconditionally.
This also adds the previously missing utimensat syscall number for
FreeBSD and Dragonfly.
Fixes#16480
Change-Id: I367454c6168eb1f7150b988fa16cf02abff42f34
Reviewed-on: https://go-review.googlesource.com/55130
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
lookupName is only called in one location, and one of the return
values is unused, so let's remove it.
Change-Id: I35e22c7ec611e8eb349deb4f0561e212f7d9de0b
Reviewed-on: https://go-review.googlesource.com/55232
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
This reverts commit f612cd704a.
Reason for revert: We thought the original change had broken the
linux/amd64 and linux/386 builders, but it turned out to be a problem
with the build infrastructure, not the change.
Change-Id: Ic3318a63464fcba8d845ac04494115a7ba620364
Reviewed-on: https://go-review.googlesource.com/55050
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
This generates better code.
Masking B in the return statement should be unnecessary,
but the compiler is understandably not yet clever enough to see that.
Someday, it'd also be nice for the compiler to generate
a CMOV for the saturation if statement.
Change-Id: Ie1c157b21f5212610da1f3c7823a93816b3b61b9
Reviewed-on: https://go-review.googlesource.com/54656
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Combine conditions into a single if statement.
This is more readable.
It should generate identical machine code, but it doesn't.
The new code is shorter.
Change-Id: I9bf52f8f288b0df97a2b9b4e4183f6ca74175e8a
Reviewed-on: https://go-review.googlesource.com/54651
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
This reduces the wall time to run these benchmarks by about 30%.
Change-Id: I494a93c93e5acb1514510d85f65796f62e1629a5
Reviewed-on: https://go-review.googlesource.com/54650
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Currently we only support finding symbols in the VDSO using the old
DT_HASH. These days everything uses DT_GNU_HASH instead. To keep up
with the times and future-proof against DT_HASH disappearing from the
VDSO in the future, this commit adds support for DT_GNU_HASH and
prefers it over DT_HASH.
Tested by making sure it found a DT_GNU_HASH section and all of the
expected symbols in it, and then disabling the DT_GNU_HASH path and
making sure the old DT_HASH path still found all of the symbols.
Fixes#19649.
Change-Id: I508c8b35a019330d2c32f04f3833b69cb2686f13
Reviewed-on: https://go-review.googlesource.com/45511
Run-TryBot: Austin Clements <austin@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
The ZIP format uses uint16 to contain the length of the file name and
the length of the Extra section. This change verifies that the length
of these fields fit in an uint16 prior to writing the ZIP file. If not,
an error is returned.
Fixes#17402
Change-Id: Ief9a864d2fe16b89ddb9917838283b801a2c58a4
Reviewed-on: https://go-review.googlesource.com/50250
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
If needed cast the test table values to a higher bit size
integer type instead of casting the result values of the
tested function to a lower bit size integer type.
Change-Id: Iaa79742b2b1d90c7c7eac324f54032ebea0b1b41
Reviewed-on: https://go-review.googlesource.com/55137
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
If the value corresponding to the input string cannot be
represented by an unsigned integer of the given size,
err.Err = ErrRange and the returned value is the maximum
magnitude unsigned integer of the appropriate bitSize.
This is consistent with ParseInt's behavior and the documentation.
Expand tests to test 32 bit test value tables with bitsize 32 set.
These tests fail without the fix in this CL.
Fixes#21278
Change-Id: I8aab39279ec3e31905fcbf582a916cbf6d9b95da
Reviewed-on: https://go-review.googlesource.com/55134
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Use a simple []byte instead of bytes.Buffer to create a string.
Use bytes.IndexByte instead of our own for loop.
Change-Id: Ic4a1161d79017fd3af086a05c53d5f20a5f09326
Reviewed-on: https://go-review.googlesource.com/54752
Reviewed-by: Avelino <t@avelino.xxx>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
By replacing fmt.Sprintf with a simple string concat, we see
pretty good improvements across the board on time and memory.
name old time/op new time/op delta
FormatPAXRecord 683ns ± 2% 210ns ± 5% -69.22% (p=0.000 n=10+10)
name old alloc/op new alloc/op delta
FormatPAXRecord 112B ± 0% 32B ± 0% -71.43% (p=0.000 n=10+10)
name old allocs/op new allocs/op delta
FormatPAXRecord 8.00 ± 0% 2.00 ± 0% -75.00% (p=0.000 n=10+10)
Ran with - -cpu=1 -count=10 on an AMD64 i5-5200U CPU @ 2.20GHz
Using the following benchmark:
func BenchmarkFormatPAXRecord(b *testing.B) {
for n := 0; n < b.N; n++ {
formatPAXRecord("foo", "bar")
}
}
Change-Id: I828ddbafad2e5d937f0cf5f777b512638344acfc
Reviewed-on: https://go-review.googlesource.com/55210
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Rather than going through the complicated logic of writeHeader,
implement a writeUSTARHeader that only knows about the USTAR format.
This makes the logic much easier to reason about since you only
need to be concerned about USTAR and not all the subtle
differences between USTAR, PAX, and GNU.
We seperate out the logic in writeUSTARHeader into templateV7Plus
and writeRawHeader since the planned implementations of
writePAXHeader and writeGNUHeader will use them.
Change-Id: Ie75a54ac998420ece82686159ae6fa39f8b128e9
Reviewed-on: https://go-review.googlesource.com/54970
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: I27ff99aa7abb070f6ae79c8f964aa9bd6a83b89d
Reviewed-on: https://go-review.googlesource.com/53730
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The dieFromSignal runtime function attempts to forward crashing
signals to a signal handler registered before the runtime was
initialized, if any. However, on Darwin, a special signal handler
trampoline is invoked, even for non-Go signal handlers.
Clear the crashing signal's handlingSig entry to ensure sigtramp
forwards the signal.
Fixes the darwin/386 builder.
Updates #20392
Updates #19389
Change-Id: I441a3d30c672cdb21ed6d8f1e1322d7c0e5b9669
Reviewed-on: https://go-review.googlesource.com/55032
Run-TryBot: Elias Naur <elias.naur@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
According to http://pubs.opengroup.org/onlinepubs/009695399/functions/pthread_key_create.html,
pthread_key_create return an error number which is greater than or equal
to 0. I don't know the scenario that pthread_setspecific would fail, but
also don't know the future. Add some error handlings just in case.
Change-Id: I0774b79ef658d67e300f4a9aab1f2e3879acc7ee
Reviewed-on: https://go-review.googlesource.com/54811
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
