macOS and iOS deliver SIGPIPE signals to the main thread and not
the thread that raised it by writing to a closed socket or pipe.
SIGPIPE signals can be suppressed for sockets with the SO_NOSIGPIPE
option, but there is no similar option for pipes. We have no other
choice but to never forward SIGPIPE on macOS.
This is a fixup of reverted CL 188297.
Fixes#33384
Change-Id: I09b258b078857ad3b22025bc2902d1b12d2afd92
Reviewed-on: https://go-review.googlesource.com/c/go/+/191785
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This reverts CL 188297.
Reason for revert: broke multiple of the darwin builders.
Fixes#33943.
Change-Id: Iacff98d1450edc70402dc7a220d16fcd73337c9e
Reviewed-on: https://go-review.googlesource.com/c/go/+/191784
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
macOS and iOS deliver SIGPIPE signals to the main thread and not
the thread that raised it by writing to a closed socket or pipe.
SIGPIPE signals can be suppressed for sockets with the SO_NOSIGPIPE
option, but there is no similar option for pipes. We have no other
choice but to never forward SIGPIPE on macOS.
Fixes#33384
Change-Id: Ice3de75b121f00006ee11c26d560e619536460be
Reviewed-on: https://go-review.googlesource.com/c/go/+/188297
Run-TryBot: Elias Naur <mail@eliasnaur.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
These tests take 20 seconds each to rebuild the entire world
in their respective modes. That's too much for short mode,
including all.bash on developer machines.
Keep doing it on builders and if someone runs 'go test' by hand
in that directory.
For #26473.
Change-Id: I3dc6955bc3aa7a20fd170efcde72a7d19b37bdbf
Reviewed-on: https://go-review.googlesource.com/c/go/+/177417
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Like GOOS=android which implies the "linux" build tag, GOOS=illumos
implies the "solaris" build tag. This lets the existing ecosystem of
packages still work on illumos, but still permits packages to start
differentiating between solaris and illumos.
Fixes#20603
Change-Id: I8f4eabf1a66060538dca15d7658c1fbc6c826622
Reviewed-on: https://go-review.googlesource.com/c/go/+/174457
Run-TryBot: Benny Siegert <bsiegert@gmail.com>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
On darwin/amd64 the runtime method sigctxt.fixsigcode changes SIGSEGV
signals so that they are never marked SI_USER. CL 169120 changed the
signal handler to call fixsigcode even when the signal is delivered to
a non-Go thread. This breaks TestSignalForwardingExternal, so skip it.
Change-Id: I6740fb5a8f4f854ca69793537a983a696da3b495
Reviewed-on: https://go-review.googlesource.com/c/go/+/170446
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
I hope that this will fix the tests on iOS, but 'gomote create' isn't
giving me an instance I can test with. (Please patch and test before
approving.)
Updates #15919
Updates #30228
Change-Id: I1b7cd30d5b127a1ad3243b329fa005d229f69a24
Reviewed-on: https://go-review.googlesource.com/c/163726
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Elias Naur <mail@eliasnaur.com>
Updates #30228
Change-Id: I830e3c83416b2e5744f30d1a903a74c50462716b
Reviewed-on: https://go-review.googlesource.com/c/163210
Run-TryBot: Bryan C. Mills <bcmills@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>
This test is slightly flaky on the s390x builder and I suspect that
the 100ms timeout is a little too optimistic when the VM is starved.
Increase the timeout to 5s to match the other part of the test.
Fixes#26231.
Change-Id: Ia6572035fb3efb98749f2c37527d250a4c779477
Reviewed-on: https://go-review.googlesource.com/122315
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
We were using absolute paths in the #line directives in the export
header file. This makes the header file change if you move GOPATH.
The absolute paths aren't helpful for the final user, which is some C
program elsewhere.
Fixes#24945
Change-Id: I2da32c9b477df578bd5087435a03fe97abe462e3
Reviewed-on: https://go-review.googlesource.com/108315
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Fixes#14327
Much of the code is based on the linux/amd64 code that implements these
build modes, and code is shared where possible.
Change-Id: Ia510f2023768c0edbc863aebc585929ec593b332
Reviewed-on: https://go-review.googlesource.com/93875
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This CL makes "go install" behave the way many users expect:
install only the things named on the command line.
Future builds still run as fast, thanks to the new build cache (CL 75473).
To install dependencies as well (the old behavior), use "go install -i".
Actual definitions aside, what most users know and expect of "go install"
is that (1) it installs what you asked, and (2) it's fast, unlike "go build".
It was fast because it installed dependencies, but installing dependencies
confused users repeatedly (see for example #5065, #6424, #10998, #12329,
"go build" and "go test" so that they could be "fast" too, but that only
created new opportunities for confusion. We also had to add -installsuffix
and then -pkgdir, to allow "fast" even when dependencies could not be
installed in the usual place.
The recent introduction of precise content-based staleness logic means that
the go command detects the need for rebuilding packages more often than it
used to, with the consequence that "go install" rebuilds and reinstalls
dependencies more than it used to. This will create more new opportunities
for confusion and will certainly lead to more issues filed like the ones
listed above.
CL 75743 introduced a build cache, separate from the install locations.
That cache makes all operations equally incremental and fast, whether or
not the operation is "install" or "build", and whether or not "-i" is used.
Installing dependencies is no longer necessary for speed, it has confused
users in the past, and the more accurate rebuilds mean that it will confuse
users even more often in the future. This CL aims to end all that confusion
by not installing dependencies by default.
By analogy with "go build -i" and "go test -i", which still install
dependencies, this CL introduces "go install -i", which installs
dependencies in addition to the things named on the command line.
Fixes#5065.
Fixes#6424.
Fixes#10998.
Fixes#12329.
Fixes#18981.
Fixes#22469.
Another step toward #4719.
Change-Id: I3d7bc145c3a680e2f26416e182fa0dcf1e2a15e5
Reviewed-on: https://go-review.googlesource.com/75850
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Starting in gcc 6, -pie is passed to the linker by default
on some platforms, including ppc64le. If the objects
being linked are not built for -pie then in some cases the
executable could be in error. To avoid that problem, -no-pie
should be used with gcc to override the default -pie option
and generate a correct executable that can be run without error.
Fixes#22126
Change-Id: I4a052bba8b9b3bd6706f5d27ca9a7cebcb504c95
Reviewed-on: https://go-review.googlesource.com/70072
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Everything got a bit tangled together in b.action1.
Try to tease things apart again.
In general this is a refactoring of the existing code, with limited
changes to the effect of the code.
The main additional change is to complete a.Deps for link actions.
That list now directly contains all the inputs the linker will attempt
to read, eliminating the need for a transitive traversal of the entire
action graph to find those. The comepleteness of a.Deps will be
important when we eventually use it to decide whether an cached
action output can be reused.
all.bash passes, but it's possible I've broken some subtety of
buildmode=shared again. Certainly that code took the longest
to get working.
Change-Id: I34e849eda446dca45a9cfce02b07bec6edb6d0d4
Reviewed-on: https://go-review.googlesource.com/69831
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
In PPC64 ELF files, the st_other field indicates the number of
prologue instructions between the global and local entry points.
We add the instructions in the compiler and assembler if -shared is used.
We were assuming that the instructions were present when building a
c-archive or PIE or doing dynamic linking, on the assumption that those
are the cases where the go tool would be building with -shared.
That assumption fails when using some other tool, such as Bazel,
that does not necessarily use -shared in exactly the same way.
This CL records in the object file whether a symbol was compiled
with -shared (this will be the same for all symbols in a given compilation)
and uses that information when setting the st_other field.
Fixes#20290.
Change-Id: Ib2b77e16aef38824871102e3c244fcf04a86c6ea
Reviewed-on: https://go-review.googlesource.com/43051
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
write(2) is defined in unistd.h.
For the iOS builder.
Change-Id: I411ffe81988d8fbafffde89e4732a20af1a63325
Reviewed-on: https://go-review.googlesource.com/37962
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This ensures that SIGPROF is handled correctly when using
runtime/pprof in a c-archive or c-shared library.
Separate profiler handling into pre-process changes and per-thread
changes. Simplify the Windows code slightly accordingly.
Fixes#18220.
Change-Id: I5060f7084c91ef0bbe797848978bdc527c312777
Reviewed-on: https://go-review.googlesource.com/34018
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Austin Clements <austin@google.com>
Before this CL, Go programs in c-archive or c-shared buildmodes
would not handle SIGPIPE. That leads to surprising behaviour where
writes on a closed pipe or socket would raise SIGPIPE and terminate
the program. This CL changes the Go runtime to handle
SIGPIPE regardless of buildmode. In addition, SIGPIPE from non-Go
code is forwarded.
This is a refinement of CL 32796 that fixes the case where a non-default
handler for SIGPIPE is installed by the host C program.
Fixes#17393
Change-Id: Ia41186e52c1ac209d0a594bae9904166ae7df7de
Reviewed-on: https://go-review.googlesource.com/35960
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This reverts commit d24b57a6a1.
Reason for revert: Further complications arised (issue 18100). We'll try again in Go 1.9.
Change-Id: I5ca93d2643a4be877dd9c2d8df3359718440f02f
Reviewed-on: https://go-review.googlesource.com/33770
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Minux Ma <minux@golang.org>
Before this CL, Go programs in c-archive or c-shared buildmodes
would not handle SIGPIPE. That leads to surprising behaviour where
writes on a closed pipe or socket would raise SIGPIPE and terminate
the program. This CL changes the Go runtime to handle
SIGPIPE regardless of buildmode. In addition, SIGPIPE from non-Go
code is forwarded.
Fixes#17393
Updates #16760
Change-Id: I155e82020a03a5cdc627a147c27da395662c3fe8
Reviewed-on: https://go-review.googlesource.com/32796
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
CL 33239 changed the polling loops from using sched_yield to a sleep
for 1/1000 of a second. The loop counters were not updated, so failing
tests now take 100 seconds to complete. Lower the loop counts to 5
seconds instead.
Change-Id: I7c9a343dacc8188603ecf7e58bd00b535cfc87f5
Reviewed-on: https://go-review.googlesource.com/33280
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Apparently when GOMAXPROCS == 1 a simple sched_yield in a tight loop is
not necessarily sufficient to permit a signal handler to run. Instead,
sleep for 1/1000 of a second.
Fixes#16649.
Change-Id: I83910144228556e742b7a92a441732ef61aa49d9
Reviewed-on: https://go-review.googlesource.com/33239
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
sigfwd calls an arbitrary C signal handler function. The System V ABI
for x86_64 (and the most recent revision of the ABI for i386) requires
the stack to be 16-byte aligned.
Fixes: #17641
Change-Id: I77f53d4a8c29c1b0fe8cfbcc8d5381c4e6f75a6b
Reviewed-on: https://go-review.googlesource.com/32107
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Fixes#17439
Change-Id: I7caa28519f38692f9ca306f0789cbb975fa1d7c4
Reviewed-on: https://go-review.googlesource.com/31112
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Alex Brainman <alex.brainman@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This permits people to use -buildmode=c-archive to produce an archive
file that can be included in a PIE or shared library.
Change-Id: Ie340ee2f08bcff4f6fd1415f7d96d51ee3a7c9a1
Reviewed-on: https://go-review.googlesource.com/24180
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Buildmode c-archive now supports position independent code for
darwin/arm (in addition to darwin/arm64). Make PIC (-shared) the
default for both platforms in the default buildmode.
Without this change, gomobile will go install the standard library
into its separate package directory without PIC support.
Also add -shared to darwin/arm64 in buildmode c-archive, for
symmetry (darwin/arm64 always generates position independent code).
Fixes#15519
Change-Id: If27d2cbea8f40982e14df25da2703cbba572b5c6
Reviewed-on: https://go-review.googlesource.com/22920
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The old code assumed that the thread ID set by pthread_create would be
available in the newly created thread. While that is clearly true
eventually, it is not necessarily true immediately. Rather than try to
pass down the thread ID, just call pthread_self in the created thread.
Fixes#15576 (I hope).
Change-Id: Ic07086b00e4fd5676c04719a299c583320da64a1
Reviewed-on: https://go-review.googlesource.com/22880
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Now that darwin/arm supports position independent code, allow the
binaries generated by the c-archive tests be position independent
(PIE) as well.
Change-Id: If0517f06e92349ada29a4e3e0a951f08b0fcc710
Reviewed-on: https://go-review.googlesource.com/22841
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
After CL 22461, c-archive build on darwin/arm is by default compiled
with -shared and installed in pkg/darwin_arm_shared.
Fix build (2nd time...)
Change-Id: Ia2bb09bb6e1ebc9bc74f7570dd80c81d05eaf744
Reviewed-on: https://go-review.googlesource.com/22534
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
After CL 22461, c-archive build on darwin/arm is by default compiled
with -shared, so update the install path.
Fix build.
Change-Id: Ie93dbd226ed416b834da0234210f4b98bc0e3606
Reviewed-on: https://go-review.googlesource.com/22507
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: David Crawshaw <crawshaw@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This reverts commit ab4c9298b8.
Sysmon critically depends on system timer resolution for retaking
of Ps blocked in system calls. See #14790 for an example
of a program where execution time goes from 2ms to 30ms if
timeBeginPeriod(1) is not used.
We can remove timeBeginPeriod(1) when we support UMS (#7876).
Update #14790
Change-Id: I362b56154359b2c52d47f9f2468fe012b481cf6d
Reviewed-on: https://go-review.googlesource.com/20834
Reviewed-by: Austin Clements <austin@google.com>
Run-TryBot: Dmitry Vyukov <dvyukov@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Add supporting code for runtime initialization, including both
32- and 64-bit x86 architectures.
Add .ctors section on Windows to PE .o files, and INITENTRY to .ctors
section to plug in to the GCC C/C++ startup initialization mechanism.
This allows the Go runtime to initialize itself. Add .text section
symbol for .ctor relocations. Note: This is unlikely to be useful for
MSVC-based toolchains.
Fixes#13494
Change-Id: I4286a96f70e5f5228acae88eef46e2bed95813f3
Reviewed-on: https://go-review.googlesource.com/18057
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Try to avoid a race condition in the test. Passed 500 times on my
laptop.
Fixes#14956.
Change-Id: I5de2e1e3623832f0ab4f180149f7c57ce7cd23c0
Reviewed-on: https://go-review.googlesource.com/21171
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This is in support of https://golang.org/cl/18057 which adds
support for c-archive to the Windows platform.
The signal handling tests do not compile on Windows. This splits
them out into a separate main_unix.c file, and conditionally
includes them for non-Windows platforms.
Change-Id: Ic79ce83da7656d6703505e514554748a482b81a1
Reviewed-on: https://go-review.googlesource.com/21086
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
I failed to rebase (and re-test) CL 21102 before submit, which meant
that two extra tests sneaked into testcarchive that still referenced
runtime.GOOS and runtime.GOARCH.
Convert the new tests.
While we're here, make sure pending tasks are flushed before running
the host tests. If not, the "##### misc/cgo/testcarchive" banner
and "PASS" won't show up in the all.bash output.
Change-Id: I41fc4ec9515f9a193fa052f7c31fac452153c897
Reviewed-on: https://go-review.googlesource.com/21106
Run-TryBot: Elias Naur <elias.naur@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The c-archive test were recently converted from shell script to Go.
Unfortunately, it also lost the ability to target iOS and Android
that lack C compilers and require exec wrappers.
Compile the c-archive test for the host and run it with the target
GOOS/GOARCH environment. Change the test to rely on go env GOOS
and go env GOARCH instead of runtime.GOOS and runtime.GOARCH.
Fixes#8345
Change-Id: I290ace2f7e96b87c55d99492feb7d660140dcb32
Reviewed-on: https://go-review.googlesource.com/21102
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The current runtime attempts to forward signals generated by non-Go
code to the original signal handler. If it can't call the original
handler directly, it currently attempts to re-raise the signal after
resetting the handler. In this case, the original context is lost.
This fix prevents that problem by simply returning from the go signal
handler after resetting the original handler. It only does this when
the original handler is the system default handler, which in all cases
is known to not recover. The signal is not reset, so it is retriggered
and the original handler takes over with the proper context.
Fixes#14899
Change-Id: Ib1c19dfa4b50d9732d7a453de3784c8141e1cbb3
Reviewed-on: https://go-review.googlesource.com/21006
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This is to support https://golang.org/cl/18057, which is going to add
Windows support to this directory. Better to write the test in Go then
to have both test.bash and test.bat.
Update #13494.
Change-Id: I4af7004416309e885049ee60b9470926282f210d
Reviewed-on: https://go-review.googlesource.com/20892
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
People who want to use -buildmode=c-archive in unusual cross-compilation
setups will need something like this. It could also be done via (yet
another) environment variable but I use -extar by analogy with the
existing -extld.
Change-Id: I354cfabc4c470603affd13cd946997b3a24c0e6c
Reviewed-on: https://go-review.googlesource.com/18913
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The previous behaviour of installing the signal handlers in a separate
thread meant that Go initialization raced with non-Go initialization if
the non-Go initialization also wanted to install signal handlers. Make
installing signal handlers synchronous so that the process-wide behavior
is predictable.
Update #9896.
Change-Id: Ice24299877ec46f8518b072a381932d273096a32
Reviewed-on: https://go-review.googlesource.com/18150
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
After a failure on the build dashboard I tested testcarchive test 2 and
found that it failed an average of 1 in 475 runs on my laptop. With
this change it ran over 50,000 times without failing. I bumped up the
other iteration limits to correspond.
Change-Id: I0155c68161a2c2a09ae25c91e9269f1e8702628d
Reviewed-on: https://go-review.googlesource.com/18309
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When calling a Go function on a C thread, if the C thread already has an
alternate signal stack, use that signal stack instead of installing a
new one.
Update #9896.
Change-Id: I62aa3a6a4a1dc4040fca050757299c8e6736987c
Reviewed-on: https://go-review.googlesource.com/18108
Reviewed-by: Russ Cox <rsc@golang.org>
