to avoid unintentionally clobber R9/R10.
Thanks Lucio for the suggestion.
PS: yes, this could be considered a big change (but not an API change), but
as it turns out even temporarily changes R9/R10 in user code is unsafe and
leads to very hard to diagnose problems later, better to disable using R9/R10
when the user first uses it.
See CL 6300043 and CL 6305100 for two problems caused by misusing R9/R10.
R=golang-dev, khr, rsc
CC=golang-dev
https://golang.org/cl/9840043
When cgo is used, runtime creates an additional M to handle callbacks on threads not created by Go.
This effectively disabled deadlock detection, which is a right thing, because Go program can be blocked
and only serve callbacks on external threads.
This also disables deadlock detection under race detector, because it happens to use cgo.
With this change the additional M is created lazily on first cgo call. So deadlock detector
works for programs that import "C", "net" or "net/http/pprof" but do not use them in fact.
Also fixes deadlock detector under race detector.
It should be fine to create the M later, because C code can not call into Go before first cgo call,
because C code does not know when Go initialization has completed. So a Go program need to call into C
first either to create an external thread, or notify a thread created in global ctor that Go
initialization has completed.
Fixes#4973.
Fixes#5475.
R=golang-dev, minux.ma, iant
CC=golang-dev
https://golang.org/cl/9303046
This keeps the logic about how to set the thread-local variables
m and g in code compiled and linked by the gc toolchain,
an important property for upcoming cgo changes.
It's also just a nice cleanup: one less place to update when
these details change.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/7560048
Still to do: non-linux and non-amd64.
It may work on other ELF-based amd64 systems too, but untested.
"go test -ldflags -hostobj $GOROOT/misc/cgo/test" passes.
Much may yet change, but this seems a reasonable checkpoint.
R=iant
CC=golang-dev
https://golang.org/cl/7369057
There is a #pragma dynexport crosscall2, to help SWIG,
and 6l cannot export the symbol if it doesn't get to see it.
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/7448044
There are some function pointers declared by 6c in
package runtime without initialization and then also
declared in package runtime/cgo with initialization,
so that if runtime/cgo is linked in, the function pointers
are non-nil, and otherwise they are nil. We depend on
this property for implementing non-essential cgo hooks
in package runtime.
The declarations in package runtime are 6c-compiled
and end up in .6 files. The declarations in package runtime/cgo
are gcc-compiled and end up in .o files. Since 6l links the .6
and .o files together, this all works.
However, when we switch to "external linking" mode,
6l will not see the .o files, and it would be up to the host linker
to resolve the two into a single initialized symbol.
Not all host linkers will do this (in particular OS X gcc will not).
To fix this, move the cgo declarations into 6c-compiled code,
so that they end up in .6 files, so that 6l gets them no matter what.
R=golang-dev
CC=golang-dev
https://golang.org/cl/7440045
The naming in this package is a disaster.
Make it all consistent.
Remove some 'static' from functions that will
be referred to from other files soon.
This CL is purely renames using global search and replace.
Submitting separately so that real changes will not
be drowned out by these renames in future CLs.
TBR=iant
CC=golang-dev
https://golang.org/cl/7416046
sigprocmask() is process-wide on darwin, so two concurrent
libcgo_sys_thread_start() can result in all signals permanently
blocked, which in particular blocks handling of nil derefs.
Fixes#4833.
R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/7324058
Enable cgo on OpenBSD.
The OpenBSD ld.so(1) does not currently support PT_TLS sections. Work
around this by fixing up the TCB that has been provided by librthread
and reallocating a TCB with additional space for TLS. Also provide a
wrapper for pthread_create, allowing zeroed TLS to be allocated for
threads created externally to Go.
Joint work with Shenghou Ma (minux).
Requires change 6846064.
Fixes#3205.
R=golang-dev, minux.ma, iant, rsc, iant
CC=golang-dev
https://golang.org/cl/6853059
Otherwise a poorly timed GC can collect the memory before it
is returned to the Go program.
R=golang-dev, dave, dvyukov, minux.ma
CC=golang-dev
https://golang.org/cl/6819119
Ignore signals while we are spawning a new thread. Previously, a
signal arriving just before runtime.minit setting up the signal
handler triggers a "double fault" in signal trampolining.
Fixes#3017.
R=rsc, mikioh.mikioh, minux.ma, adg
CC=golang-dev
https://golang.org/cl/5684060
Consequently, remove many package Makefiles,
and shorten the few that remain.
gomake becomes 'go tool make'.
Turn off test phases of run.bash that do not work,
flagged with $BROKEN. Future CLs will restore these,
but this seemed like a big enough CL already.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5601057
Also rename -v to -x in the build and install commands,
to match the flag in go test (which we can't change
because -v is taken). Matches sh -x anyway.
R=r, iant, ality
CC=golang-dev
https://golang.org/cl/5504045
Fixes crash when cgo consumes more than 8K
of stack and makes a callback.
Fixes#1328.
R=golang-dev, rogpeppe, rsc
CC=golang-dev, mpimenov
https://golang.org/cl/5371042
Otherwise some OS X toolchains complain about the redeclaration
of libcgo_thread_start by multiple object files. The real definition
is in util.c.
Fixes#2167.
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5364045
Add support for the go runtime on openbsd/amd64. This is based on
the existing freebsd runtime.
Threads are implemented using OpenBSD's rthreads, which are currently
disabled by default, however can be enabled via the kern.rthreads
sysctl.
For now, cgo is disabled.
R=rsc
CC=golang-dev
https://golang.org/cl/4815067
