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5 Commits

Author SHA1 Message Date
Shenghou Ma
38631846bf syscall: add explicit build tags
Auto-generated using the following bash script:
for i in z*_*_*.go; do
        goosgoarch=`basename ${i/${i/_*/}_/} .go`
        goos=${goosgoarch/_*/}
        goarch=${goosgoarch/*_/}
        echo $i $goos $goarch
        [ "$goos" = "windows" ] && continue
        sed -i -e "/^package /i\/\/ +build $goarch,$goos\n" "$i"
done

Change-Id: I756fee551d1698080e4591fed8f058ae0450aaa5
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/10113
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-05-15 01:04:27 +00:00
Brad Fitzpatrick
6bf00075ad syscall: don't allocate when boxing common Errno values into errors
Fixes #8859

Change-Id: If8098e6edad1f83dc35fa84f4431689e8ee97678
Reviewed-on: https://go-review.googlesource.com/6701
Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-03-27 06:47:27 +00:00
Ian Lance Taylor
28074d5baa syscall: change Dup,Dup2,Dup3 to use Syscall, not RawSyscall
This avoids hanging when a Go program uses a FUSE filesystem and the
dup system call has to close a file descriptor.  When dup uses
RawSyscall then the goroutine calling dup will occupy a scheduler slot
(a p structure) during the call, and may block waiting for some other
goroutine to respond to the close call on the FUSE filesystem.
Changing to Syscall avoids the problem.  This makes Dup a tiny bit
slower but is quite unlikely to make a difference for any real
programs.

Fixes #10202.

Change-Id: If6490a8f9b3c9cfed6acbfb4bfd1eaeac62ced17
Reviewed-on: https://go-review.googlesource.com/8095
Reviewed-by: Rob Pike <r@golang.org>
2015-03-26 17:29:08 +00:00
Russ Cox
cf622d758c syscall: keep allocated C string live across call to Syscall
Given:

        p := alloc()
        fn_taking_ptr(p)

p is NOT recorded as live at the call to fn_taking_ptr:
it's not needed by the code following the call.
p was passed to fn_taking_ptr, and fn_taking_ptr must keep
it alive as long as it needs it.
In practice, fn_taking_ptr will keep its own arguments live
for as long as the function is executing.

But if instead you have:

        p := alloc()
        i := uintptr(unsafe.Pointer(p))
        fn_taking_int(i)

p is STILL NOT recorded as live at the call to fn_taking_int:
it's not needed by the code following the call.
fn_taking_int is responsible for keeping its own arguments
live, but fn_taking_int is written to take an integer, so even
though fn_taking_int does keep its argument live, that argument
does not keep the allocated memory live, because the garbage
collector does not dereference integers.

The shorter form:

        p := alloc()
        fn_taking_int(uintptr(unsafe.Pointer(p)))

and the even shorter form:

        fn_taking_int(uintptr(unsafe.Pointer(alloc())))

are both the same as the 3-line form above.

syscall.Syscall is like fn_taking_int: it is written to take a list
of integers, and yet those integers are sometimes pointers.
If there is no other copy of those pointers being kept live,
the memory they point at may be garbage collected during
the call to syscall.Syscall.

This is happening on Solaris: for whatever reason, the timing
is such that the garbage collector manages to free the string
argument to the open(2) system call before the system call
has been invoked.

Change the system call wrappers to insert explicit references
that will keep the allocations alive in the original frame
(and therefore preserve the memory) until after syscall.Syscall
has returned.

Should fix Solaris flakiness.

This is not a problem for cgo, because cgo wrappers have
correctly typed arguments.

LGTM=iant, khr, aram, rlh
R=iant, khr, bradfitz, aram, rlh
CC=dvyukov, golang-codereviews, r
https://golang.org/cl/139360044
2014-09-08 16:59:59 -04:00
Russ Cox
c007ce824d build: move package sources from src/pkg to src
Preparation was in CL 134570043.
This CL contains only the effect of 'hg mv src/pkg/* src'.
For more about the move, see golang.org/s/go14nopkg.
2014-09-08 00:08:51 -04:00