On OS X 10.10 Yosemite, if you have a directory that can be returned
in a single getdirentries64 call (for example, a directory with one file),
and you read from the directory at EOF twice, you get EOF both times:
fd = open("dir")
getdirentries64(fd) returns data
getdirentries64(fd) returns 0 (EOF)
getdirentries64(fd) returns 0 (EOF)
But if you remove the file in the middle between the two calls, the
second call returns an error instead.
fd = open("dir")
getdirentries64(fd) returns data
getdirentries64(fd) returns 0 (EOF)
remove("dir/file")
getdirentries64(fd) returns ENOENT/EINVAL
Whether you get ENOENT or EINVAL depends on exactly what was
in the directory. It is deterministic, just data-dependent.
This only happens in small directories. A directory containing more data
than fits in a 4k getdirentries64 call will return EOF correctly.
(It's not clear if the criteria is that the directory be split across multiple
getdirentries64 calls or that it be split across multiple file system blocks.)
We could change package os to avoid the second read at EOF,
and maybe we should, but that's a bit involved.
For now, treat the EINVAL/ENOENT as EOF.
With this CL, all.bash passes on my MacBook Air running
OS X 10.10 (14A299l) and Xcode 6 beta 5 (6A279r).
I tried filing an issue with Apple using "Feedback Assistant", but it was
unable to send the report and lost it.
C program reproducing the issue, also at http://swtch.com/~rsc/readdirbug.c:
#include <stdio.h>
#include <dirent.h>
#include <unistd.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
static void test(int);
int
main(void)
{
int fd, n;
DIR *dir;
struct dirent *dp;
struct stat st;
char buf[10000];
long basep;
int saw;
if(stat("/tmp/readdirbug", &st) >= 0) {
fprintf(stderr, "please rm -r /tmp/readdirbug and run again\n");
exit(1);
}
fprintf(stderr, "mkdir /tmp/readdirbug\n");
if(mkdir("/tmp/readdirbug", 0777) < 0) {
perror("mkdir /tmp/readdirbug");
exit(1);
}
fprintf(stderr, "create /tmp/readdirbug/file1\n");
if((fd = creat("/tmp/readdirbug/file1", 0666)) < 0) {
perror("create /tmp/readdirbug/file1");
exit(1);
}
close(fd);
test(0);
test(1);
fprintf(stderr, "ok - everything worked\n");
}
static void
test(int doremove)
{
DIR *dir;
struct dirent *dp;
int numeof;
fprintf(stderr, "\n");
fprintf(stderr, "opendir /tmp/readdirbug\n");
dir = opendir("/tmp/readdirbug");
if(dir == 0) {
perror("open /tmp/readdirbug");
exit(1);
}
numeof = 0;
for(;;) {
errno = 0;
dp = readdir(dir);
if(dp != 0) {
fprintf(stderr, "readdir: found %s\n", dp->d_name);
continue;
}
if(errno != 0) {
perror("readdir");
exit(1);
}
fprintf(stderr, "readdir: EOF\n");
if(++numeof == 3)
break;
if(doremove) {
fprintf(stderr, "rm /tmp/readdirbug/file1\n");
if(remove("/tmp/readdirbug/file1") < 0) {
perror("remove");
exit(1);
}
}
}
fprintf(stderr, "closedir\n");
closedir(dir);
}
Fixes#8423.
LGTM=bradfitz, r
R=golang-codereviews, bradfitz, dsymonds, dave, r
CC=golang-codereviews, iant
https://golang.org/cl/119530044
Current version of Getwd calls Stat that
calls Getwd therefore infinite recursion.
LGTM=minux
R=golang-codereviews, minux
CC=golang-codereviews
https://golang.org/cl/119600043
The ast and printer don't care, and go/types can provide
a better error message.
This change requires an update to the tests for go/types
(go.tools repo). CL forthcoming.
Fixes#8493.
LGTM=adonovan
R=rsc, adonovan
CC=golang-codereviews
https://golang.org/cl/123010044
Some systems, like Ubuntu, pass --build-id when linking. The
effect is to put a note in the output file. This is not
useful when generating an object file with the -r option, as
it eventually causes multiple build ID notes in the final
executable, all but one of which are for tiny portions of the
file and are therefore useless.
Disable that by passing an explicit --build-id=none when
linking with -r on systems that might do this.
LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/119460043
There are lots of internal synchronization in gob,
so it makes sense to have parallel benchmarks.
Also add a benchmark with slices and interfaces.
LGTM=r
R=golang-codereviews, r
CC=golang-codereviews
https://golang.org/cl/115960043
This lets us have non-main packages like cmd/internal or cmd/nm/internal/whatever.
The src/pkg migration (see golang.org/s/go14mainrepo) will allow this
as a natural side effect. The explicit change here just allows use of the
effect a little sooner.
LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/117630043
To do in another CL: make cmd/objdump use cmd/internal/objfile too.
There is a package placement decision in this CL:
cmd/internal/objfile instead of internal/objfile.
I chose to put internal under cmd to make clear (and enforce)
that no standard library packages should use this
(it's a bit dependency-heavy).
LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/123910043
Eliminating use of this extension makes it easier to port the Go runtime
to other compilers. This CL also disables the extension in cc to prevent
accidental use.
LGTM=rsc, khr
R=rsc, aram, khr, dvyukov
CC=axwalk, golang-codereviews
https://golang.org/cl/106790044
This makes os.Getwd mimic C getwd on OS X,
and possibly other systems. The change on OS X
was a regression from 1.2 to 1.3.
Fixes#8400.
LGTM=bradfitz
R=iant, bradfitz
CC=golang-codereviews
https://golang.org/cl/118970043
FlagNoGC is unused now.
FlagNoInvokeGC is unneeded as we don't invoke GC
on g0 and when holding locks anyway.
mal/malloc have very few uses and you never remember
the exact set of flags they use and the difference between them.
Moreover, eventually we need to give exact types to all allocations,
something what mal/malloc do not support.
LGTM=khr
R=golang-codereviews, khr
CC=golang-codereviews, rsc
https://golang.org/cl/117580043
Shrinkstack does not touch normal heap anymore,
so we can shink stacks concurrently with marking.
LGTM=khr
R=golang-codereviews, khr
CC=golang-codereviews, khr, rlh, rsc
https://golang.org/cl/122130043
Among other things, this allows users to match the decoded
pieces with the original XML, which can be necessary for
implementing standards like XML signatures.
Fixes#8484.
LGTM=bradfitz
R=bradfitz
CC=golang-codereviews
https://golang.org/cl/122960043
This fixes two problems: x/internal/y/z was using parent = x/internal/y instead of x,
and hasPathPrefix only looks at /, not \ for Windows.
LGTM=bradfitz
R=bradfitz
CC=golang-codereviews
https://golang.org/cl/121280045
Introduce the mFunction type to represent an mcall/onM-able function.
Name such functions using _m.
LGTM=bradfitz
R=bradfitz
CC=golang-codereviews
https://golang.org/cl/121320043
Hashing on the bytes instead of the words does
a (much) better job of using all the bits, so that
maps of floats have linear performance.
LGTM=khr
R=golang-codereviews, khr
CC=adonovan, golang-codereviews
https://golang.org/cl/126720044
The implementation 'return 0' results in too many collisions.
LGTM=khr
R=golang-codereviews, adonovan, khr
CC=golang-codereviews, iant, khr, r
https://golang.org/cl/125720044
hg insists that we not list explicit files for a merge.
for benefit of other tools reading logs, include branch prefix
at start of every commit message.
LGTM=minux
R=minux
CC=golang-codereviews
https://golang.org/cl/124780044
1) The arrayindexof lookup function is O(n). Replace with O(1) lookups.
2) The checkptxt function is O(n²) and is purely for debugging.
Only run when the debugging flags are turned on.
3) Iterating over sparse bitmaps can be done faster word by word.
Introduce and use bvnext for that.
Run times before and after, on my 2.5 GHz Core i5 MacBook Pro.
x.go 9.48 0.84 issue 8259
x100.go 0.01 0.01 issue 8354
x1000.go 0.10 0.10
x2000.go 0.62 0.19
x3000.go 1.33 0.34
x4000.go 2.29 0.49
x5000.go 3.89 0.67
x6000.go 5.00 0.90
x7000.go 6.70 1.13
x8000.go 9.44 1.38
x9000.go 11.23 1.87
x10000.go 13.78 2.09
Fixes#8259.
Fixes#8354.
LGTM=iant, r
R=golang-codereviews, iant, r
CC=golang-codereviews
https://golang.org/cl/125720043
The linker currently produces the DWARF 3 DW_TAG_unspecified_type tag, however the Reader in debug/dwarf will panic whenever that tag is encountered.
Fixes#8437.
LGTM=rsc
R=golang-codereviews, bradfitz, iant, rsc
CC=golang-codereviews
https://golang.org/cl/117280043
