runtime: drop chan circular linked list in favor of circular buffer
The list elements are already being allocated out of a
single memory buffer. We can drop the Link* pointer
following and the memory it requires, replacing it with
index operations.
The change also keeps a channel from containing a pointer
back into its own allocation block, which would create a
cycle. Blocks involved in cycles are not guaranteed to be
finalized properly, and channels depend on finalizers to
free OS-level locks on some systems. The self-reference
was keeping channels from being garbage collected.
runtime-gdb.py will need to be updated in order to dump
the content of buffered channels with the new data structure.
Fixes #1676.
R=ken2, r
CC=golang-dev
https://golang.org/cl/4411045
This CL is only cut-and-paste, moving code around.
Moving it in a separate CL should simplify the diffs in later CLs.
There are three patterns here.
1. A function like
func (v Value) M() (...) {
return v.panicIfNot(K).(*kValue).M()
}
becomes
func (v Value) M() (...) {
vv := v.panicIfNot(K).(*kValue)
// body of (*kValue).M, s/v./vv./g
}
2. A function like
func (v Value) M() (...) {
return v.panicIfNots(kList).(mer).M()
}
becomes
func (v Value) M() (...) {
switch vv := v.panicIfNots(kList).(type) {
case *k1Value:
// body of (*k1Value).M, s/v./vv./g
case *k2Value:
// body of (*k2Value).M, s/v./vv./g
...
}
panic("not reached")
}
3. The rewrite of Value.Set follows 2, but each case
is built from the bodies of (*kValue).SetValue and (*kValue).Set.
func (v *kValue) SetValue(x Value) {
v.Set(x.panicIfNot(K).(*kValue)
}
func (v *kValue) Set(x *kValue) {
... body
}
becomes, in the switch from 2,
case *kValue:
xx := x.panicIfNot(K).(*kValue)
... body, s/v./vv./g; s/x./xx./g
This CL changes the behavior of 'make install' and 'make test'
in the src/cmd directory and the src/pkg directory to have
each recursive make clean up after itself immediately.
It does the same in test/run, removing $F.$A and $A.out
(the common byproducts) between runs.
On machines with slow disks and aggressive kernel caching,
cleaning up immediately can mean that the intermediate
objects never get written to disk.
This change eliminates almost all the disk waiting during
all.bash on my laptop (a Thinkpad X201s with an SSD running Linux).
147.50u 19.95s 277.34r before
148.53u 21.64s 179.59r after
Adam Langley [Wed, 13 Apr 2011 19:12:28 +0000 (15:12 -0400)]
bufio: add ReadLine
It matches encoding/line exactly and the tests are copied from there.
If we land this, then encoding/line will get marked as deprecated then
deleted in time.
Robert Griesemer [Wed, 13 Apr 2011 16:38:13 +0000 (09:38 -0700)]
gofmt: avoid endless loops
With the (partial) resolution of identifiers done
by the go/parser, ast.Objects point may introduce
cycles in the AST. Don't follow *ast.Objects, and
replace them with nil instead (they are likely
incorrect after a rewrite anyway).
- minor manual cleanups after reflect change automatic rewrite
- includes fix by rsc related to reflect change
The changes were not tested for real in an App Engine environment,
so extra care should be taken. That said, some static testing
was done with pyflakes, and a few existent problems were fixed on
the way.
The ld time was dominated by symbol table processing, so
* increase hash table size
* emit fewer symbols in gc (just 1 per string, 1 per type)
* add read-only lookup to avoid creating spurious symbols
* add linked list to speed whole-table traversals
Breaks dwarf generator (no idea why), so disable dwarf.
Robert Griesemer [Fri, 8 Apr 2011 22:47:21 +0000 (15:47 -0700)]
go/printer, gofmt: use blank to separate import rename from import path
Note that declarations.golden is not using spaces for alignment (so
that the alignment tabs are visible) which is why this change affects
the test cases significantly. gofmt uses spaces for alignment (by default)
and only tabs for indentation.
In the current codereview, if a patch was written against
a version of a file that had subsequently been edited,
hg clpatch would fail, even if the patch and the edits were
in different parts of the file. In this situation the reviewer
typically wrote back saying "please hg sync and hg mail
to update the patch".
This change rewrites the patch automatically, using the
same transformation that hg sync + hg mail would.
If the interim changes (since the patch was created)
affect the same line ranges as the patch, clpatch will
still refuse to apply it. But this CL should make
of the trivial conflicts we see just go away.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/4377046
* add -diff command line option
* use scoping information in refersTo, isPkgDot, isPtrPkgDot.
* add new scoping-based helpers countUses, rewriteUses, assignsTo, isTopName.
* rename rewrite to walk, add walkBeforeAfter.
* add toy typechecker, a placeholder for go/types
Type is now an interface that implements all the possible type methods.
Instead of a type switch on a reflect.Type t, switch on t.Kind().
If a method is invoked on the wrong kind of type (for example,
calling t.Field(0) when t.Kind() != Struct), the call panics.
There is one method renaming: t.(*ChanType).Dir() is now t.ChanDir().
Value is now a struct value that implements all the possible value methods.
Instead of a type switch on a reflect.Value v, switch on v.Kind().
If a method is invoked on the wrong kind of value (for example,
calling t.Recv() when t.Kind() != Chan), the call panics.
Since Value is now a struct, not an interface, its zero value
cannot be compared to nil. Instead of v != nil, use v.IsValid().
Instead of other uses of nil as a Value, use Value{}, the zero value.
Many methods have been renamed, most due to signature conflicts:
Part of the motivation for this change is to enable a more
efficient implementation of Value, one that does not allocate
memory during most operations. To reduce the size of the CL,
this CL's implementation is a wrapper around the old API.
Later CLs will make the implementation more efficient without
changing the API.
Other CLs to be submitted at the same time as this one
add support for this change to gofix (4343047) and update
the Go source tree (4353043).
Robert Griesemer [Fri, 8 Apr 2011 04:40:37 +0000 (21:40 -0700)]
go/types: New Go type hierarchy implementation for AST.
This CL defines a new, more Go-like representation of
Go types (different structs for different types as
opposed to a single Type node). It also implements
an ast.Importer for object/archive files generated
by the gc compiler tool chain. Besides the individual
type structs, the main difference is the handling of
named types: In the old world, a named type had a
non-nil *Object pointer but otherwise looked no
different from other types. In this new model, named
types have their own representation types.Name. As
a result, resolving cycles is a bit simpler during
construction, at the cost of having to deal with
types.Name nodes explicitly later. It remains to be
seen if this is a good approach. Nevertheless, code
involving types reads more nicely and benefits from
full type checking. Also, the representation seems
to more closely match the spec wording.
Credits: The original version of the gc importer was
written by Evan Shaw (chickencha@gmail.com). The new
version in this CL is based largely on Evan's original
code but contains bug fixes, a few simplifications,
some restructuring, and was adjusted to use the
new type hierarchy. I have added a comprehensive test
that imports all packages found under $GOROOT/pkg (with
a 3s time-out to limit the run-time of the test). Run
gotest -v for details.
The original version of ExportData (exportdata.go) was
written by Russ Cox (rsc@golang.org). The current version
is returning the internal buffer positioned at the beginning
of the export data instead of printing the export data to
stdout.
With the new types package, the existing in-progress
typechecker package is deprecated. I will delete it
once all functionality has been brought over.
John DeNero [Fri, 8 Apr 2011 01:05:15 +0000 (18:05 -0700)]
A codewalk through a simple program that illustrates several aspects of Go functions: function objects, higher-order functions, variadic functions, tail recursion, etc. The example program simulates the game of Pig, a dice game with simple rules but a nontrivial solution.
R=adg, rsc, iant2, r
CC=golang-dev
https://golang.org/cl/4306045
Right now if a Go developer makes a patch on one machine
and then clpatches it onto another machine, changes
subsequently made to the description are kept only
locally, under the assumption that you are running
clpatch because someone else wrote the CL, so you
don't have permission to update the web.
This change makes clpatch discard the "this was a
clpatch" information from the metadata when you
clpatch your own CLs from one machine to another.
This should eliminate some confusion (for example
in CL 4314054) but will no doubt introduce other
confusion.
src/pkg/Makefile: trim per-directory make output except on failure
Not committed to this but it sure makes
the output easier to skim. With this CL:
$ make
install runtime
install sync/atomic
install sync
install unicode
install utf16
install syscall
install os
...
install ../cmd/govet
install ../cmd/goyacc
install ../cmd/hgpatch
$ make test
test archive/tar
test archive/zip
test asn1
test big
test bufio
...
test path
test path/filepath
TEST FAIL reflect
gotest
rm -f _test/reflect.a
6g -o _gotest_.6 deepequal.go type.go value.go
rm -f _test/reflect.a
gopack grc _test/reflect.a _gotest_.6
all_test.go:210: invalid type assertion: reflect.NewValue(tt.i).(*StructValue) (non-interface type reflect.Value on left)
all_test.go:217: cannot type switch on non-interface value v (type reflect.Value)
all_test.go:218: undefined: IntValue
all_test.go:221: cannot use 132 (type int) as type reflect.Value in function argument
all_test.go:223: cannot use 8 (type int) as type reflect.Value in function argument
all_test.go:225: cannot use 16 (type int) as type reflect.Value in function argument
all_test.go:227: cannot use 32 (type int) as type reflect.Value in function argument
all_test.go:229: cannot use 64 (type int) as type reflect.Value in function argument
all_test.go:231: undefined: UintValue
all_test.go:234: cannot use 132 (type int) as type reflect.Value in function argument
all_test.go:234: too many errors
gotest: "/Users/rsc/g/go/bin/6g -I _test -o _xtest_.6 all_test.go tostring_test.go" failed: exit status 1
make[1]: *** [test] Error 2
make: *** [reflect.test] Error 1
Rob Pike [Wed, 6 Apr 2011 18:48:03 +0000 (11:48 -0700)]
log: generalize getting and setting flags and prefix.
- used to be only for standard log, not for user-built.
- there were no getters.
Also rearrange the code a little so we can avoid allocating
a buffer on every call. Logging is expensive but we should
avoid unnecessary cost.