When a string is #frozen, it's capacity is resized to fit (if it is much
larger), since we know it will no longer be mutated.
> puts ObjectSpace.dump(String.new("a"*30, capacity: 1000))
{"type":"STRING", "class":"0x7feaf00b7bf0", "bytesize":30, "capacity":1000, "value":"...
> puts ObjectSpace.dump(String.new("a"*30, capacity: 1000).freeze)
{"type":"STRING", "class":"0x7feaf00b7bf0", "frozen":true, "bytesize":30, "value":"...
(ObjectSpace.dump doesn't show capacity if capacity is equal to bytesize)
Previously, if we dedup into an fstring, using String#-@, capacity would
not be reduced.
> puts ObjectSpace.dump(-String.new("a"*30, capacity: 1000))
{"type":"STRING", "class":"0x7feaf00b7bf0", "frozen":true, "fstring":true, "bytesize":30, "capacity":1000, "value":"...
This commit makes rb_fstring call rb_str_resize, the same as
rb_str_freeze does.
Closes: https://github.com/ruby/ruby/pull/2256
This is a follow up for 3f9562015e.
Before this commit, it was possible to create a shared string which
shares with another shared string by passing a frozen shared string
to `str_duplicate`.
Such string looks like:
```
-------- -----------------
| root | ------ owns -----> | root's buffer |
-------- -----------------
^ ^ ^
----------- | |
| shared1 | ------ references ----- |
----------- |
^ |
----------- |
| shared2 | ------ references ---------
-----------
```
This is bad news because `rb_fstring(shared2)` can make `shared1`
independent, which severs the reference from `shared1` to `root`:
```c
/* from fstr_update_callback() */
str = str_new_frozen(rb_cString, shared2); /* can return shared1 */
if (STR_SHARED_P(str)) { /* shared1 is also a shared string */
str_make_independent(str); /* no frozen check */
}
```
If `shared1` was the only reference to `root`, then `root` can be
reclaimed by the GC, leaving `shared2` in a corrupted state:
```
----------- --------------------
| shared1 | -------- owns --------> | shared1's buffer |
----------- --------------------
^
|
----------- -------------------------
| shared2 | ------ references ----> | root's buffer (freed) |
----------- -------------------------
```
Here is a reproduction script for the situation this commit fixes.
```ruby
a = ('a' * 24).strip.freeze.strip
-a
p a
4.times { GC.start }
p a
```
- string.c (str_duplicate): always share with the root string when
the original is a shared string.
- test_rb_str_dup.rb: specifically test `rb_str_dup` to make
sure it does not try to share with a shared string.
[Bug #15792]
Closes: https://github.com/ruby/ruby/pull/2159
FrozenError will be used instead of RuntimeError for exceptions
raised when there is an attempt to modify a frozen object. The
reason for this change is to differentiate exceptions related
to frozen objects from generic exceptions such as those generated
by Kernel#raise without an exception class.
From: Jeremy Evans <code@jeremyevans.net>
Signed-off-by: Urabe Shyouhei <shyouhei@ruby-lang.org>
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61131 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* io.c (io_setstrbuf): return true if the buffer is newly created.
* io.c (io_set_read_length): shrink the read buffer if it is a new
object and is too large. [ruby-core:81370] [Bug #13597]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59701 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* test/-ext-/string/test_modify_expand.rb (test_integer_overflow):
no longer happens on platforms where size_t is larger than long,
e.g. 64bit windows, since r57122.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57156 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* string.c (rb_str_set_len): The buffer overflow check is wrong. The
space for termlen is allocated outside the capacity returned by
rb_str_capacity(). This fixes r41920 ("string.c: multi-byte
terminator", 2013-07-11). [ruby-core:77257] [Bug #12757]
* test/-ext-/string/test_set_len.rb (test_capacity_equals_to_new_size):
Test for this change. Applying only the test will trigger [BUG].
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56148 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
When you change this to true, you may need to add more tests.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53141 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* string.c (rb_string_value_cstr): should not raise on frozen
string.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52833 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* string.c (str_replace_shared_without_enc): fill the terminator
of embedded strings in wide char encodings.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51372 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* string.c (fstr_update_callback): pool bare strings only.
* string.c (rb_fstring): return the original string with sharing a
fstring if it has extra attributes, not the fstring itself.
[ruby-dev:49188] [Bug #11386]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51360 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* encoding.c (enc_autoload): drop dummy encoding flag from
the loaded encoding index. this flag is used only in this
source.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51251 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* file.c (rb_str_normalize_ospath): skip invalid byte sequence not
to loop infinitely. this case usually does not happen as the
input name should come from real file systems.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51180 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* test/-ext-/string/test_nofree.rb (test_no_memory_leak): remove
limit and make the interation longer.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50843 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* string.c (str_make_independent_expand): terminate String when
moved from heap to embedded. [Fix GH-821].
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49405 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* test/-ext-/string/test_cstr.rb (assert_wchars_term_char): test
for all wide char encodings.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48755 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* test/-ext-/string/test_cstr.rb (test_wchar_long): show the
failed encoding name in error messages.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48753 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
In this test, jemalloc and tcmalloc are both more hesitant to
release memory to the kernel than the stock glibc allocator.
Tested on jemalloc 3.6.0 (self-built) and libtcmalloc-minimal 2.0-2
(Debian package) on x86_64-linux
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47620 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* test/-ext-/string/test_ellipsize.rb (Test_StringEllipsize#test_nonascii):
rb_str_ellipsize() does not support BOM.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43032 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Previous table is used on Mac OS X 10.1 or prior.
This table is used on 10.2 or later. [ruby-dev:47680]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42789 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
HFS Plus (Mac OS Extended) uses a variant of Normal Form D in which
U+2000 through U+2FFF, U+F900 through U+FAFF, and U+2F800 through
U+2FAFF are not decomposed (this avoids problems with round trip
conversions from old Mac text encodings).
http://developer.apple.com/library/mac/qa/qa1173/_index.html
Therefore fix r42457 to exclude the range.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42498 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
