9ae43169cf
Previously: 1. old_val = atomic_add(&object->ref_count); 2. if (old_val == 1 && OBJECT_HAS_TOGGLE_REF (object)) { toggle_notify() } As old_val was 1, you might think that no other thread can have a valid reference to object. However, that's not the case. For one, GWeakRef can be used to create another strong reference. More easily, the single reference can be shared between multiple threads (as long as the code takes care that the object lives long enough). That means, another thread can easily add and drop references (including toggle references). All between step 1 and 2. A race here might be hard to hit, and the effect might not be obviously bad. However, consider old_val is 1 due to a normal reference, and another thread adds a toggle ref between step 1. and 2. Then we would notify a toggle from 1->2, although a newly added toggle ref is expected to always start with a normal and a toggle reference. The first toggle notification is expected to notify about the loss of other references, not about getting a second reference. To handle this properly, when we increase the reference count from 1 to 2, we must do so under a lock and check for the toggle notification. As we now correctly track the toggle behavior, we can also assert in toggle_refs_get_notify_unlocked() that n_toggle_refs agrees with the number of references, that is, that the user did always match g_object_add_toggle_ref() with g_object_remove_toggle_ref(). The downside is here too, that there is now a case (when increasing the reference count from 1 to 2) where we need to take the global lock. That performance problem should be addresses by using per-object locks instead of a global lock. |
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.gitlab-ci | ||
.reuse | ||
docs | ||
fuzzing | ||
gio | ||
girepository | ||
glib | ||
gmodule | ||
gobject | ||
gthread | ||
introspection | ||
LICENSES | ||
m4macros | ||
po | ||
subprojects | ||
tests | ||
tools | ||
.clang-format | ||
.dir-locals.el | ||
.editorconfig | ||
.gitignore | ||
.gitlab-ci.yml | ||
.gitmodules | ||
.lcovrc | ||
CODE_OF_CONDUCT.md | ||
CONTRIBUTING.md | ||
COPYING | ||
glib.doap | ||
INSTALL.md | ||
meson_options.txt | ||
meson.build | ||
NEWS | ||
README.md | ||
SECURITY.md |
GLib
GLib is the low-level core library that forms the basis for projects such as GTK and GNOME. It provides data structure handling for C, portability wrappers, and interfaces for such runtime functionality as an event loop, threads, dynamic loading, and an object system.
The official download locations are: https://download.gnome.org/sources/glib
The official web site is: https://www.gtk.org/
Installation
See the file ‘INSTALL.md’. There is separate and more in-depth documentation for building GLib on Windows.
Supported versions
Upstream GLib only supports the most recent stable release series, the previous stable release series, and the current development release series. All older versions are not supported upstream and may contain bugs, some of which may be exploitable security vulnerabilities.
See SECURITY.md for more details.
Documentation
API documentation is available online for GLib for the:
Discussion
If you have a question about how to use GLib, seek help on GNOME’s Discourse
instance. Alternatively, ask a question
on StackOverflow and tag it glib
.
Reporting bugs
Bugs should be reported to the GNOME issue tracking system. You will need to create an account for yourself. You may also submit bugs by e-mail (without an account) by e-mailing incoming+gnome-glib-658-issue-@gitlab.gnome.org, but this will give you a degraded experience.
Bugs are for reporting problems in GLib itself, not for asking questions about how to use it. To ask questions, use one of our discussion forums.
In bug reports please include:
- Information about your system. For instance:
- What operating system and version
- For Linux, what version of the C library
- And anything else you think is relevant.
- How to reproduce the bug.
- If you can reproduce it with one of the test programs that are built
in the
tests/
subdirectory, that will be most convenient. Otherwise, please include a short test program that exhibits the behavior. As a last resort, you can also provide a pointer to a larger piece of software that can be downloaded.
- If you can reproduce it with one of the test programs that are built
in the
- If the bug was a crash, the exact text that was printed out when the crash occurred.
- Further information such as stack traces may be useful, but is not necessary.
Contributing to GLib
Please follow the contribution guide to know how to start contributing to GLib.
Patches should be submitted as merge requests to gitlab.gnome.org. If the patch fixes an existing issue, please refer to the issue in your commit message with the following notation (for issue 123):
Closes: #123
Otherwise, create a new merge request that introduces the change. Filing a separate issue is not required.