Commit Graph

73 Commits

Author SHA1 Message Date
Matthias Clasen
f999481ec2 GTask: Document issues
We may not be able to fix GTasks broken design,
but at least we should document it and not let
users stumble into this bear trap without warning.

Helps: #1346
2023-01-16 08:19:23 -05:00
Philip Withnall
fe89940572 gtask: Emit a debug message if a GTask is finalised without returning
This typically indicates a bug in the program, where a GTask has been
created, but a bug in the control flow has caused it to not return a
value.

There is one situation where it might be legitimate to finalise a GTask
without returning: if an error happens in your *_async() start function
after you’ve created a GTask, but before the async operation returns to
the main loop; and you report the error using g_task_report_*error()
rather than reporting it using the newly constructed GTask.

Another situation is where you are just using GTask as a convenient way
to move some work to another thread, without the complexity of creating
and running your own thread pool. GDBus does this with
g_dbus_interface_method_dispatch_helper(), for example.

In most other cases, it’s a bug. Emit a debug message about it, but not
a full-blown warning, as that would create noise in the legitimate
cases.

Signed-off-by: Philip Withnall <withnall@endlessm.com>
2022-11-10 14:25:47 +00:00
Matthias Clasen
99c7d60869 gtask: Add g_task_set_static_name()
Similar to g_source_set_static_name, this avoids
strdup overhead for debug-only information in
possibly hot code paths.

We also add a macro wrapper for g_task_set_name that
uses __builtin_constant_p to decide whether to use
g_task_set_name or g_task_set_static_name.
2022-11-01 11:48:38 +00:00
Matthias Clasen
01f2c5aec9 gtask: Don't overwrite source names
Only set a name in g_task_attach_source
if the source does not already have one.

Including a new test by Philip Withnall.
2022-11-01 11:48:08 +00:00
Marco Trevisan (Treviño)
4398d140c7 gtask: Use unsigned bit-field struct values to avoid warnings
In recent Clang we may get a build warning as per:

  ../gio/gtask.c: warning: implicit truncation from 'int' to a
    one-bit wide bit-field changes value from 1 to -1
    [-Wsingle-bit-bitfield-constant-conversion]

This is because we use gboolean (and thus a signed type) for bit-fields.
Now, this is not an issue in practice for the way we're using them, but
still better to mute such compiler warns in the right way.
2022-10-18 21:28:00 +02:00
Jason Francis
9cd9787c52
gio: make g_task_get_cancellable return value nullable 2022-09-16 01:27:12 -04:00
Simon McVittie
7045260c22 gsignal: Add G_CONNECT_DEFAULT
This makes calls to g_signal_connect_data() and g_signal_connect_object()
with default flags more self-documenting.

Signed-off-by: Simon McVittie <smcv@collabora.com>
2022-06-23 10:46:45 +01:00
Philip Withnall
5942cd7984 gio: Add SPDX license headers automatically
Add SPDX license (but not copyright) headers to all files which follow a
certain pattern in their existing non-machine-readable header comment.

This commit was entirely generated using the command:
```
git ls-files gio/*.[ch] | xargs perl -0777 -pi -e 's/\n \*\n \* This library is free software; you can redistribute it and\/or\n \* modify it under the terms of the GNU Lesser General Public/\n \*\n \* SPDX-License-Identifier: LGPL-2.1-or-later\n \*\n \* This library is free software; you can redistribute it and\/or\n \* modify it under the terms of the GNU Lesser General Public/igs'
```

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

Helps: #1415
2022-05-18 09:18:52 +01:00
Ignacio Casal Quinteiro
f38d74b233 gtask: use g_strconcat() in g_task_return() only if needed
If the task name is NULL there is no need to allocate the string
since this can be expensive if called very often
2022-05-16 13:25:50 +01:00
Gabor Karsay
7e64004db0 docs: mark macros, flags, enums with percent sign 2022-03-04 16:21:55 +00:00
Philip Withnall
c1293acb27 gtask: Document that task name is set by g_task_set_source_tag()
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
2022-03-03 12:42:28 +00:00
Philip Withnall
ef72bed1c0 gtask: Document dependency on GMainContext more explicitly
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

Fixes: #2404
2021-09-24 07:57:49 +01:00
Philip Withnall
8e963e0e31 Port internal uses to use g_source_set_static_name()
This should reduce allocations.

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
2021-07-26 11:01:07 +01:00
Philip Withnall
13ba8d82ab gtask: Clarify what counts as ‘too many tasks’ for rate limiting
However, GLib still can’t guarantee to do rate limiting, as the type of
rate limiting which is appropriate depends on what tasks are being run,
and the GTask thread pool is shared between all tasks (of many different
types) in a process space.

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

Fixes: #2368
2021-04-14 11:38:13 +01:00
Emmanuel Fleury
f885d80ea3 Fix missing initializer warning in gio/gtask.c
gio/gtask.c:2153:1: error: missing initializer for field ‘closure_callback’ of ‘GSourceFuncs’ {aka ‘struct _GSourceFuncs’}
 2153 | };
      | ^
2021-01-21 11:59:09 +01:00
Matthias Clasen
e53e8b28dd gio: Add some tracing to GTask
Set counters for the number of running tasks and
for the max. threadpool size. These are meant to
get a sense for whether G_TASK_POOL_SIZE and related
constants are still suitable for current gio and
GTask usage patterns.
2020-11-14 19:04:45 +00:00
Philip Withnall
b08bd04abe gtask: Improve task names used internally within GLib
And improve them externally, where not otherwise set, by setting them
from the function name passed to `g_task_set_source_tag()`, if called by
third party code.

This should make profiling and debug output from GLib more useful.

Signed-off-by: Philip Withnall <withnall@endlessm.com>
2020-07-07 11:17:10 +01:00
Philip Withnall
6f281ce2e5 gtask: Include task name in complete_in_idle_cb source name
`complete_in_idle_cb()` shows up in a lot of sysprof traces, so it’s
quite useful to include the most specific contextual information we can
in it.

Signed-off-by: Philip Withnall <withnall@endlessm.com>
2020-07-07 11:17:10 +01:00
Philip Withnall
00bfb3ab44 tree: Fix various typos and outdated terminology
This was mostly machine generated with the following command:
```
codespell \
    --builtin clear,rare,usage \
    --skip './po/*' --skip './.git/*' --skip './NEWS*' \
    --write-changes .
```
using the latest git version of `codespell` as per [these
instructions](https://github.com/codespell-project/codespell#user-content-updating).

Then I manually checked each change using `git add -p`, made a few
manual fixups and dropped a load of incorrect changes.

There are still some outdated or loaded terms used in GLib, mostly to do
with git branch terminology. They will need to be changed later as part
of a wider migration of git terminology.

If I’ve missed anything, please file an issue!

Signed-off-by: Philip Withnall <withnall@endlessm.com>
2020-06-12 15:01:08 +01:00
Philip Withnall
7a3c4a415c gtask: Fix GIR annotation
Spotted by gtk-doc.

Signed-off-by: Philip Withnall <withnall@endlessm.com>
2019-12-11 12:30:47 +00:00
Garrett Regier
6cac760551 task: Add return/propagate API for GValue
This is useful for bindings.

Related: https://gitlab.gnome.org/GNOME/glib/issues/668
2019-11-15 10:37:42 +00:00
Garrett Regier
42369df7c6 task: Add scope annotation to run_in_thread{,_sync}()
Without specifying the scope, the two functions are non-introspectable
and GTask cannot be used meaningfully by bindings.

Related: https://gitlab.gnome.org/GNOME/glib/issues/668
2019-11-05 09:34:05 +01:00
Philip Withnall
13da7e5c2e Merge branch 'wip/ignazp/gtask-wait-time-fix' into 'master'
gtask: fix task_wait_time estimation

Closes #1683

See merge request GNOME/glib!644
2019-05-20 11:07:54 +00:00
Tomasz Miąsko
fef1ce37e4 gtask: Separate GTask fields memory locations to avoid data races
Ensure that fields that might be accessed in two different threads,
through conflicting actions are stored in seprate memory locations.
2019-02-22 22:22:07 +01:00
Ignazio Pillai
b465cb158b gtask: fix task_wait_time estimation
The wait time is estimated as function of the number of running threads

Fixes #1683
2019-02-08 10:53:26 +01:00
Debarshi Ray
6f3d57d2ee gtask: Return cancelled tasks asynchronously
Once cancelled, a GTask's callback should not only be invoked
asynchronously with respect to the creation of the task, but also with
respect to the GCancellable::cancelled handler. This is particularly
relevant in cases where the cancellation happened in the same thread
where the task is running.

Spotted by Dan Winship and Michael Catanzaro.

Closes https://gitlab.gnome.org/GNOME/glib/issues/1608
2019-02-06 13:30:01 +00:00
Philip Withnall
ae381d795e gtask: Ensure to return 1 or 0 from getters rather than truthy ints
Since commit 290bb0dd, where various members of GTask were converted to
a bitfield, some of the getters:
 • g_task_get_check_cancellable()
 • g_task_get_return_on_cancel()
 • g_task_get_completed()
have been returning truthy ints (zero or an arbitrary non-zero integer)
as boolean values, rather than the canonical boolean ints of 1 and 0.

This broke the `yield` statement in Vala, whose generated C code
compares `g_task_get_completed (…) != TRUE`. i.e. Whether the
`completed` field has a value not equal to 1.

Fix this by explicitly converting truthy ints to canonical boolean ints
in all getters.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

https://gitlab.gnome.org/GNOME/glib/issues/1636
2019-01-05 07:51:14 +00:00
Philip Withnall
e89128a935 gtask: Add a g_task_set_name() method
Similarly to g_source_set_name(), this sets a name on a GTask for
debugging and profiling. Importantly, this name is propagated to the
GSource for idle callbacks for the GTask, ending the glorious reign of
`[gio] complete_in_idle_cb`.

The name can be queried using g_task_get_name(). Locking is avoided by
only allowing the name to be set before the GTask is used from another
thread.

Includes tests.

Signed-off-by: Philip Withnall <withnall@endlessm.com>
2018-10-30 11:51:50 +00:00
Philip Withnall
290bb0dd1b gtask: Compress GTask struct using a bitfield
There are a lot of gbooleans in the private GTask struct, which seems a
bit wasteful. Use a bitfield to compress the struct a bit.

This reduces the size of the struct from 216 bytes to 168 bytes on my
64-bit machine.

One of the fields needs to remain separate, since it’s used from a
TRACE() macro which calls typeof() on it.

Signed-off-by: Philip Withnall <withnall@endlessm.com>
2018-10-02 09:59:13 +01:00
Philip Withnall
bea3770935 gtask: Check an error hasn’t been returned when calling g_task_return*()
These functions already check to see if a successful result has already
been returned; expand them to also check to see if an error has been
returned.

We can’t just check GTask.result_set, as that’s actually an indicator
for whether the GTask.result member is filled — when
g_task_propagate_*() is called, it’s cleared again. We need a new state
bit.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

https://gitlab.gnome.org/GNOME/glib/issues/1525
2018-10-01 21:45:48 +01:00
Pavlo Solntsev
7e2dfa8c44 DOC: Documentation fix in GTask description 2018-08-08 00:17:15 -05:00
Philip Withnall
208a6e815a gmain: Add names to various GSources constructed in GLib
For the purposes of debugging, it is quite useful for every GSource to
have a name set. Ensure that any GSource we construct inside GLib has a
name set. For GSources which are then returned to the caller, this name
can then be overridden with something even more useful by the caller.

Since this data is only used for debugging, avoid doing any allocations
for it; just use static strings.

https://gitlab.gnome.org/GNOME/glib/issues/1175
2018-06-26 09:25:39 +01:00
Philip Withnall
8e8f4e6486 docs: Fix various minor syntax errors in gtk-doc comments
This will fix a few broken links in the documentation, and shut up a
load of gtk-doc warnings (but certainly not all of them).

Signed-off-by: Philip Withnall <withnall@endlessm.com>

https://bugzilla.gnome.org/show_bug.cgi?id=790015
2017-11-07 14:51:12 +00:00
Debarshi Ray
61ea1e7ca4 docs: Don't be vague about where GTask dispatches the result
https://bugzilla.gnome.org/show_bug.cgi?id=783825
2017-10-26 13:48:39 +02:00
Rico Tzschichholz
1fb56be6ab gio: Mark g_task_get_source_object as nullable
In conjunction with ca4fe5942a

Reviewed-by: Philip Withnall <withnall@endlessm.com>
2017-10-11 17:14:11 +02:00
Sébastien Wilmet
3bf4a720c3 gio/: LGPLv2+ -> LGPLv2.1+
Sub-directories inside gio/ already processed in a previous commit:
- fam/
- gdbus-2.0/ (which contains only codegen/)
- gvdb/
- inotify/
- tests/
- win32/
- xdgmime/

Other sub-directories inside gio/:
- completion/: no license headers
- kqueue/: not LGPL, BSD-style license

https://bugzilla.gnome.org/show_bug.cgi?id=776504
2017-05-29 19:53:34 +02:00
Christian Hergert
18a33f72db introspection: use (nullable) or (optional) instead of (allow-none)
If we have an input parameter (or return value) we need to use (nullable).
However, if it is an (inout) or (out) parameter, (optional) is sufficient.

It looks like (nullable) could be used for everything according to the
Annotation documentation, but (optional) is more specific.
2016-11-22 14:14:37 -08:00
Pavel Grunt
c99fe67817 gtask: Add guards for public functions
https://bugzilla.gnome.org/show_bug.cgi?id=769745
2016-11-22 13:23:25 -05:00
Philip Withnall
195a0cb6bb gio: Add SystemTap and DTrace probes for GTask
This adds a basic tapset for GIO, covering various interesting parts of
GTask.

https://bugzilla.gnome.org/show_bug.cgi?id=759813
2016-06-15 16:15:12 -04:00
Debarshi Ray
a17e1e6d19 gtask: Don't forget about the error after g_task_propagate_*
The use of past tense in g_task_had_error makes one assume that it
won't forget about any errors that might have occurred. Except, in
reality, it would.

Let's use a boolean flag to remember the error once it's been
propagated, as opposed to keeping the error around. This ensures that
the g_task_propagate_* methods continue to give invalid results when
called more than once, as mentioned in the documentation.

https://bugzilla.gnome.org/show_bug.cgi?id=764163
2016-05-04 09:33:49 +02:00
Christian Hergert
d95030a2fd task: avoid context lock when setting source name
If you set the source name after attaching to the context, you have to
lock the context to free/assign the new source name.

https://bugzilla.gnome.org/show_bug.cgi?id=765861
2016-04-30 15:18:31 -07:00
Ben Iofel
7ab79b3879 GTask: fix example code in docs
https://bugzilla.gnome.org/show_bug.cgi?id=758181
2015-11-16 12:33:02 -05:00
Daiki Ueno
863bffdac7 doc: fix g_task_attach_source() example
The 3rd argument of the function is not a GCallback, but a GSourceFunc.

https://bugzilla.gnome.org/show_bug.cgi?id=757451
2015-11-02 11:14:04 +09:00
Dan Winship
4dae2d8289 gtask: re-fix tasks-blocking-other-tasks
The new "slowly add more task threads" code doesn't fully deal with
apps that queue lots and lots of tasks which then block on tasks from
their task threads. Fix this by bringing back the "task is blocking
other task" check and making sure that such tasks get bumped to the
front of the queue.

https://bugzilla.gnome.org/show_bug.cgi?id=687223
2015-10-24 10:37:22 -04:00
Matthias Clasen
368c3f205f GTask: Remove unused function
We no longer resort the queue, so this function can go.

https://bugzilla.gnome.org/show_bug.cgi?id=751160
2015-06-29 08:20:26 -07:00
Matthias Clasen
e419e1c4e2 GTask: Avoid resorting
When a task is cancelled, we want to move it to the front
of the queue - our sort function does that for us, but there
is no need to resort the entire queue here, we can just
move the one item and be done with it. This uses just-introduced
threadpool api for this purpose.

https://bugzilla.gnome.org/show_bug.cgi?id=751160
2015-06-29 08:20:26 -07:00
Dan Winship
86866a2a6d gtask: remove hardcoded GTask thread-pool size
GTask used a 10-thread thread pool for g_task_run_in_thread() /
g_task_run_in_thread_sync(), but this ran into problems when task
threads blocked waiting for another g_task_run_in_thread_sync()
operation to complete. Previously there was a workaround for this, by
bumping up the thread limit when that case was detected, but deadlocks
could still happen if there were non-GTask threads involved. (Eg, task
A sends a message to thread X and waits for a response, but thread X
needs to complete task B in a thread before returning the response to
task A.)

So, allow GTask's thread pool to be expanded dynamically, by watching
it from the glib worker thread, and growing it (at an
exponentially-decreasing rate) if too much time passes without any
tasks completing. This should solve the deadlocking problems without
causing sudden breakage in apps that assume they can queue huge
numbers of tasks at once without consequences.

https://bugzilla.gnome.org/show_bug.cgi?id=687223
2015-04-04 09:27:50 -04:00
Philip Withnall
4f1f68e6be gtask: Add a GTask:completed property
This can be used to query whether the task has completed, in the sense
that it has had a result set on it, and has already – or will soon –
invoke its callback function.

Notifications for this property are emitted immediately after the task’s
main callback, in the same main context as that callback. This allows
for multiple bits of code to listen for completion of the GTask, which
opens the door for blocking on cancellation of the GTask and improved
handling of ‘pending’ behaviour.

https://bugzilla.gnome.org/show_bug.cgi?id=743636
2015-03-10 08:37:45 +00:00
Philip Withnall
f41ebebd34 gtask: Ignore errors from g_thread_pool_push()
g_thread_pool_push() only returns an error if it fails to spawn a new
thread. However, it unconditionally adds the task to its worker queue,
so:
 • if _any_ threads exist in the pool, the task will eventually be
   handled; and
 • if _no_ threads exist in the pool, the task will be handled if one
   is eventually successfully spawned.
If no more threads are ever spawned, the process probably has bigger
problems than a single GTask which is taking forever to complete.

https://bugzilla.gnome.org/show_bug.cgi?id=736806
2014-09-23 08:08:45 +01:00
Philip Withnall
925913d8dd gtask: Document signal handler reference counting
Explain why the signal handler holds a reference to the GTask, even
though that causes a reference loop at first glance.

https://bugzilla.gnome.org/show_bug.cgi?id=736806
2014-09-23 08:08:25 +01:00