Atomic APIs provide a way to exchange values only if we compare a value
that is equal to the old value, but not to just exchange the value
returning the old one.
However, compilers provide such built-in functions, so we can use them
to expose such functionality to GLib.
The only drawback is that when using an old version of gcc not providing
atomic APIs to swap values, we need to re-implement it with an
implementation that may not be fully atomic, but that is safe enough.
However this codepath should really not be used currently as gcc
introduced __atomic_exchange_n() at version 4.7.4, so 8 years ago.
Dynamically, all the right elements of `ps` are initialised before they
are used. However, scan-build doesn’t think so. It (probably) thinks
that `number_of_blocks` could change value between the different loops
over `ps`.
Try and avoid that by marking `number_of_blocks` (and related variables)
as `const`.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
It seems that scan-build assumes `n_threads > 0`, but doesn’t assume a
tighter condition than that, and hence assumes that the two loops to
initialise and join the threads have different numbers of iterations.
That’s obviously not the case.
Try and help scan-build out here by marking `n_threads` as `const`. I
don’t know if this will work, but it’s correct regardless.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
It does some unusual things with memory pages and allocation, and
testing that with valgrind (a) fails and (b) probably isn’t useful
anyway.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
None of these messages are particularly helpful, but they increase the
overall test log output size, which has to be stored by the CI for every
test run.
With these messages removed, the size of a full test log is reduced from
6.5MB to 1.8MB for me.
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
GArray supports a "zero_terminated" flag, but GPtrArray doesn't.
This is odd, because especially for a pointer array it makes sense
to have a %NULL sentinel. This would be for example useful to track
or construct a strv array with a GPtrArray.
As workaround for this missing feature you could use a GArray instead
(ugly) or to explicitly add the %NULL element. However the latter increases
the "len" of the array, which can be problematic if you want to still use
the GPtrArray for other purposes.
Add API for marking a GPtrArray as %NULL terminated. In that case, the
API will ensure that there is always a valid %NULL sentinel after the
array. Note that the API does not enforce that a %NULL terminated API
actually has any data allocated. That means, even with a %NULL terminated
array, pdata can still be %NULL (only if len is zero).
Add g_ptr_array_new_null_terminated() constructor. The null-terminated flag
cannot be cleared. Once the GPtrArray is flagged to be %NULL terminated, it
sticks. The purpose is that once a user checks whether a GPtrArray instance
is safe to be treated as a %NULL terminated array, the decision does
not need to be re-evaluated.
Also add a g_ptr_array_is_null_terminated(). That is useful because it
allows you to check whether a GPtrArray created by somebody else is safe
to use as a %NULL terminated array. Since there is no API to make an
array not %NULL terminated anymore, this is not error prone.
The new flag is tracked as a guint8 in GRealPtrArray. On common 64 bit
architectures this does not increase the size of the struct as it fits
in an existing hole. Note that this is not a bitfield because it's
probably more efficient to access the entire guint8. However, there is
still a 3 bytes hole (on common 32 and 64 architectures), so if we need
to add more flags in the future, we still have space for 24 bits,
despite the new flag not being a bitfield.
The biggest downside of the patch is the runtime overhead that most
operations now need to check whether %NULL termination is requested.
Includes some tweaks and additional tests by Philip Withnall.
https://gitlab.gnome.org/GNOME/glib/-/issues/353
Many idle and timeout sources are installed as "one shot": called once
and immediately removed. While it's easy to write a simple callback that
returns G_SOURCE_REMOVE, it would also be useful to have some sort of
"visual" marker when reading the code; a way to immediately see that a
callback (which may be defined elsewhere in the code) is meant to be
invoked just once.
Includes additional unit tests by Philip Withnall.
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 glib/tests/*.c | 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
==24477==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffde020de20 at pc 0x7f2e6f6413f1 bp 0x7ffde020c9d0 sp 0x7ffde020c180
READ of size 4101 at 0x7ffde020de20 thread T0
#0 0x7f2e6f6413f0 in __interceptor_strlen.part.0 (/lib64/libasan.so.8+0x4c3f0)
#1 0x7f2e6ef4abee in g_build_path_va ../glib/gfileutils.c:1908
#2 0x7f2e6f085956 in g_test_build_filename_va ../glib/gtestutils.c:4294
#3 0x7f2e6f086684 in g_test_build_filename ../glib/gtestutils.c:4365
#4 0x403a33 in test_search_path_heap_allocation ../glib/tests/spawn-path-search.c:422
#5 0x7f2e6f0839a5 in test_case_run ../glib/gtestutils.c:2930
#6 0x7f2e6f0839a5 in g_test_run_suite_internal ../glib/gtestutils.c:3018
#7 0x7f2e6f0834ed in g_test_run_suite_internal ../glib/gtestutils.c:3035
#8 0x7f2e6f084879 in g_test_run_suite ../glib/gtestutils.c:3112
#9 0x7f2e6f084995 in g_test_run ../glib/gtestutils.c:2231
#10 0x40145f in main ../glib/tests/spawn-path-search.c:488
#11 0x7f2e6e31258f in __libc_start_call_main (/lib64/libc.so.6+0x2d58f)
#12 0x7f2e6e312648 in __libc_start_main_alias_1 (/lib64/libc.so.6+0x2d648)
#13 0x401524 in _start (/home/elmarco/src/gnome/glib/build/glib/tests/spawn-path-search+0x401524)
Address 0x7ffde020de20 is located in stack of thread T0 at offset 4256 in frame
#0 0x40387f in test_search_path_heap_allocation ../glib/tests/spawn-path-search.c:401
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
This bug only gets triggered on BSD, because it calls `recv_message()`
with `G_IO_HUP | G_IO_IN`. That takes two code paths in
`recv_message()`, and ends up calling `shutdown_source()` twice. The
second call causes a critical warning.
Fixes: https://gitlab.gnome.org/GNOME/glib/-/jobs/2004192
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Check the spawn implementation behaviour when the stderr is a
socket (mostly for win32).
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
It is not only shorter than `not meson.is_cross_build() or
meson.has_exe_wrapper()` but also handle the case of cross compiling to
a compatible arch such as building for i386 on an amd64.
`ret` was never read. This fixes scan-build warnings:
```
../../../../source/glib/glib/tests/thread.c:148:8: warning: Although the value stored to 'ret' is used in the enclosing expression, the value is never actually read from 'ret' [deadcode.DeadStores]
if ((ret = prlimit (getpid (), RLIMIT_NPROC, &nl, &ol)) != 0)
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../../../source/glib/glib/tests/thread.c:174:8: warning: Although the value stored to 'ret' is used in the enclosing expression, the value is never actually read from 'ret' [deadcode.DeadStores]
if ((ret = prlimit (getpid (), RLIMIT_NPROC, &ol, NULL)) != 0)
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: #1767
