binutils-gdb/gdbsupport
Michael Weghorn 9a6e099f43 gdbsupport: allow to specify dependencies between observers
Previously, the observers attached to an observable were always notified
in the order in which they had been attached.  That order is not easily
controlled, because observers are typically attached in _initialize_*
functions, which are called in an undefined order.

However, an observer may require that another observer attached only
later is called before itself is.

Therefore, extend the 'observable' class to allow explicitly specifying
dependencies when attaching observers, by adding the possibility to
specify tokens for observers that it depends on.

To make sure dependencies are notified before observers depending on
them, the vector holding the observers is sorted in a way that
dependencies come before observers depending on them.  The current
implementation for sorting uses the depth-first search algorithm for
topological sorting as described at [1].

Extend the observable unit tests to cover this case as well.  Check that
this works for a few different orders in which the observers are
attached.

This newly introduced mechanism to explicitly specify dependencies will
be used in a follow-up commit.

[1] https://en.wikipedia.org/wiki/Topological_sorting#Depth-first_search

Tested on x86_64-linux (Debian testing).

gdb/ChangeLog:

	* unittests/observable-selftests.c (dependency_test_counters):
	New.
	(observer_token0, observer_token1, observer_token2,
	observer_token3, observer_token4, observer_token5): New.
	(struct dependency_observer_data): New struct.
	(observer_dependency_test_callback): New function.
	(test_observers): New.
	(run_dependency_test): New function.
	(test_dependency): New.
	(_initialize_observer_selftest): Register dependency test.

gdbsupport/ChangeLog:

	* observable.h (class observable): Extend to allow specifying
	dependencies between observers, keep vector holding observers
	sorted so that dependencies are notified before observers
	depending on them.

Change-Id: I5399def1eeb69ca99e28c9f1fdf321d78b530bdb
2021-04-27 11:22:32 -04:00
..
.dir-locals.el Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
.gitattributes gdb, gdbserver, gdbsupport: add .gitattributes files 2020-03-05 15:59:22 +01:00
acinclude.m4 gdb: move ptrace.m4 to gdbsupport 2020-10-25 21:08:49 -04:00
aclocal.m4 gdb: use AC_PROG_CC_STDC instead of AM_PROG_CC_STDC 2020-10-31 08:30:57 -04:00
agent.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
agent.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
alt-stack.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
array-view.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
ax.def Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
block-signals.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
break-common.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
btrace-common.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
btrace-common.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
buffer.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
buffer.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
byte-vector.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
ChangeLog gdbsupport: allow to specify dependencies between observers 2021-04-27 11:22:32 -04:00
check-defines.el Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
cleanups.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
cleanups.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
common-debug.cc gdb: add remote_debug_printf 2021-01-22 12:43:27 -05:00
common-debug.h gdbsupport: allow passing format string to scoped_debug_start_end 2021-04-24 19:26:41 -04:00
common-defs.h gnulib: update to 776af40e0 2021-02-05 13:35:20 -05:00
common-exceptions.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
common-exceptions.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
common-gdbthread.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
common-inferior.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
common-inferior.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
common-regcache.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
common-regcache.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
common-types.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
common-utils.cc New memory-tag commands 2021-03-24 14:57:53 -03:00
common-utils.h New memory-tag commands 2021-03-24 14:57:53 -03:00
common.m4 Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
config.in Require kinfo_get_file and kinfo_get_vmmap for FreeBSD hosts. 2020-09-16 11:40:05 -07:00
configure gdbsupport: replace AC_TRY_COMPILE in common.m4 2020-10-31 08:31:00 -04:00
configure.ac Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
create-version.sh Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
def-vector.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
default-init-alloc.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
eintr.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
enum-flags.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
environ.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
environ.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
errors.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
errors.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
event-loop.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
event-loop.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
fileio.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
fileio.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
filestuff.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
filestuff.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
filtered-iterator.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
format.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
format.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
forward-scope-exit.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
function-view.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb-dlfcn.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb-dlfcn.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb-safe-ctype.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb-sigmask.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_assert.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_binary_search.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_locale.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_optional.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_proc_service.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_ref_ptr.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_select.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_setjmp.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_signals.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_splay_tree.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_string_view.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_string_view.tcc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_sys_time.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_tilde_expand.cc Improve gdb_tilde_expand logic. 2021-01-23 17:17:38 +00:00
gdb_tilde_expand.h Improve gdb_tilde_expand logic. 2021-01-23 17:17:38 +00:00
gdb_unique_ptr.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_unlinker.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_vecs.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_vecs.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_wait.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
gdb_wait.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
hash_enum.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
host-defs.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
job-control.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
job-control.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
Makefile.am Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
Makefile.in Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
netstuff.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
netstuff.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
new-op.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
next-iterator.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
observable.h gdbsupport: allow to specify dependencies between observers 2021-04-27 11:22:32 -04:00
offset-type.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
parallel-for.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
pathstuff.cc gdb: check for empty strings in get_standard_cache_dir/get_standard_config_dir 2021-01-08 13:46:56 -05:00
pathstuff.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
poison.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
preprocessor.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
print-utils.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
print-utils.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
ptid.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
ptid.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
ptrace.m4 Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
README
refcounted-object.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
rsp-low.cc New memory-tag commands 2021-03-24 14:57:53 -03:00
rsp-low.h New memory-tag commands 2021-03-24 14:57:53 -03:00
run-time-clock.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
run-time-clock.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
safe-iterator.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
safe-strerror.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
scope-exit.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
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scoped_restore.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
search.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
search.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
selftest.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
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signals-state-save-restore.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
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signals.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
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version.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
warning.m4 Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
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xml-utils.cc Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00
xml-utils.h Update copyright year range in all GDB files 2021-01-01 12:12:21 +04:00

This is a helper library that is used by gdb and gdbserver.

To send patches, follow the gdb patch submission instructions in
../gdb/CONTRIBUTE.  For maintainers, see ../gdb/MAINTAINERS.