The CONST_MAX() macro is similar to MAX(), but verifies that both
arguments have the same type and are constant expressions. Furthermore,
the result of CONST_MAX() is again a constant-expression.
CONST_MAX() avoids any statement-expressions and other non-trivial
expression-types. This avoids rather arbitrary restrictions in both GCC
and LLVM, which both either fail with statement-expressions inside
type-declarations or statement-expressions inside static-const
initializations.
If anybody knows how to circumvent this, please feel free to unify
CONST_MAX() and MAX().
The "0,5" syntax was actually right. The real problem is, the test should
only run if the local system has the de_DE.UTF-8 locale. Therefore, skip
the tests if setlocale() fails. This is kinda ugly, as it is done
silently, but we cannot skip partial tests with the current
infrastructure. Should be fine this way.
One strtod() test is broken since:
commit 8e21100002
Author: Thomas Hindoe Paaboel Andersen <phomes@gmail.com>
Date: Mon Aug 4 23:13:31 2014 +0200
test: use fabs on doubles
The commit was right, so no reason to revert it, but the test was broken
before and only worked by coincidence. Convert "0,5" to "0.5" so we don't
depend on locales for double conversion (or well, we depend on "C" which
seems reasonable).
getopt is usually good at printing out a nice error message when
commandline options are invalid. It distinguishes between an unknown
option and a known option with a missing arg. It is better to let it
do its job and not use opterr=0 unless we actually want to suppress
messages. So remove opterr=0 in the few places where it wasn't really
useful.
When an error in options is encountered, we should not print a lengthy
help() and overwhelm the user, when we know precisely what is wrong
with the commandline. In addition, since help() prints to stdout, it
should not be used except when requested with -h or --help.
Also, simplify things here and there.
String which ended in an unfinished quote were accepted, potentially
with bad memory accesses.
Reject anything which ends in a unfished quote, or contains
non-whitespace characters right after the closing quote.
_FOREACH_WORD now returns the invalid character in *state. But this return
value is not checked anywhere yet.
Also, make 'word' and 'state' variables const pointers, and rename 'w'
to 'word' in various places. Things are easier to read if the same name
is used consistently.
mbiebl_> am I correct that something like this doesn't work
mbiebl_> ExecStart=/usr/bin/encfs --extpass='/bin/systemd-ask-passwd "Unlock EncFS"'
mbiebl_> systemd seems to strip of the quotes
mbiebl_> systemctl status shows
mbiebl_> ExecStart=/usr/bin/encfs --extpass='/bin/systemd-ask-password Unlock EncFS $RootDir $MountPoint
mbiebl_> which is pretty weird
The barrier_wait_next_twice* test-cases run:
Parent: Child:
set_alarm(10) sleep_for(1);
... set_alarm(1);
sleep_for(2) ...
Therefore, the parent exits after 2+ periods, the client's alarm fires
after 2+ periods. This race turns out to be lost by the child on other
machines, so avoid it by increasing the parent's sleep-interval to 4. This
way, the client has 2 periods to run the barrier test, which is far more
than enough.
Avoid using msecs in favor of usec_t. This is more consistent with the
other parts of systemd and avoids the confusion between msec and usec. We
always use usecs, end of story.
Require exact matches in all cases instead of treating strings
starting with 't' ('f') as true (false).
This is required for config_parse_protect_system to parse ProtectSystem=full
correctly: it uses parse_boolean and only tries a more specific parsing
function if that did not return a valid result. Thus "full" was treated as
"false" before.
Commit 637f421e5c ("cgroups: always propagate controller membership
to siblings") changed the mask propagation logic, but the test wasn't
updated.
Move to normal tests from manual tests, it should not touch the system
anymore.
It seems that unit_get_siblings_mask returns the controllers
filtered by what is available, but get_members_mask and
get_cgroup_mask do not. This just fixes the test following the
symptoms.
Also add a bit of debugging output to help diagnose problems,
add missing units, and simplify cppflags.
Move test-engine to normal tests from manual tests, it should now
work without destroying the system.
Explicitly initalize descriptors using explicit assignment like
bus_error. This makes barriers follow the same conventions as
everything else and makes things a bit simpler too.
Rename barier_init to barier_create so it is obvious that it is
not about initialization.
Remove some parens, etc.
This Pty API wraps the ugliness that is POSIX PTY. It takes care of:
- edge-triggered HUP handling (avoid heavy CPU-usage on vhangup)
- HUP vs. input-queue draining (handle HUP _after_ draining the whole
input queue)
- SIGCHLD vs. HUP (HUP is no reliable way to catch PTY deaths, always
use SIGCHLD. Otherwise, vhangup() and friends will break.)
- Output queue buffering (async EPOLLOUT handling)
- synchronous setup (via Barrier API)
At the same time, the PTY API does not execve(). It simply fork()s and
leaves everything else to the caller. Usually, they execve() but we
support other setups, too.
This will be needed by multiple UI binaries (systemd-console, systemd-er,
...) so it's placed in src/shared/. It's not strictly related to
libsystemd-terminal, so it's not included there.
The "Barrier" object is a simple inter-process barrier implementation. It
allows placing synchronization points and waiting for the other side to
reach it. Additionally, it has an abortion-mechanism as second-layer
synchronization to send abortion-events asynchronously to the other side.
The API is usually used to synchronize processes during fork(). However,
it can be extended to pass state through execve() so you could synchronize
beyond execve().
Usually, it's used like this (error-handling replaced by assert() for
simplicity):
Barrier b;
r = barrier_init(&b);
assert_se(r >= 0);
pid = fork();
assert_se(pid >= 0);
if (pid == 0) {
barrier_set_role(&b, BARRIER_CHILD);
...do child post-setup...
if (CHILD_SETUP_FAILED)
exit(1);
...child setup done...
barrier_place(&b);
if (!barrier_sync(&b)) {
/* parent setup failed */
exit(1);
}
barrier_destroy(&b); /* redundant as execve() and exit() imply this */
/* parent & child setup successful */
execve(...);
}
barrier_set_role(&b, BARRIER_PARENT);
...do parent post-setup...
if (PARENT_SETUP_FAILED) {
barrier_abort(&b); /* send abortion event */
barrier_wait_abortion(&b); /* wait for child to abort (exit() implies abortion) */
barrier_destroy(&b);
...bail out...
}
...parent setup done...
barrier_place(&b);
if (!barrier_sync(&b)) {
...child setup failed... ;
barrier_destroy(&b);
...bail out...
}
barrier_destroy(&b);
...child setup successfull...
This is the most basic API. Using barrier_place() to place barriers and
barrier_sync() to perform a full synchronization between both processes.
barrier_abort() places an abortion barrier which superceeds any other
barriers, exit() (or barrier_destroy()) places an abortion-barrier that
queues behind existing barriers (thus *not* replacing existing barriers
unlike barrier_abort()).
This example uses hard-synchronization with wait_abortion(), sync() and
friends. These are all optional. Barriers are highly dynamic and can be
used for one-way synchronization or even no synchronization at all
(postponing it for later). The sync() call performs a full two-way
synchronization.
The API is documented and should be fairly self-explanatory. A test-suite
shows some special semantics regarding abortion, wait_next() and exit().
Internally, barriers use two eventfds and a pipe. The pipe is used to
detect exit()s of the remote side as eventfds do not allow that. The
eventfds are used to place barriers, one for each side. Barriers itself
are numbered, but the numbers are reused once both sides reached the same
barrier, thus you cannot address barriers by the index. Moreover, the
numbering is implicit and we only store a counter. This makes the
implementation itself very lightweight, which is probably negligible
considering that we need 3 FDs for a barrier..
Last but not least: This barrier implementation is quite heavy. It's
definitely not meant for fast IPC synchronization. However, it's very easy
to use. And given the *HUGE* overhead of fork(), the barrier-overhead
should be negligible.
