tree-wide: remove Emacs lines from all files This should be handled fine now by .dir-locals.el, so need to carry that stuff in every file.

sd-event: permit a USEC_INFINITY timeout as an alternative to a disabling an event source This should simplify handling of time events in clients and is in-line with the USEC_INFINITY macro we already have. This way setting a timeout to 0 indicates "elapse immediately", and a timeout of USEC_INFINITY "elapse never".

sd-event: when determining the last allowed time a time event may elapse, deal with overflows

sd-event: fix theoretical leak on error in event_make_signal_data

sd-event: check clock argument to sd_event_now() sd_event_now() is a public function, so we must check all arguments for validity. Update man page and add tests. Sample debug message: Assertion 'IN_SET(clock, CLOCK_REALTIME, CLOCK_REALTIME_ALARM, CLOCK_MONOTONIC, CLOCK_BOOTTIME, CLOCK_BOOTTIME_ALARM)' failed at src/libsystemd/sd-event/sd-event.c:2719, function sd_event_now(). Ignoring.

sd-event: minor fixups to delays profiling changes

sd-event: instrument sd_event_run() for profiling delays Set SD_EVENT_PROFILE_DELAYS to activate accounting and periodic logging of the distribution of delays between sd_event_run() calls. Time spent in dispatching as well as time spent outside of sd_event_run() is measured and accounted for. Every 5 seconds a logarithmic histogram loop iteration delays since 5 seconds previous is logged. This is useful in identifying the frequency and magnitude of latencies affecting the event loop, which should be kept to a minimum.

sd-event: improve debugging of event source errors Printing the pointer variable really doesn't help, so drop that. Instead, add a string lookup table for the EventSourceType enum, and print the type of event source in case of errors.

sd-event: use prioq_ensure_allocated where possible

sd-event: define a new PREPARING state We already have a state RUNNING and EXITING when we dispatch regular and exit callbacks. Let's introduce a new state called PREPARING that is active while we invoke preparation callbacks. This way we have a state each for all three kinds of event handlers. The states are currently not documented, hence let's add a new state to the end, before we start documenting this.

sd-event: make _ref() calls NOPs when NULL is passed to them Let's make _ref() calls happy when NULL is passed to them, and simply return NULL without any assertion logic. This makes them nicely symmetric to the _unref() calls which also are happy to take NULL and become NOPs then.

tree-wide: use right cast macros for UIDs, GIDs and PIDs

util-lib: split out allocation calls into alloc-util.[ch]

util-lib: split out fd-related operations into fd-util.[ch] There are more than enough to deserve their own .c file, hence move them over.

util-lib: split our string related calls from util.[ch] into its own file string-util.[ch] There are more than enough calls doing string manipulations to deserve its own files, hence do something about it. This patch also sorts the #include blocks of all files that needed to be updated, according to the sorting suggestions from CODING_STYLE. Since pretty much every file needs our string manipulation functions this effectively means that most files have sorted #include blocks now. Also touches a few unrelated include files.

sd-bus: fix error handling of pthread API calls pthread APIs (unlike the rest of libc) return their errors as positive error codes directly from the functions, rather than using errno. Let's make sure we always handle things that way.

sd-event: don't provide priority stability Currently, we guarantee that if two event-sources with the same priority fire at the same time, they're always dispatched in the same order. While this might sound nice in theory, there's is little benefit in providing stability on that level. We have no control over the order the events are reported, hence, we cannot guarantee that we get notified about both at the same time. By dropping the stability guarantee, we loose roughly 10% Heap swaps in the prioq on a desktop cold-boot. Krzysztof Kotlenga even reported up to 20% on his tests. This sounds worth optimizing, so drop the stability guarantee.

sd-event: fix prepare priority queue comparison function Otherwise a disabled event source can get swapped with an enabled one and cause a severe sd-event malfunction. http://lists.freedesktop.org/archives/systemd-devel/2015-September/034356.html

sd-event: make sure to create a signal queue for the right signal We should never access the "signal" part of the event source unless the event source is actually for a signal. In this case it's a child pid handler however, hence make sure to use the right signal. This is a fix for PR #1177, which in turn was a fix for 9da4cb2be260ed123f2676cb85cb350c527b1492.

sd-event: fix call to event_make_signal_data This looks like a typo from commit 9da4cb2b where it was added.

sd-event: make sure RT signals are not dropped RT signals operate in a queue, and we should be careful to never merge two queued signals into one. Hence, makes sure we only ever dequeue a single signal at a time and leave the remaining ones queued in the signalfd. In order to implement correct priorities for the signals introduce one signalfd per priority, so that we only process the highest priority signal at a time.

sd-event: improve debug message when we fail to remove and fd from an epoll Let's help users to debug issues with epoll fd removal by printing the name of the event source.

tree-wide: generate EBADF when we get invalid fds This is a follow-up to #907, and makes the same change for all our other public APIs.

sd-event: make sure sd_event_now() cannot fail Previously, if the event loop never ran before sd_event_now() would fail. With this change it will instead fall back to invoking now(). This way, the function cannot fail anymore, except for programming error when invoking it with wrong parameters. This takes into account the fact that many callers did not handle the error condition correctly, and if the callers did, then they kept simply invoking now() as fall back on their own. Hence let's shorten the code using this call, and make things more robust, and let's just fall back to now() internally. Whether now() is used or the cache timestamp may still be detected via the return value of sd_event_now(). If > 0 is returned, then the fall back to now() was used, if == 0 is returned, then the cached value was returned. This patch also simplifies many of the invocations of sd_event_now(): the manual fall back to now() can be removed. Also, in cases where the call is invoked withing void functions we can now protect the invocation via assert_se(), acknowledging the fact that the call cannot fail anymore except for programming errors with the parameters. This change is inspired by #841.

sd-event: make errors on EPOLL_CTL_DEL pseudo-fatal If we call EPOLL_CTL_DEL, we *REALLY* expect the file-descriptor to be present in that given epoll-set. We actually track such state via our s->io.registered flag, so it better be true. Make sure if that's not true, we treat it similar to assert_return() (ie., print a loud warning).

logind,sd-event: drop spurious new-lines

sd-event: don't touch fd's accross forks We protect most of the API from use accross forks, but we still allow both sd_event and sd_event_source objects to be unref'ed. This would cause problems as it would unregister sources from the underlying eventfd, hence also affecting the original instance in the parent process. This fixes the issue by not touching the fds on unref when done accross a fork, but still free the memory. This fixes a regression introduced by "udevd: move main-loop to sd-event": 693d371d30fee where the worker processes were disabling the inotify event source in the main daemon.

util: split out signal-util.[ch] from util.[ch] No functional changes.

sd-event: simplify sd_event_run()

sd-event: sd_event_run - only return 0 on timeout sd_event_dispatch() returns 0 on FINISH, so let's eat that up.

sd-event: rename PASSIVE/PREPARED to INITIAL/ARMED

tree-wide: there is no ENOTSUP on linux Replace ENOTSUP by EOPNOTSUPP as this is what linux actually uses.

sd-event: fix typo

Remove the cap on epoll events Currently the code will silently blank out events if there are more then 512 epoll events, causing them never to be handled at all. This patch removes the cap on the number of events for epoll_wait, thereby avoiding this issue.

remove unused includes This patch removes includes that are not used. The removals were found with include-what-you-use which checks if any of the symbols from a header is in use.

sd-event: treat NULL callback for timer events like sig events In both cases exit the event loop.

treewide: no need to negate errno for log_*_errno() It corrrectly handles both positive and negative errno values.

treewide: auto-convert the simple cases to log_*_errno() As a followup to 086891e5c1 "log: add an "error" parameter to all low-level logging calls and intrdouce log_error_errno() as log calls that take error numbers", use sed to convert the simple cases to use the new macros: find . -name '*.[ch]' | xargs sed -r -i -e \ 's/log_(debug|info|notice|warning|error|emergency)\("(.*)%s"(.*), strerror\(-([a-zA-Z_]+)\)\);/log_\1_errno(-\4, "\2%m"\3);/' Multi-line log_*() invocations are not covered. And we also should add log_unit_*_errno().

sd-bus,sd-event: unify error handling of object descriptions a) When getting the description return ENXIO if none is set b) Allow setting a description to NULL c) return ECHILD on fork() like for other calls

sd-event: implicitly set signal event source's descriptions to the signal name

sd-event: rename sd_event_source_set_name() to sd_event_source_get_name() To mirror the recent name change of the concept for sd_bus objects, follow the same logic for sd_event_source objects, too.

sd-event: also update signal mask when disconnecting sources

sd-event: be more careful when enabling/disabling signals When a child event is disabled (in order to be freed) and there is no SIGCHLD signal event, sd_event_source_set_enabled will disable SIGCHLD even if there are other child events. Also remove some unneeded signalfd updates. https://bugs.freedesktop.org/show_bug.cgi?id=84659 Based-on-a-patch-by: Hristo Venev <mustrumr97@gmail.com>

sd-event: check the value of received signal Appease coverity report #1237775. Also rename ss to n, to make it visually different from ss.

hashmap: introduce hash_ops to make struct Hashmap smaller It is redundant to store 'hash' and 'compare' function pointers in struct Hashmap separately. The functions always comprise a pair. Store a single pointer to struct hash_ops instead. systemd keeps hundreds of hashmaps, so this saves a little bit of memory.

sd-event: simplify sd_event_source_set_name() free_and_strdup() does exactly the same as sd_event_source_set_name(), use it!

sd-event: use event source name rather than address in debug messages

sd-event: allow naming event sources

sd-event: sd_event_prepare - stay in PREPARED if sd_event_wait() indicates that no sources are pending

sd-event: split run into prepare/wait/dispatch This will allow sd-event to be integrated into an external event loop, which in turn will allow (say) glib-based applications to use our various libraries, without manually integrating each of them (bus, rtnl, dhcp, ...). The external event-loop should integrate sd-event int he following way: Every iteration must start with a call to sd_event_prepare(), which will return 0 if no event sources are ready to be processed, a positive value if they are and a negative value on error. sd_event_prepare() may only be called following sd_event_dispatch(); a call to sd_event_wait() indicating that no sources are ready to be dispatched; or a failed call to sd_event_dispatch() or sd_event_wait(). A successful call to sd_event_prepare() indicating that no event sources are ready to be dispatched must be followed by a call to sd_event_wait(), which will return 0 if it timed out without event sources being ready to be processed, a negative value on error and a positive value otherwise. sd_event_wait() may only be called following a successful call to sd_event_prepare() indicating that no event sources are ready to be dispatched. If sd_event_wait() indicates that some events sources are ready to be dispatched, it must be followed by a call to sd_event_dispatch(). This is the only time sd_event_dispatch() may be called.

sd-event: add API to access epoll_fd This is a prerequisite for integrating sd-event into an external event loop.

sd-event: return 'r' rather than '-errno'

sd-event: fix missing needs_rearm

sd-event: drop _likely_() This is not certain to be likely. Lennart says: a frequent usecase is invoking some function regularly in intervals in such a case every single iteration we'll have to rearm

sd-event: do not arm timers unnecessarily Rather than recalculating the next timeout on every loop, we only do it when something changed.

time-util: add and use USEC/NSEC_INFINIY

sd-event: add support for CLOCK_BOOTTIME This requires a very recent kernel (3.15), so care should be taken when using this functionality.

sd-event: don't require a signal event source to be enabled for the child event source to work

sd-event: always call epoll_ctl() on mask-updates if edge-triggered A call to sd_event_source_set_io_events() skipps calling into the kernel if the new event-mask matches the old one. This is safe for level-triggered sources as the kernel moves them onto the ready-list automatically if events change. However, edge-triggered sources might not be on the ready-list even though events are present. A call to sd_event_source_set_io_events() with EPOLLET set might thus be used to just move the io-source onto the ready-list so the next poll will return it again. This is very useful to avoid starvation in priority-based event queues. Imagine a read() loop on an edge-triggered fd. If we cannot read data fast enough to drain the receive queue, we might decide to skip reading for now and schedule it for later. On edge-triggered io-sources we have to make sure it's put on the ready-list so the next dispatch-round will return it again if it's still the highest priority task. We could make sd-event handle edge-triggered sources directly and allow marking them ready again. However, it's much simpler to let the kernel do that for now via EPOLL_CTL_MOD.

sd-event: restore correct timeout behaviour

sd-resolve: add "floating" resolve queries Same story as for sd-bus and sd-event: allow passing NULL to store query in in which case the query is freed automatically.

sd-event: introduce concept of "floating" event sources These are the counterpart of "floating" bus slots, i.e. event sources that are bound to the lifetime of the event object itself, and thus don't require an explicit reference to be kept.

sd-event: allow disabling event sources when an event object is dying anyway

sd-event: make it easy to bind signal handling to event loop exits By passing a NULL callback provide a simple way to make event loops exit on SIGTERM and other signals.

silence warnings

sd-event: don't accidentally turn of watchdog timer event if we determine 0

sd-event: initialization perturbation value right before we use it That way, we don't forget to initialize it when the watchdog is initialized before all event sources.

networkd: fix a couple of memory leaks

sd-event: rework API to support CLOCK_REALTIME_ALARM and CLOCK_BOOTTIME_ALARM, too

util: replace close_nointr_nofail() by a more useful safe_close() safe_close() automatically becomes a NOP when a negative fd is passed, and returns -1 unconditionally. This makes it easy to write lines like this: fd = safe_close(fd); Which will close an fd if it is open, and reset the fd variable correctly. By making use of this new scheme we can drop a > 200 lines of code that was required to test for non-negative fds or to reset the closed fd variable afterwards.

Remove dead lines in various places As pointed-out by clang -Wunreachable-code. No behaviour changes.

event: add new kind of event source called "post" This new event source is triggered by the dispatching of any non-post event source. It can thus be used to do clean-up or recheck work, triggered by any other event source having been executed. This is different from "defer" event source which are unconditionally triggered as long as they are enabled. A "defer" event source that does nothing will result in the event loop busy looping unless it is turned off eventually. This is different for "post" event sources that will be only triggered when some other non-post ran, and will thus not keep the event loop busy on its own.

sd-event: Fix systemd crash when using timer units. There was a copy-paste error introduced in commit c2ba3ad6604ef2e189d7e0a36d6911116e84d3ab which causes the following error when using timer units: Assertion '(x->type == SOURCE_MONOTONIC && y->type == SOURCE_MONOTONIC) || (x->type == SOURCE_REALTIME && y->type == SOURCE_REALTIME)' failed at src/libsystemd/sd-event/sd-event.c:264, function latest_time_prioq_compare(). Aborting.

api: in constructor function calls, always put the returned object pointer first (or second) Previously the returned object of constructor functions where sometimes returned as last, sometimes as first and sometimes as second parameter. Let's clean this up a bit. Here are the new rules: 1. The object the new object is derived from is put first, if there is any 2. The object we are creating will be returned in the next arguments 3. This is followed by any additional arguments Rationale: For functions that operate on an object we always put that object first. Constructors should probably not be too different in this regard. Also, if the additional parameters might want to use varargs which suggests to put them last. Note that this new scheme only applies to constructor functions, not to all other functions. We do give a lot of freedom for those. Note that this commit only changes the order of the new functions we added, for old ones we accept the wrong order and leave it like that.

make gcc shut up If -flto is used then gcc will generate a lot more warnings than before, among them a number of use-without-initialization warnings. Most of them without are false positives, but let's make them go away, because it doesn't really matter.

event: fix crash on child-source state modifications Setting a child-source state to anything but SD_EVENT_OFF currently does nothing. The condition logic is flawed. Move the state update *below* the test for the previous state. Fixes a crash if you call: sd_event_source_set_enabled(source, SD_EVENT_ON); sd_event_source_unref(source); on a child-source in its own callback.

libsystemd: split up into subdirs We still only produce on .so, but let's keep the sources separate to make things a bit less messy.