The API addition `uv_metrics_idle_time()` is a thread safe call that
allows the user to retrieve the amount of time the event loop has spent
in the kernel's event provider (i.e. poll). It was done this way to
allow retrieving this value without needing to interrupt the execution
of the event loop. This option can be enabled by passing
`UV_METRICS_IDLE_TIME` to `uv_loop_configure()`.
One important aspect of this change is, when enabled, to always first
call the event provider with a `timeout == 0`. This allows libuv to know
whether any events were waiting in the event queue when the event
provider was called. The importance of this is because libuv is tracking
the amount of "idle time", not "poll time". Thus the provider entry time
is not recorded when `timeout == 0` (the event provider never idles in
this case).
While this does add a small amount of overhead, when enabled, but the
overhead decreases when the event loop has a heavier load. This is
because poll events will be waiting when the event provider is called.
Thus never actually recording the provider entry time.
Checking if `uv_loop_t` is configured with `UV_METRICS_IDLE_TIME` always
happens in `uv__metrics_set_provider_entry_time()` and
`uv__metrics_update_idle_time()`. Making the conditional logic wrapping
each call simpler and allows for instrumentation to always hook into
those two function calls.
Rather than placing the fields directly on `uv__loop_internal_fields_t`
add the struct `uv__loop_metrics_t` as a location for future metrics API
additions.
Tests and additional documentation has been included.
PR-URL: https://github.com/libuv/libuv/pull/2725
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
Reviewed-By: Jameson Nash <vtjnash@gmail.com>
Add getter/setter functions for the fields of public structs that
might be relevant to e.g. Node.js addons.
Through these methods, ABI compatibility for a subset of the ABI
is easier to achieve, since using them makes code independent
of the exact offsets of these fields.
The intended use case that prompted this are N-API addons for
Node.js, which look for more long-term ABI compatibility guarantees
than typical Node code. With these helper functions, using libuv
directly should no longer be an obstacle for such addons.
PR-URL: https://github.com/libuv/libuv/pull/1657
Refs: https://github.com/nodejs/node/issues/13512
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
This function not only returns true if there are active handles or
requests. First of all, it also takes into account whether handles are
referenced. Second, handles that are being closed also contribute to
whether a loop is alive.
Fixes: https://github.com/libuv/libuv/issues/1592
PR-URL: https://github.com/libuv/libuv/pull/1594
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
Mea culpa, I forgot to update the documentation in commit ff0ae10
("unix: preserve loop->data across loop init/done") from July 2016.
PR-URL: https://github.com/libuv/libuv/pull/1299
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
Added the uv_loop_fork() API that must be called in a child process to
continue using an existing loop. Internally this calls a uv__io_fork
function for each supported platform, similar to the way
uv__platform_loop_init works.
After this call, existing and new IO, async and signal watchers will
contiue working as before on all platforms, as will the
threadpool (although any threads it was using are of course gone).
On Linux and BSDs that use kqueue, existing and new fsevent watchers
will also continue to work as expected. On OS X, though, directory
fsevents will not be able to use the optimized CoreFoundation path if
they had already been used in the parent process, instead falling back
to the kqueue path used on other BSDs.
Existing fsevent watchers will not function on AIX or SunOS. This
could be relatively easily fixed by someone with AIX knowledge in the
future, but SunOS will require some additional work to keep track if
the watchers.
A new test file, test/test-fork.c, was added to contain fork-related
tests to verify functionality in the child process.
PR-URL: https://github.com/libuv/libuv/pull/846
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>
Make explicit that handles and requests should be closed before calling
uv_loop_close().
Fixes: https://github.com/libuv/libuv/issues/765
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>
Saying uv_run() always returns zero is incorrect in the presence of
calls to uv_stop().
PR-URL: https://github.com/libuv/libuv/pull/337
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>
Indicate that it can (and should) also be closed, currently it's not
"special" in any way.
PR-URL: https://github.com/libuv/libuv/pull/147
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Fix various typos and spelling mistakes in the documentation
PR-URL: https://github.com/libuv/libuv/pull/17
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
