systemd, dbus-broker, and many glib applications heavily
utilize the GNU C attribute "cleanup" to achieve C++ RAII-like
semantics for local resource management. This commit introduces
essentialy same mechanism into pipewire.
At the moment, this is inteded to be a strictly private API.
free() and close() as cleanup targets are sufficiently common
to warrant their own special macros:
spa_autofree char *s = strdup(p);
// will call `free(s)` at the end of the lifetime of `s`
spa_autoclose int fd = openat(...);
// will call `close(fd)` if `fd >= 0` at the end of the lifetime of `fd`
However, with `spa_auto()` or `spa_autoptr()` it is possible to define
other variables that will be cleaned up properly. Currently four are supported:
spa_autoptr(FILE) f = fopen(...);
// `f` has type `FILE *`
// will call `fclose(f)` if `f != NULL`
spa_autoptr(DIR) d = opendir(...);
// `d` has type `DIR *`
// will call `closedir(d)` if `d != NULL`
spa_autoptr(pw_properties) p = pw_properties_new(NULL, NULL);
// `p` has type `struct pw_properties *`
// will call `pw_properties_free(p)`
spa_auto(pw_strv) v = pw_split_strv(...);
// `v` has type `char **`
// will call `pw_strv_free(v)`
It is possible to add support for other types, e.g.
SPA_DEFINE_AUTOPTR_CLEANUP(pw_main_loop, struct pw_main_loop, {
// the pointer can be accessed using `*thing`
// `thing` has type `struct pw_main_loop **`
spa_clear_ptr(*thing, pw_main_loop_destroy);
})
spa_autoptr(pw_main_loop) l = ...;
// `l` has type `struct pw_main_loop *`
// will call `pw_main_loop_destroy(l)`
or
SPA_DEFINE_AUTO_CLEANUP(spa_pod_dynamic_builder, struct spa_pod_dynamic_builder, {
// `thing` has type `struct spa_pod_dynamic_builder *`
spa_pod_dynamic_builder_clean(thing);
})
spa_auto(spa_pod_dynamic_builder) builder = ...
// `builder` has type `struct spa_pod_dynamic_builder`
// will call `spa_pod_dynamic_builder_clean(&builder)`
The first argument is always an arbitrary name. This name must be passed to
`spa_auto()` and `spa_autoptr()` as it is what determines the actual type
and destructor used. The second parameter is the concrete type. For
`SPA_DEFINE_AUTO_CLEANUP()` this is the concrete type to be used, while for
`SPA_DEFINE_AUTOPTR_CLEANUP()` it is the concrete type without the
outermost pointer. That is,
SPA_DEFINE_AUTOPTR_CLEANUP(A, foo, ...)
SPA_DEFINE_AUTO_CLEANUP(B, foo, ...)
spa_autoptr(A) x; // `x` has type `foo *`
spa_auto(B) y; // `y` has type `foo`
A couple other macros are also added:
spa_clear_ptr(ptr, destructor)
// calls `destructor(ptr)` if `ptr != NULL` and sets `ptr` to `NULL`
spa_clear_fd(fd)
// calls `close(fd)` if `fd >= 0` and sets `fd` to -1
spa_steal_ptr(ptr)
// sets `ptr` to `NULL` and returns the old value,
// useful for preventing the auto cleanup mechanism from kicking in
// when returning the pointer from a function
spa_steal_fd(fd)
// sets `fd` to -1 and returns the old value
When we destroy a node, we need to remove the node as a current
driver peer.
Not doing this has 2 problems:
- remote drivers still trigger our node
- the client-node does not clean up the memid for the activation and
we might reuse it later for a new node with the same fd.
See #3316
We have SPA_ID_INVALID mix id for all ports to handle the formats and
buffers, we don't need to init/release the mix for this or else our
n_mix accounting is wrong and we might not clear the format right.
When the samplerate is smaller than half of the default, try to find a
rate less than the default to upsample to.
pavucontrol now asks for a 1/144 rate, which resulted in a graph rate of
88200 before this change.
See #3320
The function already returns `ssize_t`, so do not use `errno`
to communicate the reason for failure, instead, return the
negative errno.
`pw_getrandom()` was inconsistent in this regard because
sometimes it simply returned a negative errno without
setting `errno`. This change fixes that as well.
On some filesystems, the directory entry type is immediately
available, so use that to check if the entity is a directory,
and only use `stat()` when the entity type cannot be determined
from the directory entry.
Document the pulse.fix properties.
Add an option to disable handling of the FIX flags when the pulse.fix.
property is set to an invalid value/0.
See #3317
`pw_proxy::core` must be initialized for `pw_proxy_init()`
to succeed, so take it as a parameter instead of relying
on the caller to initialize that field beforehand.
