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/* Simple Plugin API */
/* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
/* SPDX-License-Identifier: MIT */
#ifndef SPA_LOOP_H
#define SPA_LOOP_H
#ifdef __cplusplus
extern "C" {
#endif
#include <errno.h>
#include <spa/utils/defs.h>
#include <spa/utils/hook.h>
#include <spa/support/system.h>
#ifndef SPA_API_LOOP
#ifdef SPA_API_IMPL
#define SPA_API_LOOP SPA_API_IMPL
#else
#define SPA_API_LOOP static inline
#endif
#endif
/** \defgroup spa_loop Loop
* Event loop interface
*/
/**
* \addtogroup spa_loop
* \{
*/
#define SPA_TYPE_INTERFACE_Loop SPA_TYPE_INFO_INTERFACE_BASE "Loop"
#define SPA_TYPE_INTERFACE_DataLoop SPA_TYPE_INFO_INTERFACE_BASE "DataLoop"
#define SPA_VERSION_LOOP 0
struct spa_loop { struct spa_interface iface; };
#define SPA_TYPE_INTERFACE_LoopControl SPA_TYPE_INFO_INTERFACE_BASE "LoopControl"
#define SPA_VERSION_LOOP_CONTROL 1
struct spa_loop_control { struct spa_interface iface; };
#define SPA_TYPE_INTERFACE_LoopUtils SPA_TYPE_INFO_INTERFACE_BASE "LoopUtils"
#define SPA_VERSION_LOOP_UTILS 0
struct spa_loop_utils { struct spa_interface iface; };
struct spa_source;
typedef void (*spa_source_func_t) (struct spa_source *source);
struct spa_source {
struct spa_loop *loop;
spa_source_func_t func;
void *data;
int fd;
uint32_t mask;
uint32_t rmask;
/* private data for the loop implementer */
void *priv;
};
typedef int (*spa_invoke_func_t) (struct spa_loop *loop,
bool async,
uint32_t seq,
const void *data,
size_t size,
void *user_data);
/**
* Register sources and work items to an event loop
*/
struct spa_loop_methods {
/* the version of this structure. This can be used to expand this
* structure in the future */
#define SPA_VERSION_LOOP_METHODS 0
uint32_t version;
/** Add a source to the loop. Must be called from the loop's own thread.
*
* \param[in] object The callbacks data.
* \param[in] source The source.
* \return 0 on success, negative errno-style value on failure.
*/
int (*add_source) (void *object,
struct spa_source *source);
/** Update the source io mask. Must be called from the loop's own thread.
*
* \param[in] object The callbacks data.
* \param[in] source The source.
* \return 0 on success, negative errno-style value on failure.
*/
int (*update_source) (void *object,
struct spa_source *source);
/** Remove a source from the loop. Must be called from the loop's own thread.
*
* \param[in] object The callbacks data.
* \param[in] source The source.
* \return 0 on success, negative errno-style value on failure.
*/
int (*remove_source) (void *object,
struct spa_source *source);
/** Invoke a function in the context of this loop.
* May be called from any thread and multiple threads at the same time.
* If called from the loop's thread, all callbacks previously queued with
* invoke() will be run synchronously, which might cause unexpected
* reentrancy problems.
*
* \param[in] object The callbacks data.
* \param func The function to be invoked.
* \param seq An opaque sequence number. This will be made
* available to func.
* \param[in] data Data that will be copied into the internal ring buffer and made
* available to func. Because this data is copied, it is okay to
* pass a pointer to a local variable, but do not pass a pointer to
* an object that has identity.
* \param size The size of data to copy.
* \param block If \true, do not return until func has been called. Otherwise,
* returns immediately. Passing \true does not risk a deadlock because
* the data thread is never allowed to wait on any other thread.
* \param user_data An opaque pointer passed to func.
* \return `-EPIPE` if the internal ring buffer filled up,
* if block is \false, 0 if seq was SPA_ID_INVALID or
* seq with the ASYNC flag set
* or the return value of func otherwise. */
int (*invoke) (void *object,
spa_invoke_func_t func,
uint32_t seq,
const void *data,
size_t size,
bool block,
void *user_data);
};
SPA_API_LOOP int spa_loop_add_source(struct spa_loop *object, struct spa_source *source)
{
return spa_api_method_r(int, -ENOTSUP,
spa_loop, &object->iface, add_source, 0, source);
}
SPA_API_LOOP int spa_loop_update_source(struct spa_loop *object, struct spa_source *source)
{
return spa_api_method_r(int, -ENOTSUP,
spa_loop, &object->iface, update_source, 0, source);
}
SPA_API_LOOP int spa_loop_remove_source(struct spa_loop *object, struct spa_source *source)
{
return spa_api_method_r(int, -ENOTSUP,
spa_loop, &object->iface, remove_source, 0, source);
}
SPA_API_LOOP int spa_loop_invoke(struct spa_loop *object,
spa_invoke_func_t func, uint32_t seq, const void *data,
size_t size, bool block, void *user_data)
{
return spa_api_method_r(int, -ENOTSUP,
spa_loop, &object->iface, invoke, 0, func, seq, data,
size, block, user_data);
}
/** Control hooks. These hooks can't be removed from their
* callbacks and must be removed from a safe place (when the loop
* is not running or when it is locked). */
struct spa_loop_control_hooks {
#define SPA_VERSION_LOOP_CONTROL_HOOKS 0
uint32_t version;
/** Executed right before waiting for events. It is typically used to
* release locks. */
void (*before) (void *data);
/** Executed right after waiting for events. It is typically used to
* reacquire locks. */
void (*after) (void *data);
};
SPA_API_LOOP void spa_loop_control_hook_before(struct spa_hook_list *l)
{
struct spa_hook *h;
spa_list_for_each_reverse(h, &l->list, link)
spa_callbacks_call_fast(&h->cb, struct spa_loop_control_hooks, before, 0);
}
SPA_API_LOOP void spa_loop_control_hook_after(struct spa_hook_list *l)
{
struct spa_hook *h;
spa_list_for_each(h, &l->list, link)
spa_callbacks_call_fast(&h->cb, struct spa_loop_control_hooks, after, 0);
}
/**
* Control an event loop
*
* The event loop control function provide API to run the event loop.
*
* The below (pseudo)code is a minimal example outlining the use of the loop
* control:
* \code{.c}
* spa_loop_control_enter(loop);
* while (running) {
* spa_loop_control_iterate(loop, -1);
* }
* spa_loop_control_leave(loop);
* \endcode
*
* It is also possible to add the loop to an existing event loop by using the
* spa_loop_control_get_fd() call. This fd will become readable when activity
* has been detected on the sources in the loop. spa_loop_control_iterate() with
* a 0 timeout should be called to process the pending sources.
*
* spa_loop_control_enter() and spa_loop_control_leave() should be called once
* from the thread that will run the iterate() function.
*/
struct spa_loop_control_methods {
/* the version of this structure. This can be used to expand this
* structure in the future */
#define SPA_VERSION_LOOP_CONTROL_METHODS 1
uint32_t version;
/** get the loop fd
* \param object the control to query
*
* Get the fd of this loop control. This fd will be readable when a
* source in the loop has activity. The user should call iterate()
* with a 0 timeout to schedule one iteration of the loop and dispatch
* the sources.
* \return the fd of the loop
*/
int (*get_fd) (void *object);
/** Add a hook
* \param object the control to change
* \param hooks the hooks to add
*
* Adds hooks to the loop controlled by \a ctrl.
*/
void (*add_hook) (void *object,
struct spa_hook *hook,
const struct spa_loop_control_hooks *hooks,
void *data);
/** Enter a loop
* \param object the control
*
* This function should be called before calling iterate and is
* typically used to capture the thread that this loop will run in.
* It should ideally be called once from the thread that will run
* the loop.
*/
void (*enter) (void *object);
/** Leave a loop
* \param object the control
*
* It should ideally be called once after calling iterate when the loop
* will no longer be iterated from the thread that called enter().
*/
void (*leave) (void *object);
/** Perform one iteration of the loop.
* \param ctrl the control
* \param timeout an optional timeout in milliseconds.
* 0 for no timeout, -1 for infinite timeout.
*
* This function will block
* up to \a timeout milliseconds and then dispatch the fds with activity.
* The number of dispatched fds is returned.
*/
int (*iterate) (void *object, int timeout);
/** Check context of the loop
* \param ctrl the control
*
* This function will check if the current thread is currently the
* one that did the enter call. Since version 1:1.
*
* returns 1 on success, 0 or negative errno value on error.
*/
int (*check) (void *object);
};
SPA_API_LOOP int spa_loop_control_get_fd(struct spa_loop_control *object)
{
return spa_api_method_r(int, -ENOTSUP,
spa_loop_control, &object->iface, get_fd, 0);
}
SPA_API_LOOP void spa_loop_control_add_hook(struct spa_loop_control *object,
struct spa_hook *hook, const struct spa_loop_control_hooks *hooks,
void *data)
{
spa_api_method_v(spa_loop_control, &object->iface, add_hook, 0,
hook, hooks, data);
}
SPA_API_LOOP void spa_loop_control_enter(struct spa_loop_control *object)
{
spa_api_method_v(spa_loop_control, &object->iface, enter, 0);
}
SPA_API_LOOP void spa_loop_control_leave(struct spa_loop_control *object)
{
spa_api_method_v(spa_loop_control, &object->iface, leave, 0);
}
SPA_API_LOOP int spa_loop_control_iterate(struct spa_loop_control *object,
int timeout)
{
return spa_api_method_r(int, -ENOTSUP,
spa_loop_control, &object->iface, iterate, 0, timeout);
}
SPA_API_LOOP int spa_loop_control_iterate_fast(struct spa_loop_control *object,
int timeout)
{
return spa_api_method_fast_r(int, -ENOTSUP,
spa_loop_control, &object->iface, iterate, 0, timeout);
}
SPA_API_LOOP int spa_loop_control_check(struct spa_loop_control *object)
{
return spa_api_method_r(int, -ENOTSUP,
spa_loop_control, &object->iface, check, 1);
}
typedef void (*spa_source_io_func_t) (void *data, int fd, uint32_t mask);
typedef void (*spa_source_idle_func_t) (void *data);
typedef void (*spa_source_event_func_t) (void *data, uint64_t count);
typedef void (*spa_source_timer_func_t) (void *data, uint64_t expirations);
typedef void (*spa_source_signal_func_t) (void *data, int signal_number);
/**
* Create sources for an event loop
*/
struct spa_loop_utils_methods {
/* the version of this structure. This can be used to expand this
* structure in the future */
#define SPA_VERSION_LOOP_UTILS_METHODS 0
uint32_t version;
struct spa_source *(*add_io) (void *object,
int fd,
uint32_t mask,
bool close,
spa_source_io_func_t func, void *data);
int (*update_io) (void *object, struct spa_source *source, uint32_t mask);
struct spa_source *(*add_idle) (void *object,
bool enabled,
spa_source_idle_func_t func, void *data);
int (*enable_idle) (void *object, struct spa_source *source, bool enabled);
struct spa_source *(*add_event) (void *object,
spa_source_event_func_t func, void *data);
int (*signal_event) (void *object, struct spa_source *source);
struct spa_source *(*add_timer) (void *object,
spa_source_timer_func_t func, void *data);
int (*update_timer) (void *object,
struct spa_source *source,
struct timespec *value,
struct timespec *interval,
bool absolute);
struct spa_source *(*add_signal) (void *object,
int signal_number,
spa_source_signal_func_t func, void *data);
/** destroy a source allocated with this interface. This function
* should only be called when the loop is not running or from the
* context of the running loop */
void (*destroy_source) (void *object, struct spa_source *source);
};
SPA_API_LOOP struct spa_source *
spa_loop_utils_add_io(struct spa_loop_utils *object, int fd, uint32_t mask,
bool close, spa_source_io_func_t func, void *data)
{
return spa_api_method_r(struct spa_source *, NULL,
spa_loop_utils, &object->iface, add_io, 0, fd, mask, close, func, data);
}
SPA_API_LOOP int spa_loop_utils_update_io(struct spa_loop_utils *object,
struct spa_source *source, uint32_t mask)
{
return spa_api_method_r(int, -ENOTSUP,
spa_loop_utils, &object->iface, update_io, 0, source, mask);
}
SPA_API_LOOP struct spa_source *
spa_loop_utils_add_idle(struct spa_loop_utils *object, bool enabled,
spa_source_idle_func_t func, void *data)
{
return spa_api_method_r(struct spa_source *, NULL,
spa_loop_utils, &object->iface, add_idle, 0, enabled, func, data);
}
SPA_API_LOOP int spa_loop_utils_enable_idle(struct spa_loop_utils *object,
struct spa_source *source, bool enabled)
{
return spa_api_method_r(int, -ENOTSUP,
spa_loop_utils, &object->iface, enable_idle, 0, source, enabled);
}
SPA_API_LOOP struct spa_source *
spa_loop_utils_add_event(struct spa_loop_utils *object, spa_source_event_func_t func, void *data)
{
return spa_api_method_r(struct spa_source *, NULL,
spa_loop_utils, &object->iface, add_event, 0, func, data);
}
SPA_API_LOOP int spa_loop_utils_signal_event(struct spa_loop_utils *object,
struct spa_source *source)
{
return spa_api_method_r(int, -ENOTSUP,
spa_loop_utils, &object->iface, signal_event, 0, source);
}
SPA_API_LOOP struct spa_source *
spa_loop_utils_add_timer(struct spa_loop_utils *object, spa_source_timer_func_t func, void *data)
{
return spa_api_method_r(struct spa_source *, NULL,
spa_loop_utils, &object->iface, add_timer, 0, func, data);
}
SPA_API_LOOP int spa_loop_utils_update_timer(struct spa_loop_utils *object,
struct spa_source *source, struct timespec *value,
struct timespec *interval, bool absolute)
{
return spa_api_method_r(int, -ENOTSUP,
spa_loop_utils, &object->iface, update_timer, 0, source,
value, interval, absolute);
}
SPA_API_LOOP struct spa_source *
spa_loop_utils_add_signal(struct spa_loop_utils *object, int signal_number,
spa_source_signal_func_t func, void *data)
{
return spa_api_method_r(struct spa_source *, NULL,
spa_loop_utils, &object->iface, add_signal, 0,
signal_number, func, data);
}
SPA_API_LOOP void spa_loop_utils_destroy_source(struct spa_loop_utils *object,
struct spa_source *source)
{
spa_api_method_v(spa_loop_utils, &object->iface, destroy_source, 0, source);
}
/**
* \}
*/
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* SPA_LOOP_H */