loop.h

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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
 
#include <errno.h>
 
#include <spa/utils/defs.h>
#include <spa/utils/hook.h>
#include <spa/support/system.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
#ifndef SPA_API_LOOP
 #ifdef SPA_API_IMPL
  #define SPA_API_LOOP SPA_API_IMPL
 #else
  #define SPA_API_LOOP static inline
 #endif
#endif


 
#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        2
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);

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;

        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);

        int (*remove_source) (void *object,
                        struct spa_source *source);

        int (*invoke) (void *object,
                       spa_invoke_func_t func,
                       uint32_t seq,
                       const void *data,
                       size_t size,
                       bool block,
                       void *user_data);

        int (*locked) (void *object,
                       spa_invoke_func_t func,
                       uint32_t seq,
                       const void *data,
                       size_t size,
                       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);
}
SPA_API_LOOP int spa_loop_locked(struct spa_loop *object,
                spa_invoke_func_t func, uint32_t seq, const void *data,
                size_t size, void *user_data)
{
        return spa_api_method_r(int, -ENOTSUP,
                        spa_loop, &object->iface, locked, 0, func, seq, data,
                        size, user_data);
}
 

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 or integrate other fds into the loop. */
        void (*before) (void *data);
        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);
}


 * 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        2
        uint32_t version;

        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);

        void (*enter) (void *object);
        void (*leave) (void *object);

        int (*iterate) (void *object, int timeout);

        int (*check) (void *object);

        int (*lock) (void *object);

        int (*unlock) (void *object);

        int (*get_time) (void *object, struct timespec *abstime, int64_t timeout);

        int (*wait) (void *object, const struct timespec *abstime);

        int (*signal) (void *object, bool wait_for_accept);

        int (*accept) (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);
}
SPA_API_LOOP int spa_loop_control_lock(struct spa_loop_control *object)
{
        return spa_api_method_r(int, -ENOTSUP,
                        spa_loop_control, &object->iface, lock, 2);
}
SPA_API_LOOP int spa_loop_control_unlock(struct spa_loop_control *object)
{
        return spa_api_method_r(int, -ENOTSUP,
                        spa_loop_control, &object->iface, unlock, 2);
}
SPA_API_LOOP int spa_loop_control_get_time(struct spa_loop_control *object,
                struct timespec *abstime, int64_t timeout)
{
        return spa_api_method_r(int, -ENOTSUP,
                        spa_loop_control, &object->iface, get_time, 2, abstime, timeout);
}
SPA_API_LOOP int spa_loop_control_wait(struct spa_loop_control *object,
                const struct timespec *abstime)
{
        return spa_api_method_r(int, -ENOTSUP,
                        spa_loop_control, &object->iface, wait, 2, abstime);
}
SPA_API_LOOP int spa_loop_control_signal(struct spa_loop_control *object, bool wait_for_accept)
{
        return spa_api_method_r(int, -ENOTSUP,
                        spa_loop_control, &object->iface, signal, 2, wait_for_accept);
}
SPA_API_LOOP int spa_loop_control_accept(struct spa_loop_control *object)
{
        return spa_api_method_r(int, -ENOTSUP,
                        spa_loop_control, &object->iface, accept, 2);
}
 
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);

        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 */