path: root/player/client.c

/* Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <assert.h>

#include "common/common.h"
#include "common/msg.h"
#include "common/msg_control.h"
#include "input/input.h"
#include "input/cmd_list.h"
#include "misc/dispatch.h"
#include "options/m_config.h"
#include "options/m_option.h"
#include "options/m_property.h"
#include "options/path.h"
#include "options/parse_configfile.h"
#include "osdep/threads.h"
#include "osdep/timer.h"
#include "osdep/io.h"
#include "stream/stream.h"

#include "command.h"
#include "core.h"
#include "client.h"

#include "config.h"

/*
 * Locking hierarchy:
 *
 *  MPContext > mp_client_api.lock > mpv_handle.lock > * > mpv_handle.wakeup_lock
 *
 * MPContext strictly speaking has no locks, and instead is implicitly managed
 * by MPContext.dispatch, which basically stops the playback thread at defined
 * points in order to let clients access it in a synchronized manner. Since
 * MPContext code accesses the client API, it's on top of the lock hierarchy.
 *
 */

struct mp_client_api {
    struct MPContext *mpctx;

    pthread_mutex_t lock;

    // -- protected by lock
    struct mpv_handle **clients;
    int num_clients;
    uint64_t event_masks;   // combined events of all clients, or 0 if unknown
};

struct observe_property {
    char *name;
    int id;                 // ==mp_get_property_id(name)
    uint64_t event_mask;    // ==mp_get_property_event_mask(name)
    int64_t reply_id;
    mpv_format format;
    bool changed;           // property change should be signaled to user
    bool need_new_value;    // a new value should be retrieved
    bool updating;          // a new value is being retrieved
    bool dead;              // property unobserved while retrieving value
    bool new_value_valid, user_value_valid;
    union m_option_value new_value, user_value;
    struct mpv_handle *client;
};

struct mpv_handle {
    // -- immmutable
    char *name;
    bool owner;
    struct mp_log *log;
    struct MPContext *mpctx;
    struct mp_client_api *clients;

    // -- not thread-safe
    struct mpv_event *cur_event;
    struct mpv_event_property cur_property_event;

    pthread_mutex_t lock;

    pthread_mutex_t wakeup_lock;
    pthread_cond_t wakeup;

    // -- protected by wakeup_lock
    bool need_wakeup;
    void (*wakeup_cb)(void *d);
    void *wakeup_cb_ctx;
    int wakeup_pipe[2];

    // -- protected by lock

    uint64_t event_mask;
    bool queued_wakeup;
    bool choke_warning;

    mpv_event *events;      // ringbuffer of max_events entries
    int max_events;         // allocated number of entries in events
    int first_event;        // events[first_event] is the first readable event
    int num_events;         // number of readable events
    int reserved_events;    // number of entries reserved for replies

    struct observe_property **properties;
    int num_properties;
    int lowest_changed;     // attempt at making change processing incremental
    int properties_updating;
    uint64_t property_event_masks; // or-ed together event masks of all properties

    bool fuzzy_initialized;
    struct mp_log_buffer *messages;
};

static bool gen_property_change_event(struct mpv_handle *ctx);
static void notify_property_events(struct mpv_handle *ctx, uint64_t event_mask);

void mp_clients_init(struct MPContext *mpctx)
{
    mpctx->clients = talloc_ptrtype(NULL, mpctx->clients);
    *mpctx->clients = (struct mp_client_api) {
        .mpctx = mpctx,
    };
    pthread_mutex_init(&mpctx->clients->lock, NULL);
}

void mp_clients_destroy(struct MPContext *mpctx)
{
    if (!mpctx->clients)
        return;
    assert(mpctx->clients->num_clients == 0);
    pthread_mutex_destroy(&mpctx->clients->lock);
    talloc_free(mpctx->clients);
    mpctx->clients = NULL;
}

int mp_clients_num(struct MPContext *mpctx)
{
    pthread_mutex_lock(&mpctx->clients->lock);
    int num_clients = mpctx->clients->num_clients;
    pthread_mutex_unlock(&mpctx->clients->lock);
    return num_clients;
}

// Test for "fuzzy" initialization of all clients. That is, all clients have
// at least called mpv_wait_event() at least once since creation (or exited).
bool mp_clients_all_initialized(struct MPContext *mpctx)
{
    bool all_ok = true;
    pthread_mutex_lock(&mpctx->clients->lock);
    for (int n = 0; n < mpctx->clients->num_clients; n++) {
        struct mpv_handle *ctx = mpctx->clients->clients[n];
        pthread_mutex_lock(&ctx->lock);
        all_ok &= ctx->fuzzy_initialized;
        pthread_mutex_unlock(&ctx->lock);
    }
    pthread_mutex_unlock(&mpctx->clients->lock);
    return all_ok;
}

static void invalidate_global_event_mask(struct mpv_handle *ctx)
{
    pthread_mutex_lock(&ctx->clients->lock);
    ctx->clients->event_masks = 0;
    pthread_mutex_unlock(&ctx->clients->lock);
}

static struct mpv_handle *find_client(struct mp_client_api *clients,
                                      const char *name)
{
    for (int n = 0; n < clients->num_clients; n++) {
        if (strcmp(clients->clients[n]->name, name) == 0)
            return clients->clients[n];
    }
    return NULL;
}

struct mpv_handle *mp_new_client(struct mp_client_api *clients, const char *name)
{
    pthread_mutex_lock(&clients->lock);

    char *unique_name = NULL;
    if (find_client(clients, name)) {
        for (int n = 2; n < 1000; n++) {
            unique_name = talloc_asprintf(NULL, "%s%d", name, n);
            if (!find_client(clients, unique_name))
                break;
            talloc_free(unique_name);
            unique_name = NULL;
        }
        if (!unique_name) {
            pthread_mutex_unlock(&clients->lock);
            return NULL;
        }
    }
    if (!unique_name)
        unique_name = talloc_strdup(NULL, name);

    int num_events = 1000;

    struct mpv_handle *client = talloc_ptrtype(NULL, client);
    *client = (struct mpv_handle){
        .name = talloc_steal(client, unique_name),
        .log = mp_log_new(client, clients->mpctx->log, unique_name),
        .mpctx = clients->mpctx,
        .clients = clients,
        .cur_event = talloc_zero(client, struct mpv_event),
        .events = talloc_array(client, mpv_event, num_events),
        .max_events = num_events,
        .event_mask = (1ULL << INTERNAL_EVENT_BASE) - 1, // exclude internal events
        .wakeup_pipe = {-1, -1},
    };
    pthread_mutex_init(&client->lock, NULL);
    pthread_mutex_init(&client->wakeup_lock, NULL);
    pthread_cond_init(&client->wakeup, NULL);


    MP_TARRAY_APPEND(clients, clients->clients, clients->num_clients, client);

    clients->event_masks = 0;
    pthread_mutex_unlock(&clients->lock);

    mpv_request_event(client, MPV_EVENT_TICK, 0);

    return client;
}

const char *mpv_client_name(mpv_handle *ctx)
{
    return ctx->name;
}

struct mp_log *mp_client_get_log(struct mpv_handle *ctx)
{
    return ctx->log;
}

struct MPContext *mp_client_get_core(struct mpv_handle *ctx)
{
    return ctx->mpctx;
}

static void wakeup_client(struct mpv_handle *ctx)
{
    pthread_mutex_lock(&ctx->wakeup_lock);
    if (!ctx->need_wakeup) {
        ctx->need_wakeup = true;
        pthread_cond_signal(&ctx->wakeup);