/* -*- c-file-style: "ruby"; indent-tabs-mode: nil -*- */
/*
 *  Copyright (C) 2011  Ruby-GNOME2 Project Team
 *  Copyright (C) 2005  Masao Mutoh
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 *  MA  02110-1301  USA
 */

#include "rbgprivate.h"

#ifndef HAVE_RB_THREAD_BLOCKING_REGION
#  include <version.h>
#  include <rubysig.h>
#  include <node.h>
#  include <time.h>
#  ifdef HAVE_CURR_THREAD
#    define rb_curr_thread curr_thread
#  endif
#endif

GStaticPrivate rg_polling_key = G_STATIC_PRIVATE_INIT;

/*
static ID id_poll_func;
*/
static ID id_call;

static VALUE mGLibSource;
static ID id__callbacks__;
static GHashTable *callbacks_table;

typedef struct _callback_info_t
{
    VALUE callback;
    guint id;
} callback_info_t;

/*****************************************/
static GPollFunc default_poll_func;

#ifdef HAVE_RB_THREAD_BLOCKING_REGION

/* just for ruby-1.9.0. */
#if !defined(RUBY_UBF_IO) && defined(RB_UBF_DFL)
#  define RUBY_UBF_IO RB_UBF_DFL
#endif

typedef struct _PollInfo
{
    GPollFD *ufds;
    guint nfsd;
    gint timeout;
    gint result;
} PollInfo;

static VALUE
rg_poll_in_blocking(void *data)
{
    PollInfo *info = data;

    info->result = default_poll_func(info->ufds, info->nfsd, info->timeout);

    return Qnil;
}

static gint
rg_poll(GPollFD *ufds, guint nfsd, gint timeout)
{
    PollInfo info;

    info.ufds = ufds;
    info.nfsd = nfsd;
    info.timeout = timeout;
    info.result = 0;

    g_static_private_set(&rg_polling_key, GINT_TO_POINTER(TRUE), NULL);
    rb_thread_blocking_region(rg_poll_in_blocking, &info, RUBY_UBF_IO, NULL);
    g_static_private_set(&rg_polling_key, GINT_TO_POINTER(FALSE), NULL);

    return info.result;
}

static VALUE
ruby_source_set_priority (VALUE self, VALUE priority)
{
    return Qnil;
}

#else
static gint
rg_poll(GPollFD *ufds, guint nfsd, gint timeout)
{
    gint result;

    TRAP_BEG;
    result = default_poll_func(ufds, nfsd, timeout);
    TRAP_END;

    return result;
}
#endif

static void
restore_poll_func(G_GNUC_UNUSED VALUE data)
{
    if (g_main_context_get_poll_func(NULL) == (GPollFunc)rg_poll) {
        g_main_context_set_poll_func(NULL, default_poll_func);
    }
}

#ifndef HAVE_RB_THREAD_BLOCKING_REGION
static guint ruby_source_id = 0;

/* from eval.c */
#define WAIT_FD     (1<<0)
#define WAIT_SELECT (1<<1)
#define WAIT_TIME   (1<<2)
#define WAIT_JOIN   (1<<3)
#define WAIT_PID    (1<<4)

#define DELAY_INFTY 1E30

#ifdef RUBY_RELEASE_YEAR
#  define CHECK_RUBY_RELEASE_DATE(year, month, day)     \
    (RUBY_RELEASE_YEAR >= (year) &&                     \
     RUBY_RELEASE_MONTH >= (month) &&                   \
     RUBY_RELEASE_DAY >= (day))
#else
#  define CHECK_RUBY_RELEASE_DATE(year, month, day) 0
#endif

static double
timeofday(void)
{
    struct timeval tv;
#if CHECK_RUBY_RELEASE_DATE(2009, 1, 7)
/* The following CLOCK_MONOTONIC change was introduced into
 * Ruby 1.8.6 and 1.8.7 at 2009-01-07.
 *
 * 1.8.6:
 * Wed Jan  7 10:06:12 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 *
 *        * eval.c (timeofday): use monotonic clock.  based on a patch
 *          from zimbatm <zimbatm@oree.ch> in [ruby-core:16627].
 *
 * 1.8.7:
 * Wed Jan  7 10:09:46 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 *
 *        * eval.c (timeofday): use monotonic clock.  based on a patch
 *          from zimbatm <zimbatm@oree.ch> in [ruby-core:16627].
 */
#  ifdef CLOCK_MONOTONIC
    struct timespec tp;

    if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0) {
        return (double)tp.tv_sec + (double)tp.tv_nsec * 1e-9;
    }
#  endif
#endif
    gettimeofday(&tv, NULL);
    return (double)tv.tv_sec + (double)tv.tv_usec * 1e-6;
}

/*****************************************/
typedef struct _RGSource
{
    GSource source;

    GList *poll_fds;
    GList *old_poll_fds;
    gboolean ready;
} RGSource;

static void
source_cleanup_poll_fds(GSource *source)
{
    RGSource *rg_source = (RGSource *)source;
    GList *node;

    for (node = rg_source->old_poll_fds; node; node = g_list_next(node)) {
        GPollFD *poll_fd = node->data;

        g_source_remove_poll(source, poll_fd);
        g_slice_free(GPollFD, poll_fd);
    }
    g_list_free(rg_source->old_poll_fds);
    rg_source->old_poll_fds = NULL;
}

static inline void
source_prepare_add_poll_fd(GSource *source, gint fd, guchar events)
{
    GPollFD *poll_fd;
    GList *node;
    RGSource *rg_source = (RGSource *)source;

    for (node = rg_source->old_poll_fds; node; node = g_list_next(node)) {
        poll_fd = node->data;
        if (poll_fd->fd == fd && poll_fd->events == events) {
            rg_source->old_poll_fds =
                g_list_remove_link(rg_source->old_poll_fds, node);
            rg_source->poll_fds = g_list_concat(rg_source->poll_fds, node);
            return;
        }
    }

    poll_fd = g_slice_new0(GPollFD);
    poll_fd->fd = fd;
    poll_fd->events = events;

    g_source_add_poll(source, poll_fd);
    rg_source->poll_fds = g_list_prepend(rg_source->poll_fds, poll_fd);
}

static inline void
source_prepare_add_poll(GSource *source, rb_thread_t thread)
{
    if (thread->wait_for == WAIT_FD) {
        /* The thread is blocked on thread->fd for read. */
        source_prepare_add_poll_fd(source, thread->fd, G_IO_IN);
        return;
    }

    if (thread->wait_for & WAIT_SELECT) {
        /* thread->fd is the maximum fd of the fds in the various sets. Need to
         * check the sets to see which fd's to wait for */
        int fd;

        for (fd = 0; fd < thread->fd; fd++) {
            gushort events = 0;

            if (FD_ISSET(fd, &thread->readfds))
                events |= G_IO_IN;
            if (FD_ISSET(fd, &thread->writefds))
                events |= G_IO_OUT;
            if (FD_ISSET(fd, &thread->exceptfds))
                events |= G_IO_PRI | G_IO_ERR | G_IO_HUP;

            if (events != 0)
              source_prepare_add_poll_fd(source, fd, events);
        }
    }
}

static inline gboolean
source_prepare_setup_poll_fd(GSource *source, gint *timeout)
{
    RGSource *rg_source = (RGSource *)source;
    rb_thread_t thread;
    gdouble now;

    g_assert(rg_source->old_poll_fds == NULL);
    rg_source->old_poll_fds = rg_source->poll_fds;
    rg_source->poll_fds = NULL;

    now = timeofday();
    thread = rb_curr_thread;
    do {
        thread = thread->next;

        if ((thread->wait_for == 0 && thread->status == THREAD_RUNNABLE &&
             thread != rb_curr_thread) ||
            (thread->wait_for & WAIT_JOIN &&
             thread->join->status == THREAD_KILLED)) {
            rg_source->poll_fds = g_list_concat(rg_source->poll_fds,
                                                rg_source->old_poll_fds);
            rg_source->old_poll_fds = NULL;
            return TRUE;
        }

        if (thread->wait_for & WAIT_TIME && thread->delay != DELAY_INFTY) {
            gint delay;

            delay = (thread->delay - now) * 1000;
            if (delay <= 0) {
                rg_source->poll_fds = g_list_concat(rg_source->poll_fds,
                                                    rg_source->old_poll_fds);
                rg_source->old_poll_fds = NULL;
                return TRUE;
            }
            if (*timeout == -1 || delay < *timeout)
                *timeout = delay;
        }

        if (thread->wait_for == WAIT_FD || thread->wait_for & WAIT_SELECT)
            source_prepare_add_poll(source, thread);
    } while (thread != rb_curr_thread);

    source_cleanup_poll_fds(source);

    return FALSE;
}

static gboolean
source_prepare(GSource *source, gint *timeout)
{
    RGSource *rg_source = (RGSource *)source;

    *timeout = -1;
    rg_source->ready = source_prepare_setup_poll_fd(source, timeout);

    return rg_source->ready;
}

static gboolean
source_check(GSource *source)
{
    RGSource *rg_source = (RGSource *)source;
    GList *node;

    if (rg_source->ready)
        return TRUE;

    for (node = rg_source->poll_fds; node; node = g_list_next(node)) {
        GPollFD *poll_fd = node->data;

        if (poll_fd->revents)
            return TRUE;
    }

    return FALSE;
}

static gboolean
source_dispatch(G_GNUC_UNUSED GSource *source,
                G_GNUC_UNUSED GSourceFunc callback,
                G_GNUC_UNUSED gpointer user_data)
{
    TRAP_BEG;
    rb_thread_schedule();
    TRAP_END;

    return TRUE;
}

static void
source_finalize(GSource *source)
{
    RGSource *rg_source = (RGSource *)source;
    GList *node;

    for (node = rg_source->old_poll_fds; node; node = g_list_next(node)) {
        GPollFD *poll_fd = node->data;
        g_slice_free(GPollFD, poll_fd);
    }

    for (node = rg_source->poll_fds; node; node = g_list_next(node)) {
        GPollFD *poll_fd = node->data;
        g_slice_free(GPollFD, poll_fd);
    }

    g_list_free(rg_source->old_poll_fds);
    rg_source->old_poll_fds = NULL;

    g_list_free(rg_source->poll_fds);
    rg_source->poll_fds = NULL;
}

static GSourceFuncs source_funcs = {
    source_prepare,
    source_check,
    source_dispatch,
    source_finalize,
    NULL,
    NULL
};

static GSource *
ruby_source_new(void)
{
    GSource *source;
    RGSource *rg_source;

    source = g_source_new(&source_funcs, sizeof(RGSource));
    g_source_set_can_recurse(source, TRUE);

    rg_source = (RGSource *)source;
    rg_source->poll_fds = NULL;
    rg_source->old_poll_fds = NULL;

    return source;
}

static VALUE
ruby_source_set_priority(G_GNUC_UNUSED VALUE self, VALUE priority)
{
    GSource *ruby_source = NULL;

    if (ruby_source_id != 0)
        ruby_source = g_main_context_find_source_by_id(NULL, ruby_source_id);

    if (ruby_source)
        g_source_set_priority(ruby_source, NUM2INT(priority));

    return Qnil;
}
#endif

static VALUE
source_remove(G_GNUC_UNUSED VALUE self, VALUE tag)
{
    VALUE callback;
    callback = G_GET_RELATIVE(mGLibSource, id__callbacks__, tag);
    G_REMOVE_RELATIVE(mGLibSource, id__callbacks__, tag);
    g_hash_table_remove(callbacks_table, (gpointer)callback);
    return CBOOL2RVAL(g_source_remove(NUM2UINT(tag)));
}

#if GLIB_CHECK_VERSION(2,12,0)
static VALUE
source_current_source(G_GNUC_UNUSED VALUE self)
{
    return BOXED2RVAL(g_main_current_source, G_TYPE_SOURCE);
}
#endif

static gboolean
invoke_source_func(gpointer data)
{
    callback_info_t *info = (callback_info_t *)data;
    gboolean ret;

    ret = RVAL2CBOOL(rb_funcall(info->callback, id_call, 0));
    if (!ret)
        G_REMOVE_RELATIVE(mGLibSource, id__callbacks__, UINT2NUM(info->id));
    return ret;
}

/*****************************************/
#if !GLIB_CHECK_VERSION(2,30,0)
GType
g_main_context_get_type(void)
{
  static GType our_type = 0;
  if (our_type == 0)
    our_type = g_boxed_type_register_static ("GMainContext",
                    (GBoxedCopyFunc)g_main_context_ref,
                    (GBoxedFreeFunc)g_main_context_unref);
  return our_type;
}
#endif
/*****************************************/

#define RG_TARGET_NAMESPACE cMainContext
#define _SELF(s) ((GMainContext*)RVAL2BOXED(s, G_TYPE_MAIN_CONTEXT))

static VALUE
rg_initialize(VALUE self)
{
    GMainContext *context;

    context = g_main_context_new();

    g_main_context_set_poll_func(context, rg_poll);
#ifndef HAVE_RB_THREAD_BLOCKING_REGION
    {
        GSource *source;
        source = ruby_source_new();
        g_source_attach(source, context);
        g_source_unref(source);
    }
#endif

    G_INITIALIZE(self, context);
    return Qnil;
}

static VALUE
rg_s_default(G_GNUC_UNUSED VALUE self)
{
    return BOXED2RVAL(g_main_context_default(), G_TYPE_MAIN_CONTEXT);
}

static VALUE
rg_iteration(VALUE self, VALUE may_block)
{
    return CBOOL2RVAL(g_main_context_iteration(_SELF(self), RVAL2CBOOL(may_block)));
}

static VALUE
rg_pending_p(VALUE self)
{
    return CBOOL2RVAL(g_main_context_pending(_SELF(self)));
}

static VALUE
rg_find_source(VALUE self, VALUE source_id)
{
    GSource* src = g_main_context_find_source_by_id(_SELF(self), NUM2UINT(source_id));
    return BOXED2RVAL(src, G_TYPE_SOURCE);
}

/*
GSource*    g_main_context_find_source_by_user_data
                                            (GMainContext *context,
                                             gpointer user_data);
GSource*    g_main_context_find_source_by_funcs_user_data
                                            (GMainContext *context,
                                             GSourceFuncs *funcs,
                                             gpointer user_data);
*/

static VALUE
rg_wakeup(VALUE self)
{
    g_main_context_wakeup(_SELF(self));
    return self;
}

static VALUE
rg_acquire(VALUE self)
{
    return CBOOL2RVAL(g_main_context_acquire(_SELF(self)));
}

static VALUE
rg_release(VALUE self)
{
    g_main_context_release(_SELF(self));
    return self;
}

#if GLIB_CHECK_VERSION(2,10,0)
static VALUE
rg_owner_p(VALUE self)
{
    return CBOOL2RVAL(g_main_context_is_owner(_SELF(self)));
}
#endif

/*
gboolean    g_main_context_wait             (GMainContext *context,
                                             GCond *cond,
                                             GMutex *mutex);
*/

static VALUE
rg_prepare(VALUE self)
{
    gint priority;
    gboolean ret = g_main_context_prepare(_SELF(self), &priority);

    return rb_assoc_new(CBOOL2RVAL(ret), INT2NUM(priority));
}

struct mc_query_body_args {
    gint timeout_;
    GPollFD *fds;
    gint n_fds;
};

static VALUE
mc_query_body(VALUE value)
{
    struct mc_query_body_args *args = (struct mc_query_body_args *)value;
    gint i;
    VALUE ary = rb_ary_new();

    for (i = 0; i < args->n_fds; i++)
        rb_ary_push(ary, BOXED2RVAL(&args->fds[i], G_TYPE_POLL_FD));

    return rb_assoc_new(INT2NUM(args->timeout_), ary);
}

static VALUE
mc_query_ensure(VALUE value)
{
    g_free((GPollFD *)value);

    return Qnil;
}

#define QUERY_DEFAULT_FDS 100

static VALUE
rg_query(VALUE self, VALUE rbmax_priority)
{
    GMainContext *context = _SELF(self);
    gint max_priority = NUM2INT(rbmax_priority);
    gint timeout_;
    GPollFD *fds;
    gint n_fds;
    struct mc_query_body_args args;

    fds = g_new(GPollFD, QUERY_DEFAULT_FDS);
    n_fds = g_main_context_query(context, max_priority, &timeout_, fds, QUERY_DEFAULT_FDS);
    if (n_fds > QUERY_DEFAULT_FDS) {
        g_free(fds);
        fds = g_new(GPollFD, n_fds);
        g_main_context_query(context, max_priority, &timeout_, fds, n_fds);
    }

    args.timeout_ = timeout_;
    args.fds = fds;
    args.n_fds = n_fds;
    return rb_ensure(mc_query_body, (VALUE)&args,
                     mc_query_ensure, (VALUE)fds);
}

/* How can I implement this?
static VALUE
rg_check(VALUE self, VALUE max_priority)
{
    gint i, timeout_;
    VALUE ary;

    GPollFD* fds;
    gint ret, n_fds;

    fds = g_new (GPollFD, 10);    
    n_fds = g_main_context_query(_SELF(self), NUM2INT(max_priority), 
                                      &timeout_, fds, 10);
    printf("n_fds = %d\n", n_fds);

    g_free(fds);
    fds = g_new (GPollFD, n_fds);    

    ret = g_main_context_check(_SELF(self), NUM2INT(max_priority),
                               fds, n_fds);
    printf("ret = %d\n", ret);
    ary = rb_ary_new();
    for (i = 0; i < ret; i++)
        rb_ary_push(ary, BOXED2RVAL(&fds[i], G_TYPE_POLL_FD));

    g_free(fds);    
    return ary;
}
*/

static VALUE
rg_dispatch(VALUE self)
{
    g_main_context_dispatch(_SELF(self));
    return self;
}

/* How can I get "self" or something like it as key .... 
static gint
poll_func(GPollFD *ufds, guint nfsd, gint timeout_)
{
    VALUE func = rb_ivar_get(self, id_poll_func);
    if NIL_P(func) return -1;

    return INT2NUM(rb_funcall(func, 3, BOXED2RVAL(ufds, G_TYPE_POLL_FD),
                              UINT2NUM(nfsd), INT2NUM(timeout_)));
}

static VALUE
rg_set_poll_func(VALUE self)
{
    rb_ivar_set(self, id_poll_func, rb_block_proc());
    g_main_context_set_poll_func(_SELF(self), (GPollFunc)poll_func);

    return self;
}
*/

/*
GPollFunc   g_main_context_get_poll_func    (GMainContext *context);
*/

static VALUE
rg_add_poll(VALUE self, VALUE fd, VALUE priority)
{
    g_main_context_add_poll(_SELF(self), RVAL2BOXED(fd, G_TYPE_POLL_FD),
                            NUM2INT(priority));
    return self;
}

static VALUE
rg_remove_poll(VALUE self, VALUE fd)
{
    g_main_context_remove_poll(_SELF(self), RVAL2BOXED(fd, G_TYPE_POLL_FD));
    return self;
}

#ifdef HAVE_G_MAIN_DEPTH
static VALUE
rg_s_depth(VALUE self)
{
    return INT2NUM(g_main_depth());
}
#endif

static VALUE
timeout_source_new(G_GNUC_UNUSED VALUE self, VALUE interval)
{
    return BOXED2RVAL(g_timeout_source_new(NUM2UINT(interval)), G_TYPE_SOURCE);
}
#if GLIB_CHECK_VERSION(2,14,0)
static VALUE
timeout_source_new_seconds(G_GNUC_UNUSED VALUE self, VALUE interval)
{
    return BOXED2RVAL(g_timeout_source_new_seconds(NUM2UINT(interval)), G_TYPE_SOURCE);
}
#endif

static VALUE
timeout_add(int argc, VALUE *argv, G_GNUC_UNUSED VALUE self)
{
    VALUE interval, rb_priority, func, rb_id;
    gint priority;
    callback_info_t *info;
    guint id;

    rb_scan_args(argc, argv, "11&", &interval, &rb_priority, &func);

    priority = NIL_P(rb_priority) ? G_PRIORITY_DEFAULT : NUM2INT(rb_priority);
    info = ALLOC(callback_info_t);
    info->callback = func;
    id = g_timeout_add_full(priority, NUM2UINT(interval),
                            (GSourceFunc)invoke_source_func,
                            (gpointer)info, g_free);
    info->id = id;
    rb_id = UINT2NUM(id);
    G_RELATIVE2(mGLibSource, func, id__callbacks__, rb_id);
    g_hash_table_insert(callbacks_table, (gpointer)func, info);
    return rb_id;
}

#if GLIB_CHECK_VERSION(2,14,0)
static VALUE
timeout_add_seconds(int argc, VALUE *argv, G_GNUC_UNUSED VALUE self)
{
    VALUE interval, rb_priority, func, rb_id;
    gint priority;
    callback_info_t *info;
    guint id;

    rb_scan_args(argc, argv, "11&", &interval, &rb_priority, &func);

    priority = NIL_P(rb_priority) ? G_PRIORITY_DEFAULT : NUM2INT(rb_priority);
    info = ALLOC(callback_info_t);
    info->callback = func;
    id = g_timeout_add_seconds_full(priority,
                                    NUM2UINT(interval),
                                    (GSourceFunc)invoke_source_func,
                                    (gpointer)info,
                                    g_free);
    info->id = id;
    rb_id = UINT2NUM(id);
    G_RELATIVE2(mGLibSource, func, id__callbacks__, rb_id);
    g_hash_table_insert(callbacks_table, (gpointer)func, info);
    return rb_id;
}
#endif

static VALUE
idle_source_new(G_GNUC_UNUSED VALUE self)
{
    return BOXED2RVAL(g_idle_source_new(), G_TYPE_SOURCE);
}

static VALUE
idle_add(gint argc, VALUE *argv, G_GNUC_UNUSED VALUE self)
{
    VALUE arg1, arg2, func, rb_id;
    callback_info_t *info;
    guint id;
    gint priority = G_PRIORITY_DEFAULT_IDLE;

    rb_scan_args(argc, argv, "02", &arg1, &arg2);

    if (RVAL2CBOOL(rb_obj_is_kind_of(arg1, rb_cProc))) {
        func = arg1;
    } else if (RVAL2CBOOL(rb_obj_is_kind_of(arg1, rb_cInteger))) {
        priority = NUM2INT(arg1);
        func = rb_block_proc();
    } else {
        func = rb_block_proc();
    }

    info = ALLOC(callback_info_t);
    info->callback = func;
    id = g_idle_add_full(priority, (GSourceFunc)invoke_source_func,
                         (gpointer)info, g_free);
    info->id = id;
    rb_id = UINT2NUM(id);
    G_RELATIVE2(mGLibSource, func, id__callbacks__, rb_id);
    g_hash_table_insert(callbacks_table, (gpointer)func, info);
    return rb_id;
}

static VALUE
idle_remove(G_GNUC_UNUSED VALUE self, VALUE func)
{
    callback_info_t *info;

    info = g_hash_table_lookup(callbacks_table, (gpointer)func);
    G_REMOVE_RELATIVE(mGLibSource, id__callbacks__, UINT2NUM(info->id));
    g_hash_table_remove(callbacks_table, (gpointer)func);
    return CBOOL2RVAL(g_idle_remove_by_data((gpointer)info));
}

#if GLIB_CHECK_VERSION(2,4,0)
static VALUE
child_watch_source_new(G_GNUC_UNUSED VALUE self, VALUE pid)
{
    return BOXED2RVAL(g_child_watch_source_new((GPid)NUM2INT(pid)), G_TYPE_SOURCE);
}

static void
child_watch_func(GPid pid, gint status, gpointer func)
{
    rb_funcall((VALUE)func, id_call, 2, INT2NUM((long)pid), INT2NUM(status));
}

static VALUE
child_watch_add(VALUE self, VALUE pid)
{
    VALUE func = rb_block_proc();
    G_RELATIVE(self, func);
    return UINT2NUM(g_child_watch_add((GPid)NUM2INT(pid), 
                                      (GChildWatchFunc)child_watch_func, (gpointer)func));
}
#endif

#ifndef HAVE_RB_THREAD_BLOCKING_REGION
static void
ruby_source_remove(G_GNUC_UNUSED VALUE data)
{
    if (ruby_source_id != 0) {
        g_source_remove(ruby_source_id);
        ruby_source_id = 0;
    }
}
#endif

void
Init_glib_main_context(void)
{
    VALUE RG_TARGET_NAMESPACE = G_DEF_CLASS(G_TYPE_MAIN_CONTEXT, "MainContext", mGLib); 

    VALUE timeout = rb_define_module_under(mGLib, "Timeout");
    VALUE idle = rb_define_module_under(mGLib, "Idle");
#if GLIB_CHECK_VERSION(2,4,0)
    VALUE child_watch = rb_define_module_under(mGLib, "ChildWatch");
#endif

    id_call = rb_intern("call");
    id__callbacks__ = rb_intern("__callbacks__");
    callbacks_table = g_hash_table_new(NULL, NULL);

    rb_define_singleton_method(mGLib, "set_ruby_thread_priority",
                               ruby_source_set_priority, 1);
    rb_define_singleton_method(mGLib, "ruby_thread_priority=",
                               ruby_source_set_priority, 1);

    mGLibSource = rb_const_get(mGLib, rb_intern("Source"));
    rb_define_singleton_method(mGLibSource, "remove", source_remove, 1);
#if GLIB_CHECK_VERSION(2,12,0)
    rb_define_singleton_method(mGLibSource, "current", source_current_source, 0);
#endif
/*
    id_poll_func = rb_intern("__poll_func__");
*/
    RG_DEF_METHOD(initialize, 0);
    RG_DEF_SMETHOD(default, 0);
    RG_DEF_METHOD(iteration, 1);
    RG_DEF_METHOD_P(pending, 0);
    RG_DEF_METHOD(find_source, 1);
    RG_DEF_METHOD(wakeup, 0);
    RG_DEF_METHOD(acquire, 0);
    RG_DEF_METHOD(release, 0);
#if GLIB_CHECK_VERSION(2,10,0)
    RG_DEF_METHOD_P(owner, 0);
#endif
    RG_DEF_METHOD(prepare, 0);
    RG_DEF_METHOD(query, 1);
/*
    RG_DEF_METHOD(check, 1);
*/
    RG_DEF_METHOD(dispatch, 0);
/*
    RG_DEF_METHOD(set_poll_func, 0);
*/
    RG_DEF_METHOD(add_poll, 2);
    RG_DEF_METHOD(remove_poll, 1);
#ifdef HAVE_G_MAIN_DEPTH
    RG_DEF_SMETHOD(depth, 0);
#endif
    rb_define_module_function(timeout, "source_new", timeout_source_new, 1);
#if GLIB_CHECK_VERSION(2,14,0)
    rb_define_module_function(timeout, "source_new_seconds", timeout_source_new_seconds, 1);
#endif
    rb_define_module_function(timeout, "add", timeout_add, -1);
#if GLIB_CHECK_VERSION(2,14,0)
    rb_define_module_function(timeout, "add_seconds", timeout_add_seconds, -1);
#endif
    rb_define_module_function(idle, "source_new", idle_source_new, 0);
    rb_define_module_function(idle, "add", idle_add, -1);
    rb_define_module_function(idle, "remove", idle_remove, 1);

#if GLIB_CHECK_VERSION(2,4,0)
    rb_define_module_function(child_watch, "source_new", child_watch_source_new, 1);
    rb_define_module_function(child_watch, "add", child_watch_add, 1);
#endif

    default_poll_func = g_main_context_get_poll_func(NULL);
    g_main_context_set_poll_func(NULL, rg_poll);
    rb_set_end_proc(restore_poll_func, Qnil);

#ifndef HAVE_RB_THREAD_BLOCKING_REGION
    {
        GSource *source;

        source = ruby_source_new();
        g_source_set_priority(source, G_PRIORITY_DEFAULT_IDLE);
        ruby_source_id = g_source_attach(source, NULL);
        g_source_unref(source);
        rb_set_end_proc(ruby_source_remove, Qnil);
    }
#endif
}