7 #include "chimara-glk.h"
8 #include "chimara-glk-private.h"
10 extern GPrivate *glk_data_key;
12 #define EVENT_TIMEOUT_MICROSECONDS (3000000)
14 /* Internal function: push an event onto the event queue. If the event queue is
15 full, wait for max three seconds and then drop the event. If the event queue is
16 NULL, i.e. freed, then fail silently. */
18 event_throw(ChimaraGlk *glk, glui32 type, winid_t win, glui32 val1, glui32 val2)
20 ChimaraGlkPrivate *priv = CHIMARA_GLK_PRIVATE(glk);
22 if(!priv->event_queue)
26 g_get_current_time(&timeout);
27 g_time_val_add(&timeout, EVENT_TIMEOUT_MICROSECONDS);
29 g_mutex_lock(priv->event_lock);
31 /* Wait for room in the event queue */
32 while( g_queue_get_length(priv->event_queue) >= EVENT_QUEUE_MAX_LENGTH )
33 if( !g_cond_timed_wait(priv->event_queue_not_full, priv->event_lock, &timeout) )
35 /* Drop the event after 3 seconds */
36 g_mutex_unlock(priv->event_lock);
40 event_t *event = g_new0(event_t, 1);
45 g_queue_push_head(priv->event_queue, event);
47 /* Signal that there is an event */
48 g_cond_signal(priv->event_queue_not_empty);
50 g_mutex_unlock(priv->event_lock);
55 * @event: Pointer to an #event_t.
57 * Causes the program to wait for an event, and then store it in the structure
58 * pointed to by @event. Unlike most Glk functions that take pointers, the
59 * argument of glk_select() may not be %NULL.
61 * Most of the time, you only get the events that you request. However, there
62 * are some events which can arrive at any time. This is why you must always
63 * call glk_select() in a loop, and continue the loop until you get the event
67 glk_select(event_t *event)
69 g_return_if_fail(event != NULL);
71 ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
73 g_mutex_lock(glk_data->event_lock);
75 /* Wait for an event */
76 while( g_queue_is_empty(glk_data->event_queue) )
77 g_cond_wait(glk_data->event_queue_not_empty, glk_data->event_lock);
79 event_t *retrieved_event = g_queue_pop_tail(glk_data->event_queue);
80 if(retrieved_event == NULL)
82 g_mutex_unlock(glk_data->event_lock);
83 WARNING("Retrieved NULL event from non-empty event queue");
86 memcpy(event, retrieved_event, sizeof(event_t));
87 g_free(retrieved_event);
89 /* Signal that the event queue is no longer full */
90 g_cond_signal(glk_data->event_queue_not_full);
92 g_mutex_unlock(glk_data->event_lock);
94 /* Check for interrupt */
97 /* If the event was a line input event, the library must release the buffer */
98 if(event->type == evtype_LineInput && glk_data->unregister_arr)
100 if(event->win->input_request_type == INPUT_REQUEST_LINE_UNICODE)
101 (*glk_data->unregister_arr)(event->win->line_input_buffer_unicode, event->win->line_input_buffer_max_len, "&+#!Iu", event->win->buffer_rock);
103 (*glk_data->unregister_arr)(event->win->line_input_buffer, event->win->line_input_buffer_max_len, "&+#!Cn", event->win->buffer_rock);
106 /* If an abort event was generated, the thread should have exited by now */
107 g_assert(event->type != evtype_Abort);
112 * @event: Return location for an event.
114 * You can also inquire if an event is available, without stopping to wait for
117 * This checks if an internally-spawned event is available. If so, it stores it
118 * in the structure pointed to by @event. If not, it sets
119 * <code>@event->type</code> to %evtype_None. Either way, it returns almost
122 * The first question you now ask is, what is an internally-spawned event?
123 * glk_select_poll() does not check for or return %evtype_CharInput,
124 * %evtype_LineInput, %evtype_MouseInput, or %evtype_Hyperlink events. It is
125 * intended for you to test conditions which may have occurred while you are
126 * computing, and not interfacing with the player. For example, time may pass
127 * during slow computations; you can use glk_select_poll() to see if a
128 * %evtype_Timer event has occured. (See <link
129 * linkend="chimara-Timer-Events">Timer Events</link>.)
131 * At the moment, glk_select_poll() checks for %evtype_Timer, %evtype_Arrange,
132 * %evtype_Redraw and %evtype_SoundNotify events. But see <link
133 * linkend="chimara-Other-Events">Other Events</link>.
135 * The second question is, what does it mean that glk_select_poll() returns
136 * <quote>almost immediately</quote>? In some Glk libraries, text that you send
137 * to a window is buffered; it does not actually appear until you request player
138 * input with glk_select(). glk_select_poll() attends to this buffer-flushing
139 * task in the same way. (Although it does not do the <quote><computeroutput>Hit
140 * any key to scroll down</computeroutput></quote> waiting which may be done in
141 * glk_select(); that's a player-input task.)
143 * Similarly, on multitasking platforms, glk_select() may yield time to other
144 * processes; and glk_select_poll() does this as well.
146 * The upshot of this is that you should not call glk_select_poll() very often.
147 * If you are not doing much work between player inputs, you should not need to
151 * For example, in a virtual machine interpreter, you should not call
152 * glk_select_poll() after every opcode.
155 * However, if you are doing intense computation, you may wish to call
156 * glk_select_poll() every so often to yield time to other processes. And if you
157 * are printing intermediate results during this computation, you should
158 * glk_select_poll() every so often, so that you can be certain your output will
159 * be displayed before the next glk_select().
162 * However, you should call glk_tick() often — once per opcode in a VM
163 * interpreter. See <link linkend="chimara-The-Tick-Thing">The Tick
168 glk_select_poll(event_t *event)
170 g_return_if_fail(event != NULL);
172 ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
174 event->type = evtype_None;
176 g_mutex_lock(glk_data->event_lock);
178 if( !g_queue_is_empty(glk_data->event_queue) )
182 for(count = 0; (link = g_queue_peek_nth_link(glk_data->event_queue, count)) != NULL; count++)
184 glui32 type = ((event_t *)link->data)->type;
185 if(type != evtype_CharInput && type != evtype_LineInput && type != evtype_MouseInput && type != evtype_Hyperlink)
187 memcpy(event, link->data, sizeof(event_t));
189 g_queue_delete_link(glk_data->event_queue, link);
190 g_cond_signal(glk_data->event_queue_not_full);
196 g_mutex_unlock(glk_data->event_lock);
198 /* Check for interrupt */
201 /* If an abort event was generated, the thread should have exited by now */
202 g_assert(event->type != evtype_Abort);