Separated library source code from testing code, fixing #6

[projects/chimara/chimara.git] / libchimara / event.c

diff --git a/libchimara/event.c b/libchimara/event.c
new file mode 100644 (file)
index 0000000..d7cb659
--- /dev/null
+++ b/libchimara/event.c
@@ -0,0 +1,94 @@
+#include "event.h"
+#include "magic.h"
+#include "glk.h"
+#include <string.h>
+
+#include "chimara-glk-private.h"
+
+extern ChimaraGlkPrivate *glk_data;
+
+#define EVENT_TIMEOUT_MICROSECONDS (3000000)
+
+/* Internal function: push an event onto the event queue. If the event queue is
+full, wait for max three seconds and then drop the event. If the event queue is
+NULL, i.e. freed, then fail silently. */
+void
+event_throw(glui32 type, winid_t win, glui32 val1, glui32 val2)
+{
+       if(!glk_data->event_queue)
+               return;
+
+       GTimeVal timeout;
+       g_get_current_time(&timeout);
+       g_time_val_add(&timeout, EVENT_TIMEOUT_MICROSECONDS);
+
+       g_mutex_lock(glk_data->event_lock);
+
+       /* Wait for room in the event queue */
+       while( g_queue_get_length(glk_data->event_queue) >= EVENT_QUEUE_MAX_LENGTH )
+               if( !g_cond_timed_wait(glk_data->event_queue_not_full, glk_data->event_lock, &timeout) ) 
+               {
+                       /* Drop the event after 3 seconds */
+                       g_mutex_unlock(glk_data->event_lock);
+                       return;
+               }
+
+       event_t *event = g_new0(event_t, 1);
+       event->type = type;
+       event->win = win;
+       event->val1 = val1;
+       event->val2 = val2;
+       g_queue_push_head(glk_data->event_queue, event);
+
+       /* Signal that there is an event */
+       g_cond_signal(glk_data->event_queue_not_empty);
+
+       g_mutex_unlock(glk_data->event_lock);
+}
+
+/**
+ * glk_select:
+ * @event: Pointer to an #event_t.
+ *
+ * Causes the program to wait for an event, and then store it in the structure
+ * pointed to by @event. Unlike most Glk functions that take pointers, the
+ * argument of glk_select() may not be %NULL.
+ *
+ * Most of the time, you only get the events that you request. However, there
+ * are some events which can arrive at any time. This is why you must always
+ * call glk_select() in a loop, and continue the loop until you get the event
+ * you really want.
+ */
+void
+glk_select(event_t *event)
+{
+       g_return_if_fail(event != NULL);
+
+       g_mutex_lock(glk_data->event_lock);
+
+       /* Wait for an event */
+       while( g_queue_is_empty(glk_data->event_queue) )
+               g_cond_wait(glk_data->event_queue_not_empty, glk_data->event_lock);
+
+       event_t *retrieved_event = g_queue_pop_tail(glk_data->event_queue);
+       if(retrieved_event == NULL)
+       {
+               g_mutex_unlock(glk_data->event_lock);
+               WARNING("Retrieved NULL event from non-empty event queue");
+               return;
+       }
+       memcpy(event, retrieved_event, sizeof(event_t));
+       g_free(retrieved_event);
+
+       /* Signal that the event queue is no longer full */
+       g_cond_signal(glk_data->event_queue_not_full);
+
+       g_mutex_unlock(glk_data->event_lock);
+       
+       /* Check for interrupt */
+       glk_tick();
+       
+       /* If an abort event was generated, the thread should have exited by now */
+       g_assert(event->type != evtype_Abort);
+}
+