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authorinmarket <andrewh@inmarket.com.au>2015-01-21 17:26:24 +1000
committerinmarket <andrewh@inmarket.com.au>2015-01-21 17:26:24 +1000
commitfa8167b94d13e94a6cb953e7f549a89f155f77c6 (patch)
tree8c33f78c45ca72ac2653327607f1d7caed668c5e /src/gevent/gevent.h
parent34939386d7390b0876973a1969f336b814313a22 (diff)
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Big file rename to reduce problems with brain-dead IDE's that don't handle project file hierarchies well.
Naming is more consistent with the new scheme. May affect some third party drivers (header file renames).
Diffstat (limited to 'src/gevent/gevent.h')
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diff --git a/src/gevent/gevent.h b/src/gevent/gevent.h
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+/*
+ * This file is subject to the terms of the GFX License. If a copy of
+ * the license was not distributed with this file, you can obtain one at:
+ *
+ * http://ugfx.org/license.html
+ */
+
+/**
+ * @file src/gevent/gevent.h
+ *
+ * @addtogroup GEVENT
+ *
+ * @brief Module to build a complete many-to-many event system
+ *
+ * @details GEVENT provides a simple to use but yet powerful event
+ * system.
+ *
+ * @pre GFX_USE_GEVENT must be set to TRUE in your gfxconf.h
+ *
+ * @{
+ */
+#ifndef _GEVENT_H
+#define _GEVENT_H
+
+#include "gfx.h"
+
+#if GFX_USE_GEVENT || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Type definitions */
+/*===========================================================================*/
+
+typedef uint16_t GEventType;
+ #define GEVENT_NULL 0x0000 // Null Event - Do nothing
+ #define GEVENT_EXIT 0x0001 // The listener is being forced to exit (someone is destroying the listener)
+
+ /* Other event types are allocated in ranges in their respective include files */
+ #define GEVENT_GINPUT_FIRST 0x0100 // GINPUT events range from 0x0100 to 0x01FF
+ #define GEVENT_GWIN_FIRST 0x0200 // GWIN events range from 0x0200 to 0x02FF
+ #define GEVENT_GADC_FIRST 0x0300 // GADC events range from 0x0300 to 0x033F
+ #define GEVENT_GAUDIO_FIRST 0x0340 // GAUDIO events range from 0x0340 to 0x037F
+ #define GEVENT_USER_FIRST 0x8000 // Any application defined events start at 0x8000
+
+// This object can be typecast to any GEventXxxxx type to allow any sub-system (or the application) to create events.
+// The prerequisite is that the new status structure type starts with a field named 'type' of type 'GEventType'.
+// The total status structure also must not exceed GEVENT_MAXIMUM_SIZE bytes.
+// For example, this is used by GWIN button events, GINPUT data streams etc.
+typedef union GEvent_u {
+ GEventType type; // The type of this event
+ char pad[GEVENT_MAXIMUM_SIZE]; // This is here to allow static initialisation of GEventObject's in the application.
+} GEvent;
+
+// A special callback function
+typedef void (*GEventCallbackFn)(void *param, GEvent *pe);
+
+// The Listener Object
+typedef struct GListener {
+ gfxSem waitqueue; // Private: Semaphore for the listener to wait on.
+ uint16_t flags; // Private: Flags for operation
+ GEventCallbackFn callback; // Private: Call back Function
+ void *param; // Private: Parameter for the callback function.
+ GEvent event; // Public: The event object into which the event information is stored.
+ } GListener;
+
+// The Source Object
+typedef struct GSource_t GSource, *GSourceHandle;
+
+// This structure is passed to a source to describe a contender listener for sending the current event.
+typedef struct GSourceListener_t {
+ GListener *pListener; // The listener
+ GSource *pSource; // The source
+ unsigned listenflags; // The flags the listener passed when the source was assigned to it.
+ unsigned srcflags; // For the source's exclusive use. Initialised as 0 for a new listener source assignment.
+ } GSourceListener;
+
+/*===========================================================================*/
+/* External declarations. */
+/*===========================================================================*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* How to listen for events (act as a Listener)...
+ 1. Get handles for all the event sources you are interested in.
+ 2. Initialise a listener
+ 3. Attach sources to your listener.
+ - Sources can be attached or detached from a listener at any time.
+ - A source can be attached to more than one listener.
+ 4. Loop on getting listener events
+ 5. When finished detach all sources from the listener
+
+ How to create events (act as a Source)...
+ 1. Provide a funtion to the application that returns a GSourceHandle (which can be a pointer to whatever the source wants)
+ 2. Whenever a possible event occurs call geventGetSourceListener to get a pointer to a GSourceListener.
+ This will return NULL when there are no more listeners.
+ For each listener - check the flags to see if an event should be sent.
+ - use geventGetEvent() to get the event buffer supplied by the listener
+ and then call geventSendEvent to send the event.
+ - Note: geventGetEvent() may return FALSE to indicate the listener is currently not listening and
+ therefore no event should be sent. This situation enables the source to (optionally) flag
+ to the listener on its next wait that there have been missed events.
+ - Note: The GSourceListener pointer (and the GEvent buffer) are only valid between
+ the geventGetSourceListener call and either the geventSendEvent call or the next
+ geventGetSourceListener call.
+ - Note: All listeners must be processed for this event before anything else is processed.
+*/
+
+/*---------- Listener Functions --------------------------------------------*/
+
+/**
+ * @brief Create a Listener
+ * @details If insufficient resources are available it will either assert or return NULL
+ * depending on the value of GEVENT_ASSERT_NO_RESOURCE.
+ *
+ * @param[in] pl A listener
+ */
+void geventListenerInit(GListener *pl);
+
+/**
+ * @brief Attach a source to a listener
+ * @details Flags are interpreted by the source when generating events for each listener.
+ * If this source is already assigned to the listener it will update the flags.
+ * If insufficient resources are available it will either assert or return FALSE
+ * depending on the value of GEVENT_ASSERT_NO_RESOURCE.
+ *
+ * @param[in] pl The listener
+ * @param[in] gsh The source which has to be attached to the listener
+ * @param[in] flags The flags
+ *
+ * @return TRUE if succeeded, FALSE otherwise
+ */
+bool_t geventAttachSource(GListener *pl, GSourceHandle gsh, unsigned flags);
+
+/**
+ * @brief Detach a source from a listener
+ * @details If gsh is NULL detach all sources from this listener and if there is still
+ * a thread waiting for events on this listener, it is sent the exit event.
+ *
+ * @param[in] pl The listener
+ * @param[in] gsh The source
+ */
+void geventDetachSource(GListener *pl, GSourceHandle gsh);
+
+/**
+ * @brief Wait for an event on a listener from an assigned source.
+ * @details The type of the event should be checked (pevent->type) and then pevent should
+ * be typecast to the actual event type if it needs to be processed.
+ * timeout specifies the time to wait in system ticks.
+ * TIME_INFINITE means no timeout - wait forever for an event.
+ * TIME_IMMEDIATE means return immediately
+ * @note The returned GEvent is released when this routine is called again
+ * or when optionally @p geventEventComplete() is called. Calling @p geventEventComplete()
+ * allows the GEvent object to be reused earlier which can reduce missed events. The GEvent
+ * object MUST NOT be used after this function is called (and is blocked waiting for the next
+ * event) or after geventEventComplete() is called.
+ *
+ * @param[in] pl The listener
+ * @param[in] timeout The timeout
+ *
+ * @return NULL on timeout
+ */
+GEvent *geventEventWait(GListener *pl, delaytime_t timeout);
+
+/**
+ * @brief Release the GEvent buffer associated with a listener.
+ * @details The GEvent returned by @p geventEventWait() is released.
+ * @note The GEvent pointer returned by @p geventEventWait() is released when @p geventEventWait()
+ * is called again or when this function is called. The GEvent
+ * object MUST NOT be used after this function is called.
+ *
+ * @param[in] pl The listener
+ */
+void geventEventComplete(GListener *pl);
+
+/* @brief Register a callback for an event on a listener from an assigned source.
+ * @details The type of the event should be checked (pevent->type) and then pevent should be typecast to the
+ * actual event type if it needs to be processed.
+ *
+ * @params[in] pl The Listener
+ * @params[in] fn The function to call back
+ * @params[in] param A parameter to pass the callback function
+ *
+ * @note The GEvent buffer is valid only during the time of the callback. The callback MUST NOT save
+ * a pointer to the buffer for use outside the callback.
+ * @note An existing callback function is de-registered by passing a NULL for 'fn'. Any existing
+ * callback function is replaced. Any thread currently waiting using geventEventWait will be sent the exit event.
+ * @note Callbacks occur in a thread context but stack space must be kept to a minumum and
+ * the callback must process quickly as all other events are performed on a single thread.
+ * @note In the callback function you should never call ANY event functions using your own GListener handle
+ * as it WILL create a deadlock and lock the system up.
+ * @note Applications should not use this call - geventEventWait() is the preferred mechanism for an
+ * application. This call is provided for GUI objects that may not have their own thread.
+ */
+void geventRegisterCallback(GListener *pl, GEventCallbackFn fn, void *param);
+
+/*---------- Source Functions --------------------------------------------*/
+
+/**
+ * @brief Called by a source with a possible event to get a listener record.
+ * @details @p lastlr should be NULL on the first call and thereafter the result of the previous call.
+ *
+ * @param[in] gsh The source handler
+ * @param[in] lastlr The source listener
+ *
+ * @return NULL when there are no more listeners for this source
+ */
+GSourceListener *geventGetSourceListener(GSourceHandle gsh, GSourceListener *lastlr);
+
+/**
+ * @brief Get the event buffer from the GSourceListener.
+ * @details A NULL return allows the source to record (perhaps in glr->scrflags) that the listener
+ * has missed events. This can then be notified as part of the next event for the listener.
+ * The buffer can only be accessed untill the next call to geventGetSourceListener
+ * or geventSendEvent
+ *
+ * @param[in] psl The source listener
+ *
+ * @return NULL if the listener is not currently listening.
+ */
+GEvent *geventGetEventBuffer(GSourceListener *psl);
+
+/**
+ * @brief Called by a source to indicate the listener's event buffer has been filled.
+ * @details After calling this function the source must not reference in fields in the GSourceListener or the event buffer.
+ *
+ * @param[in] psl The source listener
+ */
+void geventSendEvent(GSourceListener *psl);
+
+/**
+ * @brief Detach any listener that has this source attached
+ *
+ * @param[in] gsh The source handle
+ */
+void geventDetachSourceListeners(GSourceHandle gsh);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* GFX_USE_GEVENT */
+
+#endif /* _GEVENT_H */
+/** @} */
+