--- /dev/null
+/*****************************************************************************/
+/* */
+/* callback.c */
+/* */
+/* Chip callbacks */
+/* */
+/* */
+/* */
+/* (C) 2003 Ullrich von Bassewitz */
+/* Römerstrasse 52 */
+/* D-70794 Filderstadt */
+/* EMail: uz@cc65.org */
+/* */
+/* */
+/* This software is provided 'as-is', without any expressed or implied */
+/* warranty. In no event will the authors be held liable for any damages */
+/* arising from the use of this software. */
+/* */
+/* Permission is granted to anyone to use this software for any purpose, */
+/* including commercial applications, and to alter it and redistribute it */
+/* freely, subject to the following restrictions: */
+/* */
+/* 1. The origin of this software must not be misrepresented; you must not */
+/* claim that you wrote the original software. If you use this software */
+/* in a product, an acknowledgment in the product documentation would be */
+/* appreciated but is not required. */
+/* 2. Altered source versions must be plainly marked as such, and must not */
+/* be misrepresented as being the original software. */
+/* 3. This notice may not be removed or altered from any source */
+/* distribution. */
+/* */
+/*****************************************************************************/
+
+
+
+/* common */
+#include "xmalloc.h"
+
+/* sim65 */
+#include "error.h"
+#include "callback.h"
+
+
+
+/*****************************************************************************/
+/* Data */
+/*****************************************************************************/
+
+
+
+struct Callback {
+ Callback* Next; /* Next entry in list */
+ unsigned Ticks; /* Remaining ticks */
+ CallbackFunc UserFunc; /* User function */
+ void* UserData; /* User data */
+};
+
+/* Delta list that keeps existing callbacks */
+static Callback* List = 0;
+
+
+
+/*****************************************************************************/
+/* Routines that handle the delta list */
+/*****************************************************************************/
+
+
+
+static void InsertCallback (Callback* C, unsigned Ticks)
+/* Insert the callback C into the delta list */
+{
+ /* Search for the insertion point */
+ Callback* N;
+ Callback** L = &List;
+ while ((N = *L) != 0) {
+ /* Check if the next callback in the list has a higher wait time */
+ if (N->Ticks > Ticks) {
+ /* Insert before this callback */
+ N->Ticks -= Ticks;
+ break;
+ } else {
+ /* Insert behind this callback */
+ Ticks -= N->Ticks;
+ L = &N->Next;
+ }
+ }
+
+ /* Insert the new task */
+ C->Ticks = Ticks;
+ C->Next = N;
+ *L = C;
+}
+
+
+
+static void RemoveCallback (Callback* C)
+/* Remove a callback from the list. If the callback is not in the list, this
+ * is a fatal error.
+ */
+{
+ Callback* N;
+ Callback** L = &List;
+ while ((N = *L) != 0) {
+ if (N == C) {
+ /* Found, remove it */
+ if (C->Next) {
+ /* Adjust the counter of the following callback */
+ C->Next->Ticks += C->Ticks;
+ }
+ *L = C->Next;
+ return;
+ } else {
+ L = &N->Next;
+ }
+ }
+
+ /* Callback was not found */
+ Internal ("RemoveCallback: Callback not found in list!");
+}
+
+
+
+/*****************************************************************************/
+/* Code */
+/*****************************************************************************/
+
+
+
+Callback* NewCallback (unsigned Ticks, CallbackFunc Func, void* Data)
+/* Create a callback for function F to be called in Ticks ticks. */
+{
+ /* Allocate memory */
+ Callback* C = xmalloc (sizeof (Callback));
+
+ /* Initialize the fields */
+ C->UserFunc = Func;
+ C->UserData = Data;
+
+ /* Insert the callback into the delta list */
+ InsertCallback (C, Ticks);
+
+ /* Return the new callback */
+ return C;
+}
+
+
+
+void FreeCallback (Callback* C)
+/* Delete a callback (remove from the queue) */
+{
+ /* Remove the callback from the list */
+ RemoveCallback (C);
+
+ /* Delete it */
+ xfree (C);
+}
+
+
+
+void HandleCallbacks (unsigned TicksSinceLastCall)
+/* Handle the callback queue */
+{
+ while (List) {
+
+ /* Check if this one is due */
+ if (List->Ticks <= TicksSinceLastCall) {
+
+ /* Calclulate the tick offset */
+ int TickOffs = ((int) List->Ticks) - ((int) TicksSinceLastCall);
+
+ /* Retrieve the first callback from the list */
+ Callback* C = List;
+ List = C->Next;
+
+ /* Call the user function */
+ C->UserFunc (TickOffs, C->UserData);
+
+ /* Delete the callback */
+ xfree (C);
+
+ } else {
+
+ List->Ticks -= TicksSinceLastCall;
+ break;
+
+ }
+ }
+}
+
+
+
--- /dev/null
+/*****************************************************************************/
+/* */
+/* callback.h */
+/* */
+/* Chip callbacks */
+/* */
+/* */
+/* */
+/* (C) 2003 Ullrich von Bassewitz */
+/* Römerstrasse 52 */
+/* D-70794 Filderstadt */
+/* EMail: uz@cc65.org */
+/* */
+/* */
+/* This software is provided 'as-is', without any expressed or implied */
+/* warranty. In no event will the authors be held liable for any damages */
+/* arising from the use of this software. */
+/* */
+/* Permission is granted to anyone to use this software for any purpose, */
+/* including commercial applications, and to alter it and redistribute it */
+/* freely, subject to the following restrictions: */
+/* */
+/* 1. The origin of this software must not be misrepresented; you must not */
+/* claim that you wrote the original software. If you use this software */
+/* in a product, an acknowledgment in the product documentation would be */
+/* appreciated but is not required. */
+/* 2. Altered source versions must be plainly marked as such, and must not */
+/* be misrepresented as being the original software. */
+/* 3. This notice may not be removed or altered from any source */
+/* distribution. */
+/* */
+/*****************************************************************************/
+
+
+
+#ifndef CALLBACK_H
+#define CALLBACK_H
+
+
+
+/*****************************************************************************/
+/* Data */
+/*****************************************************************************/
+
+
+
+/* Type of a callback function */
+typedef void (*CallbackFunc) (int TickOffs, void* UserData);
+
+/* Forward */
+typedef struct Callback Callback;
+
+
+
+/*****************************************************************************/
+/* Code */
+/*****************************************************************************/
+
+
+
+Callback* NewCallback (unsigned Ticks, CallbackFunc Func, void* Data);
+/* Create a callback for function F to be called in Ticks ticks. */
+
+void FreeCallback (Callback* C);
+/* Delete a callback (remove from the queue) */
+
+void HandleCallbacks (unsigned TicksSinceLastCall);
+/* Handle the callback queue */
+
+
+
+/* End of callback.h */
+
+#endif
+
+
+
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