Advanced deferred_exec for core-side code. (#15579)

2 files changed, 149 insertions, 55 deletions

diff --git a/quantum/deferred_exec.c b/quantum/deferred_exec.c
index 5b0a5b1425..a64b451df2 100644
--- a/quantum/deferred_exec.c
+++ b/quantum/deferred_exec.c
@@ -9,32 +9,27 @@
 #    define MAX_DEFERRED_EXECUTORS 8
 #endif
 
-typedef struct deferred_executor_t {
-    deferred_token         token;
-    uint32_t               trigger_time;
-    deferred_exec_callback callback;
-    void *                 cb_arg;
-} deferred_executor_t;
-
-static deferred_token      current_token                     = 0;
-static uint32_t            last_deferred_exec_check          = 0;
-static deferred_executor_t executors[MAX_DEFERRED_EXECUTORS] = {0};
-
-static inline bool token_can_be_used(deferred_token token) {
+//------------------------------------
+// Helpers
+//
+
+static deferred_token current_token = 0;
+
+static inline bool token_can_be_used(deferred_executor_t *table, size_t table_count, deferred_token token) {
     if (token == INVALID_DEFERRED_TOKEN) {
         return false;
     }
-    for (int i = 0; i < MAX_DEFERRED_EXECUTORS; ++i) {
-        if (executors[i].token == token) {
+    for (int i = 0; i < table_count; ++i) {
+        if (table[i].token == token) {
             return false;
         }
     }
     return true;
 }
 
-static inline deferred_token allocate_token(void) {
+static inline deferred_token allocate_token(deferred_executor_t *table, size_t table_count) {
     deferred_token first = ++current_token;
-    while (!token_can_be_used(current_token)) {
+    while (!token_can_be_used(table, table_count, current_token)) {
         ++current_token;
         if (current_token == first) {
             // If we've looped back around to the first, everything is already allocated (yikes!). Need to exit with a failure.
@@ -44,18 +39,22 @@ static inline deferred_token allocate_token(void) {
     return current_token;
 }
 
-deferred_token defer_exec(uint32_t delay_ms, deferred_exec_callback callback, void *cb_arg) {
-    // Ignore queueing if it's a zero-time delay, or invalid callback
-    if (delay_ms == 0 || !callback) {
+//------------------------------------
+// Advanced API: used when a custom-allocated table is used, primarily for core code.
+//
+
+deferred_token defer_exec_advanced(deferred_executor_t *table, size_t table_count, uint32_t delay_ms, deferred_exec_callback callback, void *cb_arg) {
+    // Ignore queueing if the table isn't valid, it's a zero-time delay, or the token is not valid
+    if (!table || table_count == 0 || delay_ms == 0 || !callback) {
         return INVALID_DEFERRED_TOKEN;
     }
 
     // Find an unused slot and claim it
-    for (int i = 0; i < MAX_DEFERRED_EXECUTORS; ++i) {
-        deferred_executor_t *entry = &executors[i];
+    for (int i = 0; i < table_count; ++i) {
+        deferred_executor_t *entry = &table[i];
         if (entry->token == INVALID_DEFERRED_TOKEN) {
             // Work out the new token value, dropping out if none were available
-            deferred_token token = allocate_token();
+            deferred_token token = allocate_token(table, table_count);
             if (token == INVALID_DEFERRED_TOKEN) {
                 return false;
             }
@@ -73,15 +72,15 @@ deferred_token defer_exec(uint32_t delay_ms, deferred_exec_callback callback, vo
     return INVALID_DEFERRED_TOKEN;
 }
 
-bool extend_deferred_exec(deferred_token token, uint32_t delay_ms) {
-    // Ignore queueing if it's a zero-time delay, or the token is not valid
-    if (delay_ms == 0 || token == INVALID_DEFERRED_TOKEN) {
+bool extend_deferred_exec_advanced(deferred_executor_t *table, size_t table_count, deferred_token token, uint32_t delay_ms) {
+    // Ignore queueing if the table isn't valid, it's a zero-time delay, or the token is not valid
+    if (!table || table_count == 0 || delay_ms == 0 || token == INVALID_DEFERRED_TOKEN) {
         return false;
     }
 
     // Find the entry corresponding to the token
-    for (int i = 0; i < MAX_DEFERRED_EXECUTORS; ++i) {
-        deferred_executor_t *entry = &executors[i];
+    for (int i = 0; i < table_count; ++i) {
+        deferred_executor_t *entry = &table[i];
         if (entry->token == token) {
             // Found it, extend the delay
             entry->trigger_time = timer_read32() + delay_ms;
@@ -93,15 +92,15 @@ bool extend_deferred_exec(deferred_token token, uint32_t delay_ms) {
     return false;
 }
 
-bool cancel_deferred_exec(deferred_token token) {
-    // Ignore request if the token is not valid
-    if (token == INVALID_DEFERRED_TOKEN) {
+bool cancel_deferred_exec_advanced(deferred_executor_t *table, size_t table_count, deferred_token token) {
+    // Ignore request if the table/token are not valid
+    if (!table || table_count == 0 || token == INVALID_DEFERRED_TOKEN) {
         return false;
     }
 
     // Find the entry corresponding to the token
-    for (int i = 0; i < MAX_DEFERRED_EXECUTORS; ++i) {
-        deferred_executor_t *entry = &executors[i];
+    for (int i = 0; i < table_count; ++i) {
+        deferred_executor_t *entry = &table[i];
         if (entry->token == token) {
             // Found it, cancel and clear the table entry
             entry->token        = INVALID_DEFERRED_TOKEN;
@@ -116,16 +115,16 @@ bool cancel_deferred_exec(deferred_token token) {
     return false;
 }
 
-void deferred_exec_task(void) {
+void deferred_exec_advanced_task(deferred_executor_t *table, size_t table_count, uint32_t *last_execution_time) {
     uint32_t now = timer_read32();
 
     // Throttle only once per millisecond
-    if (((int32_t)TIMER_DIFF_32(now, last_deferred_exec_check)) > 0) {
-        last_deferred_exec_check = now;
+    if (((int32_t)TIMER_DIFF_32(now, (*last_execution_time))) > 0) {
+        *last_execution_time = now;
 
         // Run through each of the executors
-        for (int i = 0; i < MAX_DEFERRED_EXECUTORS; ++i) {
-            deferred_executor_t *entry = &executors[i];
+        for (int i = 0; i < table_count; ++i) {
+            deferred_executor_t *entry = &table[i];
 
             // Check if we're supposed to execute this entry
             if (entry->token != INVALID_DEFERRED_TOKEN && ((int32_t)TIMER_DIFF_32(entry->trigger_time, now)) <= 0) {
@@ -150,3 +149,15 @@ void deferred_exec_task(void) {
         }
     }
 }
+
+//------------------------------------
+// Basic API: used by user-mode code, guaranteed to not collide with core deferred execution
+//
+
+static uint32_t            last_deferred_exec_check                = 0;
+static deferred_executor_t basic_executors[MAX_DEFERRED_EXECUTORS] = {0};
+
+deferred_token defer_exec(uint32_t delay_ms, deferred_exec_callback callback, void *cb_arg) { return defer_exec_advanced(basic_executors, MAX_DEFERRED_EXECUTORS, delay_ms, callback, cb_arg); }
+bool           extend_deferred_exec(deferred_token token, uint32_t delay_ms) { return extend_deferred_exec_advanced(basic_executors, MAX_DEFERRED_EXECUTORS, token, delay_ms); }
+bool           cancel_deferred_exec(deferred_token token) { return cancel_deferred_exec_advanced(basic_executors, MAX_DEFERRED_EXECUTORS, token); }
+void           deferred_exec_task(void) { deferred_exec_advanced_task(basic_executors, MAX_DEFERRED_EXECUTORS, &last_deferred_exec_check); }
diff --git a/quantum/deferred_exec.h b/quantum/deferred_exec.h
index f80d353169..97ef0f6c0e 100644
--- a/quantum/deferred_exec.h
+++ b/quantum/deferred_exec.h
@@ -5,34 +5,117 @@
 
 #include <stdbool.h>
 #include <stdint.h>
+#include <stdlib.h>
 
-// A token that can be used to cancel an existing deferred execution.
+//------------------------------------
+// Common
+//------------------------------------
+
+/**
+ * @typedef A token that can be used to cancel or extend an existing deferred execution.
+ */
 typedef uint8_t deferred_token;
+
+/**
+ * @def The constant used to denote an invalid deferred execution token.
+ */
 #define INVALID_DEFERRED_TOKEN 0
 
-// Callback to execute.
-//  -- Parameter trigger_time: the intended trigger time to execute the callback -- equivalent time-space as timer_read32()
-//               cb_arg: the callback argument specified when enqueueing the deferred executor
-//  -- Return value: Non-zero re-queues the callback to execute after the returned number of milliseconds. Zero cancels repeated execution.
+/**
+ * @typedef Callback to execute.
+ * @param trigger_time[in] the intended trigger time to execute the callback -- equivalent time-space as timer_read32()
+ * @param cb_arg[in] the callback argument specified when enqueueing the deferred executor
+ * @return non-zero re-queues the callback to execute after the returned number of milliseconds. Zero cancels repeated execution.
+ */
 typedef uint32_t (*deferred_exec_callback)(uint32_t trigger_time, void *cb_arg);
 
-// Configures the supplied deferred executor to be executed after the required number of milliseconds.
-//  -- Parameter delay_ms: the number of milliseconds before executing the callback
-//  --           callback: the executor to invoke
-//  --           cb_arg: the argument to pass to the executor, may be NULL if unused by the executor
-//  -- Return value: a token usable for cancellation, or INVALID_DEFERRED_TOKEN if an error occurred
+//------------------------------------
+// Basic API: used by user-mode code, guaranteed to not collide with core deferred execution
+//------------------------------------
+
+/**
+ * Configures the supplied deferred executor to be executed after the required number of milliseconds.
+ *
+ * @param delay_ms[in] the number of milliseconds before executing the callback
+ * @param callback[in] the executor to invoke
+ * @param cb_arg[in] the argument to pass to the executor, may be NULL if unused by the executor
+ * @return a token usable for extension/cancellation, or INVALID_DEFERRED_TOKEN if an error occurred
+ */
 deferred_token defer_exec(uint32_t delay_ms, deferred_exec_callback callback, void *cb_arg);
 
-// Allows for extending the timeframe before an existing deferred execution is invoked.
-//  -- Parameter token: the returned value from defer_exec for the deferred execution you wish to extend.
-//  --           delay_ms: the new delay (with respect to the current time)
-//  -- Return value: if the token was found, and the delay was extended
+/**
+ * Allows for extending the timeframe before an existing deferred execution is invoked.
+ *
+ * @param token[in] the returned value from defer_exec for the deferred execution you wish to extend
+ * @param delay_ms[in] the number of milliseconds before executing the callback
+ * @return true if the token was extended successfully, otherwise false
+ */
 bool extend_deferred_exec(deferred_token token, uint32_t delay_ms);
 
-// Allows for cancellation of an existing deferred execution.
-//  -- Parameter token: the returned value from defer_exec for the deferred execution you wish to cancel.
-//  -- Return value: if the token was found, and the executor was cancelled
+/**
+ * Allows for cancellation of an existing deferred execution.
+ *
+ * @param token[in] the returned value from defer_exec for the deferred execution you wish to cancel
+ * @return true if the token was cancelled successfully, otherwise false
+ */
 bool cancel_deferred_exec(deferred_token token);
 
-// Forward declaration for the main loop in order to execute any deferred executors. Should not be invoked by keyboard/user code.
+/**
+ * Forward declaration for the main loop in order to execute any deferred executors. Should not be invoked by keyboard/user code.
+ */
 void deferred_exec_task(void);
+
+//------------------------------------
+// Advanced API: used when a custom-allocated table is used, primarily for core code.
+//------------------------------------
+
+/**
+ * @struct Structure for containing self-hosted deferred executor tables.
+ * @brief Core-side code can use this to create their own tables without impacting on the use of users' ability to add deferred execution.
+ *        Code outside deferred_exec.c should not worry about internals of this struct, and should just allocate the required number in an array.
+ */
+typedef struct deferred_executor_t {
+    deferred_token         token;
+    uint32_t               trigger_time;
+    deferred_exec_callback callback;
+    void *                 cb_arg;
+} deferred_executor_t;
+
+/**
+ * Configures the supplied deferred executor to be executed after the required number of milliseconds.
+ *
+ * @param table[in] the custom table used for storage
+ * @param table_count[in] the number of available items in the table
+ * @param delay_ms[in] the number of milliseconds before executing the callback
+ * @param callback[in] the executor to invoke
+ * @param cb_arg[in] the argument to pass to the executor, may be NULL if unused by the executor
+ * @return a token usable for extension/cancellation, or INVALID_DEFERRED_TOKEN if an error occurred
+ */
+deferred_token defer_exec_advanced(deferred_executor_t *table, size_t table_count, uint32_t delay_ms, deferred_exec_callback callback, void *cb_arg);
+
+/**
+ * Allows for extending the timeframe before an existing deferred execution is invoked.
+ *
+ * @param token[in] the returned value from defer_exec for the deferred execution you wish to extend
+ * @param delay_ms[in] the number of milliseconds before executing the callback
+ * @return true if the token was extended successfully, otherwise false
+ */
+bool extend_deferred_exec_advanced(deferred_executor_t *table, size_t table_count, deferred_token token, uint32_t delay_ms);
+
+/**
+ * Allows for cancellation of an existing deferred execution.
+ *
+ * @param token[in] the returned value from defer_exec for the deferred execution you wish to cancel
+ * @return true if the token was cancelled successfully, otherwise false
+ */
+bool cancel_deferred_exec_advanced(deferred_executor_t *table, size_t table_count, deferred_token token);
+
+/**
+ * Forward declaration for the main loop in order to execute any custom table deferred executors. Should not be invoked by keyboard/user code.
+ * Needed for any custom-allocated deferred execution tables. Any core tasks should add appropriate invocation to quantum/main.c.
+ *
+ * @param table[in] the custom table used for storage
+ * @param table_count[in] the number of available items in the table
+ * @param last_execution_time[in,out] the last execution time -- this will be checked first to determine if execution is needed, and updated if execution occurred
+ */
+void deferred_exec_advanced_task(deferred_executor_t *table, size_t table_count, uint32_t *last_execution_time);