From a493ab687e96ca1cbb5270ea78d6668105ebba32 Mon Sep 17 00:00:00 2001
From: Aryan Kashem <aryankashem@gmail.com>
Date: Sun, 2 Jun 2024 00:59:49 -0400
Subject: [PATCH] [QUEUE/MUTEX] header file setup

---
 inc/mutex.h             | 16 ++++++++++++++++
 inc/queue.h             | 19 +++++++++++++++++++
 inc/scheduler.h         | 10 ++++++++++
 inc/task.h              | 27 +++++++++++++++++++++++++++
 scripts/check_format.sh |  2 +-
 src/mutex.c             |  1 +
 src/queue.c             | 33 +++++++++++++++++++++++++++++++++
 src/scheduler.c         | 28 ++++++++++++++++++++++++++++
 8 files changed, 135 insertions(+), 1 deletion(-)
 create mode 100644 inc/mutex.h
 create mode 100644 inc/queue.h
 create mode 100644 inc/scheduler.h
 create mode 100644 inc/task.h
 create mode 100644 src/mutex.c
 create mode 100644 src/queue.c
 create mode 100644 src/scheduler.c

diff --git a/inc/mutex.h b/inc/mutex.h
new file mode 100644
index 0000000..ccd2dee
--- /dev/null
+++ b/inc/mutex.h
@@ -0,0 +1,16 @@
+#ifndef MUTEX_H
+#define MUTEX_H
+
+#include "task.h"
+
+typedef struct {
+    bool locked;
+    bool original_polarity;
+    TaskControlBlock *owner;
+} Mutex;
+
+void init_mutex(Mutex* mutex);
+bool lock_mutex(Mutex* mutex);
+void unlock_mutex(Mutex* mutex);
+
+#endif
\ No newline at end of file
diff --git a/inc/queue.h b/inc/queue.h
new file mode 100644
index 0000000..68d418e
--- /dev/null
+++ b/inc/queue.h
@@ -0,0 +1,19 @@
+#ifndef QUEUE_H
+#define QUEUE_H
+
+#include <cstdint>
+#include <stdbool.h>
+
+typedef struct {
+    uint8_t *buffer;
+    uint32_t head;
+    uint32_t tail;
+    uint32_t maxLen;
+    bool full;
+} Queue;
+
+void init_queue(Queue *q, uint8_t *buffer, uint32_t size);
+bool enqueue(Queue *q, uint8_t data);
+bool dequeue(Queue *q, uint8_t *data);
+
+#endif
\ No newline at end of file
diff --git a/inc/scheduler.h b/inc/scheduler.h
new file mode 100644
index 0000000..807baa0
--- /dev/null
+++ b/inc/scheduler.h
@@ -0,0 +1,10 @@
+#ifndef SCHEDULER_H
+#define SCHEDULER_H
+
+#include "task.h"
+
+void init_scheduler();
+void start_scheduler();
+void create_task(TaskFunction taskFunction, uint8_t priority, const char *name);
+
+#endif
\ No newline at end of file
diff --git a/inc/task.h b/inc/task.h
new file mode 100644
index 0000000..aa2deeb
--- /dev/null
+++ b/inc/task.h
@@ -0,0 +1,27 @@
+#ifndef TASK_H
+#define TASK_H
+
+#include <cstdint>
+
+typedef enum {
+    TASK_READY,
+    TASK_RUNNING,
+    TASK_BLOCKED,
+    TASK_SUSPENDED
+} TaskState;
+
+typedef void (*TaskFunction)(void);
+
+typedef struct {
+    TaskFunction taskFunction;  // Task function pointer
+    uint32_t *stackPointer;     // Pointer to the task's stack
+    TaskState state;            // Current state of the task
+    uint8_t priority;           // Task priority
+    uint32_t delay;             // Delay for task to unblock (for time-delayed tasks)
+    char taskName[16];          // Task name for debugging
+} TaskControlBlock;
+
+#define MAX_TASKS 10
+#define STACK_SIZE 1024
+
+#endif
\ No newline at end of file
diff --git a/scripts/check_format.sh b/scripts/check_format.sh
index 8e9d5ce..61757af 100644
--- a/scripts/check_format.sh
+++ b/scripts/check_format.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-FILES=$(find . -name "*.c" -o -name "*.h")
+FILES=$(find . -name "*.c" -o -name "*.h" -not -path "./cpputest/*")
 
 format_check=0
 
diff --git a/src/mutex.c b/src/mutex.c
new file mode 100644
index 0000000..008933e
--- /dev/null
+++ b/src/mutex.c
@@ -0,0 +1 @@
+#include "mutex.h"
\ No newline at end of file
diff --git a/src/queue.c b/src/queue.c
new file mode 100644
index 0000000..8510720
--- /dev/null
+++ b/src/queue.c
@@ -0,0 +1,33 @@
+#include "queue.h"
+
+void init_queue(Queue *q, uint8_t *buffer, uint32_t size) {
+    q->buffer = buffer;
+    q->maxLen = size;
+    q->head = 0;
+    q->tail = 0;
+    q->full = false;
+}
+
+bool enqueue(Queue *q, uint8_t data) {
+    if (q->full) {
+        return false;
+    }
+
+    q->buffer[q->head] = data;
+    q->head = (q->head + 1) % q->maxLen;
+    q->full = (q->head == q->tail);
+}
+
+
+bool dequeue(Queue *q, uint8_t *data) {
+    if (q->head == q->tail && !q->full) {
+        enableInterrupts();
+        return false;
+    }
+
+    *data = q->buffer[q->tail];
+    q->tail = (q->tail + 1) % q->maxLen;
+    q->full = false;
+
+    return true;
+}
\ No newline at end of file
diff --git a/src/scheduler.c b/src/scheduler.c
new file mode 100644
index 0000000..70f47d0
--- /dev/null
+++ b/src/scheduler.c
@@ -0,0 +1,28 @@
+#include "scheduler.h"
+
+TaskControlBlock task_list[MAX_TASKS];
+uint8_t task_stacks[MAX_TASKS][STACK_SIZE];
+
+void init_scheduler() {
+    for (int i = 0; i < MAX_TASKS; i++) {
+        task_list[i].state = TASK_SUSPENDED;
+        task_list[i].stackPointer = &task_stacks[i][STACK_SIZE - 1];
+    }
+}
+
+void create_task(TaskFunction task_function, uint8_t priority, const char *name) {
+    for (int i = 0; i < MAX_TASKS; i++) {
+        if (task_list[i].state == TASK_SUSPENDED) {
+            task_list[i].taskFunction = task_function;
+            task_list[i].priority = priority;
+            task_list[i].state = TASK_READY;
+            // Copies over name into taskName and states string end using \0
+            strncpy(task_list[i].taskName, name, sizeof(task_list[i].taskName));
+            task_list[i].taskName[sizeof(task_list[i].taskName) - 1] = '\0';
+
+            task_list[i].stackPointer = &task_stacks[i][STACK_SIZE - 1];
+
+            break;
+        }
+    }
+}