From f6a144987cc403de8ad6bddd055f756120f8d405 Mon Sep 17 00:00:00 2001
From: Ethan Werner <mail@ethanwerner.com>
Date: Wed, 17 Apr 2024 16:00:00 -0700
Subject: archival commit

---
 include/pool.h | 124 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 124 insertions(+)
 create mode 100755 include/pool.h

(limited to 'include/pool.h')

diff --git a/include/pool.h b/include/pool.h
new file mode 100755
index 0000000..d418142
--- /dev/null
+++ b/include/pool.h
@@ -0,0 +1,124 @@
+// pool.h - Fixed block size, free list based, memory pool
+
+#ifndef POOL_H
+#define POOL_H
+
+#include <complex.h>
+#include <setjmp.h>
+#include <stdint.h>
+
+typedef struct pool_t {
+  uint32_t block_n; // Block capacity
+  uint32_t block_i; // Block count
+  uint32_t block_s; // Block size in bytes
+  void *data;       // Blocks
+  void *free;       // Free chunk
+} pool_t;
+
+pool_t *pool_init(uint32_t, uint32_t);
+void pool_fini(pool_t *);
+void *pool_malloc(pool_t *);
+void pool_free(pool_t *, void *);
+
+#endif // POOL_H
+
+#define POOL_IMPLEMENTATION
+#ifdef POOL_IMPLEMENTATION // IMPLEMENTATION
+
+#define POOL_MULTIPLIER_RESIZE 2
+#define POOL_BLOCK_N 10
+
+#include <stdio.h>
+#include <stdlib.h>
+
+static void pool_print(pool_t *pool);
+static void pool_free_list(uintptr_t *, uint32_t, uint32_t);
+
+// pool_init()
+//
+// Initializes a memory pool and returns a pointer to the memory pool
+//
+// block_s - The size of a block in bytes
+// block_n - The number of initial blocks
+
+pool_t *pool_init( uint32_t block_s, uint32_t block_n) {
+  pool_t *pool = (pool_t *)malloc(sizeof(pool_t));
+
+  // Set size and count
+  pool->block_n = block_n;
+  pool->block_s = block_s;
+
+  pool->data = calloc(block_n, block_s);
+  pool->free = pool->data;
+
+  pool_free_list((uintptr_t *)pool->data, block_n, block_s);
+
+  return pool;
+}
+
+// pool_malloc()
+//
+// Return a block of free memory
+//
+// pool - A pointer to the pool object
+
+void *pool_malloc(pool_t *pool) {
+  uintptr_t *free = (uintptr_t *)pool->free;
+
+  if (free) {
+    pool->free = (uintptr_t *)*free;
+    pool->block_i++;
+  }
+
+  return free;
+}
+
+// pool_free()
+//
+// Free the memory at the pointer p
+//
+// pool - A pointer to the pool object
+
+void pool_free(pool_t *pool, void *p) {
+  // Convert the pointer into a usable type
+  uintptr_t *free = (uintptr_t *)p;
+
+  // Set the value at the address to the current front of the free list
+  *free = (uintptr_t)pool->free;
+
+  // Set the pool's free head to the newly freed pointer
+  pool->free = (void *)free;
+
+  pool->block_i--;
+}
+
+uint32_t pool_capacity(pool_t *pool) {
+	return pool->block_n;
+}
+
+uint32_t pool_size(pool_t *pool) {
+	return pool->block_i;
+}
+
+static void pool_print(pool_t *pool) {
+  uintptr_t *ptr = (uintptr_t *)pool->free;
+  while (((uintptr_t)ptr - (uintptr_t)pool->data) <
+         pool->block_n * pool->block_s) {
+    printf("%p %lx\n", ptr, *ptr);
+    ptr = (uintptr_t *)(((uint8_t *)ptr) + pool->block_s);
+  }
+}
+
+static void pool_free_list(uintptr_t *block, uint32_t block_n,
+                           uint32_t block_s) {
+  uint8_t *ptr = (uint8_t *)block;
+  for (int i = 0; i < block_n - 1; i++) {
+    uintptr_t *tmp = (uintptr_t *)ptr;
+    *tmp = (uintptr_t)ptr + block_s;
+    ptr = ptr + block_s;
+  }
+
+  *(uintptr_t *)ptr = (uintptr_t)0;
+}
+
+#endif // POOL_IMPLEMENTATION
-- 
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