Initial

include/lpool.h

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+#ifndef LPOOL_H_
+#define LPOOL_H_
+
+#include <stddef.h>
+#include <stdint.h>
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef union LPoolBlock LPoolBlock;
+union LPoolBlock {
+    LPoolBlock *next;       // next free block (when not allocated)
+    unsigned char data[0];  // data when allocated
+};
+
+/** @file
+ * Pool allocator.
+ *
+ *  An LPool allocates fixed size memory chunks from a provided buffer,
+ *  and memory allocations can be free'd in any order.
+ *
+ * The backing array should be suitable aligned to the types
+ * that will be allocated from it. Use .e.g
+ * @code
+ * _Alignas(16) char mem[1024];
+ * @endcode
+ * as the backing buffer.
+ *
+ */
+typedef struct LPool LPool;
+struct LPool {
+    LPoolBlock *free_list;  // free list
+    LPoolBlock *start;      // start of user buffer
+    LPoolBlock *end;        // one past end of user buffer
+    uint32_t block_size;    // aligned size of each block
+    uint32_t capacity;      // number of blocks
+    uint32_t align;         // alignment
+};
+
+/** Initialize the pool.
+ *
+ * Block size will be rounded up by alignment, or to size of a pointer if alignment is less that a pointer.
+ * Prefer to use lock sizes that's pointer aligned
+ *
+ * @param buffer      backing buffer for the pool
+ * @param buffer_size size of @buffer
+ * @param block_size  size of each allocation.
+ * @param alignment   alignment of each block (must be power of 2)
+ */
+void lpool_init(LPool *pool, void *buffer, size_t buffer_size, uint32_t block_size, uint32_t alignment);
+
+// Allocate a block from the pool. Returns NULL if no more space
+[[gnu::assume_aligned(_Alignof(LPoolBlock))]]
+void *lpool_alloc(LPool *pool);
+
+// Free @p . Returns memory to the pool
+void lpool_free(LPool *pool, void *p);
+
+// Frees all memory in the pool, resetting it to initial state.
+void lpool_reset(LPool *pool);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif