checker

1 files changed, 55 insertions, 0 deletions

diff --git a/magic_buddy/magic_buddy.h b/magic_buddy/magic_buddy.h
new file mode 100644
index 0000000..c8778d6
--- /dev/null
+++ b/magic_buddy/magic_buddy.h
@@ -0,0 +1,55 @@
+#pragma once
+#include <stdint.h>
+#include <stddef.h>
+
+#define MAGIC_COOKIE_BYTES 32
+#define ADDRESS_BITS (8 * sizeof(void*))
+
+struct buddy {
+    uint8_t magic[MAGIC_COOKIE_BYTES];
+    struct free_block *(avail[ADDRESS_BITS]);
+    size_t root_logsize;
+    void *base;
+};
+
+// Initialize a buddy with (constant) global state stored in @state.
+// NOTE: after initializing the buddy, you should always pass the exact same
+// pointer in for @state in future calls. If you need to move @state, use
+// move_buddy(...).
+void init_buddy(uint8_t *base, size_t size, uint8_t magic[MAGIC_COOKIE_BYTES],
+                struct buddy *state);
+
+// Allocate a block of size >= @size
+void *allocate(size_t size, struct buddy *state);
+
+// Liberate a block of size @size starting at @base.
+void  liberate(void *base, size_t size, struct buddy *state);
+
+// Print debug information for the allocator.
+void debug_buddy(struct buddy *state);
+
+// Simulates @new = allocate, memcpy(@new, @old), free(@old), with some
+// optimizations for cases where the reallocation can be done in place.
+void *reallocate(void *old, size_t old_size, size_t new_size,
+                 struct buddy *state);
+
+// Attempts to reserve a range [@start,@start+@size).
+// Returns 1 if success, 0 otherwise.
+// Whenever possible, we avoid writing anything into the reserved region.
+int reserve(void *start, size_t size, struct buddy *state);
+
+// Update @state to assume the memory pool has been copied to
+// [@new_base,@new_base+@new_size)
+// Can *ONLY* be used when @new_size >= the existing size.
+void grow_buddy(uint8_t *new_base, size_t new_size, struct buddy *state);
+
+// Update @state to only use the subset of the pool in range
+// [@state->base,@state->base+new_size)
+// Can *ONLY* be used when @new_size <= the existing size.
+// This *CAN* write to anything in the old pool.
+// This *CAN* fail, in which case everything is unmodified and 0 is returned.
+// Upon success, 1 is returned.
+int shrink_buddy(size_t new_size, struct buddy *state);
+
+// Used to move the global state of the buddy.
+void move_buddy(struct buddy *new_state, struct buddy *old_state);