1 files changed, 54 insertions, 0 deletions
diff --git a/lib/arena.c b/lib/arena.c
new file mode 100644
index 0000000..49ef7f1
--- /dev/null
+++ b/lib/arena.c
@@ -0,0 +1,54 @@
+#include <lib/arena.h>
+
+#include <platform/osal.h>
+
+#include <sys/mman.h>
+
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+
+int region_init(struct region *r)
+{
+	void * mem = mmap(NULL, REGION_MAX_CAPACITY, PROT_READ | PROT_WRITE,
+			  MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); // Abstract this under platform
+
+	if (mem == NULL) {
+		print("errno: %s\n", strerror(errno));
+		return -1;
+	}
+
+	r->capacity = REGION_MAX_CAPACITY;
+	r->start = mem;
+	r->end = r->start;
+	r->size = 0;
+
+	return 0;		
+}
+
+void *region_alloc(struct region *r, size_t b)
+{
+	if (r->capacity <= r->size + b) {
+		print("compiler error: region memory exceeded trying to allocate %zu bytes!", b); // Make this debug error, only present with verbose flag.
+		return NULL;
+	}
+       
+	void* ptr = r->end;
+	r->end = (char*)r->end + b;
+	r->size += b;
+	return ptr;
+}
+
+// such a dumb workaround, fix this.
+int region_pop(struct region *r, size_t b)
+{
+	assert(r != NULL);
+
+	if (r->size > b) {
+		return -1;
+	}
+
+	r->end = (char*)r->end - b;
+	r->size -= b;
+	return 0;
+}