start weak

Makefile

@@ -1,10 +1,10 @@
 SRC = $(wildcard src/*.c)
 INCLUDE = include
 
-CFLAGS = -Wall $(addprefix -I,$(INCLUDE)) --std=gnu11 -pedantic
-CFLAGS+= -O3 -flto -fgraphite
+CFLAGS?= -O3 -flto -fgraphite
+CFLAGS+= -Wall $(addprefix -I,$(INCLUDE)) --std=gnu11 -pedantic
 
-LDFLAGS = -O3 -flto
+LDFLAGS?= -O3 -flto
 
 OBJ:= obj
 

include/rc.h

@@ -1,6 +1,7 @@
 #ifndef _RC_H
 #define _RC_H
 
+
 #ifdef __cplusplus
 #define _rc_restrict __restrict
 extern "C" {
@@ -8,17 +9,44 @@ extern "C" {
 #define _rc_restrict restrict
 #endif
 
+#include <stdbool.h>
+
 #ifndef __GNUC__
 #define _rc_attr(_)
 #else
 #define _rc_attr(v) __attribute__(v)
 #endif
 
+#define _rc_alloc_fn _rc_attr((returns_nonnull, malloc))
+#define _rc_gmut_fn _rc_attr((nonnull))
+#define _rc_mut_fn _rc_attr((pure, nonnull))
+#define _rc_fn _rc_attr((const, nonnull))
+
+#if __bool_true_false_are_defined
+#define RC_TRUE true
+#define RC_FALSE false
+typedef bool rc_bool;
+#else
+#define RC_TRUE 1
+#define RC_FALSE 0
+typedef int rc_bool;
+#endif
+
 typedef struct rc* rc_t;
+typedef struct rc_weak rc_weak_t;
+
+typedef void* _rc_attr((may_alias)) rc_ptr_t;
+typedef const void* _rc_attr((may_alias)) rc_const_ptr_t;
 
 void* _rc_restrict rc_malloc(size_t sz) _rc_attr((malloc, alloc_size(1), returns_nonnull));
-void rc_free(void* ptr) _rc_attr((nonnull));
-void* _rc_attr((may_alias)) rc_clone(void* ptr) _rc_attr((pure, nonnull, returns_nonnull)); 
+void rc_free(rc_ptr_t ptr) _rc_gmut_fn;
+rc_ptr_t rc_clone(rc_const_ptr_t ptr) _rc_mut_fn _rc_attr((returns_nonnull));
+
+size_t rc_refs(rc_const_ptr_t ptr)_rc_fn;
+rc_bool rc_is_valid(rc_const_ptr_t ptr) _rc_fn;
+
+rc_weak_t* _rc_restrict rc_create_weak(rc_const_ptr_t ptr) _rc_gmut_fn _rc_alloc_fn;
+void rc_weak_free(rc_weak_t* _rc_restrict ptr) _rc_gmut_fn;
 
 #ifdef __cplusplus
 }

src/rc.c

@@ -7,13 +7,21 @@
 
 #define RC_CHK 0xabadcafe
 
+
 struct rc {
 	uint32_t check;
 	_Atomic size_t refs;
+	_Atomic size_t weak_refs;
+	//TODO: Keep all weak pointers here. rc_weak_free() should remove its own pointer address from that.
 
 	uint8_t ptr[];
 };
 
+struct rc_weak {
+	_Atomic int is_valid;
+	const struct rc* _rc_attr((may_alias)) _ptr;
+}; 
+
 _rc_attr((noreturn)) static void panic(const char* string, ...)
 {
 	va_list args;
@@ -34,14 +42,26 @@ _rc_attr((noinline, noreturn, cold)) static void _fail_invptr()
 {
 	panic("malloc() failed to allocate %d bytes (%d + sizeof(struct rc))", sz+sizeof(struct rc), sz);
 }
+_rc_attr((artificial, const, always_inline)) inline static const struct rc* ptr_crev(const void* ptr)
+{
+	if (!ptr) _fail_invptr();
+	return (const struct rc*)(((const uint8_t*)ptr) - sizeof(struct rc));
+}
 
-_rc_attr((artificial, always_inline)) inline static rc_t ptr_rev(void* ptr)
+_rc_attr((artificial, const, always_inline)) inline static rc_t ptr_rev(void* ptr)
 {
 	if (!ptr) _fail_invptr();
 	return (rc_t)(((uint8_t*)ptr) - sizeof(struct rc));
 }
 
-_rc_attr((nonnull)) inline static void rc_checkptr(const rc_t rc)
+
+_rc_attr((artificial, const, always_inline)) inline static rc_t ptr_ucrev(const void* ptr)
+{
+	if (!ptr) _fail_invptr();
+	return (rc_t)(((uintptr_t)ptr) - sizeof(struct rc));
+}
+
+_rc_attr((nonnull)) inline static void rc_checkptr(const struct rc* rc)
 {
 	if (rc->check != RC_CHK) _fail_invptr();
 }
@@ -54,21 +74,58 @@ _rc_attr((nonnull)) inline static void rc_checkptr(const rc_t rc)
 
 	rc->check = RC_CHK;
 	rc->refs = 1;
+	rc->weak_refs =0;
 
 	return (void*) rc->ptr;	
 }
 
- _rc_attr((nonnull)) void rc_free(void* ptr)
+ _rc_gmut_fn void rc_free(rc_ptr_t ptr)
 {
 	register rc_t rc = ptr_rev(ptr);
 	rc_checkptr(rc);
 	if (!--rc->refs) free(rc);
 }
 
-_rc_attr((pure, nonnull, returns_nonnull)) void* _rc_attr((may_alias)) rc_clone(void* ptr)
+_rc_mut_fn _rc_attr((returns_nonnull)) rc_ptr_t rc_clone(rc_const_ptr_t ptr)
 {
-	register rc_t rc = ptr_rev(ptr);
+	register rc_t rc = ptr_ucrev(ptr);
 	rc_checkptr(rc);
 	++rc->refs;
-	return ptr;
+	return rc->ptr;
+}
+
+_rc_fn size_t rc_refs(rc_const_ptr_t ptr)
+{
+	register const struct rc* rc = ptr_crev(ptr);
+	rc_checkptr(rc);
+	return rc->refs;
+}
+
+_rc_fn rc_bool rc_is_valid(rc_const_ptr_t ptr)
+{
+	register const struct rc* rc = ptr_crev(ptr);
+	return rc->check == RC_CHK 
+		&& rc->refs>0;
+}
+
+_rc_alloc_fn _rc_gmut_fn rc_weak_t* _rc_restrict rc_create_weak(rc_const_ptr_t ptr)
+{
+	register rc_t rc = ptr_ucrev(ptr);
+	rc_weak_t* weak = calloc(sizeof(rc_weak_t), 1);
+	
+	weak->_ptr = rc;
+	weak->is_valid = 1;
+
+	rc->weak_refs++;
+	return weak;
+}
+
+_rc_gmut_fn void rc_weak_free(rc_weak_t* _rc_restrict ptr)
+{
+	if (ptr->is_valid) {
+		struct rc* _rc_attr((may_alias)) rc = (struct rc* _rc_attr((may_alias)))ptr->_ptr;
+		rc_checkptr(rc);
+		rc->weak_refs--;
+	}
+	free(ptr);
 }