FEAT: exporting new library functions for registering, creation and releasing handles (so these may be also used from external native modules.

Author: Oldes

src/core/a-lib.c

@@ -1121,6 +1121,60 @@ RL_API REBSER* RL_Decode_UTF_String(REBYTE *src, REBCNT len, REBINT utf, REBFLG
 	return Decode_UTF_String(src, len, utf, ccr, uni);
 }
 
+/***********************************************************************
+**
+*/	RL_API REBCNT RL_Register_Handle(REBYTE *name, REBCNT size, void* free_func)
+/*
+**	Stores handle's specification (required data size and optional free callback.
+**
+**	Returns:
+**		table index for the word (whether found or new)
+**		or NOT_FOUND if handle with give ID is already registered.
+**	Arguments:
+**		name      - handle's name as a c-string (length is being detected)
+**		size      - size of needed memory to handle
+**		free_func - custom function to be called when handle is released
+**
+***********************************************************************/
+{
+	REBCNT sym;
+	REBCNT len;
+	// Convert C-string to Rebol word
+	len = strlen(cs_cast(name));
+	sym = Scan_Word(name, len);
+	if (!sym) return NOT_FOUND; //TODO: use different value if word is invalid?
+	return Register_Handle(sym, size, (REB_HANDLE_FREE_FUNC)free_func);
+}
+
+RL_API REBHOB* RL_Make_Handle_Context(REBCNT sym)
+/*
+**	Allocates memory large enough to hold given handle's id
+**
+**	Returns:
+**		A pointer to a Rebol's handle value.
+**	Arguments:
+**		sym - handle's word id
+**
+***********************************************************************/
+{
+	return Make_Handle_Context(sym);
+}
+
+RL_API void RL_Free_Handle_Context(REBHOB *hob)
+/*
+**	Frees memory of given handle's context
+**
+**	Returns:
+**		nothing
+**	Arguments:
+**		hob - handle's context
+**
+***********************************************************************/
+{
+	Free_Hob(hob);
+}
+
+
 
 
 #include "reb-lib-lib.h"

src/include/reb-ext.h

@@ -68,7 +68,9 @@ typedef union rxi_arg_val {
 	};
 	struct {
 		void  *ptr;
-		REBCNT type;
+		REBCNT type;      // Handle's name (symbol)
+		REBFLG flags:16;  // Handle_Flags
+		REBCNT index:16;  // Index into Reb_Handle_Spec value
 	} handle;
 } RXIARG;
 
@@ -113,7 +115,9 @@ typedef int (*RXICAL)(int cmd, RXIFRM *args, REBCEC *ctx);
 #define RXA_MODULE(f,n)	(RXA_ARG(f,n).addr)
 #define RXA_HANDLE(f,n)	(RXA_ARG(f,n).handle.ptr)
 #define RXA_HANDLE_TYPE(f,n)  (RXA_ARG(f,n).handle.type)
-#define RXA_IMAGE(f,n)	(RXA_ARG(f,n).image)
+#define RXA_HANDLE_FLAGS(f,n)  (RXA_ARG(f,n).handle.flags)
+#define RXA_HANDLE_INDEX(f,n)  (RXA_ARG(f,n).handle.index)
+#define RXA_IMAGE(f,n)	      (RXA_ARG(f,n).image)
 #define RXA_IMAGE_BITS(f,n)	  ((REBYTE *)RL_SERIES((RXA_ARG(f,n).image), RXI_SER_DATA))
 #define RXA_IMAGE_WIDTH(f,n)  (RXA_ARG(f,n).width)
 #define RXA_IMAGE_HEIGHT(f,n) (RXA_ARG(f,n).height)

src/include/sys-value.h

@@ -1075,6 +1075,7 @@ enum Handle_Flags {
 	HANDLE_CONTEXT        = 1 << 2,
 	HANDLE_CONTEXT_MARKED = 1 << 3,  // used in handle's context (HOB)
 	HANDLE_CONTEXT_USED   = 1 << 4,  // --//--
+	HANDLE_CONTEXT_LOCKED = 1 << 5,  // so Rebol will not GC the handle if C side still depends on it
 };
 
 typedef struct Reb_Handle_Spec {
@@ -1131,7 +1132,7 @@ typedef struct Reb_Handle {
 #define IS_USED_HOB(h)         ((h)->flags &   HANDLE_CONTEXT_USED)   // used to detect if handle's context is still valid
 #define     USE_HOB(h)         ((h)->flags |=  HANDLE_CONTEXT_USED)
 #define   UNUSE_HOB(h)         ((h)->flags &= ~HANDLE_CONTEXT_USED)
-#define IS_MARK_HOB(h)         ((h)->flags &   HANDLE_CONTEXT_MARKED) // GC marks still used handles, so these are not released
+#define IS_MARK_HOB(h)         ((h)->flags &  (HANDLE_CONTEXT_MARKED | HANDLE_CONTEXT_LOCKED)) // GC marks still used handles, so these are not released
 #define    MARK_HOB(h)         ((h)->flags |=  HANDLE_CONTEXT_MARKED)
 #define  UNMARK_HOB(h)         ((h)->flags &= ~HANDLE_CONTEXT_MARKED)
 #define MARK_HANDLE_CONTEXT(v) (MARK_HOB(VAL_HANDLE_CTX(v)))