remote object

lualib-src/lua-remoteobj.c

@@ -0,0 +1,180 @@
+#include <lua.h>
+#include <lauxlib.h>
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define MAX_REMOTE_OBJECT 0x40000
+
+struct remote_address {
+	int handle;
+	uint32_t address;
+};
+
+struct remote_objects {
+	int handle_index;
+	struct remote_address addr[MAX_REMOTE_OBJECT];
+};
+
+static struct remote_objects * _R = NULL;
+
+static struct remote_objects *
+_create() {
+	struct remote_objects * r = malloc(sizeof(*r));
+	r->handle_index = 0;
+	memset(r, 0, sizeof(*r));
+	r->addr[0].address = 0xffffffff;
+	return r;
+}
+
+static void
+_remove(struct remote_objects *r, uint32_t address) {
+	int i;
+	for (i=0;i<MAX_REMOTE_OBJECT;i++) {
+		if (r->addr[i].address == address) {
+			r->addr[i].address = 0;
+		}
+	}
+}
+
+static int
+_alloc(struct remote_objects *r, uint32_t address) {
+	int i = 0;
+	for (i=0;i<MAX_REMOTE_OBJECT;i++) {
+		int handle = __sync_add_and_fetch(&r->handle_index, 1);
+		struct remote_address * slot = r->addr + handle % MAX_REMOTE_OBJECT;
+		if (slot->address == 0) {
+			if (__sync_bool_compare_and_swap(&slot->address, 0, address)) {
+				slot->handle = handle;
+				return handle;
+			}
+		}
+	}
+
+	return -1;
+}
+
+static int
+_bind(struct remote_objects *r, int handle, uint32_t address) {
+	struct remote_address * slot = r->addr + handle % MAX_REMOTE_OBJECT;
+	if (slot->handle != handle) {
+		return 0;
+	}
+	for (;;) {
+		uint32_t old = slot->address;
+		if (__sync_bool_compare_and_swap(&slot->address, old, address)) {
+			return old;
+		}
+	}
+}
+
+static uint32_t
+_query(struct remote_objects *r, int handle) {
+	struct remote_address * slot = r->addr + handle % MAX_REMOTE_OBJECT;
+	if (slot->handle == handle) {
+		return slot->address;
+	}
+	return 0;
+}
+
+static uint32_t
+_getaddr(lua_State *L, int index) {
+	size_t sz;
+	const char * addr = luaL_checklstring(L,index,&sz);
+	if (addr[0] != ':') {
+		luaL_error(L, "Invalid address %s",addr);
+	}
+	return strtoul(addr+1, NULL, 16);
+}
+
+static void
+_id_to_hex(char * str, uint32_t id) {
+	int i;
+	static char hex[16] = { '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F' };
+	str[0] = ':';
+	for (i=0;i<8;i++) {
+		str[i+1] = hex[(id >> ((7-i) * 4))&0xf];
+	}
+	str[9] = '\0';
+}
+
+static int
+lbind(lua_State *L) {
+	uint32_t addr = lua_tounsigned(L,lua_upvalueindex(1));
+	int handle = luaL_checkinteger(L,1);
+	uint32_t old = _bind(_R, handle, addr);
+	if (old == 0) {
+		luaL_error(L, "handle %d is not exist", handle);
+	}
+	char tmp[10];
+	_id_to_hex(tmp, old);
+	lua_pushlstring(L,tmp,9);
+	return 1;
+}
+
+static int
+lremove(lua_State *L) {
+	uint32_t * addr = lua_touserdata(L,1);
+	_remove(_R, *addr);
+	return 0;
+}
+
+static int
+lalloc(lua_State *L) {
+	uint32_t addr = lua_tounsigned(L,lua_upvalueindex(1));
+	int handle = _alloc(_R, addr);
+	if (handle < 0) {
+		return luaL_error(L, "Too many remote object");
+	}
+	lua_pushinteger(L,handle);
+	return 1;
+}
+
+static int
+lquery(lua_State *L) {
+	int handle = luaL_checkinteger(L,1);
+	uint32_t addr = _query(_R, handle);
+	if (addr == 0) {
+		return 0;
+	}
+	char tmp[10];
+	_id_to_hex(tmp, addr);
+	lua_pushlstring(L,tmp,9);
+	return 1;
+}
+
+int
+remoteobj_init(lua_State *L) {
+	if (_R == NULL) {
+		struct remote_objects * r = _create();
+		if (!__sync_bool_compare_and_swap(&_R, NULL, r)) {
+			free(r);
+		}
+	}
+
+	uint32_t address = _getaddr(L, -1);
+	lua_pushcfunction(L, lquery);
+	lua_pushnumber(L, address);
+
+	uint32_t * addr = lua_newuserdata(L, sizeof(*addr));
+	*addr = address;
+	lua_createtable(L, 0, 1);
+	lua_pushcfunction(L, lremove);
+	lua_setfield(L, -2, "__gc");
+	lua_setmetatable(L,-2);
+
+	lua_pushcclosure(L, lalloc, 2);
+	lua_pushnumber(L, address);
+	lua_pushcclosure(L, lbind, 1);
+
+	return 3;
+}
+
+
+
+
+
+
+
+