MINOR: lua-thread: Use NULL context for main lua state
The goal is to no longer use "struct hlua" with global main lua_state.
This patch returns NULL value when some code tries go get the hlua struct
associated with a task through hlua_gethlua(). This functions is useful
only during runtime because the struct hlua contains only runtime states.
Some Lua functions allowed to yield are called from init environment.
I'm not sure this is a good practice. Maybe it will be clever to
disallow calling this kind of functions.
diff --git a/doc/lua-api/index.rst b/doc/lua-api/index.rst
index c45753d..adeec11 100644
--- a/doc/lua-api/index.rst
+++ b/doc/lua-api/index.rst
@@ -762,8 +762,8 @@
Immediately stops the current Lua execution and returns to the caller which
may be a sample fetch, a converter or an action and returns the specified
- value (ignored for actions). It is used when the LUA process finishes its
- work and wants to give back the control to HAProxy without executing the
+ value (ignored for actions and init). It is used when the LUA process finishes
+ its work and wants to give back the control to HAProxy without executing the
remaining code. It can be seen as a multi-level "return".
.. js:function:: core.yield()
diff --git a/src/hlua.c b/src/hlua.c
index 6530a39..3d92c7d 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -965,7 +965,13 @@
__LJMP void hlua_yieldk(lua_State *L, int nresults, int ctx,
lua_KFunction k, int timeout, unsigned int flags)
{
- struct hlua *hlua = hlua_gethlua(L);
+ struct hlua *hlua;
+
+ /* Get hlua struct, or NULL if we execute from main lua state */
+ hlua = hlua_gethlua(L);
+ if (!hlua) {
+ return;
+ }
/* Set the wake timeout. If timeout is required, we set
* the expiration time.
@@ -1119,7 +1125,12 @@
void hlua_hook(lua_State *L, lua_Debug *ar)
{
- struct hlua *hlua = hlua_gethlua(L);
+ struct hlua *hlua;
+
+ /* Get hlua struct, or NULL if we execute from main lua state */
+ hlua = hlua_gethlua(L);
+ if (!hlua)
+ return;
/* Lua cannot yield when its returning from a function,
* so, we can fix the interrupt hook to 1 instruction,
@@ -1339,7 +1350,12 @@
/* This function exit the current code. */
__LJMP static int hlua_done(lua_State *L)
{
- struct hlua *hlua = hlua_gethlua(L);
+ struct hlua *hlua;
+
+ /* Get hlua struct, or NULL if we execute from main lua state */
+ hlua = hlua_gethlua(L);
+ if (!hlua)
+ return 0;
hlua->flags |= HLUA_EXIT;
WILL_LJMP(lua_error(L));
@@ -1817,7 +1833,12 @@
struct hlua_socket *socket;
struct appctx *appctx;
struct xref *peer;
- struct hlua *hlua = hlua_gethlua(L);
+ struct hlua *hlua;
+
+ /* Get hlua struct, or NULL if we execute from main lua state */
+ hlua = hlua_gethlua(L);
+ if (!hlua)
+ return 0;
socket = MAY_LJMP(hlua_checksocket(L, 1));
@@ -1866,7 +1887,7 @@
{
struct hlua_socket *socket = MAY_LJMP(hlua_checksocket(L, 1));
int wanted = lua_tointeger(L, 2);
- struct hlua *hlua = hlua_gethlua(L);
+ struct hlua *hlua;
struct appctx *appctx;
size_t len;
int nblk;
@@ -1881,6 +1902,9 @@
struct xref *peer;
int missing_bytes;
+ /* Get hlua struct, or NULL if we execute from main lua state */
+ hlua = hlua_gethlua(L);
+
/* Check if this lua stack is schedulable. */
if (!hlua || !hlua->task)
WILL_LJMP(luaL_error(L, "The 'receive' function is only allowed in "
@@ -2094,7 +2118,7 @@
static int hlua_socket_write_yield(struct lua_State *L,int status, lua_KContext ctx)
{
struct hlua_socket *socket;
- struct hlua *hlua = hlua_gethlua(L);
+ struct hlua *hlua;
struct appctx *appctx;
size_t buf_len;
const char *buf;
@@ -2105,6 +2129,9 @@
struct stream_interface *si;
struct stream *s;
+ /* Get hlua struct, or NULL if we execute from main lua state */
+ hlua = hlua_gethlua(L);
+
/* Check if this lua stack is schedulable. */
if (!hlua || !hlua->task)
WILL_LJMP(luaL_error(L, "The 'write' function is only allowed in "
@@ -2429,12 +2456,17 @@
__LJMP static int hlua_socket_connect_yield(struct lua_State *L, int status, lua_KContext ctx)
{
struct hlua_socket *socket = MAY_LJMP(hlua_checksocket(L, 1));
- struct hlua *hlua = hlua_gethlua(L);
+ struct hlua *hlua;
struct xref *peer;
struct appctx *appctx;
struct stream_interface *si;
struct stream *s;
+ /* Get hlua struct, or NULL if we execute from main lua state */
+ hlua = hlua_gethlua(L);
+ if (!hlua)
+ return 0;
+
/* Check if we run on the same thread than the xreator thread.
* We cannot access to the socket if the thread is different.
*/
@@ -2570,7 +2602,10 @@
}
s->flags |= SF_ADDR_SET;
+ /* Get hlua struct, or NULL if we execute from main lua state */
hlua = hlua_gethlua(L);
+ if (!hlua)
+ return 0;
/* inform the stream that we want to be notified whenever the
* connection completes.
@@ -3068,7 +3103,14 @@
const char *str = MAY_LJMP(luaL_checklstring(L, 2, &len));
int l = MAY_LJMP(luaL_checkinteger(L, 3));
int max;
- struct hlua *hlua = hlua_gethlua(L);
+ struct hlua *hlua;
+
+ /* Get hlua struct, or NULL if we execute from main lua state */
+ hlua = hlua_gethlua(L);
+ if (!hlua) {
+ lua_pushnil(L);
+ return 1;
+ }
if (chn_strm(chn)->be->mode == PR_MODE_HTTP) {
lua_pushfstring(L, "Cannot manipulate HAProxy channels in HTTP mode.");
@@ -3172,7 +3214,12 @@
int len;
int l;
int max;
- struct hlua *hlua = hlua_gethlua(L);
+ struct hlua *hlua;
+
+ /* Get hlua struct, or NULL if we execute from main lua state */
+ hlua = hlua_gethlua(L);
+ if (!hlua)
+ return 1;
chn = MAY_LJMP(hlua_checkchannel(L, 1));
@@ -5297,7 +5344,11 @@
* runs only in a stream context.
*/
MAY_LJMP(hlua_checktxn(L, 1));
+
+ /* Get hlua struct, or NULL if we execute from main lua state */
hlua = hlua_gethlua(L);
+ if (!hlua)
+ return 0;
/* Remove previous value. */
luaL_unref(L, LUA_REGISTRYINDEX, hlua->Mref);
@@ -5319,7 +5370,13 @@
* runs only in a stream context.
*/
MAY_LJMP(hlua_checktxn(L, 1));
+
+ /* Get hlua struct, or NULL if we execute from main lua state */
hlua = hlua_gethlua(L);
+ if (!hlua) {
+ lua_pushnil(L);
+ return 1;
+ }
/* Push configuration index in the stack. */
lua_rawgeti(L, LUA_REGISTRYINDEX, hlua->Mref);
@@ -6155,10 +6212,12 @@
int nice;
MAY_LJMP(check_args(L, 1, "set_nice"));
- hlua = hlua_gethlua(L);
nice = MAY_LJMP(luaL_checkinteger(L, 1));
+ /* Get hlua struct, or NULL if we execute from main lua state */
+ hlua = hlua_gethlua(L);
+
- /* If he task is not set, I'm in a start mode. */
+ /* If the task is not set, I'm in a start mode. */
if (!hlua || !hlua->task)
return 0;
@@ -6700,10 +6759,16 @@
*/
__LJMP static int hlua_set_wake_time(lua_State *L)
{
- struct hlua *hlua = hlua_gethlua(L);
+ struct hlua *hlua;
unsigned int delay;
unsigned int wakeup_ms;
+ /* Get hlua struct, or NULL if we execute from main lua state */
+ hlua = hlua_gethlua(L);
+ if (!hlua) {
+ return 0;
+ }
+
MAY_LJMP(check_args(L, 1, "wake_time"));
delay = MAY_LJMP(luaL_checkinteger(L, 1));
@@ -8321,6 +8386,7 @@
struct sample_conv *sc;
char *p;
const char *error_msg;
+ void **context;
#ifdef USE_OPENSSL
struct srv_kw *kw;
int tmp_error;
@@ -8338,10 +8404,13 @@
gL.flags = 0;
LIST_INIT(&gL.com);
gL.T = lua_newstate(hlua_alloc, &hlua_global_allocator);
- hlua_sethlua(&gL);
gL.Tref = LUA_REFNIL;
gL.task = NULL;
+ /* Initialise Lua context to NULL */
+ context = lua_getextraspace(gL.T);
+ *context = NULL;
+
/* From this point, until the end of the initialisation function,
* the Lua function can fail with an abort. We are in the initialisation
* process of HAProxy, this abort() is tolerated.