degesch: implement Lua coroutine async basics
This commit is contained in:
parent
50599e09bd
commit
572f4e2ea3
339
degesch.c
339
degesch.c
@ -8300,7 +8300,7 @@ struct lua_plugin
|
||||
{
|
||||
struct plugin super; ///< The structure we're deriving
|
||||
struct app_context *ctx; ///< Application context
|
||||
lua_State *L; ///< Lua state
|
||||
lua_State *L; ///< Lua state for the main thread
|
||||
|
||||
struct lua_schema_item *schemas; ///< Registered schema items
|
||||
};
|
||||
@ -8385,6 +8385,7 @@ static bool
|
||||
lua_plugin_call (struct lua_plugin *self,
|
||||
int n_params, int n_results, struct error **e)
|
||||
{
|
||||
// FIXME: this may be called from a thread, then this is wrong
|
||||
lua_State *L = self->L;
|
||||
|
||||
// We need to pop the error handler at the end
|
||||
@ -8450,6 +8451,15 @@ lua_plugin_log_error
|
||||
error_free (error);
|
||||
}
|
||||
|
||||
static void
|
||||
lua_plugin_pack (lua_State *L, int n)
|
||||
{
|
||||
lua_createtable (L, n, 0);
|
||||
lua_insert (L, -n - 1);
|
||||
for (int i = n; i; i--)
|
||||
lua_rawseti (L, -i - 1, i);
|
||||
}
|
||||
|
||||
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
||||
|
||||
static void
|
||||
@ -8497,6 +8507,309 @@ lua_plugin_parse (lua_State *L)
|
||||
|
||||
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
||||
|
||||
// The script can create as many wait channels as wanted. They only actually
|
||||
// do anything once they get yielded to the main lua_resume() call.
|
||||
|
||||
/// Identifier for the Lua metatable
|
||||
#define XLUA_WCHANNEL_METATABLE "wchannel"
|
||||
|
||||
struct lua_wait_channel
|
||||
{
|
||||
LIST_HEADER (struct lua_wait_channel)
|
||||
|
||||
struct lua_task *task; ///< The task we're active in
|
||||
|
||||
/// Check if the event is ready and eventually push values to the thread;
|
||||
/// the channel then may release any resources
|
||||
bool (*check) (struct lua_wait_channel *self);
|
||||
|
||||
/// Release all resources held by the subclass
|
||||
void (*cleanup) (struct lua_wait_channel *self);
|
||||
};
|
||||
|
||||
static int
|
||||
lua_wchannel_gc (lua_State *L)
|
||||
{
|
||||
struct lua_wait_channel *self =
|
||||
luaL_checkudata (L, 1, XLUA_WCHANNEL_METATABLE);
|
||||
if (self->cleanup)
|
||||
self->cleanup (self);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static luaL_Reg lua_wchannel_table[] =
|
||||
{
|
||||
{ "__gc", lua_wchannel_gc },
|
||||
{ NULL, NULL }
|
||||
};
|
||||
|
||||
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
||||
|
||||
// A task encapsulates a thread so that wait channels yielded from its main
|
||||
// function get waited upon by the event loop
|
||||
|
||||
#define XLUA_TASK_METATABLE "task" ///< Identifier for the Lua metatable
|
||||
|
||||
struct lua_task
|
||||
{
|
||||
LIST_HEADER (struct lua_task)
|
||||
|
||||
struct lua_plugin *plugin; ///< The plugin we belong to
|
||||
lua_State *thread; ///< Lua thread
|
||||
struct lua_wait_channel *active; ///< Channels we're waiting on
|
||||
struct poller_idle idle; ///< Idle job
|
||||
};
|
||||
|
||||
static void
|
||||
lua_task_unregister_channels (struct lua_task *self)
|
||||
{
|
||||
LIST_FOR_EACH (struct lua_wait_channel, iter, self->active)
|
||||
{
|
||||
iter->task = NULL;
|
||||
LIST_UNLINK (self->active, iter);
|
||||
lua_cache_invalidate (self->plugin->L, iter);
|
||||
}
|
||||
}
|
||||
|
||||
static void
|
||||
lua_task_cancel_internal (struct lua_task *self)
|
||||
{
|
||||
if (self->thread)
|
||||
{
|
||||
lua_cache_invalidate (self->plugin->L, self->thread);
|
||||
self->thread = NULL;
|
||||
}
|
||||
lua_task_unregister_channels (self);
|
||||
poller_idle_reset (&self->idle);
|
||||
|
||||
// The task no longer has to stay alive
|
||||
lua_cache_invalidate (self->plugin->L, self);
|
||||
}
|
||||
|
||||
static int
|
||||
lua_task_cancel (lua_State *L)
|
||||
{
|
||||
struct lua_task *self = luaL_checkudata (L, 1, XLUA_TASK_METATABLE);
|
||||
// We could also yield and make lua_task_resume() check "self->thread",
|
||||
// however the main issue here is that the script should just return
|
||||
luaL_argcheck (L, L != self->thread, 1,
|
||||
"cannot cancel task from within itself");
|
||||
lua_task_cancel_internal (self);
|
||||
return 0;
|
||||
}
|
||||
|
||||
#define lua_task_wakeup(self) poller_idle_set (&(self)->idle)
|
||||
|
||||
static bool
|
||||
lua_task_schedule (struct lua_task *self, int n, struct error **e)
|
||||
{
|
||||
lua_State *L = self->thread;
|
||||
for (int i = -1; -i <= n; i--)
|
||||
{
|
||||
struct lua_wait_channel *channel =
|
||||
luaL_testudata (L, i, XLUA_WCHANNEL_METATABLE);
|
||||
if (!channel)
|
||||
return error_set (e, "bad argument #%d to yield: %s", -i + n + 1,
|
||||
"tasks can only yield wait channels");
|
||||
if (channel->task)
|
||||
return error_set (e, "bad argument #%d to yield: %s", -i + n + 1,
|
||||
"wait channels can only be active in one task at most");
|
||||
}
|
||||
for (int i = -1; -i <= n; i--)
|
||||
{
|
||||
// Quietly ignore duplicate channels
|
||||
struct lua_wait_channel *channel = lua_touserdata (L, i);
|
||||
if (channel->task)
|
||||
continue;
|
||||
|
||||
// By going in reverse the list ends up in the right order
|
||||
channel->task = self;
|
||||
LIST_PREPEND (self->active, channel);
|
||||
lua_cache_store (self->plugin->L, channel, i);
|
||||
}
|
||||
lua_pop (L, n);
|
||||
|
||||
// There doesn't have to be a single channel
|
||||
// We can also be waiting on a channel that is already ready
|
||||
lua_task_wakeup (self);
|
||||
return true;
|
||||
}
|
||||
|
||||
static void
|
||||
lua_task_resume (struct lua_task *self, int index)
|
||||
{
|
||||
lua_State *L = self->thread;
|
||||
bool waiting_on_multiple = self->active && self->active->next;
|
||||
|
||||
// Since we've ended the wait, we don't need to hold on to them anymore
|
||||
lua_task_unregister_channels (self);
|
||||
|
||||
// On the first run we also have the main function on the stack,
|
||||
// before any initial arguments
|
||||
int n = lua_gettop (L) - (lua_status (L) == LUA_OK);
|
||||
|
||||
// Pack the values in a table and prepend the index of the channel, so that
|
||||
// the caller doesn't need to care about the number of return values
|
||||
if (waiting_on_multiple)
|
||||
{
|
||||
lua_plugin_pack (L, n);
|
||||
lua_pushinteger (L, index);
|
||||
lua_insert (L, -2);
|
||||
n = 2;
|
||||
}
|
||||
|
||||
int res = lua_resume (L, NULL, n);
|
||||
struct error *error = NULL;
|
||||
if (res == LUA_YIELD)
|
||||
{
|
||||
// AFAIK we don't get any good error context information from here
|
||||
if (lua_task_schedule (self, lua_gettop (L), &error))
|
||||
return;
|
||||
}
|
||||
// For simplicity ignore any results from successful returns
|
||||
else if (res != LUA_OK)
|
||||
{
|
||||
luaL_traceback (L, L, lua_tostring (L, -1), 0 /* or 1? */);
|
||||
lua_plugin_process_error (self->plugin, lua_tostring (L, -1), &error);
|
||||
lua_pop (L, 2);
|
||||
}
|
||||
if (error)
|
||||
lua_plugin_log_error (self->plugin, "task", error);
|
||||
lua_task_cancel_internal (self);
|
||||
}
|
||||
|
||||
static void
|
||||
lua_task_check (struct lua_task *self)
|
||||
{
|
||||
poller_idle_reset (&self->idle);
|
||||
|
||||
lua_Integer i = 0;
|
||||
LIST_FOR_EACH (struct lua_wait_channel, iter, self->active)
|
||||
{
|
||||
i++;
|
||||
if (iter->check (iter))
|
||||
{
|
||||
lua_task_resume (self, i);
|
||||
return;
|
||||
}
|
||||
}
|
||||
if (!self->active)
|
||||
lua_task_resume (self, i);
|
||||
}
|
||||
|
||||
// The task dies either when it finishes, it is cancelled, or at plugin unload
|
||||
static luaL_Reg lua_task_table[] =
|
||||
{
|
||||
{ "cancel", lua_task_cancel },
|
||||
{ "__gc", lua_task_cancel },
|
||||
{ NULL, NULL }
|
||||
};
|
||||
|
||||
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
||||
|
||||
struct lua_wait_timer
|
||||
{
|
||||
struct lua_wait_channel super; ///< The structure we're deriving
|
||||
struct poller_timer timer; ///< Timer event
|
||||
bool expired; ///< Whether the timer has expired
|
||||
};
|
||||
|
||||
static bool
|
||||
lua_wait_timer_check (struct lua_wait_channel *wchannel)
|
||||
{
|
||||
struct lua_wait_timer *self =
|
||||
CONTAINER_OF (wchannel, struct lua_wait_timer, super);
|
||||
return self->super.task && self->expired;
|
||||
}
|
||||
|
||||
static void
|
||||
lua_wait_timer_cleanup (struct lua_wait_channel *wchannel)
|
||||
{
|
||||
struct lua_wait_timer *self =
|
||||
CONTAINER_OF (wchannel, struct lua_wait_timer, super);
|
||||
poller_timer_reset (&self->timer);
|
||||
}
|
||||
|
||||
static void
|
||||
lua_wait_timer_dispatch (struct lua_wait_timer *self)
|
||||
{
|
||||
self->expired = true;
|
||||
if (self->super.task)
|
||||
lua_task_wakeup (self->super.task);
|
||||
}
|
||||
|
||||
static int
|
||||
lua_plugin_push_wait_timer (struct lua_plugin *plugin, lua_State *L,
|
||||
lua_Integer timeout)
|
||||
{
|
||||
struct lua_wait_timer *self = lua_newuserdata (L, sizeof *self);
|
||||
luaL_setmetatable (L, XLUA_WCHANNEL_METATABLE);
|
||||
memset (self, 0, sizeof *self);
|
||||
|
||||
self->super.check = lua_wait_timer_check;
|
||||
self->super.cleanup = lua_wait_timer_cleanup;
|
||||
|
||||
poller_timer_init (&self->timer, &plugin->ctx->poller);
|
||||
self->timer.dispatcher = (poller_timer_fn) lua_wait_timer_dispatch;
|
||||
self->timer.user_data = self;
|
||||
|
||||
if (timeout)
|
||||
poller_timer_set (&self->timer, timeout);
|
||||
else
|
||||
self->expired = true;
|
||||
return 1;
|
||||
}
|
||||
|
||||
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
||||
|
||||
static int
|
||||
lua_async_go (lua_State *L)
|
||||
{
|
||||
struct lua_plugin *plugin = lua_touserdata (L, lua_upvalueindex (1));
|
||||
luaL_checktype (L, 1, LUA_TFUNCTION);
|
||||
|
||||
lua_State *thread = lua_newthread (L);
|
||||
lua_cache_store (L, thread, -1);
|
||||
lua_pop (L, 1);
|
||||
|
||||
// Move the main function w/ arguments to the thread
|
||||
lua_xmove (L, thread, lua_gettop (L));
|
||||
|
||||
struct lua_task *task = lua_newuserdata (L, sizeof *task);
|
||||
luaL_setmetatable (L, XLUA_TASK_METATABLE);
|
||||
memset (task, 0, sizeof *task);
|
||||
task->plugin = plugin;
|
||||
task->thread = thread;
|
||||
|
||||
poller_idle_init (&task->idle, &plugin->ctx->poller);
|
||||
task->idle.dispatcher = (poller_idle_fn) lua_task_check;
|
||||
task->idle.user_data = task;
|
||||
poller_idle_set (&task->idle);
|
||||
|
||||
// Make sure the task doesn't get garbage collected and return it
|
||||
lua_cache_store (L, task, -1);
|
||||
return 1;
|
||||
}
|
||||
|
||||
static int
|
||||
lua_async_timer_ms (lua_State *L)
|
||||
{
|
||||
struct lua_plugin *plugin = lua_touserdata (L, lua_upvalueindex (1));
|
||||
lua_Integer timeout = luaL_checkinteger (L, 1);
|
||||
if (timeout < 0)
|
||||
luaL_argerror (L, 1, "timeout mustn't be negative");
|
||||
return lua_plugin_push_wait_timer (plugin, L, timeout);
|
||||
}
|
||||
|
||||
static luaL_Reg lua_async_library[] =
|
||||
{
|
||||
{ "go", lua_async_go },
|
||||
{ "timer_ms", lua_async_timer_ms },
|
||||
{ NULL, NULL },
|
||||
};
|
||||
|
||||
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
||||
|
||||
// Lua code can use weakly referenced wrappers for internal objects.
|
||||
|
||||
typedef struct weak_ref_link *
|
||||
@ -8534,6 +8847,7 @@ static void
|
||||
lua_weak_push (struct lua_plugin *plugin, void *object,
|
||||
struct lua_weak_info *info)
|
||||
{
|
||||
// FIXME: this may be called from a thread, then this is wrong
|
||||
lua_State *L = plugin->L;
|
||||
if (!object)
|
||||
{
|
||||
@ -9014,6 +9328,7 @@ static struct lua_hook *
|
||||
lua_plugin_push_hook (struct lua_plugin *plugin, int callback_index,
|
||||
enum lua_hook_type type, int priority)
|
||||
{
|
||||
// FIXME: this may be called from a thread, then this is wrong
|
||||
lua_State *L = plugin->L;
|
||||
luaL_checktype (L, callback_index, LUA_TFUNCTION);
|
||||
|
||||
@ -9261,6 +9576,7 @@ lua_plugin_add_config_schema (struct lua_plugin *plugin,
|
||||
struct config_item *subtree, const char *name)
|
||||
{
|
||||
struct config_item *item = str_map_find (&subtree->value.object, name);
|
||||
// FIXME: this may be called from a thread, then this is wrong
|
||||
lua_State *L = plugin->L;
|
||||
|
||||
// This should only ever happen because of a conflict with another plugin;
|
||||
@ -9992,7 +10308,7 @@ lua_plugin_property_set (lua_State *L)
|
||||
}
|
||||
|
||||
static void
|
||||
lua_plugin_reg_finish (lua_State *L, struct lua_weak_info *info)
|
||||
lua_plugin_add_accessors (lua_State *L, struct lua_weak_info *info)
|
||||
{
|
||||
// Emulate properties for convenience
|
||||
lua_pushlightuserdata (L, info);
|
||||
@ -10000,7 +10316,6 @@ lua_plugin_reg_finish (lua_State *L, struct lua_weak_info *info)
|
||||
lua_setfield (L, -2, "__index");
|
||||
lua_pushcfunction (L, lua_plugin_property_set);
|
||||
lua_setfield (L, -2, "__newindex");
|
||||
lua_pop (L, 1);
|
||||
}
|
||||
|
||||
static void
|
||||
@ -10008,7 +10323,8 @@ lua_plugin_reg_meta (lua_State *L, const char *name, luaL_Reg *fns)
|
||||
{
|
||||
luaL_newmetatable (L, name);
|
||||
luaL_setfuncs (L, fns, 0);
|
||||
lua_plugin_reg_finish (L, NULL);
|
||||
lua_plugin_add_accessors (L, NULL);
|
||||
lua_pop (L, 1);
|
||||
}
|
||||
|
||||
static void
|
||||
@ -10020,7 +10336,8 @@ lua_plugin_reg_weak (lua_State *L, struct lua_weak_info *info, luaL_Reg *fns)
|
||||
|
||||
luaL_newmetatable (L, info->name);
|
||||
luaL_setfuncs (L, fns, 0);
|
||||
lua_plugin_reg_finish (L, info);
|
||||
lua_plugin_add_accessors (L, info);
|
||||
lua_pop (L, 1);
|
||||
}
|
||||
|
||||
static struct plugin *
|
||||
@ -10050,7 +10367,14 @@ lua_plugin_load (struct app_context *ctx, const char *filename,
|
||||
luaL_newmetatable (L, lua_ctx_info.name);
|
||||
lua_pushlightuserdata (L, plugin);
|
||||
luaL_setfuncs (L, lua_plugin_library, 1);
|
||||
lua_plugin_reg_finish (L, &lua_ctx_info);
|
||||
lua_plugin_add_accessors (L, &lua_ctx_info);
|
||||
|
||||
// Add the asynchronous library underneath
|
||||
lua_newtable (L);
|
||||
lua_pushlightuserdata (L, plugin);
|
||||
luaL_setfuncs (L, lua_async_library, 1);
|
||||
lua_setfield (L, -2, "async");
|
||||
lua_pop (L, 1);
|
||||
|
||||
lua_weak_push (plugin, ctx, &lua_ctx_info);
|
||||
lua_setglobal (L, lua_ctx_info.name);
|
||||
@ -10065,6 +10389,9 @@ lua_plugin_load (struct app_context *ctx, const char *filename,
|
||||
lua_plugin_reg_meta (L, XLUA_CONNECTION_METATABLE, lua_connection_table);
|
||||
lua_plugin_reg_meta (L, XLUA_CONNECTOR_METATABLE, lua_connector_table);
|
||||
|
||||
lua_plugin_reg_meta (L, XLUA_TASK_METATABLE, lua_task_table);
|
||||
lua_plugin_reg_meta (L, XLUA_WCHANNEL_METATABLE, lua_wchannel_table);
|
||||
|
||||
struct error *error = NULL;
|
||||
if (luaL_loadfile (L, filename))
|
||||
error_set (e, "%s: %s", "Lua", lua_tostring (L, -1));
|
||||
|
Loading…
Reference in New Issue
Block a user