Merge branch 'no-yield-deferred-fibers' into 'master'

feat(fiber): implement deferred fibers without yields

Closes #14

See merge request picodata/brod/tarantool-module!47

Author: gmoshkin

hlua/ffi/src/lib.rs

@@ -125,9 +125,12 @@ pub use lua_tables::LuaTable;
 pub use lua_tables::LuaTableIterator;
 pub use tuples::TuplePushError;
 pub use userdata::UserdataOnStack;
-pub use userdata::{push_userdata, read_userdata};
+pub use userdata::{push_userdata, read_userdata, push_some_userdata};
 pub use values::StringInLua;
 
+// Needed for `lua_error` macro
+pub use ffi::luaL_error;
+
 mod any;
 mod functions_write;
 mod lua_functions;
@@ -369,7 +372,7 @@ pub trait PushOne<L>: Push<L> {}
 
 /// Type that cannot be instantiated.
 ///
-/// Will be replaced with `!` eventually (https://github.com/rust-lang/rust/issues/35121).
+/// Will be replaced with `!` eventually (<https://github.com/rust-lang/rust/issues/35121>).
 #[derive(Debug, Copy, Clone)]
 pub enum Void {}
 
@@ -520,7 +523,7 @@ impl<'lua> Lua<'lua> {
     /// Opens all standard Lua libraries.
     ///
     /// See the reference for the standard library here:
-    /// https://www.lua.org/manual/5.2/manual.html#6
+    /// <https://www.lua.org/manual/5.2/manual.html#6>
     ///
     /// This is done by calling `luaL_openlibs`.
     ///
@@ -538,71 +541,71 @@ impl<'lua> Lua<'lua> {
 
     /// Opens base library.
     ///
-    /// https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_base
+    /// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_base>
     #[inline]
     pub fn open_base(&mut self) {
         unsafe { ffi::luaopen_base(self.lua.0) }
     }
 
     /// Opens bit32 library.
     ///
-    /// https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_bit32
+    /// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_bit32>
     #[inline]
     pub fn open_bit(&mut self) {
         unsafe { ffi::luaopen_bit(self.lua.0) }
     }
 
     /// Opens debug library.
     ///
-    /// https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_debug
+    /// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_debug>
     #[inline]
     pub fn open_debug(&mut self) {
         unsafe { ffi::luaopen_debug(self.lua.0) }
     }
 
     /// Opens io library.
     ///
-    /// https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_io
+    /// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_io>
     #[inline]
     pub fn open_io(&mut self) {
         unsafe { ffi::luaopen_io(self.lua.0) }
     }
 
     /// Opens math library.
     ///
-    /// https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_math
+    /// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_math>
     #[inline]
     pub fn open_math(&mut self) {
         unsafe { ffi::luaopen_math(self.lua.0) }
     }
 
     /// Opens os library.
     ///
-    /// https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_os
+    /// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_os>
     #[inline]
     pub fn open_os(&mut self) {
         unsafe { ffi::luaopen_os(self.lua.0) }
     }
 
     /// Opens package library.
     ///
-    /// https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_package
+    /// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_package>
     #[inline]
     pub fn open_package(&mut self) {
         unsafe { ffi::luaopen_package(self.lua.0) }
     }
 
     /// Opens string library.
     ///
-    /// https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_string
+    /// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_string>
     #[inline]
     pub fn open_string(&mut self) {
         unsafe { ffi::luaopen_string(self.lua.0) }
     }
 
     /// Opens table library.
     ///
-    /// https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_table
+    /// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_table>
     #[inline]
     pub fn open_table(&mut self) {
         unsafe { ffi::luaopen_table(self.lua.0) }

hlua/hlua/src/lib.rs

@@ -60,3 +60,21 @@ macro_rules! implement_lua_read {
         }
     };
 }
+
+#[macro_export]
+macro_rules! c_ptr {
+    ($s:literal) => {
+        ::std::concat!($s, "\0").as_bytes().as_ptr() as *mut i8
+    };
+}
+
+#[macro_export]
+macro_rules! lua_error {
+    ($l:expr, $msg:literal) => {
+        {
+            $crate::luaL_error($l, c_ptr!($msg));
+            unreachable!()
+        }
+    }
+}
+

hlua/hlua/src/macros.rs

@@ -13,8 +13,45 @@ use crate::{
     LuaRead,
     InsideCallback,
     LuaTable,
+    c_ptr,
 };
 
+/// Pushes `value` of type `T` onto the stack as a userdata. The value is
+/// put inside a `Option` so that it can be safely moved out of there. Useful
+/// for example when passing `FnOnce` as a c closure, because it must be dropped
+/// after the call.
+/// *[0, +1, -]*
+pub unsafe fn push_some_userdata<T>(lua: *mut ffi::lua_State, value: T) {
+    type UDBox<T> = Option<T>;
+    let ud_ptr = ffi::lua_newuserdata(lua, std::mem::size_of::<UDBox<T>>());
+    std::ptr::write(ud_ptr as *mut UDBox<T>, Some(value));
+
+    if std::mem::needs_drop::<T>() {
+        // Creating a metatable.
+        ffi::lua_newtable(lua);
+
+        // Index "__gc" in the metatable calls the object's destructor.
+        ffi::lua_pushstring(lua, c_ptr!("__gc"));
+        ffi::lua_pushcfunction(lua, wrap_gc::<T>);
+        ffi::lua_settable(lua, -3);
+
+        ffi::lua_setmetatable(lua, -2);
+    }
+
+    /// A callback for the "__gc" event. It checks if the value was moved out
+    /// and if not it drops the value.
+    unsafe extern "C" fn wrap_gc<T>(lua: *mut ffi::lua_State) -> i32 {
+        let ud_ptr = ffi::lua_touserdata(lua, 1);
+        let ud = (ud_ptr as *mut UDBox<T>)
+            .as_mut()
+            .expect("__gc called with userdata pointing to NULL");
+        drop(ud.take());
+
+        0
+    }
+}
+
+
 // Called when an object inside Lua is being dropped.
 #[inline]
 extern "C" fn destructor_wrapper<T>(lua: *mut ffi::lua_State) -> libc::c_int {

hlua/hlua/src/userdata.rs

@@ -26,6 +26,7 @@ use rmp::decode::{MarkerReadError, NumValueReadError, ValueReadError};
 use rmp::encode::ValueWriteError;
 
 use crate::ffi::tarantool as ffi;
+use crate::hlua::LuaError;
 
 /// A specialized [`Result`] type for the crate
 pub type Result<T> = std::result::Result<T, Error>;
@@ -71,6 +72,9 @@ pub enum Error {
     #[cfg(feature = "net_box")]
     #[fail(display = "Sever respond with error: {}", _0)]
     Remote(crate::net_box::ResponseError),
+
+    #[fail(display = "Lua error: {}", _0)]
+    LuaError(LuaError),
 }
 
 impl From<io::Error> for Error {
@@ -142,6 +146,12 @@ impl From<crate::net_box::ResponseError> for Error {
     }
 }
 
+impl From<LuaError> for Error {
+    fn from(error: LuaError) -> Self {
+        Error::LuaError(error)
+    }
+}
+
 /// Transaction-related error cases
 #[derive(Debug, Fail)]
 pub enum TransactionError {