Added concurrent execution of plugins

common/state/src/plugin/memory_manager.rs

@@ -1,6 +1,6 @@
-use std::sync::atomic::{AtomicPtr, AtomicU32, AtomicU64, Ordering};
+use std::sync::atomic::{AtomicPtr, Ordering};
 
-use serde::{de::DeserializeOwned, Deserialize, Serialize};
+use serde::{Deserialize, Serialize};
 use specs::{
     storage::GenericReadStorage, Component, Entities, Entity, Read, ReadStorage, WriteStorage,
 };
@@ -104,19 +104,8 @@ impl EcsAccessManager {
     }
 }
 
-pub struct MemoryManager {
-    pub pointer: AtomicU64,
-    pub length: AtomicU32,
-}
-
-impl Default for MemoryManager {
-    fn default() -> Self {
-        Self {
-            pointer: AtomicU64::new(0),
-            length: AtomicU32::new(0),
-        }
-    }
-}
+#[derive(Default)]
+pub struct MemoryManager;
 
 impl MemoryManager {
     /// This function check if the buffer is wide enough if not it realloc the
@@ -128,9 +117,6 @@ impl MemoryManager {
         object_length: u32,
         allocator: &Function,
     ) -> Result<u64, MemoryAllocationError> {
-        if self.length.load(Ordering::SeqCst) >= object_length {
-            return Ok(self.pointer.load(Ordering::SeqCst));
-        }
         let pointer = allocator
             .call(&[Value::I32(object_length as i32)])
             .map_err(MemoryAllocationError::CantAllocate)?;
@@ -139,8 +125,6 @@ impl MemoryManager {
                 .i64()
                 .ok_or(MemoryAllocationError::InvalidReturnType)?,
         );
-        self.length.store(object_length, Ordering::SeqCst);
-        self.pointer.store(pointer, Ordering::SeqCst);
         Ok(pointer)
     }
 

common/state/src/plugin/mod.rs

@@ -38,6 +38,39 @@ pub struct Plugin {
 }
 
 impl Plugin {
+    pub fn from_path(path: &Path) -> Result<Self, PluginError> {
+        if !path.is_dir() {
+            return Err(PluginError::NoConfig);
+        }
+
+        let mut toml = PathBuf::from(path);
+
+        toml.push("plugin.toml");
+
+        let data =
+            toml::de::from_slice::<PluginData>(&std::fs::read(toml).map_err(PluginError::Io)?)
+                .map_err(PluginError::Toml)?;
+
+        let modules = data
+            .modules
+            .iter()
+            .map(|path1| {
+                let mut module_file = PathBuf::from(path);
+                module_file.push(path1);
+                let wasm_data = std::fs::read(module_file).map_err(PluginError::Io)?;
+                PluginModule::new(data.name.to_owned(), &wasm_data).map_err(|e| {
+                    PluginError::PluginModuleError(data.name.to_owned(), "<init>".to_owned(), e)
+                })
+            })
+            .collect::<Result<_, _>>()?;
+
+        Ok(Plugin {
+            data,
+            modules,
+            files: HashMap::new(),
+        })
+    }
+
     pub fn from_reader<R: Read>(mut reader: R) -> Result<Self, PluginError> {
         let mut buf = Vec::new();
         reader.read_to_end(&mut buf).map_err(PluginError::Io)?;
@@ -165,7 +198,7 @@ impl PluginMgr {
                     Plugin::from_reader(fs::File::open(entry.path()).map_err(PluginError::Io)?)
                         .map(Some)
                 } else {
-                    Ok(None)
+                    Plugin::from_path(&entry.path()).map(Some)
                 }
             })
             .filter_map(Result::transpose)

common/state/src/plugin/module.rs

@@ -3,7 +3,7 @@ use std::{
     borrow::Cow,
     convert::TryInto,
     marker::PhantomData,
-    sync::{Arc, Mutex},
+    sync::{Arc, RwLock},
 };
 
 use specs::saveload::MarkerAllocator;
@@ -17,14 +17,14 @@ use super::{
 
 use plugin_api::{
     raw::{RawAction, RawRequest, RawResponse},
-    EcsAccessError, Event,
+    Event,
 };
 
 #[derive(Clone)]
 /// This structure represent the WASM State of the plugin.
 pub struct PluginModule {
     ecs: Arc<EcsAccessManager>,
-    wasm_state: Arc<Mutex<Instance>>,
+    wasm_state: Arc<RwLock<Instance>>,
     memory_manager: Arc<MemoryManager>,
     events: HashSet<String>,
     allocator: Function,
@@ -57,7 +57,7 @@ impl PluginModule {
         fn raw_request(env: &HostFunctionEnvironment, ptr: i64, len: i64) -> i64 {
             let out = match env.read_data(from_i64(ptr), from_i64(len)) {
                 Ok(data) => request(&env.ecs, data),
-                Err(e) => Err(()),
+                Err(_) => Err(()),
             };
 
             // If an error happen set the i64 to 0 so the WASM side can tell an error
@@ -109,7 +109,7 @@ impl PluginModule {
                 .iter()
                 .map(|(name, _)| name.to_string())
                 .collect(),
-            wasm_state: Arc::new(Mutex::new(instance)),
+            wasm_state: Arc::new(RwLock::new(instance)),
             name,
         })
     }
@@ -129,8 +129,8 @@ impl PluginModule {
         }
         // Store the ECS Pointer for later use in `retreives`
         let bytes = match self.ecs.execute_with(ecs, || {
-            let mut state = self.wasm_state.lock().unwrap();
-            execute_raw(self, &mut state, &request.function_name, &request.bytes)
+            let state = self.wasm_state.read().unwrap();
+            execute_raw(self, &state, &request.function_name, &request.bytes)
         }) {
             Ok(e) => e,
             Err(e) => return Some(Err(e)),
@@ -189,7 +189,7 @@ pub fn from_i64(i: i64) -> u64 { u64::from_le_bytes(i.to_le_bytes()) }
 #[allow(clippy::needless_range_loop)]
 fn execute_raw(
     module: &PluginModule,
-    instance: &mut Instance,
+    instance: &Instance,
     event_name: &str,
     bytes: &[u8],
 ) -> Result<Vec<u8>, PluginModuleError> {

common/state/src/plugin/wasm_env.rs

@@ -1,6 +1,6 @@
 use std::sync::Arc;
 
-use serde::{de::DeserializeOwned, Deserialize, Serialize};
+use serde::{Deserialize, Serialize};
 use wasmer::{Function, HostEnvInitError, Instance, LazyInit, Memory, WasmerEnv};
 
 use super::{

plugin/rt/examples/hello.rs

@@ -14,16 +14,17 @@ pub fn on_load(game: &Game, init: event::Init) {
 
 #[event_handler]
 pub fn on_command_test(game: &Game, cmd: event::Command) -> Result<Vec<String>, String> {
-    Ok(vec![
-        format!(
-            "Entity with uid {:?} named {} with {:?} sent command with args {:?}",
-            cmd.entity().uid(),
-            cmd.entity().get_name(),
-            cmd.entity().get_health(),
-            cmd.args(),
-        )
-        .into(),
-    ])
+    Ok(vec!["test".to_owned()])
+    // Ok(vec![
+    //     format!(
+    //         "Entity with uid {:?} named {} with {:?} sent command with args
+    // {:?}",         cmd.entity().uid(),
+    //         cmd.entity().get_name(),
+    //         cmd.entity().get_health(),
+    //         cmd.args(),
+    //     )
+    //     .into(),
+    // ])
 }
 
 #[global_state]

plugin/rt/src/lib.rs

@@ -49,11 +49,14 @@ pub fn emit_actions(actions: &[api::raw::RawAction]) {
 }
 
 pub fn print_str(s: &str) {
+    #[cfg(target_arch = "wasm32")]
+    {
         let bytes = s.as_bytes();
         unsafe {
             // Safety: ptr and len are valid for byte slice
             raw_print(to_i64(bytes.as_ptr() as _), to_i64(bytes.len() as _));
         }
+    }
 }
 
 #[macro_export]
@@ -67,7 +70,15 @@ where
     T: Deserialize<'a>,
 {
     let slice = unsafe { ::std::slice::from_raw_parts(from_i64(ptr) as _, from_i64(len) as _) };
-    bincode::deserialize(slice).map_err(|_| "Failed to deserialize function input")
+    let output = bincode::deserialize(slice).map_err(|_| "Failed to deserialize function input");
+    // We free the allocated buffer if it exists.
+    if let Some((a, b)) = BUFFERS
+        .iter_mut()
+        .find(|(a, b)| !*a && b.as_ptr() as u64 == from_i64(ptr))
+    {
+        *a = true;
+    }
+    output
 }
 
 /// This function split a u128 in two u64 encoding them as le bytes
@@ -107,13 +118,25 @@ pub fn write_output(value: impl Serialize) -> i64 {
     }
 }
 
-static mut BUFFERS: Vec<u8> = Vec::new();
+// Synchronisation safety is handled by the bool which enforces the Buffer to be
+// used once at a time so no problem (is_free_to_use, data)
+static mut BUFFERS: Vec<(bool, Vec<u8>)> = Vec::new();
 
 /// Allocate buffer from wasm linear memory
 /// # Safety
 /// This function should never be used only intented to by used by the host
 #[no_mangle]
 pub unsafe fn wasm_prepare_buffer(size: i32) -> i64 {
-    BUFFERS = vec![0u8; size as usize];
-    BUFFERS.as_ptr() as i64
+    if let Some((a, x)) = BUFFERS.iter_mut().find(|(x, _)| *x) {
+        *a = false;
+        if x.len() < size as usize {
+            *x = vec![0u8; size as usize];
+        }
+        x.as_ptr() as i64
+    } else {
+        let vec = vec![0u8; size as usize];
+        let ptr = vec.as_ptr() as i64;
+        BUFFERS.push((false, vec));
+        ptr
+    }
 }