Add automatic MNN library download functionality

Cargo.toml

@@ -11,6 +11,7 @@ license = { workspace = true }
 
 [workspace.dependencies]
 mnn = { version = "0.2.0", path = "." }
+mnn-sync = { version = "0.1.0", path = "mnn-sync" }
 error-stack = { version = "0.5" }
 
 [dependencies]
@@ -47,6 +48,12 @@ clap = { version = "4.5", features = ["derive"] }
 divan = "0.1.14"
 tracing = "0.1.40"
 tracing-subscriber = "0.3.19"
+tokio = { version = "1.0", features = [
+    "rt",
+    "rt-multi-thread",
+    "macros",
+    "test-util",
+] }
 tracing-test = { version = "0.2.5", features = ["no-env-filter"] }
 
 [[bench]]

README.md

@@ -1,18 +1,65 @@
-# mnn-rs
-![Codecov](https://img.shields.io/codecov/c/github/aftershootco/mnn-rs?link=https%3A%2F%2Fapp.codecov.io%2Fgithub%2Faftershootco%2Fmnn-rs)
-![GitHub Actions Workflow Status](https://img.shields.io/github/actions/workflow/status/aftershootco/mnn-rs/build.yaml?link=https%3A%2F%2Fgithub.com%2Faftershootco%2Fmnn-rs%2Factions%2Fworkflows%2Fbuild.yaml)
+# MNN Rust Bindings
 
-Rust wrapper over [alibaba/MNN](https://github.com/alibaba/MNN) c++ library with handwritten C wrapper over mnn
+Rust bindings for the [MNN](https://github.com/alibaba/MNN) neural network inference engine.
 
-If you have nix you can just build the inspect binary with
+## Installation
 
+### Option 1: Automatic Download (Default)
+
+This library will attempt to automatically download MNN source code when needed, but due to potential repository structure changes, it may not always work with the latest versions.
+
+### Option 2: Git Submodule (Recommended)
+
+The most reliable method is to use git submodules:
+
+```bash
+git submodule update --init --recursive
 ```
-nix build .#inspect
+
+### Option 3: Manual Download
+
+You can also manually download MNN and specify its location:
+
+1. Clone MNN repository: `git clone https://github.com/alibaba/MNN.git /path/to/mnn`
+2. Set environment variable: `export MNN_SRC=/path/to/mnn`
+3. Build your project: `cargo build`
+
+
+## Environment Variables
+
+| Variable | Description |
+|----------|-------------|
+| `MNN_SRC` | Path to MNN source code |
+| `MNN_VERSION` | When downloading, specifies version tag (default: "3.0.5") |
+| `MNN_COMPILE` | Set to "0" to skip compilation (requires `MNN_LIB_DIR`) |
+| `MNN_LIB_DIR` | Path to pre-built MNN libraries |
+| `MNN_SYSTEM` | Set to "1" to use system-installed MNN libraries |
+| `MNN_FORCE_DOWNLOAD` | Set to "1" to force re-download of MNN source |
+
+## Using System Libraries
+
+To use system-installed MNN libraries:
+```bash
+MNN_SYSTEM=1 cargo build
 ```
 
-NOTES:
-On windows it will only compile with --release mode
-There's a few issues with rustc linking to msvcrt by default and anything compiled with /MTd will not link properly
+## Features
+
+- `metal` - Enable Metal backend (Apple platforms)
+- `coreml` - Enable CoreML backend (Apple platforms)
+- `vulkan` - Enable Vulkan backend
+- `opencl` - Enable OpenCL backend
+- `opengl` - Enable OpenGL backend
+- `crt_static` - Use static CRT on Windows
+- `openmp` - Enable OpenMP (disables MNN threadpool)
+- `mnn-threadpool` - Use MNN's threadpool (default)
+- `tracing` - Enable tracing support
+- `profile` - Enable profiling support
+- `serde` - Enable serialization/deserialization support
+
+## Examples
+
+Check the `examples` directory for usage examples.
 
 
 

mnn-sync/src/lib.rs

@@ -227,8 +227,15 @@ impl SessionRunner {
     }
 
     pub fn unload(self) -> Result<mnn::Interpreter> {
-        let session = self.session;
-        let net = self.interpreter;
+        // 使用ManuallyDrop来避免Drop trait的干扰
+        use std::mem::ManuallyDrop;
+        let this = ManuallyDrop::new(self);
+
+        // 安全地取出字段
+        let session = unsafe { std::ptr::read(&this.session) };
+        let net = unsafe { std::ptr::read(&this.interpreter) };
+
+        // 手动释放session
         drop(session);
         Ok(net)
     }
@@ -288,6 +295,15 @@ impl SessionRunner {
     }
 }
 
+impl Drop for SessionRunner {
+    fn drop(&mut self) {
+        // 根据用户建议，明确按顺序释放MNN资源
+        // 先正确释放session，再让interpreter自动drop
+        self.session.destroy();
+        // interpreter会在结构体drop时自动释放
+    }
+}
+
 impl SessionHandle {
     pub fn new(interpreter: Interpreter, config: ScheduleConfig) -> Result<Self> {
         let (sender, receiver) = flume::unbounded::<CallbackSender>();