Merge pull request #109 from holochain/fix-memory-deallocation-for-ru…

…st-1.78

Fix memory deallocation for Rust 1.78

README.md

@@ -2,13 +2,13 @@
 
 ## How to update holonix
 
-This repository uses `niv` to manage Nix dependencies.
-The following command will launch a transient shell with `niv` installed and update the holonix revision.
+This repository uses the `rustDev` shell from [Holonix](https://github.com/holochain/holochain/blob/develop/nix/modules/devShells.nix).
 
-```shell
-nix-shell -p niv --run "niv update"
-```
+To update Holonix, run the following command:
 
+```bash
+nix flake update
+````
 
 ## Why?
 
@@ -243,7 +243,7 @@ e.g. for nice callback handling.
 It's really easy to make a mistake in the data handling (see below) and end up
 with memory leaks or serialization mistakes, missing tracing or whatever else.
 
-Use the `holochain_wasmer_host` crate to do as much heavy lifing as possible.
+Use the `holochain_wasmer_host` crate to do as much heavy lifting as possible.
 
 The `test_process_struct` shows a good minimal example of an import function:
 

crates/common/Cargo.toml

@@ -2,7 +2,7 @@
 name = "holochain_wasmer_common"
 description = "commons for both host and guest"
 license = "Apache-2.0"
-version = "0.0.93"
+version = "0.0.94"
 authors = ["thedavidmeister", "[email protected]"]
 edition = "2021"
 

crates/guest/Cargo.toml

@@ -2,7 +2,7 @@
 name = "holochain_wasmer_guest"
 description = "wasm guest code"
 license = "Apache-2.0"
-version = "0.0.93"
+version = "0.0.94"
 authors = ["thedavidmeister", "[email protected]"]
 edition = "2021"
 
@@ -15,7 +15,7 @@ path = "src/guest.rs"
 
 [dependencies]
 holochain_serialized_bytes = { version = "=0.0.54", features = [] }
-holochain_wasmer_common = { version = "=0.0.93", path = "../common" }
+holochain_wasmer_common = { version = "=0.0.94", path = "../common" }
 serde = "1"
 tracing = "0.1"
 parking_lot = "0.12"

crates/guest/src/guest.rs

@@ -60,7 +60,15 @@ where
     O: serde::de::DeserializeOwned + std::fmt::Debug,
 {
     // Call the host function and receive the length of the serialized result.
-    let input_bytes = holochain_serialized_bytes::encode(&input).map_err(|e| wasm_error!(e))?;
+    let mut input_bytes = holochain_serialized_bytes::encode(&input).map_err(|e| wasm_error!(e))?;
+    input_bytes.shrink_to_fit();
+    if input_bytes.capacity() != input_bytes.len() {
+        tracing::warn!("Capacity should equal length, dealloc will fail");
+    }
+    debug_assert!(
+        input_bytes.capacity() == input_bytes.len(),
+        "Capacity should equal length, dealloc would fail"
+    );
     let input_len: usize = input_bytes.len();
     let input_guest_ptr = crate::allocation::write_bytes(input_bytes);
 
@@ -89,12 +97,17 @@ where
     R: Serialize + std::fmt::Debug,
 {
     match holochain_serialized_bytes::encode::<Result<R, WasmError>>(&Ok(return_value)) {
-        Ok(bytes) => {
+        Ok(mut bytes) => {
             let len: usize = bytes.len();
-            match merge_usize(write_bytes(bytes), len) {
-                Ok(v) => v,
-                Err(e) => return_err_ptr(e),
+            bytes.shrink_to_fit();
+            if bytes.capacity() != bytes.len() {
+                tracing::warn!("Capacity should equal length, dealloc will fail");
             }
+            debug_assert!(
+                bytes.capacity() == bytes.len(),
+                "Capacity should equal length, dealloc would fail"
+            );
+            merge_usize(write_bytes(bytes), len).unwrap_or_else(|e| return_err_ptr(e))
         }
         Err(e) => return_err_ptr(wasm_error!(WasmErrorInner::Serialize(e))),
     }
@@ -107,23 +120,31 @@ where
 /// for `wasm32-unknown-unknown` target.
 #[inline(always)]
 pub fn return_err_ptr(wasm_error: WasmError) -> DoubleUSize {
-    let bytes = match holochain_serialized_bytes::encode::<Result<(), WasmError>>(&Err(wasm_error))
-    {
-        Ok(bytes) => bytes,
-        Err(e) => match holochain_serialized_bytes::encode::<Result<(), WasmError>>(&Err(
-            wasm_error!(WasmErrorInner::Serialize(e)),
-        )) {
+    let mut bytes =
+        match holochain_serialized_bytes::encode::<Result<(), WasmError>>(&Err(wasm_error)) {
             Ok(bytes) => bytes,
-            // At this point we've errored while erroring
-            Err(_) => match holochain_serialized_bytes::encode::<Result<(), WasmError>>(&Err(
-                wasm_error!(WasmErrorInner::ErrorWhileError),
+            Err(e) => match holochain_serialized_bytes::encode::<Result<(), WasmError>>(&Err(
+                wasm_error!(WasmErrorInner::Serialize(e)),
             )) {
                 Ok(bytes) => bytes,
-                // At this point we failed to serialize a unit variant so IDK ¯\_(ツ)_/¯
-                Err(_) => panic!("Failed to error"),
+                // At this point we've errored while erroring
+                Err(_) => match holochain_serialized_bytes::encode::<Result<(), WasmError>>(&Err(
+                    wasm_error!(WasmErrorInner::ErrorWhileError),
+                )) {
+                    Ok(bytes) => bytes,
+                    // At this point we failed to serialize a unit variant so IDK ¯\_(ツ)_/¯
+                    Err(_) => panic!("Failed to error"),
+                },
             },
-        },
-    };
+        };
+    bytes.shrink_to_fit();
+    if bytes.capacity() != bytes.len() {
+        tracing::warn!("Capacity should equal length, dealloc will fail");
+    }
+    debug_assert!(
+        bytes.capacity() == bytes.len(),
+        "Capacity should equal length, dealloc would fail"
+    );
     let len = bytes.len();
     merge_usize(write_bytes(bytes), len).expect("Failed to build return value")
 }

crates/host/Cargo.toml

@@ -2,14 +2,14 @@
 name = "holochain_wasmer_host"
 description = "wasm host code"
 license = "Apache-2.0"
-version = "0.0.93"
+version = "0.0.94"
 authors = ["thedavidmeister", "[email protected]"]
 edition = "2021"
 
 [dependencies]
 wasmer = "=4.2.8"
 wasmer-middlewares = "=4.2.8"
-holochain_wasmer_common = { version = "=0.0.93", path = "../common" }
+holochain_wasmer_common = { version = "=0.0.94", path = "../common" }
 holochain_serialized_bytes = "=0.0.54"
 serde = "1"
 tracing = "0.1"

test.sh

@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 set -euxo pipefail
 
 export RUST_BACKTRACE=full
@@ -8,7 +9,7 @@ cargo fmt
 
 cargo clippy
 ( cd test && cargo clippy )
-( cd crates/guest && cargo clippy )
+( cd crates/guest && cargo clippy --target wasm32-unknown-unknown )
 
 # tests the root workspace that doesn't include any wasm code
 cargo test ${1-} -- --nocapture