refactor!: make UserData more generic

2026-01-11 23:08:06 -05:00 · 2024-03-18 10:24:47 -07:00
39 changed files with 217 additions and 702 deletions
--- a/.github/workflows/kernel.yml
+++ b/.github/workflows/kernel.yml
@@ -21,9 +21,6 @@ jobs:
          target: wasm32-unknown-unknown
      - uses: Swatinem/rust-cache@v2

-      - name: install wasm-tools
-        uses: bytecodealliance/actions/wasm-tools/setup@v1
-
      - name: Install deps
        run: |
          sudo apt install wabt --yes
--- a/5
+++ b/5
@@ -4,12 +4,10 @@ AEXT=a
 FEATURES?=default
 DEFAULT_FEATURES?=yes
 RUST_TARGET?=
-EXTRA_LIBS=

 UNAME := $(shell uname -s)
 ifeq ($(UNAME),Darwin)
 	SOEXT=dylib
-	EXTRA_LIBS=-framework Security
 endif

 ifeq ($(DEFAULT_FEATURES),no)
@@ -31,8 +29,7 @@ endif
 build:
 	cargo build --release $(FEATURE_FLAGS) --manifest-path libextism/Cargo.toml $(TARGET_FLAGS)
 	sed -e "s%@CMAKE_INSTALL_PREFIX@%$(DEST)%" libextism/extism.pc.in > libextism/extism.pc
-	sed -e "s%@CMAKE_INSTALL_PREFIX@%$(DEST)%" \
-	    -e "s%Libs: %Libs: $(EXTRA_LIBS) %" libextism/extism-static.pc.in > libextism/extism-static.pc
+	sed -e "s%@CMAKE_INSTALL_PREFIX@%$(DEST)%" libextism/extism-static.pc.in > libextism/extism-static.pc

 bench:
 	@(cargo criterion $(TARGET_FLAGS) || echo 'For nicer output use cargo-criterion: `cargo install cargo-criterion` - using `cargo bench`') && cargo bench $(TARGET_FLAGS)
--- a/README.md
+++ b/README.md
@@ -51,7 +51,6 @@ started:
 | Java SDK    | <img alt="Java SDK" src="https://extism.org/img/sdk-languages/java-android.svg" width="50px"/> | https://github.com/extism/java-sdk                                      | [Sonatype](https://central.sonatype.com/artifact/org.extism.sdk/extism) |
 | .NET SDK    | <img alt=".NET SDK" src="https://extism.org/img/sdk-languages/dotnet.svg" width="50px"/>       | https://github.com/extism/dotnet-sdk <br/>(supports C# & F#!)           | [Nuget](https://www.nuget.org/packages/Extism.Sdk)                      |
 | OCaml SDK   | <img alt="OCaml SDK" src="https://extism.org/img/sdk-languages/ocaml.svg" width="50px"/>       | https://github.com/extism/ocaml-sdk                                     | [opam](https://opam.ocaml.org/packages/extism/)                         |
-| Perl SDK    | <img alt="Perl SDK" src="https://extism.org/img/sdk-languages/perl.svg" width="50px"/>         | https://github.com/extism/perl-sdk                                      | [CPAN](https://metacpan.org/pod/Extism)                                 |
 | PHP SDK     | <img alt="PHP SDK" src="https://extism.org/img/sdk-languages/php.svg" width="50px"/>           | https://github.com/extism/php-sdk                                       | [Packagist](https://packagist.org/packages/extism/extism)               |
 | Python SDK  | <img alt="Python SDK" src="https://extism.org/img/sdk-languages/python.svg" width="50px"/>     | https://github.com/extism/python-sdk                                    | [PyPi](https://pypi.org/project/extism/)                                |
 | Ruby SDK    | <img alt="Ruby SDK" src="https://extism.org/img/sdk-languages/ruby.svg" width="50px"/>         | https://github.com/extism/ruby-sdk                                      | [RubyGems](https://rubygems.org/gems/extism)                            |
--- a/kernel/.cargo/config.toml
+++ b/kernel/.cargo/config.toml
--- a/kernel/.gitignore
+++ b/kernel/.gitignore
@@ -1,3 +0,0 @@
-owi-out
-*.wat
-proofs
--- a/kernel/Cargo.toml
+++ b/kernel/Cargo.toml
@@ -7,7 +7,6 @@ edition = "2021"

 [dev-dependencies]
 wasm-bindgen-test = "0.3.39"
-owi = {git = "https://github.com/dylibso/owi-rs"}

 [features]
 default = ["bounds-checking"]
@@ -16,4 +15,4 @@ bounds-checking = []
 [workspace]
 members = [
  "."
-]
+]
--- a/kernel/build.sh
+++ b/kernel/build.sh
@@ -1,7 +1,5 @@
 #!/usr/bin/env bash

-set -e
-
 export CARGO_FLAGS=""

 while getopts d flag
@@ -19,9 +17,6 @@ done

 cargo build --package extism-runtime-kernel --bin extism-runtime --release --target wasm32-unknown-unknown $CARGO_FLAGS
 cp target/wasm32-unknown-unknown/release/extism-runtime.wasm .
+wasm-strip extism-runtime.wasm
+mv extism-runtime.wasm ../runtime/src/extism-runtime.wasm

-wasm-tools parse extism-context.wat -o extism-context.wasm
-wasm-merge --enable-reference-types ./extism-runtime.wasm runtime extism-context.wasm context -o ../runtime/src/extism-runtime.wasm
-rm extism-context.wasm
-rm extism-runtime.wasm
-wasm-strip ../runtime/src/extism-runtime.wasm
--- a/kernel/examples/alloc_length.rs
+++ b/kernel/examples/alloc_length.rs
@@ -1,21 +0,0 @@
-#![no_main]
-#![no_std]
-use extism_runtime_kernel::*;
-use owi::*;
-
-main!({
-    let n = alloc(1024);
-
-    let x = u64();
-    assume(x > 0);
-
-    let m = alloc(x);
-
-    // 1. Length should equal `x` while active
-    assert(length(m) == x);
-
-    // 2. Length should equal `0` after free
-    free(m); // Free the block
-    assert(length(m) == 0);
-    free(n);
-});
--- a/kernel/examples/error.rs
+++ b/kernel/examples/error.rs
@@ -1,24 +0,0 @@
-#![no_main]
-#![no_std]
-use extism_runtime_kernel::*;
-use owi::*;
-
-main!({
-    let x = u64();
-    let n = u64();
-    let m = u64();
-    assume(x > 0);
-    assume(n > 0);
-    assume(m > 0);
-
-    alloc(n);
-    alloc(m);
-    let n = alloc(x);
-    assert(error_get() == 0);
-
-    error_set(n);
-    assert(error_get() == n);
-    alloc(m);
-    error_set(0);
-    assert(error_get() == 0);
-});
--- a/kernel/examples/load_store.rs
+++ b/kernel/examples/load_store.rs
@@ -1,17 +0,0 @@
-#![no_main]
-#![no_std]
-use extism_runtime_kernel::*;
-use owi::*;
-
-main!({
-    let x = u64();
-    assume(x > 0);
-
-    let m = alloc(x);
-    assert(length(m) == x);
-    for i in 0..x {
-        store_u8(m + i, i as u8);
-        assert(load_u8(m + i) == i as u8);
-    }
-    free(m);
-});
--- a/kernel/examples/reuse.rs
+++ b/kernel/examples/reuse.rs
@@ -1,39 +0,0 @@
-#![no_main]
-#![no_std]
-use extism_runtime_kernel::*;
-use owi::*;
-
-main!({
-    let x = u64();
-    assume(x > 0);
-
-    let y = u64();
-    assume(y > 0);
-
-    let mut tmp = 0;
-
-    for _ in 0..y {
-        let m = alloc(x);
-        if tmp == 0 {
-            tmp = m;
-        } else {
-            // Check that the existing block is being re-used
-            assert(m == tmp);
-        }
-
-        assert(length(m) == x);
-        free(m); // Free the block
-    }
-
-    let y = u64();
-    assume(y == x + 1);
-    let n = alloc(y);
-    assert(n > tmp);
-
-    let z = u64();
-    assume(z <= x);
-    assume(x - z < 32);
-    assume(z > 0);
-    let p = alloc(z);
-    assert(p == tmp);
-});
--- a/kernel/extism-context.wat
+++ b/kernel/extism-context.wat
@@ -1,3 +0,0 @@
-(module
-  (global (export "extism_context") (mut externref) (ref.null extern))
-)
--- a/kernel/src/bin/extism-runtime.rs
+++ b/kernel/src/bin/extism-runtime.rs
@@ -1,5 +1,5 @@
-#![no_std]
 #![no_main]
+#![no_std]

 pub use extism_runtime_kernel::*;

--- a/kernel/src/lib.rs
+++ b/kernel/src/lib.rs
@@ -175,7 +175,7 @@ impl MemoryRoot {
        core::ptr::write_bytes(
            self.blocks.as_mut_ptr() as *mut u8,
            MemoryStatus::Unused as u8,
-            self_position as usize - core::mem::size_of::<MemoryRoot>(),
+            self_position as usize,
        );

        // Clear extism runtime metadata
@@ -638,15 +638,4 @@ mod test {

        assert_eq!(last, 0);
    }
-
-    #[wasm_bindgen_test]
-    fn test_sym() {
-        unsafe {
-            reset();
-            let a = alloc(47);
-            let b = alloc(20);
-            assert_eq!(length(a), 47);
-            assert_eq!(length(b), 20);
-        }
-    }
 }
--- a/kernel/verify.sh
+++ b/kernel/verify.sh
@@ -1,23 +0,0 @@
-#!/usr/bin/env bash
-
-set -e
-
-OUT_DIR=./target/wasm32-unknown-unknown/release/examples/
-get_proof() {
-   cp "$OUT_DIR/$1.wasm" "./proofs/$1.wasm"
-}
-
-cargo build --examples --release --target wasm32-unknown-unknown --no-default-features
-
-mkdir -p proofs
-get_proof alloc_length
-get_proof load_store
-get_proof reuse
-get_proof error
-
-for proof in $(ls proofs/*.wasm); do
-  echo "Checking $proof"
-  owi  conc "$proof" $@
-  echo
-  echo "---"
-done
--- a/libextism/.clang-format
+++ b/libextism/.clang-format
@@ -1,2 +0,0 @@
-BasedOnStyle: LLVM
-IndentWidth: 2
--- a/libextism/API.md
+++ b/libextism/API.md
@@ -14,9 +14,7 @@ Create a new plugin.
 - `functions`: is an array of `ExtismFunction*`
 - `n_functions`: is the number of functions
 - `with_wasi`: enables/disables WASI
- `errmsg`: error message during plugin creation, this should be freed with
-  `extism_plugin_new_error_free`
-
+- `errmsg`: error message during plugin creation

 ```c
 ExtismPlugin extism_plugin_new(const uint8_t *wasm,
@@ -26,17 +24,6 @@ ExtismPlugin extism_plugin_new(const uint8_t *wasm,
                               bool with_wasi,
                               char **errmsg);
 ```
---
-
-### `extism_plugin_new_error_free`
-
-Frees the error message returned when creating a plugin
-
-```c
-void extism_plugin_new_error_free(char *err);
-```
-
---

 ### `extism_plugin_free`

@@ -46,8 +33,6 @@ Remove a plugin from the registry and free associated memory.
 void extism_plugin_free(ExtismPlugin *plugin);
 ```

---
-
 ### `extism_plugin_config`

 Update plugin config values, this will merge with the existing values.
@@ -58,8 +43,6 @@ bool extism_plugin_config(ExtismPlugin *plugin,
                          ExtismSize json_size);
 ```

---
-
 ### `extism_plugin_function_exists`

 Returns true if `func_name` exists.
@@ -69,8 +52,6 @@ bool extism_plugin_function_exists(ExtismPlugin *plugin,
                                   const char *func_name);
 ```

---
-
 ### `extism_plugin_call`

 Call a function.
@@ -78,8 +59,6 @@ Call a function.
 - `data`: is the input data
 - `data_len`: is the length of `data`

-Returns `0` when the call is successful.
-
 ```c
 int32_t extism_plugin_call(ExtismPlugin *plugin,
                           const char *func_name,
@@ -87,28 +66,6 @@ int32_t extism_plugin_call(ExtismPlugin *plugin,
                           ExtismSize data_len);
 ```

---
-
-### `extism_plugin_call_with_host_context`
-
-Call a function with additional host context that can be accessed from inside host functions.
- `func_name`: is the function to call
- `data`: is the input data
- `data_len`: is the length of `data`
- `host_ctx`: an opaque pointer that can be accessed in host functions
-
-Returns `0` when the call is successful.
-
-```c
-int32_t extism_plugin_call_with_host_context(ExtismPlugin *plugin,
-                           const char *func_name,
-                           const uint8_t *data,
-                           ExtismSize data_len,
-                           void *host_ctx);
-```
-
---
-
 ### `extism_plugin_error`

 Get the error associated with a `Plugin`
@@ -117,8 +74,6 @@ Get the error associated with a `Plugin`
 const char *extism_plugin_error(ExtismPlugin *plugin);
 ```

---
-
 ### `extism_plugin_output_length`

 Get the length of a plugin's output data.
@@ -127,8 +82,6 @@ Get the length of a plugin's output data.
 ExtismSize extism_plugin_output_length(ExtismPlugin *plugin);
 ```

---
-
 ### `extism_plugin_output_data`

 Get the plugin's output data.
@@ -137,8 +90,6 @@ Get the plugin's output data.
 const uint8_t *extism_plugin_output_data(ExtismPlugin *plugin);
 ```

---
-
 ### `extism_plugin_reset`

 Reset the Extism runtime, this will invalidate all allocated memory.
@@ -147,8 +98,6 @@ Reset the Extism runtime, this will invalidate all allocated memory.
 bool extism_plugin_reset(ExtismPlugin *plugin);
 ```

---
-
 ### `extism_log_file`

 Set log file and level.
@@ -157,8 +106,6 @@ Set log file and level.
 bool extism_log_file(const char *filename, const char *log_level);
 ```

---
-
 ### `extism_log_custom`

 Enable a custom log handler, this will buffer logs until `extism_log_drain`
@@ -168,8 +115,6 @@ is called Log level should be one of: info, error, trace, debug, warn
 bool extism_log_custom(const char *log_level);
 ```

---
-
 ### `extism_log_drain`

 Calls the provided callback function for each buffered log line.
@@ -179,8 +124,6 @@ This is only needed when `extism_log_custom` is used.
 void extism_log_drain(void (*handler)(const char *, uintptr_t));
 ```

---
-
 ### `extism_version`

 Get the Extism version string.
@@ -189,8 +132,6 @@ Get the Extism version string.
 const char *extism_version(void);
 ```

---
-
 ### `extism_current_plugin_memory`

 Returns a pointer to the memory of the currently running plugin
@@ -199,19 +140,6 @@ Returns a pointer to the memory of the currently running plugin
 uint8_t *extism_current_plugin_memory(ExtismCurrentPlugin *plugin);
 ```

---
-
-### `extism_current_plugin_host_context`
-
-Get access to the host context, passed in using `extism_plugin_call_with_host_context`
-
-```c
-void *extism_current_plugin_host_context(ExtismCurrentPlugin *plugin);
-```
-
---
-
-
 ### `extism_current_plugin_memory_alloc`

 Allocate a memory block in the currently running plugin
@@ -220,8 +148,6 @@ Allocate a memory block in the currently running plugin
 uint64_t extism_current_plugin_memory_alloc(ExtismCurrentPlugin *plugin, ExtismSize n);
 ```

---
-
 ### `extism_current_plugin_memory_length`

 Get the length of an allocated block
@@ -230,8 +156,6 @@ Get the length of an allocated block
 ExtismSize extism_current_plugin_memory_length(ExtismCurrentPlugin *plugin, ExtismSize n);
 ```

---
-
 ### `extism_current_plugin_memory_free`

 Free an allocated memory block
@@ -240,8 +164,6 @@ Free an allocated memory block
 void extism_current_plugin_memory_free(ExtismCurrentPlugin *plugin, uint64_t ptr);
 ```

---
-
 ### `extism_function_new`
 Create a new host function
 - `name`: function name, this should be valid UTF-8
@@ -268,8 +190,6 @@ ExtismFunction *extism_function_new(const char *name,
                                    void (*free_user_data)(void *_));
 ```

---
-
 ### `extism_function_set_namespace`

 Set the namespace of an `ExtismFunction`
@@ -278,8 +198,6 @@ Set the namespace of an `ExtismFunction`
 void extism_function_set_namespace(ExtismFunction *ptr, const char *namespace_);
 ```

---
-
 ### `extism_function_free`

 Free an `ExtismFunction`
@@ -288,8 +206,6 @@ Free an `ExtismFunction`
 void extism_function_free(ExtismFunction *ptr);
 ```

---
-
 ### `extism_plugin_cancel_handle`

 Get handle for plugin cancellation
@@ -298,8 +214,6 @@ Get handle for plugin cancellation
 const ExtismCancelHandle *extism_plugin_cancel_handle(const ExtismPlugin *plugin);
 ```

---
-
 ### `extism_plugin_cancel`

 Cancel a running plugin from another thread
@@ -308,14 +222,12 @@ Cancel a running plugin from another thread
 bool extism_plugin_cancel(const ExtismCancelHandle *handle);
 ```

---
-
 ## Type definitions:

 ### `ExtismPlugin`

 ```c
-typedef struct ExtismPlugin ExtismPlugin;
+typedef int32_t ExtismPlugin;
 ```

 ### `ExtismSize`
@@ -347,5 +259,3 @@ typedef struct ExtismCurrentPlugin ExtismCurrentPlugin;
 ```c
 typedef struct ExtismCancelHandle ExtismCancelHandle;
 ```
-
-
--- a/libextism/Makefile
+++ b/libextism/Makefile
@@ -4,7 +4,7 @@ build:

 .PHONY: static
 static:
-	$(CC) -g -o example example.c -l:libextism.a -lm -lpthread
+	$(CC) -g -o example example.c -l:libextism.a -lm

 # if needed, set PKG_CONFIG_PATH= to the directory with extism*.pc installed
 LDFLAGS=`pkg-config --libs extism`
--- a/libextism/README.md
+++ b/libextism/README.md
@@ -56,6 +56,7 @@ Since you may not have an Extism plug-in on hand to test, let's load a demo plug
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>

 void print_plugin_output(ExtismPlugin *plugin, int32_t rc){
  if (rc != EXTISM_SUCCESS) {
@@ -63,9 +64,9 @@ void print_plugin_output(ExtismPlugin *plugin, int32_t rc){
    return;
  }

-  ExtismSize outlen = extism_plugin_output_length(plugin);
+  size_t outlen = extism_plugin_output_length(plugin);
  const uint8_t *out = extism_plugin_output_data(plugin);
-  fwrite(out, 1, outlen, stdout);
+  write(STDOUT_FILENO, out, outlen);
 }

 int main(void) {
@@ -105,9 +106,9 @@ if (rc != EXTISM_SUCCESS) {
  exit(2);
 }

-ExtismSize outlen = extism_plugin_output_length(plugin);
+size_t outlen = extism_plugin_output_length(plugin);
 const uint8_t *out = extism_plugin_output_data(plugin);
-fwrite(out, 1, outlen, stdout);
+write(STDOUT_FILENO, out, outlen);
 ```

 Will print
@@ -170,6 +171,7 @@ We want to expose two functions to our plugin, `kv_write(key: String, value: Byt
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>

 // A stubbed out KV store
 typedef struct KVStore KVStore;
@@ -182,14 +184,14 @@ extern const uint32_t fake_kv_store_get(KVStore *kv, const char *key,

 // Our host functions to access the fake KV store
 void kv_get(ExtismCurrentPlugin *plugin, const ExtismVal *inputs,
-            ExtismSize ninputs, ExtismVal *outputs, ExtismSize noutputs,
+            size_t ninputs, ExtismVal *outputs, size_t noutputs,
            void *userdata) {
  // Cast the userdata pointer
  KVStore *kv = (KVStore *)userdata;

  // Get the offset to the key in the plugin memory
  uint64_t offs = inputs[0].v.i64;
-  ExtismSize keylen = extism_current_plugin_memory_length(plugin, offs);
+  size_t keylen = extism_current_plugin_memory_length(plugin, offs);

  // Allocate a new block to return
  uint64_t outoffs =
@@ -203,23 +205,23 @@ void kv_get(ExtismCurrentPlugin *plugin, const ExtismVal *inputs,
  *(uint64_t *)(extism_current_plugin_memory(plugin) + outoffs) = value;

  // Return the offset to our allocated block
-  outputs[0].t = EXTISM_PTR;
+  outputs[0].t = PTR;
  outputs[0].v.i64 = outoffs;
 }

 void kv_set(ExtismCurrentPlugin *plugin, const ExtismVal *inputs,
-            ExtismSize ninputs, ExtismVal *outputs, ExtismSize noutputs,
+            size_t ninputs, ExtismVal *outputs, size_t noutputs,
            void *userdata) {
  // Cast the userdata pointer
  KVStore *kv = (KVStore *)userdata;

  // Get the offset to the key in the plugin memory
  uint64_t keyoffs = inputs[0].v.i64;
-  ExtismSize keylen = extism_current_plugin_memory_length(plugin, keyoffs);
+  size_t keylen = extism_current_plugin_memory_length(plugin, keyoffs);

  // Get the offset to the value in the plugin memory
  uint64_t valueoffs = inputs[1].v.i64;
-  ExtismSize valuelen = extism_current_plugin_memory_length(plugin, valueoffs);
+  size_t valuelen = extism_current_plugin_memory_length(plugin, valueoffs);

  // Set key => value
  fake_kv_store_set(
@@ -232,13 +234,13 @@ int main(void) {
  const char *manifest = "{\"wasm\": [{\"url\": "
                         "\"https://github.com/extism/plugins/releases/latest/"
                         "download/count_vowels_kvstore.wasm\"}]}";
-  const ExtismValType kv_get_inputs[] = {EXTISM_PTR};
-  const ExtismValType kv_get_outputs[] = {EXTISM_PTR};
+  const ExtismValType kv_get_inputs[] = {PTR};
+  const ExtismValType kv_get_outputs[] = {PTR};
  ExtismFunction *kv_get_fn = extism_function_new(
      "kv_get", kv_get_inputs, 1, kv_get_outputs, 1, kv_get, kv, NULL);

-  const ExtismValType kv_set_inputs[] = {EXTISM_PTR};
-  const ExtismValType kv_set_outputs[] = {EXTISM_PTR};
+  const ExtismValType kv_set_inputs[] = {PTR};
+  const ExtismValType kv_set_outputs[] = {PTR};
  ExtismFunction *kv_set_fn = extism_function_new(
      "kv_set", kv_set_inputs, 1, kv_set_outputs, 1, kv_set, kv, NULL);
  const ExtismFunction *functions[] = {kv_get_fn};
@@ -286,3 +288,5 @@ print_plugin_output(plugin, extism_plugin_call(plugin, "count_vowels",
 # => Writing value=6 from key=count-vowels"
 # => {"count": 3, "total": 6, "vowels": "aeiouAEIOU"}
 ```
+
+
--- a/libextism/example.c
+++ b/libextism/example.c
@@ -9,7 +9,7 @@
 #include <sys/stat.h>
 #include <unistd.h>

-void log_handler(const char *line, ExtismSize length) {
+void log_handler(const char *line, uintptr_t length) {
  fwrite(line, length, 1, stderr);
 }

@@ -63,8 +63,8 @@ int main(int argc, char *argv[]) {

  size_t len = 0;
  uint8_t *data = read_file("../wasm/code-functions.wasm", &len);
-  ExtismValType inputs[] = {EXTISM_PTR};
-  ExtismValType outputs[] = {EXTISM_PTR};
+  ExtismValType inputs[] = {PTR};
+  ExtismValType outputs[] = {PTR};
  ExtismFunction *f =
      extism_function_new("hello_world", inputs, 1, outputs, 1, hello_world,
                          "Hello, again!", free_data);
--- a/libextism/extism-static.pc.in
+++ b/libextism/extism-static.pc.in
@@ -5,6 +5,6 @@ includedir=${prefix}/include
 Version: 1.0.0
 Name: Extism
 Description: The framework for building with WebAssembly (wasm).
-Libs: ${libdir}/libextism.a
-Libs.private: -lm -lpthread
+Libs: -L${libdir} -l:libextism.a
+Libs.private: -lm
 Cflags: -I${includedir}
--- a/libextism/extism.pc.in
+++ b/libextism/extism.pc.in
@@ -6,5 +6,5 @@ Version: 1.0.0
 Name: Extism
 Description: The framework for building with WebAssembly (wasm).
 Libs: -L${libdir} -lextism
-Libs.private: -lm -lpthread
+Libs.private: -lm
 Cflags: -I${includedir}
--- a/manifest/src/lib.rs
+++ b/manifest/src/lib.rs
@@ -10,6 +10,7 @@ pub type ManifestMemory = MemoryOptions;
 #[serde(deny_unknown_fields)]
 pub struct MemoryOptions {
    /// The max number of WebAssembly pages that should be allocated
+    #[serde(alias = "max")]
    pub max_pages: Option<u32>,

    /// The maximum number of bytes allowed in an HTTP response
@@ -61,6 +62,7 @@ pub struct HttpRequest {

    /// Request headers
    #[serde(default)]
+    #[serde(alias = "header")]
    pub headers: std::collections::BTreeMap<String, String>,

    /// Request method
--- a/runtime/Cargo.toml
+++ b/runtime/Cargo.toml
@@ -9,15 +9,15 @@ repository.workspace = true
 version.workspace = true

 [dependencies]
-wasmtime = ">= 20.0.0, < 22.0.0"
-wasi-common = ">= 20.0.0, < 22.0.0"
+wasmtime = ">= 14.0.0, < 18.0.0"
+wasmtime-wasi = ">= 14.0.0, < 18.0.0"
 anyhow = "1"
 serde = {version = "1", features = ["derive"]}
 serde_json = "1"
 toml = "0.8"
 sha2 = "0.10"
 tracing = "0.1"
-tracing-subscriber = {version = "0.3.18", features = ["std", "env-filter", "fmt"]}
+tracing-subscriber = {version = "0.3", features = ["std", "env-filter", "fmt"]}
 url = "2"
 glob = "0.3"
 ureq = {version = "2.5", optional=true}
--- a/runtime/README.md
+++ b/runtime/README.md
@@ -12,7 +12,7 @@ To use the `extism` crate, you can add it to your Cargo file:

 ```toml
 [dependencies]
-extism = "1.2.0"
+extism = "1.0.0"
 ```

 ## Environment variables
@@ -201,7 +201,7 @@ fn main() {
 }
 ```

-> *Note*: In order to write host functions you should get familiar with the methods on the [CurrentPlugin](https://docs.rs/extism/latest/extism/struct.CurrentPlugin.html) and [UserData](https://docs.rs/extism/latest/extism/enum.UserData.html) types.
+> *Note*: In order to write host functions you should get familiar with the methods on the [Extism::CurrentPlugin](https://docs.rs/extism/latest/extism/struct.CurrentPlugin.html) and [Extism::CurrentPlugin](https://docs.rs/extism/latest/extism/struct.UserData.html) types.

 Now we can invoke the event:

--- a/runtime/build.rs
+++ b/runtime/build.rs
@@ -7,7 +7,7 @@ fn main() {
 #define EXTISM_SUCCESS 0

 /** An alias for I64 to signify an Extism pointer */
-#define EXTISM_PTR ExtismValType_I64
+#define PTR I64
 ";
    if let Ok(x) = cbindgen::Builder::new()
        .with_crate(".")
--- a/runtime/examples/linking.rs
+++ b/runtime/examples/linking.rs
@@ -2,8 +2,6 @@ use extism::*;

 fn main() {
    let manifest = Manifest::new([
-        // upper.wat provides an export called `host_reflect` that takes a string
-        // and returns the same string uppercased
        Wasm::File {
            // See https://github.com/extism/plugins/blob/main/upper.wat
            path: "../wasm/upper.wasm".into(),
@@ -12,9 +10,6 @@ fn main() {
                hash: None,
            },
        },
-        // reflect expects host_reflect to be imported: https://github.com/extism/plugins/blob/e5578bbbdd87f9936a0a8d36df629768b2eff6bb/reflect/src/lib.rs#L5
-        // Extism will link the export from upper.wat to the import of reflect.rs at runtime so it
-        // can call it
        Wasm::File {
            // See https://github.com/extism/plugins/tree/main/reflect
            path: "../wasm/reflect.wasm".into(),
--- a/runtime/examples/readme.rs
+++ b/runtime/examples/readme.rs
@@ -1,7 +1,7 @@
 use extism::*;

 // pretend this is redis or something :)
-type KVStore = std::collections::BTreeMap<String, Vec<u8>>;
+type KVStore = std::sync::Arc<std::sync::Mutex<std::collections::BTreeMap<String, Vec<u8>>>>;

 // When a first argument separated with a semicolon is provided to `host_fn` it is used as the
 // variable name and type for the `UserData` parameter
--- a/runtime/extism.h
+++ b/runtime/extism.h
@@ -10,7 +10,7 @@
 #define EXTISM_SUCCESS 0

 /** An alias for I64 to signify an Extism pointer */
-#define EXTISM_PTR ExtismValType_I64
+#define PTR I64


 /**
@@ -20,31 +20,31 @@ typedef enum {
  /**
   * Signed 32 bit integer.
   */
-  ExtismValType_I32,
+  I32,
  /**
   * Signed 64 bit integer.
   */
-  ExtismValType_I64,
+  I64,
  /**
   * Floating point 32 bit integer.
   */
-  ExtismValType_F32,
+  F32,
  /**
   * Floating point 64 bit integer.
   */
-  ExtismValType_F64,
+  F64,
  /**
   * A 128 bit number.
   */
-  ExtismValType_V128,
+  V128,
  /**
   * A reference to a Wasm function.
   */
-  ExtismValType_FuncRef,
+  FuncRef,
  /**
   * A reference to opaque data in the Wasm instance.
   */
-  ExtismValType_ExternRef,
+  ExternRef,
 } ExtismValType;

 /**
@@ -113,12 +113,6 @@ extern "C" {
 */
 const uint8_t *extism_plugin_id(ExtismPlugin *plugin);

-/**
- * Get the current plugin's associated host context data. Returns null if call was made without
- * host context.
- */
-void *extism_current_plugin_host_context(ExtismCurrentPlugin *plugin);
-
 /**
 * Returns a pointer to the memory of the currently running plugin
 * NOTE: this should only be called from host functions.
@@ -237,20 +231,6 @@ int32_t extism_plugin_call(ExtismPlugin *plugin,
                           const uint8_t *data,
                           ExtismSize data_len);

-/**
- * Call a function with host context.
- *
- * `func_name`: is the function to call
- * `data`: is the input data
- * `data_len`: is the length of `data`
- * `host_context`: a pointer to context data that will be available in host functions
- */
-int32_t extism_plugin_call_with_host_context(ExtismPlugin *plugin,
-                                             const char *func_name,
-                                             const uint8_t *data,
-                                             ExtismSize data_len,
-                                             void *host_context);
-
 /**
 * Get the error associated with a `Plugin`
 */
--- a/runtime/src/current_plugin.rs
+++ b/runtime/src/current_plugin.rs
@@ -15,7 +15,6 @@ pub struct CurrentPlugin {
    pub(crate) available_pages: Option<u32>,
    pub(crate) memory_limiter: Option<MemoryLimiter>,
    pub(crate) id: uuid::Uuid,
-    pub(crate) start_time: std::time::Instant,
 }

 unsafe impl Send for CurrentPlugin {}
@@ -63,11 +62,6 @@ impl wasmtime::ResourceLimiter for MemoryLimiter {
 }

 impl CurrentPlugin {
-    /// Gets `Plugin`'s ID
-    pub fn id(&self) -> uuid::Uuid {
-        self.id
-    }
-
    /// Get a `MemoryHandle` from a memory offset
    pub fn memory_handle(&mut self, offs: u64) -> Option<MemoryHandle> {
        if offs == 0 {
@@ -187,23 +181,6 @@ impl CurrentPlugin {
        anyhow::bail!("{} unable to locate extism memory", self.id)
    }

-    pub fn host_context<T: Clone + 'static>(&mut self) -> Result<T, Error> {
-        let (linker, mut store) = self.linker_and_store();
-        let Some(Extern::Global(xs)) = linker.get(&mut store, EXTISM_ENV_MODULE, "extism_context")
-        else {
-            anyhow::bail!("unable to locate an extism kernel global: extism_context",)
-        };
-
-        let Val::ExternRef(Some(xs)) = xs.get(&mut store) else {
-            anyhow::bail!("expected extism_context to be an externref value",)
-        };
-
-        match xs.data(&mut store)?.downcast_ref::<T>().cloned() {
-            Some(xs) => Ok(xs.clone()),
-            None => anyhow::bail!("could not downcast extism_context",),
-        }
-    }
-
    pub fn memory_alloc(&mut self, n: u64) -> Result<MemoryHandle, Error> {
        if n == 0 {
            return Ok(MemoryHandle {
@@ -311,29 +288,25 @@ impl CurrentPlugin {
        id: uuid::Uuid,
    ) -> Result<Self, Error> {
        let wasi = if wasi {
-            let auth = wasi_common::sync::ambient_authority();
-            let random = wasi_common::sync::random_ctx();
-            let clocks = wasi_common::sync::clocks_ctx();
-            let sched = wasi_common::sync::sched_ctx();
-            let table = wasi_common::Table::new();
-            let ctx = wasi_common::WasiCtx::new(random, clocks, sched, table);
+            let auth = wasmtime_wasi::ambient_authority();
+            let mut ctx = wasmtime_wasi::WasiCtxBuilder::new();
+            for (k, v) in manifest.config.iter() {
+                ctx.env(k, v)?;
+            }

            if let Some(a) = &manifest.allowed_paths {
                for (k, v) in a.iter() {
-                    let file = Box::new(wasi_common::sync::dir::Dir::from_cap_std(
-                        wasi_common::sync::Dir::open_ambient_dir(k, auth)?,
-                    ));
-                    ctx.push_preopened_dir(file, v)?;
+                    let d = wasmtime_wasi::Dir::open_ambient_dir(k, auth)?;
+                    ctx.preopened_dir(d, v)?;
                }
            }

            // Enable WASI output, typically used for debugging purposes
            if std::env::var("EXTISM_ENABLE_WASI_OUTPUT").is_ok() {
-                ctx.set_stderr(Box::new(wasi_common::sync::stdio::stderr()));
-                ctx.set_stdout(Box::new(wasi_common::sync::stdio::stdout()));
+                ctx.inherit_stdout().inherit_stderr();
            }

-            Some(Wasi { ctx })
+            Some(Wasi { ctx: ctx.build() })
        } else {
            None
        };
@@ -358,7 +331,6 @@ impl CurrentPlugin {
            available_pages,
            memory_limiter,
            id,
-            start_time: std::time::Instant::now(),
        })
    }

@@ -469,18 +441,6 @@ impl CurrentPlugin {
        let length = self.memory_length(offs).unwrap_or_default();
        (offs, length)
    }
-
-    /// Returns the remaining time before a plugin will timeout, or
-    /// `None` if no timeout is configured in the manifest
-    pub fn time_remaining(&self) -> Option<std::time::Duration> {
-        if let Some(x) = &self.manifest.timeout_ms {
-            let elapsed = &self.start_time.elapsed().as_millis();
-            let ms_left = x.saturating_sub(*elapsed as u64);
-            return Some(std::time::Duration::from_millis(ms_left));
-        }
-
-        None
-    }
 }

 impl Internal for CurrentPlugin {
@@ -492,6 +452,14 @@ impl Internal for CurrentPlugin {
        unsafe { &mut *self.store }
    }

+    fn linker(&self) -> &Linker<CurrentPlugin> {
+        unsafe { &*self.linker }
+    }
+
+    fn linker_mut(&mut self) -> &mut Linker<CurrentPlugin> {
+        unsafe { &mut *self.linker }
+    }
+
    fn linker_and_store(&mut self) -> (&mut Linker<CurrentPlugin>, &mut Store<CurrentPlugin>) {
        unsafe { (&mut *self.linker, &mut *self.store) }
    }
--- a/runtime/src/extism-runtime.wasm
+++ b/runtime/src/extism-runtime.wasm
--- a/runtime/src/function.rs
+++ b/runtime/src/function.rs
@@ -4,7 +4,6 @@ use wasmtime::Caller;
 use crate::{error, trace, CurrentPlugin, Error};

 /// An enumeration of all possible value types in WebAssembly.
-/// cbindgen:prefix-with-name
 #[derive(Debug, Clone, Hash, Eq, PartialEq)]
 #[repr(C)]
 pub enum ValType {
@@ -38,13 +37,8 @@ impl From<wasmtime::ValType> for ValType {
            F32 => ValType::F32,
            F64 => ValType::F64,
            V128 => ValType::V128,
-            Ref(t) => {
-                if t.heap_type().is_func() {
-                    ValType::FuncRef
-                } else {
-                    ValType::ExternRef
-                }
-            }
+            FuncRef => ValType::FuncRef,
+            ExternRef => ValType::ExternRef,
        }
    }
 }
@@ -58,8 +52,8 @@ impl From<ValType> for wasmtime::ValType {
            F32 => wasmtime::ValType::F32,
            F64 => wasmtime::ValType::F64,
            V128 => wasmtime::ValType::V128,
-            FuncRef => wasmtime::ValType::FUNCREF,
-            ExternRef => wasmtime::ValType::EXTERNREF,
+            FuncRef => wasmtime::ValType::FuncRef,
+            ExternRef => wasmtime::ValType::ExternRef,
        }
    }
 }
@@ -77,9 +71,7 @@ pub struct CPtr {
 /// UserDataHandle is an untyped version of `UserData` that is stored inside `Function` to keep a live reference.
 #[derive(Clone)]
 pub(crate) enum UserDataHandle {
-    #[allow(dead_code)]
    C(Arc<CPtr>),
-    #[allow(dead_code)]
    Rust(Arc<std::sync::Mutex<dyn std::any::Any>>),
 }

@@ -89,18 +81,18 @@ pub(crate) enum UserDataHandle {
 /// using `UserData::get`. The `C` data is stored as a pointer and cleanup function and isn't usable from Rust. The cleanup function
 /// will be called when the inner `CPtr` is dropped.
 #[derive(Debug)]
-pub enum UserData<T: Sized> {
+pub enum UserData<T: Sync + Clone + Sized> {
    C(Arc<CPtr>),
-    Rust(Arc<std::sync::Mutex<T>>),
+    Rust(T),
 }

-impl<T: Default> Default for UserData<T> {
+impl<T: Default + Sync + Clone> Default for UserData<T> {
    fn default() -> Self {
        UserData::new(T::default())
    }
 }

-impl<T> Clone for UserData<T> {
+impl<T: Sync + Clone> Clone for UserData<T> {
    fn clone(&self) -> Self {
        match self {
            UserData::C(ptr) => UserData::C(ptr.clone()),
@@ -109,7 +101,7 @@ impl<T> Clone for UserData<T> {
    }
 }

-impl<T> UserData<T> {
+impl<T: Sync + Clone> UserData<T> {
    /// Create a new `UserData` from an existing pointer and free function, this is used
    /// by the C API to wrap C pointers into user data
    pub(crate) fn new_pointer(
@@ -134,12 +126,11 @@ impl<T> UserData<T> {
    ///
    /// This will wrap the provided value in a reference-counted mutex
    pub fn new(x: T) -> Self {
-        let data = Arc::new(std::sync::Mutex::new(x));
-        UserData::Rust(data)
+        UserData::Rust(x)
    }

    /// Get a copy of the inner value
-    pub fn get(&self) -> Result<Arc<std::sync::Mutex<T>>, Error> {
+    pub fn get(&self) -> Result<T, Error> {
        match self {
            UserData::C { .. } => anyhow::bail!("C UserData should not be used from Rust"),
            UserData::Rust(data) => Ok(data.clone()),
@@ -158,8 +149,8 @@ impl Drop for CPtr {
    }
 }

-unsafe impl<T> Send for UserData<T> {}
-unsafe impl<T> Sync for UserData<T> {}
+unsafe impl<T: Sync + Clone> Send for UserData<T> {}
+unsafe impl<T: Sync + Clone> Sync for UserData<T> {}
 unsafe impl Send for CPtr {}
 unsafe impl Sync for CPtr {}

@@ -176,8 +167,8 @@ pub struct Function {
    /// Module name
    pub(crate) namespace: Option<String>,

-    pub(crate) params: Vec<ValType>,
-    pub(crate) results: Vec<ValType>,
+    /// Function type
+    pub(crate) ty: wasmtime::FuncType,

    /// Function handle
    pub(crate) f: Arc<FunctionInner>,
@@ -188,10 +179,10 @@ pub struct Function {

 impl Function {
    /// Create a new host function
-    pub fn new<T: 'static, F>(
+    pub fn new<T: 'static + Sync + Clone, F>(
        name: impl Into<String>,
-        params: impl IntoIterator<Item = ValType>,
-        results: impl IntoIterator<Item = ValType>,
+        args: impl IntoIterator<Item = ValType>,
+        returns: impl IntoIterator<Item = ValType>,
        user_data: UserData<T>,
        f: F,
    ) -> Function
@@ -203,13 +194,13 @@ impl Function {
    {
        let data = user_data.clone();
        let name = name.into();
-        let params = params.into_iter().collect();
-        let results = results.into_iter().collect();
-        trace!("Creating function {name}: params={params:?}, results={results:?}");
+        let args = args.into_iter().map(wasmtime::ValType::from);
+        let returns = returns.into_iter().map(wasmtime::ValType::from);
+        let ty = wasmtime::FuncType::new(args, returns);
+        trace!("Creating function {name}: type={ty:?}");
        Function {
            name,
-            params,
-            results,
+            ty,
            f: Arc::new(
                move |mut caller: Caller<_>, inp: &[Val], outp: &mut [Val]| {
                    let x = data.clone();
@@ -219,27 +210,13 @@ impl Function {
            namespace: None,
            _user_data: match &user_data {
                UserData::C(ptr) => UserDataHandle::C(ptr.clone()),
-                UserData::Rust(x) => UserDataHandle::Rust(x.clone()),
+                UserData::Rust(x) => {
+                    UserDataHandle::Rust(std::sync::Arc::new(std::sync::Mutex::new(x.clone())))
+                }
            },
        }
    }

-    pub(crate) fn ty(&self, engine: &wasmtime::Engine) -> wasmtime::FuncType {
-        wasmtime::FuncType::new(
-            engine,
-            self.params
-                .iter()
-                .cloned()
-                .map(wasmtime::ValType::from)
-                .collect::<Vec<_>>(),
-            self.results
-                .iter()
-                .cloned()
-                .map(wasmtime::ValType::from)
-                .collect::<Vec<_>>(),
-        )
-    }
-
    /// Host function name
    pub fn name(&self) -> &str {
        &self.name
@@ -263,14 +240,9 @@ impl Function {
        self
    }

-    /// Get param types
-    pub fn params(&self) -> &[ValType] {
-        &self.params
-    }
-
-    /// Get result types
-    pub fn results(&self) -> &[ValType] {
-        &self.results
+    /// Get function type
+    pub fn ty(&self) -> &wasmtime::FuncType {
+        &self.ty
    }
 }

--- a/runtime/src/internal.rs
+++ b/runtime/src/internal.rs
@@ -3,7 +3,7 @@ use crate::*;
 /// WASI context
 pub struct Wasi {
    /// wasi
-    pub ctx: wasi_common::WasiCtx,
+    pub ctx: wasmtime_wasi::WasiCtx,
 }

 /// InternalExt provides a unified way of acessing `memory`, `store` and `internal` values
@@ -12,6 +12,10 @@ pub(crate) trait Internal {

    fn store_mut(&mut self) -> &mut Store<CurrentPlugin>;

+    fn linker(&self) -> &Linker<CurrentPlugin>;
+
+    fn linker_mut(&mut self) -> &mut Linker<CurrentPlugin>;
+
    fn linker_and_store(&mut self) -> (&mut Linker<CurrentPlugin>, &mut Store<CurrentPlugin>);

    fn current_plugin(&self) -> &CurrentPlugin {
--- a/runtime/src/manifest.rs
+++ b/runtime/src/manifest.rs
@@ -47,13 +47,9 @@ fn to_module(engine: &Engine, wasm: &extism_manifest::Wasm) -> Result<(String, M
            let name = meta.name.as_deref().unwrap_or(MAIN_KEY).to_string();

            // Load file
-            let buf = std::fs::read(path).map_err(|err| {
-                Error::msg(format!(
-                    "Unable to load Wasm file \"{}\": {}",
-                    path.display(),
-                    err.kind()
-                ))
-            })?;
+            let mut buf = Vec::new();
+            let mut file = std::fs::File::open(path)?;
+            file.read_to_end(&mut buf)?;

            check_hash(&meta.hash, &buf)?;
            Ok((name, Module::new(engine, buf)?))
--- a/runtime/src/pdk.rs
+++ b/runtime/src/pdk.rs
@@ -217,11 +217,6 @@ pub(crate) fn http_request(
            r = r.set(k, v);
        }

-        // Set HTTP timeout to respect the manifest timeout
-        if let Some(remaining) = data.time_remaining() {
-            r = r.timeout(remaining);
-        }
-
        let res = if body_offset > 0 {
            let handle = match data.memory_handle(body_offset) {
                Some(h) => h,
@@ -241,12 +236,6 @@ pub(crate) fn http_request(
                Some(res.into_reader())
            }
            Err(e) => {
-                // Catch timeout and return
-                if let Some(d) = data.time_remaining() {
-                    if e.kind() == ureq::ErrorKind::Io && d.as_nanos() == 0 {
-                        anyhow::bail!("timeout");
-                    }
-                }
                let msg = e.to_string();
                if let Some(res) = e.into_response() {
                    data.http_status = res.status();
--- a/runtime/src/plugin.rs
+++ b/runtime/src/plugin.rs
@@ -1,5 +1,4 @@
 use std::{
-    any::Any,
    collections::{BTreeMap, BTreeSet},
    path::PathBuf,
 };
@@ -101,6 +100,14 @@ impl Internal for Plugin {
        &mut self.store
    }

+    fn linker(&self) -> &Linker<CurrentPlugin> {
+        &self.linker
+    }
+
+    fn linker_mut(&mut self) -> &mut Linker<CurrentPlugin> {
+        &mut self.linker
+    }
+
    fn linker_and_store(&mut self) -> (&mut Linker<CurrentPlugin>, &mut Store<CurrentPlugin>) {
        (&mut self.linker, &mut self.store)
    }
@@ -186,12 +193,6 @@ fn add_module<T: 'static>(
    }

    for import in module.imports() {
-        let module = import.module();
-
-        if module == EXTISM_ENV_MODULE && !matches!(import.ty(), ExternType::Func(_)) {
-            anyhow::bail!("linked modules cannot access non-function exports of extism kernel");
-        }
-
        if !linked.contains(import.module()) {
            if let Some(m) = modules.get(import.module()) {
                add_module(
@@ -212,73 +213,6 @@ fn add_module<T: 'static>(
    Ok(())
 }

-fn relink(
-    engine: &Engine,
-    mut store: &mut Store<CurrentPlugin>,
-    imports: &[Function],
-    modules: &BTreeMap<String, Module>,
-    with_wasi: bool,
-) -> Result<(InstancePre<CurrentPlugin>, Linker<CurrentPlugin>), Error> {
-    let mut linker = Linker::new(engine);
-    // Define PDK functions
-    macro_rules! add_funcs {
-            ($($name:ident($($args:expr),*) $(-> $($r:expr),*)?);* $(;)?) => {
-                $(
-                    let t = FuncType::new(&engine, [$($args),*], [$($($r),*)?]);
-                    linker.func_new(EXTISM_ENV_MODULE, stringify!($name), t, pdk::$name)?;
-                )*
-            };
-        }
-
-    // Add builtins
-    use wasmtime::ValType::*;
-    add_funcs!(
-        config_get(I64) -> I64;
-        var_get(I64) -> I64;
-        var_set(I64, I64);
-        http_request(I64, I64) -> I64;
-        http_status_code() -> I32;
-        log_warn(I64);
-        log_info(I64);
-        log_debug(I64);
-        log_error(I64);
-    );
-
-    let mut linked = BTreeSet::new();
-    linker.module(&mut store, EXTISM_ENV_MODULE, &modules[EXTISM_ENV_MODULE])?;
-    linked.insert(EXTISM_ENV_MODULE.to_string());
-
-    // If wasi is enabled then add it to the linker
-    if with_wasi {
-        wasi_common::sync::add_to_linker(&mut linker, |x: &mut CurrentPlugin| {
-            &mut x.wasi.as_mut().unwrap().ctx
-        })?;
-    }
-
-    for f in imports {
-        let name = f.name();
-        let ns = f.namespace().unwrap_or(EXTISM_USER_MODULE);
-        unsafe {
-            linker.func_new(ns, name, f.ty(engine).clone(), &*(f.f.as_ref() as *const _))?;
-        }
-    }
-
-    for (name, module) in modules.iter() {
-        add_module(
-            store,
-            &mut linker,
-            &mut linked,
-            modules,
-            name.clone(),
-            module,
-        )?;
-    }
-
-    let main = &modules[MAIN_KEY];
-    let instance_pre = linker.instantiate_pre(main)?;
-    Ok((instance_pre, linker))
-}
-
 impl Plugin {
    /// Create a new plugin from a Manifest or WebAssembly module, and host functions. The `with_wasi`
    /// parameter determines whether or not the module should be executed with WASI enabled.
@@ -305,8 +239,7 @@ impl Plugin {
            .coredump_on_trap(debug_options.coredump.is_some())
            .profiler(debug_options.profiling_strategy)
            .wasm_tail_call(true)
-            .wasm_function_references(true)
-            .wasm_gc(true);
+            .wasm_function_references(true);

        match cache_dir {
            Some(None) => (),
@@ -342,9 +275,64 @@ impl Plugin {
        );
        store.set_epoch_deadline(1);

-        let imports: Vec<Function> = imports.into_iter().collect();
-        let (instance_pre, linker) = relink(&engine, &mut store, &imports, &modules, with_wasi)?;
+        let mut linker = Linker::new(&engine);
+        let mut imports: Vec<_> = imports.into_iter().collect();
+        // Define PDK functions
+        macro_rules! add_funcs {
+            ($($name:ident($($args:expr),*) $(-> $($r:expr),*)?);* $(;)?) => {
+                $(
+                    let t = FuncType::new([$($args),*], [$($($r),*)?]);
+                    linker.func_new(EXTISM_ENV_MODULE, stringify!($name), t, pdk::$name)?;
+                )*
+            };
+        }

+        // Add builtins
+        use wasmtime::ValType::*;
+        add_funcs!(
+            config_get(I64) -> I64;
+            var_get(I64) -> I64;
+            var_set(I64, I64);
+            http_request(I64, I64) -> I64;
+            http_status_code() -> I32;
+            log_warn(I64);
+            log_info(I64);
+            log_debug(I64);
+            log_error(I64);
+        );
+
+        let mut linked = BTreeSet::new();
+        linker.module(&mut store, EXTISM_ENV_MODULE, &modules[EXTISM_ENV_MODULE])?;
+        linked.insert(EXTISM_ENV_MODULE.to_string());
+
+        // If wasi is enabled then add it to the linker
+        if with_wasi {
+            wasmtime_wasi::add_to_linker(&mut linker, |x: &mut CurrentPlugin| {
+                &mut x.wasi.as_mut().unwrap().ctx
+            })?;
+        }
+
+        for f in &mut imports {
+            let name = f.name();
+            let ns = f.namespace().unwrap_or(EXTISM_USER_MODULE);
+            unsafe {
+                linker.func_new(ns, name, f.ty().clone(), &*(f.f.as_ref() as *const _))?;
+            }
+        }
+
+        for (name, module) in modules.iter() {
+            add_module(
+                &mut store,
+                &mut linker,
+                &mut linked,
+                &modules,
+                name.clone(),
+                module,
+            )?;
+        }
+
+        let main = &modules[MAIN_KEY];
+        let instance_pre = linker.instantiate_pre(main)?;
        let timer_tx = Timer::tx();
        let mut plugin = Plugin {
            modules,
@@ -382,7 +370,6 @@ impl Plugin {
        if self.store_needs_reset {
            let engine = self.store.engine().clone();
            let internal = self.current_plugin_mut();
-            let with_wasi = internal.wasi.is_some();
            self.store = Store::new(
                &engine,
                CurrentPlugin::new(
@@ -393,16 +380,6 @@ impl Plugin {
                )?,
            );
            self.store.set_epoch_deadline(1);
-
-            let (instance_pre, linker) = relink(
-                &engine,
-                &mut self.store,
-                &self._functions,
-                &self.modules,
-                with_wasi,
-            )?;
-            self.linker = linker;
-            self.instance_pre = instance_pre;
            let store = &mut self.store as *mut _;
            let linker = &mut self.linker as *mut _;
            let current_plugin = self.current_plugin_mut();
@@ -413,7 +390,14 @@ impl Plugin {
                    .limiter(|internal| internal.memory_limiter.as_mut().unwrap());
            }

+            let main = &self.modules[MAIN_KEY];
+            for (name, module) in self.modules.iter() {
+                if name != MAIN_KEY {
+                    self.linker.module(&mut self.store, name, module)?;
+                }
+            }
            self.instantiations = 0;
+            self.instance_pre = self.linker.instantiate_pre(main)?;
            **instance_lock = None;
            self.store_needs_reset = false;
        }
@@ -466,7 +450,7 @@ impl Plugin {
                if let Some(f) = x.func() {
                    let (params, mut results) = (f.params(), f.results());
                    match (params.len(), results.len()) {
-                        (0, 1) => matches!(results.next(), Some(wasmtime::ValType::I32)),
+                        (0, 1) => results.next() == Some(wasmtime::ValType::I32),
                        (0, 0) => true,
                        _ => false,
                    }
@@ -478,12 +462,7 @@ impl Plugin {
    }

    // Store input in memory and re-initialize `Internal` pointer
-    pub(crate) fn set_input(
-        &mut self,
-        input: *const u8,
-        mut len: usize,
-        host_context: Option<Rooted<ExternRef>>,
-    ) -> Result<(), Error> {
+    pub(crate) fn set_input(&mut self, input: *const u8, mut len: usize) -> Result<(), Error> {
        self.output = Output::default();
        self.clear_error()?;
        let id = self.id.to_string();
@@ -517,13 +496,6 @@ impl Plugin {
            )?;
        }

-        if let Some(Extern::Global(ctxt)) =
-            self.linker
-                .get(&mut self.store, EXTISM_ENV_MODULE, "extism_context")
-        {
-            ctxt.set(&mut self.store, Val::ExternRef(host_context))?;
-        }
-
        Ok(())
    }

@@ -616,7 +588,7 @@ impl Plugin {
                    if let Some(reactor_init) = reactor_init {
                        reactor_init.call(&mut store, &[], &mut [])?;
                    }
-                    let mut results = vec![Val::I32(0); init.ty(&store).results().len()];
+                    let mut results = vec![Val::null(); init.ty(&store).results().len()];
                    init.call(
                        &mut store,
                        &[Val::I32(0), Val::I32(0)],
@@ -701,7 +673,6 @@ impl Plugin {
        lock: &mut std::sync::MutexGuard<Option<Instance>>,
        name: impl AsRef<str>,
        input: impl AsRef<[u8]>,
-        host_context: Option<Rooted<ExternRef>>,
    ) -> Result<i32, (Error, i32)> {
        let name = name.as_ref();
        let input = input.as_ref();
@@ -715,7 +686,7 @@ impl Plugin {

        self.instantiate(lock).map_err(|e| (e, -1))?;

-        self.set_input(input.as_ptr(), input.len(), host_context)
+        self.set_input(input.as_ptr(), input.len())
            .map_err(|x| (x, -1))?;

        let func = match self.get_func(lock, name) {
@@ -746,10 +717,9 @@ impl Plugin {
            .expect("Timer should start");
        self.store.epoch_deadline_trap();
        self.store.set_epoch_deadline(1);
-        self.current_plugin_mut().start_time = std::time::Instant::now();

        // Call the function
-        let mut results = vec![wasmtime::Val::I32(0); n_results];
+        let mut results = vec![wasmtime::Val::null(); n_results];
        let mut res = func.call(self.store_mut(), &[], results.as_mut_slice());

        // Stop timer
@@ -834,7 +804,13 @@ impl Plugin {
                    }
                }

-                let wasi_exit_code = e.downcast_ref::<wasi_common::I32Exit>().map(|e| e.0);
+                let wasi_exit_code = e
+                    .downcast_ref::<wasmtime_wasi::I32Exit>()
+                    .map(|e| e.0)
+                    .or_else(|| {
+                        e.downcast_ref::<wasmtime_wasi::preview2::I32Exit>()
+                            .map(|e| e.0)
+                    });
                if let Some(exit_code) = wasi_exit_code {
                    debug!(
                        plugin = self.id.to_string(),
@@ -897,33 +873,7 @@ impl Plugin {
        let lock = self.instance.clone();
        let mut lock = lock.lock().unwrap();
        let data = input.to_bytes()?;
-        self.raw_call(&mut lock, name, data, None)
-            .map_err(|e| e.0)
-            .and_then(move |rc| {
-                if rc != 0 {
-                    Err(Error::msg(format!("Returned non-zero exit code: {rc}")))
-                } else {
-                    self.output()
-                }
-            })
-    }
-
-    pub fn call_with_host_context<'a, 'b, T, U, C>(
-        &'b mut self,
-        name: impl AsRef<str>,
-        input: T,
-        host_context: C,
-    ) -> Result<U, Error>
-    where
-        T: ToBytes<'a>,
-        U: FromBytes<'b>,
-        C: Any + Send + Sync + 'static,
-    {
-        let lock = self.instance.clone();
-        let mut lock = lock.lock().unwrap();
-        let data = input.to_bytes()?;
-        let ctx = ExternRef::new(&mut self.store, host_context)?;
-        self.raw_call(&mut lock, name, data, Some(ctx))
+        self.raw_call(&mut lock, name, data)
            .map_err(|e| e.0)
            .and_then(move |_| self.output())
    }
@@ -942,7 +892,7 @@ impl Plugin {
        let lock = self.instance.clone();
        let mut lock = lock.lock().unwrap();
        let data = input.to_bytes().map_err(|e| (e, -1))?;
-        self.raw_call(&mut lock, name, data, None)
+        self.raw_call(&mut lock, name, data)
            .and_then(move |_| self.output().map_err(|e| (e, -1)))
    }

--- a/runtime/src/plugin_builder.rs
+++ b/runtime/src/plugin_builder.rs
@@ -60,7 +60,7 @@ impl<'a> PluginBuilder<'a> {
    }

    /// Add a single host function
-    pub fn with_function<T: 'static, F>(
+    pub fn with_function<T: Sync + Clone + 'static, F>(
        mut self,
        name: impl Into<String>,
        args: impl IntoIterator<Item = ValType>,
@@ -80,7 +80,7 @@ impl<'a> PluginBuilder<'a> {
    }

    /// Add a single host function in a specific namespace
-    pub fn with_function_in_namespace<T: 'static, F>(
+    pub fn with_function_in_namespace<T: Sync + Clone + 'static, F>(
        mut self,
        namespace: impl Into<String>,
        name: impl Into<String>,
--- a/runtime/src/sdk.rs
+++ b/runtime/src/sdk.rs
@@ -41,9 +41,9 @@ pub type ExtismFunctionType = extern "C" fn(
 /// Log drain callback
 pub type ExtismLogDrainFunctionType = extern "C" fn(data: *const std::ffi::c_char, size: Size);

-impl ExtismVal {
-    fn from_val(value: &wasmtime::Val, ctx: impl AsContext) -> Self {
-        match value.ty(ctx) {
+impl From<&wasmtime::Val> for ExtismVal {
+    fn from(value: &wasmtime::Val) -> Self {
+        match value.ty() {
            wasmtime::ValType::I32 => ExtismVal {
                t: ValType::I32,
                v: ValUnion {
@@ -84,24 +84,6 @@ pub unsafe extern "C" fn extism_plugin_id(plugin: *mut Plugin) -> *const u8 {
    plugin.id.as_bytes().as_ptr()
 }

-/// Get the current plugin's associated host context data. Returns null if call was made without
-/// host context.
-#[no_mangle]
-pub unsafe extern "C" fn extism_current_plugin_host_context(
-    plugin: *mut CurrentPlugin,
-) -> *mut std::ffi::c_void {
-    if plugin.is_null() {
-        return std::ptr::null_mut();
-    }
-
-    let plugin = &mut *plugin;
-    if let Ok(CVoidContainer(ptr)) = plugin.host_context::<CVoidContainer>() {
-        ptr
-    } else {
-        std::ptr::null_mut()
-    }
-}
-
 /// Returns a pointer to the memory of the currently running plugin
 /// NOTE: this should only be called from host functions.
 #[no_mangle]
@@ -218,11 +200,7 @@ pub unsafe extern "C" fn extism_function_new(
        output_types.clone(),
        user_data,
        move |plugin, inputs, outputs, user_data| {
-            let store = &*plugin.store;
-            let inputs: Vec<_> = inputs
-                .iter()
-                .map(|x| ExtismVal::from_val(x, store))
-                .collect();
+            let inputs: Vec<_> = inputs.iter().map(ExtismVal::from).collect();
            let mut output_tmp: Vec<_> = output_types
                .iter()
                .map(|t| ExtismVal {
@@ -411,6 +389,20 @@ pub unsafe extern "C" fn extism_plugin_config(
            }
        };

+    let wasi = &mut plugin.current_plugin_mut().wasi;
+    if let Some(Wasi { ctx, .. }) = wasi {
+        for (k, v) in json.iter() {
+            match v {
+                Some(v) => {
+                    let _ = ctx.push_env(k, v);
+                }
+                None => {
+                    let _ = ctx.push_env(k, "");
+                }
+            }
+        }
+    }
+
    let id = plugin.id;
    let config = &mut plugin.current_plugin_mut().manifest.config;
    for (k, v) in json.into_iter() {
@@ -472,31 +464,6 @@ pub unsafe extern "C" fn extism_plugin_call(
    func_name: *const c_char,
    data: *const u8,
    data_len: Size,
-) -> i32 {
-    extism_plugin_call_with_host_context(plugin, func_name, data, data_len, std::ptr::null_mut())
-}
-
-#[derive(Clone)]
-#[repr(transparent)]
-struct CVoidContainer(*mut std::ffi::c_void);
-
-// "You break it, you buy it."
-unsafe impl Send for CVoidContainer {}
-unsafe impl Sync for CVoidContainer {}
-
-/// Call a function with host context.
-///
-/// `func_name`: is the function to call
-/// `data`: is the input data
-/// `data_len`: is the length of `data`
-/// `host_context`: a pointer to context data that will be available in host functions
-#[no_mangle]
-pub unsafe extern "C" fn extism_plugin_call_with_host_context(
-    plugin: *mut Plugin,
-    func_name: *const c_char,
-    data: *const u8,
-    data_len: Size,
-    host_context: *mut std::ffi::c_void,
 ) -> i32 {
    if plugin.is_null() {
        return -1;
@@ -518,11 +485,8 @@ pub unsafe extern "C" fn extism_plugin_call_with_host_context(
        name
    );
    let input = std::slice::from_raw_parts(data, data_len as usize);
-    let r = match ExternRef::new(&mut plugin.store, CVoidContainer(host_context)) {
-        Err(e) => return plugin.return_error(&mut lock, e, -1),
-        Ok(x) => x,
-    };
-    let res = plugin.raw_call(&mut lock, name, input, Some(r));
+    let res = plugin.raw_call(&mut lock, name, input);
+
    match res {
        Err((e, rc)) => plugin.return_error(&mut lock, e, rc),
        Ok(x) => x,
@@ -707,7 +671,7 @@ unsafe fn set_log_buffer(filter: &str) -> Result<(), Error> {
 /// Calls the provided callback function for each buffered log line.
 /// This is only needed when `extism_log_custom` is used.
 pub unsafe extern "C" fn extism_log_drain(handler: ExtismLogDrainFunctionType) {
-    if let Some(buf) = LOG_BUFFER.as_mut() {
+    if let Some(buf) = &mut LOG_BUFFER {
        if let Ok(mut buf) = buf.buffer.lock() {
            for (line, len) in buf.drain(..) {
                handler(line.as_ptr(), len as u64);
--- a/runtime/src/tests/runtime.rs
+++ b/runtime/src/tests/runtime.rs
@@ -240,34 +240,6 @@ fn test_timeout() {
    assert!(err == "timeout");
 }

-#[test]
-fn test_http_timeout() {
-    let f = Function::new(
-        "hello_world",
-        [PTR],
-        [PTR],
-        UserData::default(),
-        hello_world,
-    );
-
-    let manifest = Manifest::new([extism_manifest::Wasm::data(WASM_HTTP)])
-        .with_timeout(std::time::Duration::from_millis(1))
-        .with_allowed_host("www.extism.org");
-    let mut plugin = Plugin::new(manifest, [f], true).unwrap();
-
-    let start = std::time::Instant::now();
-    let output: Result<&[u8], Error> =
-        plugin.call("http_request", r#"{"url": "https://www.extism.org"}"#);
-    let end = std::time::Instant::now();
-    let time = end - start;
-    let err = output.unwrap_err().root_cause().to_string();
-    println!(
-        "Timed out plugin ran for {:?}, with error: {:?}",
-        time, &err
-    );
-    assert!(err == "timeout");
-}
-
 typed_plugin!(pub TestTypedPluginGenerics {
    count_vowels<T: FromBytes<'a>>(&str) -> T
 });
@@ -335,42 +307,6 @@ fn test_toml_manifest() {
    assert_eq!(count.get("count").unwrap().as_i64().unwrap(), 1);
 }

-#[test]
-fn test_call_with_host_context() {
-    #[derive(Clone)]
-    struct Foo {
-        message: String,
-    }
-
-    let f = Function::new(
-        "host_reflect",
-        [PTR],
-        [PTR],
-        UserData::default(),
-        |current_plugin, _val, ret, _user_data: UserData<()>| {
-            let foo = current_plugin.host_context::<Foo>()?;
-            let hnd = current_plugin.memory_new(foo.message)?;
-            ret[0] = current_plugin.memory_to_val(hnd);
-            Ok(())
-        },
-    );
-
-    let mut plugin = Plugin::new(WASM_REFLECT, [f], true).unwrap();
-
-    let message = "hello world";
-    let output: String = plugin
-        .call_with_host_context(
-            "reflect",
-            "anything, really",
-            Foo {
-                message: message.to_string(),
-            },
-        )
-        .unwrap();
-
-    assert_eq!(output, message);
-}
-
 #[test]
 fn test_fuzz_reflect_plugin() {
    // assert!(set_log_file("stdout", Some(log::Level::Trace)));
@@ -517,7 +453,7 @@ fn hello_world_user_data(
    _plugin: &mut CurrentPlugin,
    inputs: &[Val],
    outputs: &mut [Val],
-    user_data: UserData<std::fs::File>,
+    user_data: UserData<std::sync::Arc<std::sync::Mutex<std::fs::File>>>,
 ) -> Result<(), Error> {
    let data = user_data.get()?;
    let mut data = data.lock().unwrap();
@@ -534,7 +470,8 @@ fn test_userdata() {
        if path.exists() {
            std::fs::remove_file(&path).unwrap();
        }
-        let file = std::fs::File::create(&path).unwrap();
+        let file =
+            std::sync::Arc::new(std::sync::Mutex::new(std::fs::File::create(&path).unwrap()));
        let f = Function::new(
            "hello_world",
            [PTR],