Wiring SharedMemory with it's corresponding bindings (#255)

* Wiring SharedMemory with it's corresponding bindings

* Restoring _bindings.py as is being autogenerated out of the C-API
interface in the wasmtime runtime repo

* Removing SharedMemory read/write methods, as they are also not
implemented in the Rust API for wasmtime.
A SharedMemory is not associated to any Store, and the read/write
methods from the linear memory seem  to rely on the Store in order
to properly operate.

* Making SharedMemory inherit from the Manager type

* Adding runtime typechecking to SharedMemory::_from_raw

* After regenerating the bindings from wasmtime c-api (main/dev branch)
and adjusting the shared memory arguments to match the new api, I
found out that I needed to adjust other parts of the bindings that I guess
have changed since the last release.
In this commit, I only change the (shared) memory related ones, but I
think I can adjust the rest of the c-api that has changed as well in
the following commits.

* Update to latest wasmtime dev (#257)

* Retoring bindings from main branch as it was updated to latest
changes in the C-APO from Wasmtime runtime repo

* * Fixing Python types as suggested by mypy
* Adding some unit tests for shared memory

* Adding unit tests for shared memory

---------

Co-authored-by: Jesse Rusak <[email protected]>

tests/test_shared_memory.py

@@ -0,0 +1,56 @@
+import unittest
+
+from wasmtime import *
+
+
+class TestSharedMemory(unittest.TestCase):
+    def test_new(self):
+        engine = Store().engine
+        memory_type = MemoryType(Limits(1, 2), is_64=False, shared=True)
+        assert(not memory_type.is_64)
+        shared_memory = SharedMemory(engine, memory_type)
+        with self.assertRaises(TypeError):
+            shared_memory.grow('')  # type: ignore
+        with self.assertRaises(WasmtimeError):
+            shared_memory.grow(-1)
+        self.assertEqual(shared_memory.data_ptr()[0], 0)
+        self.assertEqual(shared_memory.data_len(), 65536)
+        self.assertTrue(isinstance(shared_memory.type(), MemoryType))
+
+    def test_grow(self):
+        engine = Store().engine
+        memory_type = MemoryType(Limits(1, 2), shared=True)
+        shared_memory = SharedMemory(engine, memory_type)
+        assert(shared_memory.grow(1) == 1)
+        assert(shared_memory.grow(0) == 2)
+        with self.assertRaises(WasmtimeError):
+            shared_memory.grow(1)
+
+    def test_errors(self):
+        engine = Store().engine
+        ty = MemoryType(Limits(1, 2), shared=True)
+        with self.assertRaises(AttributeError):
+            SharedMemory(1, ty)  # type: ignore
+        with self.assertRaises(AttributeError):
+            SharedMemory(engine, 1)  # type: ignore
+
+    def test_shared_memory_type_fails_if_no_max_specified(self):
+        with self.assertRaises(WasmtimeError):
+            # Shared memories must have a max size
+            MemoryType(Limits(0x100000000, None), shared=True)
+
+    def test_shared_memory_type_works_if_min_max_i64_is_set(self):
+        ty = MemoryType(Limits(0x100000000, 0x100000000), is_64=True, shared=True)
+        assert(ty.limits.min == 0x100000000)
+        assert(ty.limits.max == 0x100000000)
+        assert(ty.is_64)
+
+    def test_shared_memory_type_fails_if_is_too_large(self):
+        with self.assertRaises(WasmtimeError):
+            MemoryType(Limits(1, 0x100000000), shared=True)
+
+    def test_memory_type_has_to_be_shared(self):
+        engine = Store().engine
+        ty = MemoryType(Limits(1, 2))
+        with self.assertRaises(WasmtimeError):
+            SharedMemory(engine, ty)

wasmtime/__init__.py

@@ -31,6 +31,7 @@
 from ._instance import Instance
 from ._wasi import WasiConfig, FilePerms, DirPerms
 from ._linker import Linker
+from ._sharedmemory import SharedMemory
 
 __all__ = [
     'wat2wasm',
@@ -50,6 +51,7 @@
     'Caller',
     'Table',
     'Memory',
+    'SharedMemory',
     'Global',
     'Trap',
     'TrapCode',

wasmtime/_exportable.py

@@ -4,8 +4,9 @@
     from ._func import Func
     from ._globals import Global
     from ._memory import Memory
+    from ._sharedmemory import SharedMemory
     from ._table import Table
     from ._module import Module
     from ._instance import Instance
 
-AsExtern = typing.Union["Func", "Table", "Memory", "Global", "Instance", "Module"]
+AsExtern = typing.Union["Func", "Table", "Memory", "SharedMemory",  "Global", "Instance", "Module"]

wasmtime/_extern.py

@@ -5,7 +5,7 @@
 
 
 def wrap_extern(ptr: ffi.wasmtime_extern_t) -> AsExtern:
-    from wasmtime import Func, Table, Global, Memory, Module, Instance
+    from wasmtime import Func, Table, Global, Memory, SharedMemory, Module, Instance
 
     if ptr.kind == ffi.WASMTIME_EXTERN_FUNC.value:
         return Func._from_raw(ptr.of.func)
@@ -15,6 +15,8 @@ def wrap_extern(ptr: ffi.wasmtime_extern_t) -> AsExtern:
         return Global._from_raw(ptr.of.global_)
     if ptr.kind == ffi.WASMTIME_EXTERN_MEMORY.value:
         return Memory._from_raw(ptr.of.memory)
+    if ptr.kind == ffi.WASMTIME_EXTERN_SHAREDMEMORY.value:
+        return SharedMemory._from_ptr(ptr.of.sharedmemory)
     if ptr.kind == ffi.WASMTIME_EXTERN_INSTANCE.value:
         return Instance._from_raw(ptr.of.instance)
     if ptr.kind == ffi.WASMTIME_EXTERN_MODULE.value:
@@ -23,14 +25,16 @@ def wrap_extern(ptr: ffi.wasmtime_extern_t) -> AsExtern:
 
 
 def get_extern_ptr(item: AsExtern) -> ffi.wasmtime_extern_t:
-    from wasmtime import Func, Table, Global, Memory, Module, Instance
+    from wasmtime import Func, Table, Global, Memory, SharedMemory, Module, Instance
 
     if isinstance(item, Func):
         return item._as_extern()
     elif isinstance(item, Global):
         return item._as_extern()
     elif isinstance(item, Memory):
         return item._as_extern()
+    elif isinstance(item, SharedMemory):
+        return item._as_extern()
     elif isinstance(item, Table):
         return item._as_extern()
     elif isinstance(item, Module):

wasmtime/_ffi.py

@@ -53,6 +53,7 @@
 WASMTIME_EXTERN_GLOBAL = c_uint8(1)
 WASMTIME_EXTERN_TABLE = c_uint8(2)
 WASMTIME_EXTERN_MEMORY = c_uint8(3)
+WASMTIME_EXTERN_SHAREDMEMORY = c_uint8(4)
 WASMTIME_EXTERN_INSTANCE = c_uint8(4)
 WASMTIME_EXTERN_MODULE = c_uint8(5)
 

wasmtime/_sharedmemory.py

@@ -0,0 +1,80 @@
+from . import _ffi as ffi
+from ctypes import *
+import ctypes
+from typing import Optional, Any
+from wasmtime import MemoryType, WasmtimeError, Engine, Managed
+from ._store import Storelike
+
+
+
+class SharedMemory(Managed["ctypes._Pointer[ffi.wasmtime_sharedmemory_t]"]):
+    def __init__(self, engine: Engine, ty: MemoryType):
+        """
+        Creates a new shared memory in `store` with the given `ty`
+        """
+
+        sharedmemory_ptr = POINTER(ffi.wasmtime_sharedmemory_t)()
+        error = ffi.wasmtime_sharedmemory_new(engine.ptr(), ty.ptr(), byref(sharedmemory_ptr))
+        if error:
+            raise WasmtimeError._from_ptr(error)
+        self._set_ptr(sharedmemory_ptr)
+
+    def _delete(self, ptr: "ctypes._Pointer[ffi.wasmtime_sharedmemory_t]") -> None:
+        ffi.wasmtime_sharedmemory_delete(ptr)
+
+    @classmethod
+    def _from_ptr(cls, ptr: "ctypes._Pointer[ffi.wasmtime_sharedmemory_t]") -> "SharedMemory":
+        if not isinstance(ptr, POINTER(ffi.wasmtime_sharedmemory_t)):
+            raise TypeError("wrong shared memory pointer type provided to _from_ptr")
+
+        ty: "SharedMemory" = cls.__new__(cls)
+        ty._set_ptr(ptr)
+        return ty
+
+    def type(self) -> MemoryType:
+        """
+        Gets the type of this memory as a `MemoryType`
+        """
+
+        ptr = ffi.wasmtime_sharedmemory_type(self.ptr())
+        return MemoryType._from_ptr(ptr, None)
+
+    def grow(self, delta: int) -> int:
+        """
+        Grows this memory by the given number of pages
+        """
+
+        if delta < 0:
+            raise WasmtimeError("cannot grow by negative amount")
+        prev = ffi.c_uint64(0)
+        error = ffi.wasmtime_sharedmemory_grow(self.ptr(), delta, byref(prev))
+        if error:
+            raise WasmtimeError._from_ptr(error)
+        return prev.value
+
+    def size(self) -> int:
+        """
+        Returns the size, in WebAssembly pages, of this shared memory.
+        """
+
+        return ffi.wasmtime_sharedmemory_size(byref(self.ptr()))
+
+    def data_ptr(self) -> "ctypes._Pointer[c_ubyte]":
+        """
+        Returns the raw pointer in memory where this wasm shared memory lives.
+
+        Remember that all accesses to wasm shared memory should be bounds-checked
+        against the `data_len` method.
+        """
+        return ffi.wasmtime_sharedmemory_data(self.ptr())
+
+    def data_len(self) -> int:
+        """
+        Returns the raw byte length of this memory.
+        """
+
+        return ffi.wasmtime_sharedmemory_data_size(self.ptr())
+
+    def _as_extern(self) -> ffi.wasmtime_extern_t:
+        union = ffi.wasmtime_extern_union(sharedmemory=pointer(self.ptr()))
+        return ffi.wasmtime_extern_t(ffi.WASMTIME_EXTERN_SHAREDMEMORY, union)

wasmtime/_types.py

@@ -334,10 +334,18 @@ def is_64(self) -> bool:
         Returns whether or not this is a 64-bit memory
         """
         return ffi.wasmtime_memorytype_is64(self.ptr())
+
+    @property
+    def is_shared(self) -> bool:
+        """
+        Returns whether or not this is a shared memory
+        """
+        return ffi.wasmtime_memorytype_isshared(self.ptr())
+
 
     def _as_extern(self) -> "ctypes._Pointer[ffi.wasm_externtype_t]":
         return ffi.wasm_memorytype_as_externtype_const(self.ptr())
-
+    
 
 def wrap_externtype(ptr: "ctypes._Pointer[ffi.wasm_externtype_t]", owner: Optional[Any]) -> "AsExternType":
     if not isinstance(ptr, POINTER(ffi.wasm_externtype_t)):