Merge pull request #1083 from EOSIO/reset-wasm-globals

Reset WASM globals on each invocation

libraries/chain/wasm_interface.cpp

@@ -308,6 +308,7 @@ namespace eosio { namespace chain {
                memset( memstart + info.mem_end, 0, ((1<<16) - info.mem_end) );
                memcpy( memstart, info.mem_image.data(), info.mem_end);
             }
+            resetGlobalInstances(entry.instance);
 
             // under a lock, put this entry back in the available instances side of the instances vector
             with_lock([&,this](){

libraries/wasm-jit/Include/Runtime/Runtime.h

@@ -216,6 +216,7 @@ namespace Runtime
 	RUNTIME_API TableInstance* getDefaultTable(ModuleInstance* moduleInstance);
 
 	RUNTIME_API void runInstanceStartFunc(ModuleInstance* moduleInstance);
+	RUNTIME_API void resetGlobalInstances(ModuleInstance* moduleInstance);
 
 	// Gets an object exported by a ModuleInstance by name.
 	RUNTIME_API ObjectInstance* getInstanceExport(ModuleInstance* moduleInstance,const std::string& name);

libraries/wasm-jit/Source/Runtime/ModuleInstance.cpp

@@ -204,6 +204,11 @@ namespace Runtime
 		if(moduleInstance->startFunctionIndex != UINTPTR_MAX)
 			invokeFunction(moduleInstance->functions[moduleInstance->startFunctionIndex],{});
 	}
+
+	void resetGlobalInstances(ModuleInstance* moduleInstance) {
+		for(GlobalInstance*& gi : moduleInstance->globals)
+			memcpy(&gi->value, &gi->initialValue, sizeof(gi->value));
+	}
 	
 	ObjectInstance* getInstanceExport(ModuleInstance* moduleInstance,const std::string& name)
 	{

libraries/wasm-jit/Source/Runtime/RuntimePrivate.h

@@ -97,8 +97,9 @@ namespace Runtime
 	{
 		GlobalType type;
 		UntaggedValue value;
+		UntaggedValue initialValue;
 
-		GlobalInstance(GlobalType inType,UntaggedValue inValue): GCObject(ObjectKind::global), type(inType), value(inValue) {}
+		GlobalInstance(GlobalType inType,UntaggedValue inValue): GCObject(ObjectKind::global), type(inType), value(inValue), initialValue(value) {}
 	};
 
 	// An instance of a WebAssembly module.

tests/wasm_tests/test_wasts.hpp

@@ -53,4 +53,30 @@ static const char simple_no_memory_wast[] = R"=====(
     )
  )
 )
+)=====";
+
+static const char mutable_global_wast[] = R"=====(
+(module
+ (import "env" "assert" (func $assert (param i32 i32)))
+ (table 0 anyfunc)
+ (memory $0 1)
+ (export "memory" (memory $0))
+ (export "init" (func $init))
+ (export "apply" (func $apply))
+ (func $init
+   (set_global $g0
+     (i32.const 444)
+   )
+ )
+ (func $apply (param $0 i64) (param $1 i64)
+  (call $assert
+   (i32.eq
+    (get_global $g0)
+    (i32.const 2)
+   )
+   (i32.const 0)
+  )
+ )
+ (global $g0 (mut i32) (i32.const 2))
+)
 )=====";
\ No newline at end of file

tests/wasm_tests/wasm_tests.cpp

@@ -569,7 +569,33 @@ BOOST_FIXTURE_TEST_CASE( simple_no_memory_check, tester ) try {
 
    trx.sign(get_private_key( N(nomem), "active" ), chain_id_type());
    BOOST_CHECK_THROW(control->push_transaction( trx ), wasm_execution_error);
+} FC_LOG_AND_RETHROW()
+
+//Make sure globals are all reset to their inital values
+BOOST_FIXTURE_TEST_CASE( check_global_reset, tester ) try {
+   produce_blocks(2);
+
+   create_accounts( {N(globalreset)}, asset::from_string("1000.0000 EOS") );
+   transfer( N(inita), N(globalreset), "10.0000 EOS", "memo" );
+   produce_block();
+
+   set_code(N(globalreset), mutable_global_wast);
+   produce_blocks(1);
+
+   signed_transaction trx;
+   action act;
+   act.account = N(globalreset);
+   act.name = N();
+   act.authorization = vector<permission_level>{{N(globalreset),config::active_name}};
+   trx.actions.push_back(act);
 
+   set_tapos(trx);
+   trx.sign(get_private_key( N(globalreset), "active" ), chain_id_type());
+   control->push_transaction(trx);
+   produce_blocks(1);
+   BOOST_REQUIRE_EQUAL(true, chain_has_transaction(trx.id()));
+   const auto& receipt = get_transaction_receipt(trx.id());
+   BOOST_CHECK_EQUAL(transaction_receipt::executed, receipt.status);
 } FC_LOG_AND_RETHROW()
 
 BOOST_AUTO_TEST_SUITE_END()