core, core/vm, tests: changed the initialisation behaviour of the EVM

The EVM was previously initialised and created for every CALL, CALLCODE,
DELEGATECALL and CREATE. This PR changes this behaviour so that the same
EVM can be used through the session and beyond as long as the
Environment sticks around.

1 files changed, 5 insertions, 7 deletions

diff --git a/core/vm/jump_table.go b/core/vm/jump_table.go
index 37d7bb160..8297d3e1d 100644
--- a/core/vm/jump_table.go
+++ b/core/vm/jump_table.go
@@ -13,19 +13,15 @@ type jumpPtr struct {
 
 type vmJumpTable [256]jumpPtr
 
-func (jt vmJumpTable) init(blockNumber *big.Int) {
+func newJumpTable(blockNumber *big.Int) vmJumpTable {
+	var jumpTable vmJumpTable
+
 	// when initialising a new VM execution we must first check the homestead
 	// changes.
 	if params.IsHomestead(blockNumber) {
 		jumpTable[DELEGATECALL] = jumpPtr{opDelegateCall, true}
-	} else {
-		jumpTable[DELEGATECALL] = jumpPtr{nil, false}
 	}
-}
 
-var jumpTable vmJumpTable
-
-func init() {
 	jumpTable[ADD] = jumpPtr{opAdd, true}
 	jumpTable[SUB] = jumpPtr{opSub, true}
 	jumpTable[MUL] = jumpPtr{opMul, true}
@@ -156,4 +152,6 @@ func init() {
 	jumpTable[JUMP] = jumpPtr{nil, true}
 	jumpTable[JUMPI] = jumpPtr{nil, true}
 	jumpTable[STOP] = jumpPtr{nil, true}
+
+	return jumpTable
 }