Added erlang_v8:reset_vm/1.

README.md

@@ -8,11 +8,11 @@ proper attention if the experiment works out.
 
 The most notable feature is that you can eval things like "while (true) {}"
 and have the v8 VM actually terminate when it times out. I'm also planning
-two-way communication, resetting context etc.
+two-way communication, loading scripts etc.
 
 ## Building
 
-Git, Subversion, and Python 2.6-2.7 (for GYP) are required to build v8.
+Subversion, and Python 2.6-2.7 (by GYP) are required to build v8.
 
 Build using make:
 
@@ -27,7 +27,7 @@ Or with rebar:
 
 You can run a few tests to verify basic functionality:
 
-    make test
+    make tests
 
 ## Usage
 
@@ -37,19 +37,26 @@ Start a VM:
 
 Define a function:
 
-    {ok, undefined} = erlang_v8:eval(VM, <<"function sum(a, b) { return a + b }">>).
+    {ok, undefined} =
+        erlang_v8:eval(VM, <<"function sum(a, b) { return a + b }">>).
 
 Run the function: 
 
     {ok, 2} = erlang_v8:call(VM, <<"sum">>, [1, 1]).
 
+You can reset the VM:
+
+    ok = erlang_v8:reset_vm(VM).
+    {error, <<"ReferenceError: sum is not defined">>} =
+        erlang_v8:call(VM, <<"sum">>, [1, 1]).
+
 Stop the VM:
 
     ok = erlang_v8:stop_vm(VM).
 
 ## TODO
 
-Lots of testing, improve the communication protocol, clean up api, add
-features like reset context and stuff, experiment with calling Erlang from JS,
-load initial context from args, supervisor strategy, experiment with different
-ways of passing args to calls (maybe via the communication protocol) etc.
+Lots of testing, improve the communication protocol, clean up api, experiment
+with calling Erlang from JS, load initial context from args, supervisor
+strategy, experiment with different ways of passing args to calls (maybe via
+the communication protocol) etc.

c_src/erlang_v8.cc

@@ -134,26 +134,48 @@ void eval(Isolate* isolate, string input) {
     }
 }
 
-int main(int argc, char* argv[]) {
-    ios_base::sync_with_stdio(false);
+Handle<ObjectTemplate> create_global(Isolate* isolate) {
+    Handle<ObjectTemplate> global =  ObjectTemplate::New(isolate);
+    global->Set(String::NewFromUtf8(isolate, "erlang_v8"),
+                String::NewFromUtf8(isolate, "yes"));
+    return global;
+}
 
+Handle<Context> create_context(Isolate* isolate, Handle<ObjectTemplate> global) {
+    return Context::New(isolate, NULL, create_global(isolate));
+}
+
+bool command_loop() {
     Isolate* isolate = Isolate::GetCurrent();
+
     HandleScope handle_scope(isolate);
-    Handle<Context> context = Context::New(isolate);
+
+    Handle<ObjectTemplate> global = create_global(isolate);
+    Handle<Context> context = create_context(isolate, global);
+
     Context::Scope context_scope(context);
 
+    bool reset = false;
     Packet packet;
-    while (next_packet(&packet)) {
+    while (!reset && next_packet(&packet)) {
         switch(packet.op) {
             case EVAL_R:
                 eval(isolate, packet.data);
                 break;
+            case RESET_VM_R:
+                reset = true;
+                break;
         }
-
         packet = (const struct Packet){ 0 };
     }
+    V8::ContextDisposedNotification();
+    return reset;
+}
+
+int main(int argc, char* argv[]) {
+    ios_base::sync_with_stdio(false);
 
-    V8::TerminateExecution(isolate);
+    while (command_loop());
 
     return 0;
 }

src/erlang_v8.erl

@@ -3,6 +3,9 @@
 -export([start_vm/0]).
 -export([stop_vm/1]).
 
+-export([reset_vm/1]).
+-export([restart_vm/1]).
+
 -export([eval/2]).
 -export([eval/3]).
 -export([call/3]).
@@ -14,6 +17,12 @@ start_vm() ->
 stop_vm(Pid) ->
     erlang_v8_vm:stop(Pid).
 
+reset_vm(Pid) ->
+    erlang_v8_vm:reset(Pid).
+
+restart_vm(Pid) ->
+    erlang_v8_vm:restart(Pid).
+
 eval(Pid, Source) ->
     erlang_v8_vm:eval(Pid, Source).
 

src/erlang_v8_vm.erl

@@ -6,6 +6,7 @@
 -export([start_link/0]).
 -export([stop/1]).
 -export([reset/1]).
+-export([restart/1]).
 
 -export([eval/2]).
 -export([eval/3]).
@@ -23,6 +24,9 @@
 -define(SPAWN_OPTS, [{packet, 2}, binary]).
 -define(DEFAULT_TIMEOUT, 5000).
 
+-define(OP_EVAL, 0).
+-define(OP_RESET, 2).
+
 -record(state, {
         port,
         monitor_pid
@@ -51,6 +55,9 @@ call(Pid, FunctionName, Args, Timeout) ->
 reset(Pid) ->
     gen_server:call(Pid, reset).
 
+restart(Pid) ->
+    gen_server:call(Pid, restart).
+
 stop(Pid) ->
     gen_server:call(Pid, stop).
 
@@ -78,7 +85,11 @@ handle_call({eval, Source, Timeout}, _From, #state{port = Port} = State) ->
             {reply, {error, Reason}, State}
     end;
 
-handle_call(reset, _From, State) ->
+handle_call(reset, _From, #state{port = Port} = State) ->
+    Port ! {self(), {command, <<?OP_RESET:8>>}},
+    {reply, ok, State};
+
+handle_call(restart, _From, State) ->
     {reply, ok, start_port(close_port(State))};
 
 handle_call(stop, _From, State) ->
@@ -149,7 +160,7 @@ os_kill(OSPid) ->
 
 %% @doc Evaluate source on port
 eval_js(Port, Source, Timeout) ->
-    Port ! {self(), {command, <<0:8, Source/binary>>}},
+    Port ! {self(), {command, <<?OP_EVAL:8, Source/binary>>}},
     receive
         {Port, {data, <<_:8, "undefined">>}} ->
             {ok, undefined};

test/port_SUITE.erl

@@ -13,6 +13,7 @@
 -export([errors/1]).
 -export([timeout/1]).
 -export([reset/1]).
+-export([restart/1]).
 
 %% Callbacks
 
@@ -24,7 +25,8 @@ all() ->
         nested_return_type,
         errors,
         timeout,
-        reset
+        reset,
+        restart
     ].
 
 init_per_suite(Config) ->
@@ -122,11 +124,50 @@ timeout(_Config) ->
 reset(_Config) ->
     {ok, P} = erlang_v8:start_vm(),
 
+    {ok, <<"yes">>} = erlang_v8:eval(P, <<"erlang_v8">>),
+    erlang_v8:reset_vm(P),
+    {ok, <<"yes">>} = erlang_v8:eval(P, <<"erlang_v8">>),
+
+    {ok, <<"no">>} = erlang_v8:eval(P, <<"erlang_v8 = 'no';">>),
+    erlang_v8:reset_vm(P),
+    {ok, <<"yes">>} = erlang_v8:eval(P, <<"erlang_v8">>),
+
+    {ok, <<"test">>} = erlang_v8:eval(P, <<"String.imposter = 'test';">>),
+    erlang_v8:reset_vm(P),
+    {ok, undefined} = erlang_v8:eval(P, <<"String.imposter">>),
+
+    {ok, undefined} =
+        erlang_v8:eval(P, <<"function sum(a, b) { return a + b }">>),
+    {ok, 2} = erlang_v8:call(P, <<"sum">>, [1, 1]),
+
+    erlang_v8:reset_vm(P),
+
+    {error, <<"ReferenceError: sum", _/binary>>} =
+        erlang_v8:call(P, <<"sum">>, [1, 1]),
+
+    erlang_v8:stop_vm(P),
+    ok.
+
+restart(_Config) ->
+    {ok, P} = erlang_v8:start_vm(),
+
+    {ok, <<"yes">>} = erlang_v8:eval(P, <<"erlang_v8">>),
+    erlang_v8:restart_vm(P),
+    {ok, <<"yes">>} = erlang_v8:eval(P, <<"erlang_v8">>),
+
+    {ok, <<"no">>} = erlang_v8:eval(P, <<"erlang_v8 = 'no';">>),
+    erlang_v8:restart_vm(P),
+    {ok, <<"yes">>} = erlang_v8:eval(P, <<"erlang_v8">>),
+
+    {ok, <<"test">>} = erlang_v8:eval(P, <<"String.imposter = 'test';">>),
+    erlang_v8:restart_vm(P),
+    {ok, undefined} = erlang_v8:eval(P, <<"String.imposter">>),
+
     {ok, undefined} =
         erlang_v8:eval(P, <<"function sum(a, b) { return a + b }">>),
     {ok, 2} = erlang_v8:call(P, <<"sum">>, [1, 1]),
 
-    erlang_v8_vm:reset(P),
+    erlang_v8:restart_vm(P),
 
     {error, <<"ReferenceError: sum", _/binary>>} =
         erlang_v8:call(P, <<"sum">>, [1, 1]),