Fix for segfault durring init:reload().

c_src/main.c

@@ -53,7 +53,7 @@ rem_worker(ErlNifEnv* env, int argc, CENTERM argv[])
 {
     state_ptr state = (state_ptr) enif_priv_data(env);
 
-    if(!state_rem_worker(state))
+    if(!state_rem_worker(state, FALSE))
     {
         return state_error(state);
     }

c_src/state.c

@@ -83,25 +83,23 @@ state_create(ErlNifEnv* env)
 }
 
 void
-vm_dtor(void* obj)
+blank_dtor(void* obj)
 {
-    // VM's are ref counted. They'll die later.
+    // VM's are ref counted.
+    // Workers are handled by state_rem_worker.
 }
 
 void
 state_destroy(state_ptr state)
 {
-    int w;
-
     if(state == NULL)
     {
         return;
     }
 
-    for(w = 0; w < state->num_workers; w++)
+    while(state->num_workers > 0)
     {
-        worker_destroy(state->workers[w]);
-        state->workers[w] = NULL;
+        state_rem_worker(state, TRUE);
     }
 
     if(state->topts != NULL)
@@ -111,12 +109,12 @@ state_destroy(state_ptr state)
 
     if(state->dth_q != NULL)
     {
-        queue_destroy(state->dth_q, worker_destroy);
+        queue_destroy(state->dth_q, blank_dtor);
     }
 
     if(state->req_q != NULL)
     {
-        queue_destroy(state->req_q, vm_dtor);
+        queue_destroy(state->req_q, blank_dtor);
     }
 
     // XXX: Big assumption that we can't call this destructor with
@@ -231,7 +229,7 @@ state_add_worker(state_ptr state)
 }
 
 int
-state_rem_worker(state_ptr state)
+state_rem_worker(state_ptr state, int closing)
 {
     worker_ptr worker;
     int w, found;
@@ -244,7 +242,7 @@ state_rem_worker(state_ptr state)
     // Check if we have a worker to remove. We keep at least one worker.
 
     assert(state->num_workers > 0 && "Invalid state: No workers.");
-    if(state->num_workers < 2)
+    if(state->num_workers < 2 && !closing)
     {
         enif_mutex_unlock(state->lock);
         return 0;

c_src/state.h

@@ -7,6 +7,14 @@
 #include "alias.h"
 #include "queue.h"
 
+#ifndef TRUE
+#define TRUE 1
+#endif
+
+#ifndef FALSE
+#define FALSE 0
+#endif
+
 typedef struct state_t* state_ptr;
 
 state_ptr state_create(ErlNifEnv* env);
@@ -21,6 +29,6 @@ ENTERM state_error(state_ptr state);
 
 unsigned int state_num_workers(state_ptr state);
 int state_add_worker(state_ptr state);
-int state_rem_worker(state_ptr state);
+int state_rem_worker(state_ptr state, int closing);
 
 #endif // Included state.h

test/smoke/restarts.erl

@@ -0,0 +1,18 @@
+-module(restarts).
+
+-export([run/0]).
+
+run(0) ->
+    ok;
+run(N) ->
+    {ok, Ctx} = emonk:create_ctx(),
+    emonk:eval(Ctx, <<"var f = function(x) {return x*3;};">>),
+    {ok, 27} = emonk:call(Ctx, <<"f">>, [9]),
+    run(N-1).
+
+run() ->
+    io:format(".", []),
+    code:add_path("ebin"),
+    run(5),
+    init:restart().
+