work on memory saftey

1 files changed, 37 insertions, 5 deletions

diff --git a/src/thread.c b/src/thread.c
index 441793b..393d3fb 100644
--- a/src/thread.c
+++ b/src/thread.c
@@ -13,14 +13,15 @@
 struct thread_info {

     str* function;

     lua_State* L;

-    int return_count;

+    int return_count, done;

     pthread_t tid;

-    pthread_cond_t cond;

     pthread_mutex_t lock;

 };

 

 #include "io.h"

 

+//give the current thread priority to locking thread_lock_lock (fixes race conds)

+pthread_mutex_t thread_priority_lock = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;

 pthread_mutex_t thread_lock_lock = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;

 larray_t* thread_locks = NULL;

 

@@ -28,6 +29,8 @@ int l_tlock(lua_State* L){
     int idx = luaL_checkinteger(L, 1);

 

     pthread_mutex_lock(&thread_lock_lock);

+    pthread_mutex_lock(&thread_priority_lock);

+    pthread_mutex_unlock(&thread_priority_lock);

     pthread_mutex_t mutex;

     if(thread_locks == NULL) thread_locks = larray_init();

     int i = 0;

@@ -37,9 +40,13 @@ int l_tlock(lua_State* L){
         larray_set(&thread_locks, idx, (void*)mutex);

     } else {

         pthread_mutex_t m = (pthread_mutex_t)thread_locks->arr[i].value;

+        pthread_mutex_lock(&thread_priority_lock);

+    

         pthread_mutex_unlock(&thread_lock_lock);

         pthread_mutex_lock(&m);

         pthread_mutex_lock(&thread_lock_lock);

+

+        pthread_mutex_unlock(&thread_priority_lock);

         thread_locks->arr[i].value = (void*)m;

 

     }

@@ -90,6 +97,7 @@ int l_res(lua_State* L){
 void* handle_thread(void* _args){

   struct thread_info* args = (struct thread_info*)_args;

   lua_State* L = args->L;

+  lua_gc(L, LUA_GCSTOP);

 

   lua_newtable(L);

   int res_idx = lua_gettop(L);

@@ -117,20 +125,37 @@ int l_await(lua_State* L){
     lua_gettable(L, 1);

     struct thread_info* info = lua_touserdata(L, -1);

 

-    pthread_mutex_lock(&info->lock);

+    if(info->L == NULL) p_fatal("thread has already been cleaned");

+    if(!info->done) pthread_mutex_lock(&info->lock);

+    info->done = 1;

 

     for(int i = 0; i != info->return_count; i++){

         int ot = lua_gettop(info->L);

 

         lua_pushvalue(info->L, ot - info->return_count + i);

         i_dcopy(info->L, L, NULL);

-

+        

         lua_settop(info->L, ot);

     }

 

     return info->return_count;

 }

 

+int l_clean(lua_State* L){

+    lua_pushstring(L, "_");

+    lua_gettable(L, 1);

+    struct thread_info* info = lua_touserdata(L, -1);

+    if(info->L != NULL){

+        lua_gc(info->L, LUA_GCRESTART);

+        lua_gc(info->L, LUA_GCCOLLECT);

+        lua_close(info->L);

+        info->L = NULL;

+        pthread_mutex_destroy(&info->lock);

+        free(info);

+    }

+    return 0;

+}

+

 int l_async(lua_State* oL){

    lua_State* L = luaL_newstate(); 

 

@@ -142,7 +167,6 @@ int l_async(lua_State* oL){
 

   struct thread_info* args = calloc(1, sizeof * args);

   args->L = L;

-  args->cond = (pthread_cond_t)PTHREAD_COND_INITIALIZER;

   args->lock = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;

   pthread_mutex_lock(&args->lock);

   args->return_count = 0;

@@ -157,7 +181,15 @@ int l_async(lua_State* oL){
   lua_newtable(oL);

   int res_idx = lua_gettop(oL);

   luaI_tsetcf(oL, res_idx, "await", l_await);

+  luaI_tsetcf(oL, res_idx, "clean", l_clean);

   luaI_tsetlud(oL, res_idx, "_", args);

+

+  lua_newtable(oL);

+  int meta_idx = lua_gettop(oL);

+  luaI_tsetcf(oL, meta_idx, "__gc", l_clean);

+

+  lua_pushvalue(oL, meta_idx);

+  lua_setmetatable(oL, res_idx);

   lua_pushvalue(oL, res_idx);

   return 1;

 }