mod_python: fix seg on unload when scripts are running (MODLANG-107)

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@13721 d0543943-73ff-0310-b7d9-9358b9ac24b2

diff --git a/src/mod/languages/mod_python/mod_python.c b/src/mod/languages/mod_python/mod_python.c
index 6aee93e579a90a6e2fde10f5ef2d72b8de70b1ca..0df273e1e74562036913e1caef37805390711966 100644 (file)
--- a/src/mod/languages/mod_python/mod_python.c
+++ b/src/mod/languages/mod_python/mod_python.c
@@ -59,7 +59,17 @@ static struct {
        char *xml_handler;
 } globals;
 
-static void eval_some_python(const char *funcname, char *args, switch_core_session_t *session, switch_stream_handle_t *stream, switch_event_t *params, char **str)
+struct switch_py_thread {
+       struct switch_py_thread *prev, *next; 
+       char *cmd;
+       char *args;
+       switch_memory_pool_t *pool;
+       PyThreadState *tstate;
+};
+struct switch_py_thread *thread_pool_head = NULL;
+static switch_mutex_t *THREAD_POOL_LOCK = NULL;
+
+static void eval_some_python(const char *funcname, char *args, switch_core_session_t *session, switch_stream_handle_t *stream, switch_event_t *params, char **str, struct switch_py_thread *pt)
 {
        PyThreadState *tstate = NULL;
        char *dupargs = NULL;
@@ -110,6 +120,11 @@ static void eval_some_python(const char *funcname, char *args, switch_core_sessi
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "error acquiring tstate\n");
                goto done;
        }
+       
+       /* Save state in thread struct so we can terminate it later if needed */
+       if (pt)
+               pt->tstate = tstate;
+
        // swap in thread state
        PyEval_AcquireThread(tstate);
        init_freeswitch();
@@ -178,7 +193,8 @@ static void eval_some_python(const char *funcname, char *args, switch_core_sessi
                if (str) {
                        *str = strdup((char *) PyString_AsString(result));
                }
-       } else {
+       } else if (!PyErr_ExceptionMatches(PyExc_SystemExit)) {
+               // Print error, but ignore SystemExit 
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Error calling python script\n");
                PyErr_Print();
                PyErr_Clear();
@@ -224,7 +240,7 @@ static switch_xml_t python_fetch(const char *section,
 
                switch_assert(mycmd);
 
-               eval_some_python("xml_fetch", mycmd, NULL, NULL, params, &str);
+               eval_some_python("xml_fetch", mycmd, NULL, NULL, params, &str, NULL);
 
                if (str) {
                        if (switch_strlen_zero(str)) {
@@ -278,21 +294,36 @@ static switch_status_t do_config(void)
 
 SWITCH_STANDARD_APP(python_function)
 {
-       eval_some_python("handler", (char *) data, session, NULL, NULL, NULL);
+       eval_some_python("handler", (char *) data, session, NULL, NULL, NULL, NULL);
 
 }
 
-struct switch_py_thread {
-       char *args;
-       switch_memory_pool_t *pool;
-};
-
 static void *SWITCH_THREAD_FUNC py_thread_run(switch_thread_t *thread, void *obj)
 {
        switch_memory_pool_t *pool;
        struct switch_py_thread *pt = (struct switch_py_thread *) obj;
 
-       eval_some_python("runtime", pt->args, NULL, NULL, NULL, NULL);
+       /* Put thread in pool so we keep track of our threads */
+       switch_mutex_lock(THREAD_POOL_LOCK);
+       pt->next = thread_pool_head;
+       pt->prev = NULL;
+       if (pt->next)
+               pt->next->prev = pt;
+       thread_pool_head = pt;
+       switch_mutex_unlock(THREAD_POOL_LOCK);
+
+       /* Run the python script */
+       eval_some_python("runtime", pt->args, NULL, NULL, NULL, NULL, pt);
+
+       /* Thread is dead, remove from pool */
+       switch_mutex_lock(THREAD_POOL_LOCK);
+       if (pt->next)
+               pt->next->prev = pt->prev;
+       if (pt->prev)
+               pt->prev->next = pt->next;
+       if (thread_pool_head == pt)
+               thread_pool_head = pt->next;
+       switch_mutex_unlock(THREAD_POOL_LOCK);
 
        pool = pt->pool;
        switch_core_destroy_memory_pool(&pool);
@@ -303,7 +334,7 @@ static void *SWITCH_THREAD_FUNC py_thread_run(switch_thread_t *thread, void *obj
 SWITCH_STANDARD_API(api_python)
 {
        
-       eval_some_python("fsapi", (char *) cmd, session, stream, NULL, NULL);
+       eval_some_python("fsapi", (char *) cmd, session, stream, NULL, NULL, NULL);
 
        return SWITCH_STATUS_SUCCESS;
 }
@@ -383,6 +414,8 @@ SWITCH_MODULE_LOAD_FUNCTION(mod_python_load)
                PyEval_ReleaseLock();
        }
 
+       switch_mutex_init(&THREAD_POOL_LOCK, SWITCH_MUTEX_NESTED, pool);
+
        do_config();
 
        /* connect my internal structure to the blank pointer passed to me */
@@ -402,6 +435,53 @@ SWITCH_MODULE_SHUTDOWN_FUNCTION(mod_python_shutdown)
 {
        PyInterpreterState *mainInterpreterState;
        PyThreadState *myThreadState;
+       int thread_cnt = 0;
+       struct switch_py_thread *pt = NULL;
+       struct switch_py_thread *nextpt;
+       int i;
+
+       /* Kill all remaining threads */
+       pt = thread_pool_head;
+       PyEval_AcquireLock();
+       while (pt) {
+               thread_cnt ++;
+               nextpt = pt->next;
+               
+               switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, 
+                                                 "Forcibly terminating script [%s]\n", pt->args);
+
+               /* Kill python script */
+               PyThreadState_Swap(pt->tstate);
+               PyThreadState_SetAsyncExc(pt->tstate->thread_id, PyExc_SystemExit);
+
+               pt = nextpt;
+       }
+       PyThreadState_Swap(mainThreadState);
+       PyEval_ReleaseLock();
+       switch_yield(1000000);
+
+       switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, 
+                                         "Had to kill %d threads\n", thread_cnt);
+
+       /* Give threads a few seconds to terminate. 
+          Not using switch_thread_join() since if threads refuse to die
+          then freeswitch will hang */
+       for (i=0; i < 10 && thread_pool_head; i++) {
+               switch_yield(1000000);
+       }
+       if (thread_pool_head) {
+               /* Not all threads died in time */
+               pt = thread_pool_head;
+               while (pt) {
+                       nextpt = pt->next;
+                       switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, 
+                                                 "Script [%s] didn't exit in time\n", pt->args);
+                       pt = nextpt;
+               }
+               switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, 
+                                                 "Forcing python shutdown. This might cause freeswitch to crash!\n");
+       }
+
 
        PyEval_AcquireLock();
        mainInterpreterState = mainThreadState->interp;