From 9518ea78d139d9ef1c4fbc694a5ef6c122504c46 Mon Sep 17 00:00:00 2001
From: Edouard Tisserant <edouard@pep-project.org>
Date: Thu, 20 Apr 2017 16:39:52 +0200
Subject: [PATCH] ENGINE-187 reworked timeout impl and added remaining time
 return when timeout interrupted by message

---
 src/sync_mixin.cc | 70 +++++++++++++++++++++++++++++++++++------------
 src/sync_mixin.hh | 17 +++++++++---
 test/multipEp.py  |  1 +
 3 files changed, 66 insertions(+), 22 deletions(-)

diff --git a/src/sync_mixin.cc b/src/sync_mixin.cc
index b0315b1..0aa7d5b 100644
--- a/src/sync_mixin.cc
+++ b/src/sync_mixin.cc
@@ -70,21 +70,30 @@ namespace pEp {
 
         jmp_buf SyncMixIn::env;
         void *SyncMixIn::_msg;
-        bool SyncMixIn::running_timeout = false;
-        bool SyncMixIn::expiring_timeout = false;
+
+        timeout_state_t SyncMixIn::timeout_state = timeout_stopped;
+        bool SyncMixIn::last_turn = false;
+        time_t SyncMixIn::remaining_time = 0;
 
         int SyncMixIn::inject_sync_msg(void *msg, void *management)
         {
+            assert(timeout_state != timeout_canceling);
+            if(timeout_state == timeout_canceling) return 0;
+
+            assert(timeout_state != timeout_expiring);
+            if(timeout_state == timeout_expiring) return 0;
+
             _msg = msg;
             int val = setjmp(env);
             if (!val){
-                if(running_timeout){
+                if(timeout_state == timeout_running){
                     // call python timeout timer cancel
                     auto that = dynamic_cast< SyncMixIn_callback * >(
                             static_cast< SyncMixIn * > (management));
-                    that->cancelTimeout();
-                    running_timeout = false;
+                    remaining_time = that->cancelTimeout();
+                    timeout_state = timeout_canceling;
                 }
+                last_turn = false;
                 do_sync_protocol(session, management);
             }
             return 0;
@@ -92,21 +101,39 @@ namespace pEp {
 
         void *SyncMixIn::retrieve_next_sync_msg(void *management, time_t *timeout)
         {
-            static int twice = 1;
-            twice = !twice;
-
-            if (!twice){
-                if (expiring_timeout){
+            if (!last_turn){
+                
+                assert(timeout_state != timeout_running);
+                if(timeout_state == timeout_running) return NULL;
+
+                switch(timeout_state){
+                  case timeout_canceling :
+                    *timeout = remaining_time;
+                    break;
+                  case timeout_expiring :
+                    // "1" is arbitrary value !=0, since we don't
+                    // have original timeout value anymore
                     *timeout = 1;
-                    expiring_timeout = true;
-                } else if (_msg != NULL && *timeout != 0){
+                    break;
+                }
+
+                timeout_state = timeout_stopped;
+
+                last_turn = true;
+                return (void *) _msg;
+
+            } else {
+
+                assert(timeout_state == timeout_stopped);
+                if(timeout_state != timeout_stopped) return NULL;
+
+                if (*timeout != 0) {
                     // call python timeout timer start
                     auto that = dynamic_cast< SyncMixIn_callback * >(
                             static_cast< SyncMixIn * > (management));
                     that->setTimeout(*timeout);
-                    running_timeout = true;
+                    timeout_state = timeout_running;
                 }
-                return (void *) _msg;
             }
             longjmp(env, 1);
             return (void *) 23;
@@ -114,12 +141,19 @@ namespace pEp {
 
         // to be called from python timeout timer - may GIL protect us
         void SyncMixIn::onTimeout(){
+            assert(timeout_state != timeout_canceling);
+            if(timeout_state == timeout_canceling) return;
+
+            assert(timeout_state != timeout_expiring);
+            if(timeout_state == timeout_expiring) return;
+
             _msg = NULL;
             int val = setjmp(env);
             if (!val){
-                expiring_timeout = true;
+                timeout_state = timeout_expiring;
+
+                last_turn = false;
                 do_sync_protocol(session, (void*)this);
-                running_timeout = false;
             }
         }
 
@@ -139,9 +173,9 @@ namespace pEp {
             call_method< void >(_self, "setTimeout", timeout);
         }
 
-        void SyncMixIn_callback::cancelTimeout()
+        time_t SyncMixIn_callback::cancelTimeout()
         {
-            call_method< void >(_self, "cancelTimeout");
+            return call_method< time_t >(_self, "cancelTimeout");
         }
     }
 }
diff --git a/src/sync_mixin.hh b/src/sync_mixin.hh
index 6a62e96..6104af7 100644
--- a/src/sync_mixin.hh
+++ b/src/sync_mixin.hh
@@ -6,6 +6,14 @@
 
 namespace pEp {
     namespace PythonAdapter {
+
+        typedef enum _timeout_state_t {
+            timeout_stopped,
+            timeout_running,
+            timeout_canceling,
+            timeout_expiring 
+        } timeout_state_t;
+
         class SyncMixIn {
             public:
                 SyncMixIn() { }
@@ -34,7 +42,7 @@ namespace pEp {
                     throw runtime_error("override this method");
                 }
 
-                virtual void cancelTimeout(){
+                virtual time_t cancelTimeout(){
                     throw runtime_error("override this method");
                 }
 
@@ -46,9 +54,10 @@ namespace pEp {
                         pEp_identity *me, pEp_identity *partner, sync_handshake_signal signal);
 
                 static jmp_buf env;
-                static bool running_timeout;
-                static bool expiring_timeout;
                 static void *_msg;
+                static timeout_state_t timeout_state;
+                static bool last_turn;
+                static time_t remaining_time;
                 static int inject_sync_msg(void *msg, void *management);
                 static void *retrieve_next_sync_msg(void *management, time_t *timeout);
         };
@@ -67,7 +76,7 @@ namespace pEp {
                     sync_handshake_signal signal);
 
                 void setTimeout(time_t timeout);
-                void cancelTimeout();
+                time_t cancelTimeout();
         };
     }
 }
diff --git a/test/multipEp.py b/test/multipEp.py
index 44d99ef..4356f46 100644
--- a/test/multipEp.py
+++ b/test/multipEp.py
@@ -303,6 +303,7 @@ def pEp_instance_run(iname, _own_addresses, conn, _msgs_folders, _handshakes_see
 
         def cancelTimeout(self):
            printi("CANCEL TIMEOUT") 
+           return 42
 
     if not disable_sync:
         sync_handler = Handler()