Remote pausing

Support for remote pausing, and with it, support for Netplay pausing the
frontend correctly. With this patch alone this doesn't work, since
there's no clean way for the frontend to tell Netplay that it's paused.

network/netplay/netplay.c

@@ -299,11 +299,11 @@ static bool netplay_get_cmd(netplay_t *netplay)
          return netplay_cmd_nak(netplay);
 
       case NETPLAY_CMD_PAUSE:
-         command_event(CMD_EVENT_PAUSE, NULL);
+         netplay->remote_paused = true;
          return true;
 
       case NETPLAY_CMD_RESUME:
-         command_event(CMD_EVENT_UNPAUSE, NULL);
+         netplay->remote_paused = false;
          return true;
 
       default: break;
@@ -360,7 +360,7 @@ static int poll_input(netplay_t *netplay, bool block)
       RARCH_LOG("Network is stalling at frame %u, count %u of %d ...\n",
             netplay->self_frame_count, netplay->timeout_cnt, MAX_RETRIES);
 
-      if (netplay->timeout_cnt >= MAX_RETRIES)
+      if (netplay->timeout_cnt >= MAX_RETRIES && !netplay->remote_paused)
          return -1;
    } while (had_input || (block && (netplay->read_frame_count <= netplay->self_frame_count)));
 
@@ -434,7 +434,12 @@ static bool netplay_poll(netplay_t *netplay)
    if (netplay->stall)
    {
       retro_time_t now = cpu_features_get_time_usec();
-      if (now - netplay->stall_time >= MAX_STALL_TIME_USEC)
+      if (netplay->remote_paused)
+      {
+         /* Don't stall out while they're paused */
+         netplay->stall_time = now;
+      }
+      else if (now - netplay->stall_time >= MAX_STALL_TIME_USEC)
       {
          /* Stalled out! */
          netplay->has_connection = false;
@@ -964,11 +969,20 @@ int16_t input_state_spectate_client(unsigned port, unsigned device,
  *
  * Pre-frame for Netplay.
  * Call this before running retro_run().
+ *
+ * Returns: true (1) if the frontend is cleared to emulate the frame, false (0)
+ * if we're stalled or paused
  **/
-void netplay_pre_frame(netplay_t *netplay)
+bool netplay_pre_frame(netplay_t *netplay)
 {
    retro_assert(netplay && netplay->net_cbs->pre_frame);
+   if (netplay->local_paused)
+   {
+      /* FIXME: This is an ugly way to learn we're not paused anymore */
+      netplay_frontend_paused(netplay, false);
+   }
    netplay->net_cbs->pre_frame(netplay);
+   return (!netplay->stall && !netplay->remote_paused);
 }
 
 /**
@@ -985,6 +999,25 @@ void netplay_post_frame(netplay_t *netplay)
    netplay->net_cbs->post_frame(netplay);
 }
 
+/**
+ * netplay_frontend_paused
+ * @netplay              : pointer to netplay object
+ * @paused               : true if frontend is paused
+ *
+ * Inform Netplay of the frontend's pause state (paused or otherwise)
+ **/
+void netplay_frontend_paused(netplay_t *netplay, bool paused)
+{
+   /* Nothing to do if we already knew this */
+   if (netplay->local_paused == paused)
+      return;
+
+   fprintf(stderr, "Paused? %d\n", paused);
+   netplay->local_paused = paused;
+   if (netplay->has_connection)
+      netplay_send_raw_cmd(netplay, paused ? NETPLAY_CMD_PAUSE : NETPLAY_CMD_RESUME, NULL, 0);
+}
+
 void deinit_netplay(void)
 {
    netplay_t *netplay = (netplay_t*)netplay_data;
@@ -1060,8 +1093,7 @@ bool netplay_driver_ctl(enum rarch_netplay_ctl_state state, void *data)
          netplay_post_frame((netplay_t*)netplay_data);
          break;
       case RARCH_NETPLAY_CTL_PRE_FRAME:
-         netplay_pre_frame((netplay_t*)netplay_data);
-         break;
+         return netplay_pre_frame((netplay_t*)netplay_data);
       case RARCH_NETPLAY_CTL_FLIP_PLAYERS:
          {
             bool *state = (bool*)data;
@@ -1076,6 +1108,12 @@ bool netplay_driver_ctl(enum rarch_netplay_ctl_state state, void *data)
                command_event(CMD_EVENT_FULLSCREEN_TOGGLE, NULL);
          }
          break;
+      case RARCH_NETPLAY_CTL_PAUSE:
+         netplay_frontend_paused((netplay_t*)netplay_data, true);
+         break;
+      case RARCH_NETPLAY_CTL_UNPAUSE:
+         netplay_frontend_paused((netplay_t*)netplay_data, false);
+         break;
       default:
       case RARCH_NETPLAY_CTL_NONE:
          break;

network/netplay/netplay.h

@@ -35,7 +35,9 @@ enum rarch_netplay_ctl_state
    RARCH_NETPLAY_CTL_FULLSCREEN_TOGGLE,
    RARCH_NETPLAY_CTL_POST_FRAME,
    RARCH_NETPLAY_CTL_PRE_FRAME,
-   RARCH_NETPLAY_CTL_IS_DATA_INITED
+   RARCH_NETPLAY_CTL_IS_DATA_INITED,
+   RARCH_NETPLAY_CTL_PAUSE,
+   RARCH_NETPLAY_CTL_UNPAUSE
 };
 
 enum netplay_cmd
@@ -154,8 +156,11 @@ void netplay_free(netplay_t *handle);
  *
  * Pre-frame for Netplay.
  * Call this before running retro_run().
+ *
+ * Returns: true (1) if the frontend is clear to emulate the frame, false (0)
+ * if we're stalled or paused
  **/
-void netplay_pre_frame(netplay_t *handle);
+bool netplay_pre_frame(netplay_t *handle);
 
 /**
  * netplay_post_frame:   
@@ -167,6 +172,15 @@ void netplay_pre_frame(netplay_t *handle);
  **/
 void netplay_post_frame(netplay_t *handle);
 
+/**
+ * netplay_frontend_paused
+ * @netplay              : pointer to netplay object
+ * @paused               : true if frontend is paused
+ *
+ * Inform Netplay of the frontend's pause state (paused or otherwise)
+ **/
+void netplay_frontend_paused(netplay_t *netplay, bool paused);
+
 /**
  * init_netplay:
  *

network/netplay/netplay_net.c

@@ -136,7 +136,8 @@ static void netplay_net_post_frame(netplay_t *netplay)
       netplay->is_replay = false;
    }
 
-   /* If we're supposed to stall, rewind */
+   /* If we're supposed to stall, rewind (we shouldn't get this far if we're
+    * stalled, so this is a last resort) */
    if (netplay->stall)
    {
       retro_ctx_serialize_info_t serial_info;

network/netplay/netplay_private.h

@@ -139,8 +139,8 @@ struct netplay
 
    /* Netplay pausing
     */
-   bool pause;
-   uint32_t pause_frame;
+   bool local_paused;
+   bool remote_paused;
 
    /* And stalling */
    uint32_t stall_frames;

runloop.c

@@ -1576,7 +1576,13 @@ int runloop_iterate(unsigned *sleep_ms)
 #endif
 
 #ifdef HAVE_NETPLAY
-   netplay_driver_ctl(RARCH_NETPLAY_CTL_PRE_FRAME, NULL);
+   if (!netplay_driver_ctl(RARCH_NETPLAY_CTL_PRE_FRAME, NULL))
+   {
+      /* Paused due to Netplay */
+      core_poll();
+      *sleep_ms = 10;
+      return 1;
+   }
 #endif
 
    if (bsv_movie_ctl(BSV_MOVIE_CTL_IS_INITED, NULL))