wx: Use only one ring buffer for command queue

Avoid copying between command queues, cleaner, faster and
safer implementation.

4 files changed, 87 insertions, 80 deletions

diff --git a/lib/wx/c_src/wxe_helpers.cpp b/lib/wx/c_src/wxe_helpers.cpp
index cc57374d5b..1696b8bd50 100644
--- a/lib/wx/c_src/wxe_helpers.cpp
+++ b/lib/wx/c_src/wxe_helpers.cpp
@@ -61,6 +61,7 @@ wxeFifo::wxeFifo(unsigned int sz)
   m_max = sz;
   m_n = 0;
   m_first = 0;
+  cb_start = 0;
   m_old = NULL;
   for(unsigned int i = 0; i < sz; i++) {
     m_q[i].buffer = NULL;
@@ -76,15 +77,30 @@ wxeFifo::~wxeFifo() {
 wxeCommand * wxeFifo::Get()
 {
   unsigned int pos;
-  if(m_n > 0) {
+  do {
+    if(m_n <= 0)
+      return NULL;
+
     pos = m_first++;
     m_n--;
     m_first %= m_max;
-    return &m_q[pos];
-  }
-  return NULL;
+  } while(m_q[pos].op == -1);
+  return &m_q[pos];
+}
+
+wxeCommand * wxeFifo::Peek(unsigned int *i)
+{
+  unsigned int pos;
+  do {
+    if(*i >= m_n || m_n <= 0)
+      return NULL;
+    pos = (m_first+*i) % m_max;
+    (*i)++;
+  } while(m_q[pos].op == -1);
+  return &m_q[pos];
 }
 
+
 void wxeFifo::Add(int fc, char * cbuf,int buflen, wxe_data *sd)
 {
   unsigned int pos;
@@ -140,10 +156,12 @@ void wxeFifo::Append(wxeCommand *orig)
 
   pos = (m_first + m_n) % m_max;
   m_n++;
+
   curr = &m_q[pos];
+  curr->op = orig->op;
+  if(curr->op == -1) return;
   curr->caller = orig->caller;
   curr->port   = orig->port;
-  curr->op = orig->op;
   curr->len = orig->len;
   curr->bin[0] = orig->bin[0];
   curr->bin[1] = orig->bin[1];
@@ -171,17 +189,19 @@ void wxeFifo::Realloc()
   wxeCommand * old = m_q;
   wxeCommand * queue = (wxeCommand *)driver_alloc(new_sz*sizeof(wxeCommand));
 
+  // fprintf(stderr, "\r\nrealloc qsz %d\r\n", new_sz);fflush(stderr);
+
   m_max=new_sz;
   m_first = 0;
   m_n=0;
   m_q = queue;
 
   for(i=0; i < n; i++) {
-    unsigned int pos = i+first;
-    if(old[pos%max].op >= 0) {
-      Append(&old[pos%max]);
-    }
+    unsigned int pos = (i+first)%max;
+    if(old[pos].op >= 0)
+      Append(&old[pos]);
   }
+
   for(i = m_n; i < new_sz; i++) { // Reset the rest
     m_q[i].buffer = NULL;
     m_q[i].op = -1;
@@ -190,6 +210,26 @@ void wxeFifo::Realloc()
   m_old = old;
 }
 
+// Strip end of queue if ops are already taken care of, avoids reallocs
+void wxeFifo::Strip()
+{
+  while((m_n > 0) && (m_q[(m_first + m_n - 1)%m_max].op == -1)) {
+    m_n--;
+  }
+}
+
+unsigned int wxeFifo::Cleanup(unsigned int def)
+{
+  if(m_old) {
+    driver_free(m_old);
+    m_old = NULL;
+    // Realloced we need to start from the beginning
+    return 0;
+  } else {
+    return def;
+  }
+}
+
 /* ****************************************************************************
  * TreeItemData
  * ****************************************************************************/
diff --git a/lib/wx/c_src/wxe_helpers.h b/lib/wx/c_src/wxe_helpers.h
index 4f9d9ca9c3..ff949e332b 100644
--- a/lib/wx/c_src/wxe_helpers.h
+++ b/lib/wx/c_src/wxe_helpers.h
@@ -67,9 +67,13 @@ class wxeFifo {
     void Append(wxeCommand *Other);
 
     wxeCommand * Get();
+    wxeCommand * Peek(unsigned int *item);
 
     void Realloc();
+    void Strip();
+    unsigned int Cleanup(unsigned int peek=0);
 
+    unsigned int cb_start;
     unsigned int m_max;
     unsigned int m_first;
     unsigned int m_n;
diff --git a/lib/wx/c_src/wxe_impl.cpp b/lib/wx/c_src/wxe_impl.cpp
index 5b34f08704..f81d0bbbd9 100644
--- a/lib/wx/c_src/wxe_impl.cpp
+++ b/lib/wx/c_src/wxe_impl.cpp
@@ -57,10 +57,8 @@ extern ErlDrvTermData  init_caller;
 extern int wxe_status;
 
 wxeFifo * wxe_queue = NULL;
-wxeFifo * wxe_queue_cb_saved = NULL;
 
 unsigned int wxe_needs_signal = 0;  // inside batch if larger than 0
-unsigned int wxe_cb_invoked = 0;
 
 /* ************************************************************
  *  Commands from erlang
@@ -123,11 +121,10 @@ bool WxeApp::OnInit()
 {
 
   global_me = new wxeMemEnv();
-  wxe_queue = new wxeFifo(1000);
-  wxe_queue_cb_saved = new wxeFifo(200);
+  wxe_queue = new wxeFifo(2000);
   cb_buff = NULL;
   recurse_level = 0;
-  delayed_delete = new wxeFifo(10);
+  delayed_delete = new wxeFifo(100);
   delayed_cleanup  = new wxList;
 
   wxe_ps_init2();
@@ -173,7 +170,6 @@ void WxeApp::shutdown(wxeMetaCommand& Ecmd) {
   wxe_status = WXE_EXITING;
   ExitMainLoop();
   delete wxe_queue;
-  delete wxe_queue_cb_saved;
 }
 
 void WxeApp::dummy_close(wxEvent& Ev) {
@@ -230,11 +226,10 @@ void handle_event_callback(ErlDrvPort port, ErlDrvTermData process)
     // Should we be able to handle commands when recursing? probably
     // fprintf(stderr, "\r\nCB EV Start %lu \r\n", process);fflush(stderr);
     app->recurse_level++;
-    app->dispatch_cb(wxe_queue, wxe_queue_cb_saved, process);
+    app->dispatch_cb(wxe_queue, process);
     app->recurse_level--;
     // fprintf(stderr, "CB EV done %lu \r\n", process);fflush(stderr);
     driver_demonitor_process(port, &monitor);
-    wxe_cb_invoked = 1;
   }
 }
 
@@ -242,16 +237,11 @@ void WxeApp::dispatch_cmds()
 {
   if(wxe_status != WXE_INITIATED)
     return;
-  do {
-    wxe_cb_invoked = 0;
-    recurse_level++;
-    // fprintf(stderr, "\r\ndispatch_saved 0 \r\n");fflush(stderr);
-    int level = dispatch(wxe_queue_cb_saved, 0, WXE_STORED);
-    // fprintf(stderr, "\r\ndispatch_normal %d\r\n", level);fflush(stderr);
-    dispatch(wxe_queue, level, WXE_NORMAL);
-    // fprintf(stderr, "\r\ndispatch_done \r\n");fflush(stderr);
-    recurse_level--;
-  } while(wxe_cb_invoked);
+  recurse_level++;
+  // fprintf(stderr, "\r\ndispatch_normal %d\r\n", level);fflush(stderr);
+  dispatch(wxe_queue);
+  // fprintf(stderr, "\r\ndispatch_done \r\n");fflush(stderr);
+  recurse_level--;
 
   // Cleanup old memenv's and deleted objects
   if(recurse_level == 0) {
@@ -260,6 +250,7 @@ void WxeApp::dispatch_cmds()
       wxe_dispatch(*curr);
       curr->Delete();
     }
+    delayed_delete->Cleanup();
     if(delayed_cleanup->size() > 0)
       for( wxList::compatibility_iterator node = delayed_cleanup->GetFirst();
 	   node;
@@ -269,28 +260,19 @@ void WxeApp::dispatch_cmds()
 	destroyMemEnv(*event);
 	delete event;
       }
-    if(wxe_queue_cb_saved->m_old) {
-      driver_free(wxe_queue_cb_saved->m_old);
-      wxe_queue_cb_saved->m_old = NULL;
-    }
-    if(delayed_delete->m_old) {
-      driver_free(delayed_delete->m_old);
-      delayed_delete->m_old = NULL;
-    }
   }
 }
 
-int WxeApp::dispatch(wxeFifo * batch, int blevel, int list_type)
+int WxeApp::dispatch(wxeFifo * batch)
 {
   int ping = 0;
+  int blevel = 0;
   wxeCommand *event;
-  if(list_type == WXE_NORMAL) erl_drv_mutex_lock(wxe_batch_locker_m);
+  erl_drv_mutex_lock(wxe_batch_locker_m);
   while(true) {
     while((event = batch->Get()) != NULL) {
-      if(list_type == WXE_NORMAL) erl_drv_mutex_unlock(wxe_batch_locker_m);
+      erl_drv_mutex_unlock(wxe_batch_locker_m);
       switch(event->op) {
-      case -1:
-	break;
       case WXE_BATCH_END:
 	{--blevel; }
 	break;
@@ -321,20 +303,10 @@ int WxeApp::dispatch(wxeFifo * batch, int blevel, int list_type)
 	break;
       }
       event->Delete();
-      if(list_type == WXE_NORMAL) {
-	if(wxe_cb_invoked)
-	  return blevel;
-	else
-	  erl_drv_mutex_lock(wxe_batch_locker_m);
-      }
+      erl_drv_mutex_lock(wxe_batch_locker_m);
+      batch->Cleanup();
     }
-    if(list_type == WXE_STORED)
-      return blevel;
-    if(blevel <= 0) { // list_type == WXE_NORMAL
-      if(wxe_queue->m_old) {
-	driver_free(wxe_queue->m_old);
-	wxe_queue->m_old = NULL;
-      }
+    if(blevel <= 0) {
       erl_drv_mutex_unlock(wxe_batch_locker_m);
       return blevel;
     }
@@ -348,12 +320,13 @@ int WxeApp::dispatch(wxeFifo * batch, int blevel, int list_type)
   }
 }
 
-void WxeApp::dispatch_cb(wxeFifo * batch, wxeFifo * temp, ErlDrvTermData process) {
+void WxeApp::dispatch_cb(wxeFifo * batch, ErlDrvTermData process) {
   wxeCommand *event;
+  unsigned int peek;
   erl_drv_mutex_lock(wxe_batch_locker_m);
+  peek = batch->Cleanup(batch->cb_start);
   while(true) {
-    while((event = batch->Get()) != NULL) {
-      erl_drv_mutex_unlock(wxe_batch_locker_m);
+    while((event = batch->Peek(&peek)) != NULL) {
       wxeMemEnv *memenv = getMemEnv(event->port);
       // fprintf(stderr, "  Ev %d %lu\r\n", event->op, event->caller);
       if(event->caller == process ||  // Callbacks from CB process only
@@ -361,8 +334,8 @@ void WxeApp::dispatch_cb(wxeFifo * batch, wxeFifo * temp, ErlDrvTermData process
 	 event->op == WXE_CB_DIED ||  // Event callback process died
 	 // Allow connect_cb during CB i.e. msg from wxe_server.
 	 (memenv && event->caller == memenv->owner)) {
+	erl_drv_mutex_unlock(wxe_batch_locker_m);
 	switch(event->op) {
-	case -1:
 	case WXE_BATCH_END:
 	case WXE_BATCH_BEGIN:
 	case WXE_DEBUG_PING:
@@ -373,52 +346,42 @@ void WxeApp::dispatch_cb(wxeFifo * batch, wxeFifo * temp, ErlDrvTermData process
 	    memcpy(cb_buff, event->buffer, event->len);
 	  }  // continue
 	case WXE_CB_DIED:
+	  batch->cb_start = 0;
 	  event->Delete();
+	  erl_drv_mutex_lock(wxe_batch_locker_m);
+	  batch->Strip();
+	  erl_drv_mutex_unlock(wxe_batch_locker_m);
 	  return;
 	case WXE_CB_START:
 	  // CB start from now accept message from CB process only
 	  process = event->caller;
 	  break;
 	default:
-	  size_t start=temp->m_n;
+	  batch->cb_start = peek; // In case of recursive callbacks
 	  if(event->op < OPENGL_START) {
-	    // fprintf(stderr, "  cb %d \r\n", event->op);
 	    wxe_dispatch(*event);
 	  } else {
 	    gl_dispatch(event->op,event->buffer,event->caller,event->bin);
 	  }
-	  if(temp->m_n > start) {
-	    erl_drv_mutex_lock(wxe_batch_locker_m);
-	    // We have recursed dispatch_cb and messages for this
-	    // callback may be saved on temp list move them
-	    // to orig list
-	    for(unsigned int i=start; i < temp->m_n; i++) {
-	      wxeCommand *ev = &temp->m_q[(temp->m_first+i) % temp->m_max];
-	      if(ev->caller == process) {
-		batch->Append(ev);
-	      }
-	    }
-	    erl_drv_mutex_unlock(wxe_batch_locker_m);
-	  }
 	  break;
 	}
 	event->Delete();
-      } else {
-	// fprintf(stderr, "  save %d %lu\r\n", event->op, event->caller);
-	temp->Append(event);
+	erl_drv_mutex_lock(wxe_batch_locker_m);
+	peek = batch->Cleanup(peek);
       }
-      erl_drv_mutex_lock(wxe_batch_locker_m);
     }
     // sleep until something happens
     // fprintf(stderr, "%s:%d sleep %d %d\r\n", __FILE__, __LINE__,
-    //         batch->m_n, temp->m_n);fflush(stderr);
+    // 	    peek, batch->m_n);fflush(stderr);
     wxe_needs_signal = 1;
-    while(batch->m_n == 0) {
+    while(peek >= batch->m_n) {
       erl_drv_cond_wait(wxe_batch_locker_c, wxe_batch_locker_m);
+      peek = batch->Cleanup(peek);
     }
     wxe_needs_signal = 0;
   }
 }
+
 /* Memory handling */
 
 void WxeApp::newMemEnv(wxeMetaCommand& Ecmd) {
diff --git a/lib/wx/c_src/wxe_impl.h b/lib/wx/c_src/wxe_impl.h
index d6d3095a0f..fd25296c73 100644
--- a/lib/wx/c_src/wxe_impl.h
+++ b/lib/wx/c_src/wxe_impl.h
@@ -67,8 +67,8 @@ public:
 
   void shutdown(wxeMetaCommand& event);
 
-  int dispatch(wxeFifo *, int, int);
-  void dispatch_cb(wxeFifo * batch, wxeFifo * temp, ErlDrvTermData process);
+  int dispatch(wxeFifo *);
+  void dispatch_cb(wxeFifo * batch, ErlDrvTermData process);
 
   void wxe_dispatch(wxeCommand& event);