Fix issue #413: Commit 29d9e31 creates memory handling problem under macOS.

src/Fl.cxx

@@ -479,29 +479,6 @@ void Fl::run_idle() {
  occurs (this will happen on X11 if a signal happens).
 */
 double Fl::wait(double time_to_wait) {
-
-  // platform independent part:
-
-  // delete all widgets that were listed during callbacks
-  do_widget_deletion();
-
-  Fl_Timeout::do_timeouts(); // execute timer callbacks
-
-  Fl::run_checks();
-
-  Fl::run_idle();
-
-  // the idle function may turn off idle, we can then wait,
-  // or it leaves Fl::idle active and we set time_to_wait to 0
-  if (Fl::idle) {
-    time_to_wait = 0.0;
-  } else {
-    // limit time by next timer interval
-    time_to_wait = Fl_Timeout::time_to_wait(time_to_wait);
-  }
-
-  // platform dependent part:
-
   return system_driver()->wait(time_to_wait);
 }
 

src/Fl_System_Driver.H

@@ -2,7 +2,7 @@
 // A base class for platform specific system calls
 // for the Fast Light Tool Kit (FLTK).
 //
-// Copyright 2010-2021 by Bill Spitzak and others.
+// Copyright 2010-2022 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -241,7 +241,7 @@ public:
   virtual Fl_Sys_Menu_Bar_Driver *sys_menu_bar_driver() { return NULL; }
   virtual void lock_ring() {}
   virtual void unlock_ring() {}
-  virtual double wait(double) { return 0.0; } // must override
+  virtual double wait(double);                             // must override
   virtual int ready() { return 0; }                        // must override
 };
 

src/Fl_System_Driver.cxx

@@ -1,7 +1,7 @@
 //
 // A base class for platform specific system calls.
 //
-// Copyright 1998-2016 by Bill Spitzak and others.
+// Copyright 1998-2022 by Bill Spitzak and others.
 //
 // This library is free software. Distribution and use rights are outlined in
 // the file "COPYING" which should have been included with this file.  If this
@@ -22,6 +22,7 @@
 
 #include "Fl_System_Driver.H"
 #include <FL/Fl.H>
+#include "Fl_Timeout.h"
 #include <FL/Fl_File_Icon.H>
 #include <FL/fl_utf8.h>
 #include <stdlib.h>
@@ -502,6 +503,43 @@ void Fl_System_Driver::gettime(time_t *sec, int *usec) {
   *usec = 0;
 }
 
+/**
+  Execute platform independent parts of Fl::wait(double).
+
+  Platform drivers \b MUST override this virtual method to do
+  their own stuff and call this base class method to run
+  the platform independent wait functions.
+ 
+  Overriden methods will typically call this method early and perform
+  platform-specific operations after that in order to work with the
+ \p time_to_wait value possibly modified by this method.
+  However, some platform drivers may need to do extra stuff before
+  calling this method, for instance setting up a memory pool on macOS.
+
+  \param[in] time_to_wait max time to wait
+
+  \return   new (max) time to wait after elapsing timeouts
+*/
+double Fl_System_Driver::wait(double time_to_wait) {
+
+  // delete all widgets that were listed during callbacks
+  Fl::do_widget_deletion();
+
+  Fl_Timeout::do_timeouts();
+  Fl::run_checks();
+  Fl::run_idle();
+
+  // the idle function may turn off idle, we can then wait,
+  // or it leaves Fl::idle active and we set time_to_wait to 0
+  if (Fl::idle) {
+    time_to_wait = 0.0;
+  } else {
+    // limit time by next timer interval
+    time_to_wait = Fl_Timeout::time_to_wait(time_to_wait);
+  }
+  return time_to_wait;
+}
+
 /**
  \}
  \endcond

src/Fl_cocoa.mm

@@ -792,6 +792,9 @@ double Fl_Darwin_System_Driver::wait(double time_to_wait)
     drain_dropped_files_list();
   }
   NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
+
+  time_to_wait = Fl_System_Driver::wait(time_to_wait);
+
   if (fl_mac_os_version < 101100) NSDisableScreenUpdates(); // 10.3 Makes updates to all windows appear as a single event
   Fl::flush();
   if (fl_mac_os_version < 101100) NSEnableScreenUpdates(); // 10.3

src/Fl_win32.cxx

@@ -417,6 +417,8 @@ static void process_awake_handler_requests(void) {
 // always returns 1.
 double Fl_WinAPI_System_Driver::wait(double time_to_wait) {
 
+  time_to_wait = Fl_System_Driver::wait(time_to_wait);
+
   int have_message = 0;
 
   if (nfds) {

src/drivers/Unix/Fl_Unix_System_Driver.cxx

@@ -837,6 +837,7 @@ int Fl_Unix_System_Driver::poll_or_select() {
 
 double Fl_Unix_System_Driver::wait(double time_to_wait)
 {
+  time_to_wait = Fl_System_Driver::wait(time_to_wait);
   if (time_to_wait <= 0.0) {
     // do flush second so that the results of events are visible:
     int ret = this->poll_or_select_with_delay(0.0);