Make coroutines stack size configurable

This allows rapid debugging of the coroutine memory issues.  It moves
the default stack size to 256 * 4096 = 2^20, which will utilize full
pages on all architectures.

common/advanced_config.cpp

@@ -39,6 +39,18 @@
  */
 static const wxChar AdvancedConfigMask[] = wxT( "KICAD_ADVANCED_CONFIG" );
 
+/**
+ * Limits and default settings for the coroutine stack size allowed.
+ * Warning! Setting the stack size below the default may lead to unexplained crashes
+ * This configuration setting is intended for developers only.
+ */
+namespace AC_STACK
+{
+    static constexpr int min_stack = 32 * 4096;
+    static constexpr int default_stack = 256 * 4096;
+    static constexpr int max_stack = 4096 * 4096;
+}
+
 /**
  * List of known keys for advanced configuration options.
  *
@@ -72,6 +84,12 @@ static const wxChar RealtimeConnectivity[] = wxT( "RealtimeConnectivity" );
  */
 static const wxChar AllowLegacyCanvasInGtk3[] = wxT( "AllowLegacyCanvasInGtk3" );
 
+/**
+ * Configure the coroutine stack size in bytes.  This should be allocated in multiples of
+ * the system page size (n*4096 is generally safe)
+ */
+static const wxChar CoroutineStackSize[] = wxT( "CoroutineStackSize" );
+
 /**
  * Draw zones in pcbnew with the stroked outline.
  */
@@ -158,6 +176,7 @@ ADVANCED_CFG::ADVANCED_CFG()
     m_allowLegacyCanvasInGtk3 = false;
     m_realTimeConnectivity = true;
     m_forceThickOutlinesInZones = true;
+    m_coroutineStackSize = AC_STACK::default_stack;
 
     loadFromConfigFile();
 }
@@ -200,6 +219,10 @@ void ADVANCED_CFG::loadSettings( wxConfigBase& aCfg )
     configParams.push_back(
             new PARAM_CFG_BOOL( true, AC_KEYS::RealtimeConnectivity, &m_realTimeConnectivity, false ) );
 
+    configParams.push_back(
+            new PARAM_CFG_INT( true, AC_KEYS::CoroutineStackSize, &m_coroutineStackSize,
+                    AC_STACK::default_stack, AC_STACK::min_stack, AC_STACK::max_stack ) );
+
     configParams.push_back( new PARAM_CFG_BOOL( true, AC_KEYS::ForceThickZones,
                                                 &m_forceThickOutlinesInZones, true ) );
 

include/advanced_config.h

@@ -84,6 +84,11 @@ public:
      */
     bool m_forceThickOutlinesInZones;
 
+    /**
+     * Set the stack size for coroutines
+     */
+    int m_coroutineStackSize;
+
     /**
      * Helper to determine if legacy canvas is allowed (according to platform
      * and config)

include/tool/coroutine.h

@@ -28,13 +28,13 @@
 
 #include <cassert>
 #include <cstdlib>
-
 #include <type_traits>
 
 #ifdef KICAD_USE_VALGRIND
 #include <valgrind/valgrind.h>
 #endif
 
+#include <advanced_config.h>
 #include <system/libcontext.h>
 #include <memory>
 
@@ -148,6 +148,7 @@ public:
         ,valgrind_stack( 0 )
 #endif
     {
+        m_stacksize = ADVANCED_CFG::GetCfg().m_coroutineStackSize;
     }
 
     ~COROUTINE()
@@ -304,7 +305,7 @@ private:
 
         assert( m_stack == nullptr );
 
-        size_t stackSize = c_defaultStackSize;
+        size_t stackSize = m_stacksize;
         void* sp = nullptr;
 
         #ifndef LIBCONTEXT_HAS_OWN_STACK
@@ -380,11 +381,11 @@ private:
         }
     }
 
-    static constexpr int c_defaultStackSize = 2000000;    // fixme: make configurable
-
     ///< coroutine stack
     std::unique_ptr<char[]> m_stack;
 
+    int m_stacksize;
+
     std::function<ReturnType( ArgType )> m_func;
 
     bool m_running;