Adding POV_THREAD_STACK_SIZE macro. (POV-Ray#231)

Unix default is 4MB due regression, otherise 2MB. Checks added for a min
size of 64KB.

Author: wfpokorny

source/backend/configbackend.h

@@ -10,7 +10,7 @@
 /// @parblock
 ///
 /// Persistence of Vision Ray Tracer ('POV-Ray') version 3.7.
-/// Copyright 1991-2016 Persistence of Vision Raytracer Pty. Ltd.
+/// Copyright 1991-2017 Persistence of Vision Raytracer Pty. Ltd.
 ///
 /// POV-Ray is free software: you can redistribute it and/or modify
 /// it under the terms of the GNU Affero General Public License as
@@ -76,6 +76,20 @@
     #define POV_USE_DEFAULT_TASK_CLEANUP 1
 #endif
 
+/// @def POV_THREAD_STACK_SIZE
+///     Internally defaulted thread stack size which the user can override.
+///
+/// @note
+///     The defaulted minimum is 2MB, but later defaulted to 4MB for unix due user regression.
+///
+#ifndef POV_THREAD_STACK_SIZE
+    #define POV_THREAD_STACK_SIZE (1024 * 1024 * 2)
+#else
+    #if POV_THREAD_STACK_SIZE < (1024 * 64)
+        #error "POV_THREAD_STACK_SIZE set less than 65KB or not a byte count."
+    #endif
+#endif
+
 /// @def POV_CONVERT_TEXT_TO_UCS2
 /// Convert text from system-specific format to UCS2.
 ///

source/backend/support/task.cpp

@@ -8,7 +8,7 @@
 /// @parblock
 ///
 /// Persistence of Vision Ray Tracer ('POV-Ray') version 3.7.
-/// Copyright 1991-2016 Persistence of Vision Raytracer Pty. Ltd.
+/// Copyright 1991-2017 Persistence of Vision Raytracer Pty. Ltd.
 ///
 /// POV-Ray is free software: you can redistribute it and/or modify
 /// it under the terms of the GNU Affero General Public License as
@@ -103,7 +103,7 @@ POV_LONG Task::ConsumedCPUTime() const
 void Task::Start(const boost::function0<void>& completion)
 {
     if((done == false) && (taskThread == NULL))
-        taskThread = NewBoostThread(boost::bind(&Task::TaskThread, this, completion), 1024 * 1024 * 2); // TODO - make stack size definable
+        taskThread = NewBoostThread(boost::bind(&Task::TaskThread, this, completion), POV_THREAD_STACK_SIZE);
 }
 
 void Task::RequestStop()

unix/povconfig/syspovconfigbackend.h

@@ -11,7 +11,7 @@
 /// @parblock
 ///
 /// Persistence of Vision Ray Tracer ('POV-Ray') version 3.7.
-/// Copyright 1991-2016 Persistence of Vision Raytracer Pty. Ltd.
+/// Copyright 1991-2017 Persistence of Vision Raytracer Pty. Ltd.
 ///
 /// POV-Ray is free software: you can redistribute it and/or modify
 /// it under the terms of the GNU Affero General Public License as
@@ -50,4 +50,14 @@
 #define POV_USE_DEFAULT_TASK_INITIALIZE 1
 #define POV_USE_DEFAULT_TASK_CLEANUP    1
 
+// In regression testing an old scene for the 3.7.1 release found
+// linux machines needed more stack storage than windows.
+#ifndef POV_THREAD_STACK_SIZE
+    #define POV_THREAD_STACK_SIZE (1024 * 1024 * 4)
+#else
+    #if POV_THREAD_STACK_SIZE < (1024 * 64)
+        #error "POV_THREAD_STACK_SIZE set less than 65KB or not a byte count."
+    #endif
+#endif
+
 #endif // POVRAY_UNIX_SYSPOVCONFIGBACKEND_H