Port to new memory model (add global context 0)

m-core.h

@@ -413,6 +413,21 @@ M_BEGIN_PROTECTED_CODE
 
 
 // FIXME: Rename to M_USE_MEMORY_CONTEXT?
+/* In order to support context for memory functions, the prototypes and usages of some functions are modified
+ * so that they accept a first argument 'm_pool' which is the memory context parameter.
+ * For some functions, there is no meaning of a local memory context parameter: for all data shared between threads,
+ * only a global memory context has any meaning. For such cases, the memory context parameter is not requested to
+ * the used but set to 0.
+ * several macros are defined **globally**. Theses macros expand to nothing if memory context is not requested. 
+ * * M_P_EXPAND: expand to the first parameter 'm_pool' of type M_USE_POOL for a function that may use memory context.
+ * * M_P_EXPAND_void: same but assume that there is no argument
+ * * M_R_EXPAND: expand to the first parameter 'm_pool'
+ * * M_R_EXPAND_void: same but assume that there is no argument
+ * * M_R: add the parameter m_pool to the function call if needed,
+ * * M_P: define the prototype of a function that may have the parameter m_pool.
+ * * M_ASSERT_POOL: avoid warning of unused m_pool argument
+ * * M_GLOBAL_POOL: define m_pool to zero, meaning it is a global memory context.
+ */
 #ifndef M_USE_POOL
 // Memory pool parameter not used for memory function. Stub it with 0 as it won't be used (global definition).
 # define M_P_EXPAND
@@ -421,6 +436,7 @@ M_BEGIN_PROTECTED_CODE
 # define M_R_EXPAND_void
 # define M_R
 # define M_ASSERT_POOL()
+# define M_GLOBAL_POOL()
 #else
 // Memory pool parameter is used for function using memory. (local definition to the function).
 // Expand to a prototype to a function that may not trigger exception
@@ -430,6 +446,7 @@ M_BEGIN_PROTECTED_CODE
 # define M_R_EXPAND_void m_pool
 # define M_R(...) (m_pool, __VA_ARGS__)
 # define M_ASSERT_POOL() (void) m_pool
+# define M_GLOBAL_POOL() M_USE_POOL m_pool = { 0 }
 #endif
 
 // M_P: Expand to a prototype of a function that may trigger exception / accept memory context