[PATCH 2/2] malloc: Make deferred free support optional

[Sebastian Huber]

Only include the deferred free support if free() is actually used by the
application.
---
 cpukit/libcsupport/src/free.c            | 43 ++++++++++++++++++++++++++++++++
 cpukit/libcsupport/src/malloc_deferred.c | 40 +++--------------------------
 cpukit/libcsupport/src/malloc_p.h        |  2 --
 cpukit/libcsupport/src/realloc.c         |  8 ++++++
 4 files changed, 54 insertions(+), 39 deletions(-)

diff --git a/cpukit/libcsupport/src/free.c b/cpukit/libcsupport/src/free.c
index d8dd2bdb0e..b5e4214449 100644
--- a/cpukit/libcsupport/src/free.c
+++ b/cpukit/libcsupport/src/free.c
@@ -22,6 +22,49 @@
 #include "malloc_p.h"
 #include <stdlib.h>
 
+#include <rtems/chain.h>
+
+static RTEMS_CHAIN_DEFINE_EMPTY( _Malloc_GC_list );
+
+RTEMS_INTERRUPT_LOCK_DEFINE( static, _Malloc_GC_lock, "Malloc GC" )
+
+static void *_Malloc_Get_deferred_free( void )
+{
+  rtems_interrupt_lock_context lock_context;
+  void *p;
+
+  rtems_interrupt_lock_acquire( &_Malloc_GC_lock, &lock_context );
+  p = rtems_chain_get_unprotected( &_Malloc_GC_list );
+  rtems_interrupt_lock_release( &_Malloc_GC_lock, &lock_context );
+
+  return p;
+}
+
+void _Malloc_Process_deferred_frees( void )
+{
+  rtems_chain_node *to_be_freed;
+
+  /*
+   *  If some free's have been deferred, then do them now.
+   */
+  while ( ( to_be_freed = _Malloc_Get_deferred_free() ) != NULL ) {
+    free( to_be_freed );
+  }
+}
+
+static void _Malloc_Deferred_free( void *p )
+{
+  rtems_interrupt_lock_context lock_context;
+  rtems_chain_node *node;
+
+  node = (rtems_chain_node *) p;
+
+  rtems_interrupt_lock_acquire( &_Malloc_GC_lock, &lock_context );
+  rtems_chain_initialize_node( node );
+  rtems_chain_append_unprotected( &_Malloc_GC_list, node );
+  rtems_interrupt_lock_release( &_Malloc_GC_lock, &lock_context );
+}
+
 void free(
   void *ptr
 )
diff --git a/cpukit/libcsupport/src/malloc_deferred.c b/cpukit/libcsupport/src/malloc_deferred.c
index ccb8dc3b8b..13b3266062 100644
--- a/cpukit/libcsupport/src/malloc_deferred.c
+++ b/cpukit/libcsupport/src/malloc_deferred.c
@@ -27,14 +27,9 @@
 
 #include "malloc_p.h"
 
-#include <rtems/chain.h>
 #include <rtems/score/sysstate.h>
 #include <rtems/score/threaddispatch.h>
 
-static RTEMS_CHAIN_DEFINE_EMPTY( _Malloc_GC_list );
-
-RTEMS_INTERRUPT_LOCK_DEFINE( static, _Malloc_GC_lock, "Malloc GC" )
-
 Malloc_System_state _Malloc_System_state( void )
 {
   System_state_Codes state = _System_state_Get();
@@ -52,28 +47,12 @@ Malloc_System_state _Malloc_System_state( void )
   }
 }
 
-static void *_Malloc_Get_deferred_free( void )
-{
-  rtems_interrupt_lock_context lock_context;
-  void *p;
-
-  rtems_interrupt_lock_acquire( &_Malloc_GC_lock, &lock_context );
-  p = rtems_chain_get_unprotected( &_Malloc_GC_list );
-  rtems_interrupt_lock_release( &_Malloc_GC_lock, &lock_context );
-
-  return p;
-}
-
-void _Malloc_Process_deferred_frees( void )
+RTEMS_WEAK void _Malloc_Process_deferred_frees( void )
 {
-  rtems_chain_node *to_be_freed;
-
   /*
-   *  If some free's have been deferred, then do them now.
+   * Do nothing by default.  If free() is used by the application, then a
+   * strong implementation of this function will be provided.
    */
-  while ( ( to_be_freed = _Malloc_Get_deferred_free() ) != NULL ) {
-    free( to_be_freed );
-  }
 }
 
 void *rtems_heap_allocate_aligned_with_boundary(
@@ -125,19 +104,6 @@ void *rtems_heap_allocate_aligned_with_boundary(
   return p;
 }
 
-void _Malloc_Deferred_free( void *p )
-{
-  rtems_interrupt_lock_context lock_context;
-  rtems_chain_node *node;
-
-  node = (rtems_chain_node *) p;
-
-  rtems_interrupt_lock_acquire( &_Malloc_GC_lock, &lock_context );
-  rtems_chain_initialize_node( node );
-  rtems_chain_append_unprotected( &_Malloc_GC_list, node );
-  rtems_interrupt_lock_release( &_Malloc_GC_lock, &lock_context );
-}
-
 void *rtems_malloc( size_t size )
 {
   if ( size == 0 ) {
diff --git a/cpukit/libcsupport/src/malloc_p.h b/cpukit/libcsupport/src/malloc_p.h
index f3715a9966..cb26050ff1 100644
--- a/cpukit/libcsupport/src/malloc_p.h
+++ b/cpukit/libcsupport/src/malloc_p.h
@@ -25,8 +25,6 @@ typedef enum {
 
 Malloc_System_state _Malloc_System_state( void );
 
-void _Malloc_Deferred_free( void * );
-
 void _Malloc_Process_deferred_frees( void );
 
 #ifdef __cplusplus
diff --git a/cpukit/libcsupport/src/realloc.c b/cpukit/libcsupport/src/realloc.c
index 7912780c09..9927b3b903 100644
--- a/cpukit/libcsupport/src/realloc.c
+++ b/cpukit/libcsupport/src/realloc.c
@@ -25,6 +25,14 @@
 
 #include "malloc_p.h"
 
+RTEMS_WEAK void _Malloc_Process_deferred_frees( void )
+{
+  /*
+   * Do nothing by default.  If free() is used by the application, then a
+   * strong implementation of this function will be provided.
+   */
+}
+
 static void *new_alloc( void *old_ptr, size_t new_size, size_t old_size )
 {
   void *new_ptr;
-- 
2.16.4