Buffer allocator threading support

include/polarssl/memory.h

@@ -71,6 +71,8 @@ int memory_set_own( void * (*malloc_func)( size_t ),
  *          presented buffer and does not call malloc() and free().
  *          It sets the global polarssl_malloc() and polarssl_free() pointers
  *          to its own functions.
+ *          (Provided polarssl_malloc() and polarssl_free() are thread-safe if
+ *           POLARSSL_THREADING_C is defined)
  *
  * \note    This code is not optimized and provides a straight-forward
  *          implementation of a stack-based memory allocator.
@@ -82,6 +84,11 @@ int memory_set_own( void * (*malloc_func)( size_t ),
  */
 int memory_buffer_alloc_init( unsigned char *buf, size_t len );
 
+/**
+ * \brief   Free the mutex for thread-safety and clear remaining memory
+ */
+void memory_buffer_alloc_free();
+
 /**
  * \brief   Determine when the allocator should automatically verify the state
  *          of the entire chain of headers / meta-data.

library/memory_buffer_alloc.c

@@ -38,6 +38,10 @@
 #endif
 #endif
 
+#if defined(POLARSSL_THREADING_C)
+#include "polarssl/threading.h"
+#endif
+
 #define MAGIC1       0xFF00AA55
 #define MAGIC2       0xEE119966
 #define MAX_BT 20
@@ -74,6 +78,9 @@ typedef struct
     size_t          maximum_used;
     size_t          header_count;
 #endif
+#if defined(POLARSSL_THREADING_C)
+    threading_mutex_t   mutex;
+#endif
 }
 buffer_alloc_ctx;
 
@@ -349,7 +356,6 @@ static void buffer_alloc_free( void *ptr )
     memory_header *hdr, *old = NULL;
     unsigned char *p = (unsigned char *) ptr;
 
-
     if( ptr == NULL || heap.buf == NULL || heap.first == NULL )
         return;
 
@@ -492,14 +498,38 @@ void memory_buffer_alloc_status()
 }
 #endif /* POLARSSL_MEMORY_BUFFER_ALLOC_DEBUG */
 
+#if defined(POLARSSL_THREADING_C)
+static void *buffer_alloc_malloc_mutexed( size_t len )
+{
+    void *buf;
+    polarssl_mutex_lock( &heap.mutex );
+    buf = buffer_alloc_malloc( len );
+    polarssl_mutex_unlock( &heap.mutex );
+    return( buf );
+}
+
+static void buffer_alloc_free_mutexed( void *ptr )
+{
+    polarssl_mutex_lock( &heap.mutex );
+    buffer_alloc_free( ptr );
+    polarssl_mutex_unlock( &heap.mutex );
+}
+#endif
+
 int memory_buffer_alloc_init( unsigned char *buf, size_t len )
 {
-    polarssl_malloc = buffer_alloc_malloc;
-    polarssl_free = buffer_alloc_free;
-
     memset( &heap, 0, sizeof(buffer_alloc_ctx) );
     memset( buf, 0, len );
 
+#if defined(POLARSSL_THREADING_C)
+    polarssl_mutex_init( &heap.mutex );
+    polarssl_malloc = buffer_alloc_malloc_mutexed;
+    polarssl_free = buffer_alloc_free_mutexed;
+#else
+    polarssl_malloc = buffer_alloc_malloc;
+    polarssl_free = buffer_alloc_free;
+#endif
+
     heap.buf = buf;
     heap.len = len;
 
@@ -511,4 +541,12 @@ int memory_buffer_alloc_init( unsigned char *buf, size_t len )
     return( 0 );
 }
 
+void memory_buffer_alloc_free()
+{
+#if defined(POLARSSL_THREADING_C)
+    polarssl_mutex_free( &heap.mutex );
+#endif
+    memset( &heap, 0, sizeof(buffer_alloc_ctx) );
+}
+
 #endif /* POLARSSL_MEMORY_C && POLARSSL_MEMORY_BUFFER_ALLOC_C */

programs/ssl/ssl_server2.c

@@ -969,9 +969,12 @@ exit:
     ssl_cache_free( &cache );
 #endif
 
-#if defined(POLARSSL_MEMORY_BUFFER_ALLOC_C) && defined(POLARSSL_MEMORY_DEBUG)
+#if defined(POLARSSL_MEMORY_BUFFER_ALLOC_C)
+#if defined(POLARSSL_MEMORY_DEBUG)
     memory_buffer_alloc_status();
 #endif
+    memory_buffer_alloc_free();
+#endif
 
 #if defined(_WIN32)
     printf( "  + Press Enter to exit this program.\n" );

programs/test/selftest.c

@@ -190,6 +190,9 @@ int main( int argc, char *argv[] )
         fflush( stdout ); getchar();
 #endif
     }
+#if defined(POLARSSL_MEMORY_BUFFER_ALLOC_C)
+    memory_buffer_alloc_free();
+#endif
 
     return( ret );
 }

tests/suites/main_test.function

@@ -202,8 +202,8 @@ int main()
     char *params[50];
 
 #if defined(POLARSSL_MEMORY_BUFFER_ALLOC_C)
-    unsigned char buf[1000000];
-    memory_buffer_alloc_init( buf, sizeof(buf) );
+    unsigned char alloc_buf[1000000];
+    memory_buffer_alloc_init( alloc_buf, sizeof(alloc_buf) );
 #endif
 
     file = fopen( filename, "r" );
@@ -288,9 +288,12 @@ int main()
     fprintf( stdout, " (%d / %d tests (%d skipped))\n",
              total_tests - total_errors, total_tests, total_skipped );
 
-#if defined(POLARSSL_MEMORY_BUFFER_ALLOC_C) && defined(POLARSSL_MEMORY_DEBUG)
+#if defined(POLARSSL_MEMORY_BUFFER_ALLOC_C)
+#if defined(POLARSSL_MEMORY_DEBUG)
     memory_buffer_alloc_status();
 #endif
+    memory_buffer_alloc_free();
+#endif
 
     return( total_errors != 0 );
 }