Add RTL allocator.

Add a custom allocator that can be hooked. The default heap allocator
in this code does nothing more than wrap the libc heap allocator.

Fix up the RTL initialise to better handle the locking and
initialisation of internal structures.

1 files changed, 88 insertions, 0 deletions

diff --git a/rtl-allocator.h b/rtl-allocator.h
new file mode 100644
index 0000000..6f1e9bb
--- /dev/null
+++ b/rtl-allocator.h
@@ -0,0 +1,88 @@
+/*
+ *  COPYRIGHT (c) 2012 Chris Johns <chrisj@rtems.org>
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.org/license/LICENSE.
+ */
+/**
+ * @file
+ *
+ * @ingroup rtems_rtl
+ *
+ * @brief RTEMS Run-Time Linker Allocator
+ */
+
+#if !defined (_RTEMS_RTL_ALLOCATOR_H_)
+#define _RTEMS_RTL_ALLOCATOR_H_
+
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/**
+ * Define the types of allocation the loader requires.
+ */
+enum rtems_rtl_alloc_tags_e {
+  RTEMS_RTL_ALLOC_SYMBOL,  /**< A symbol in the symbol table. */
+  RTEMS_RTL_ALLOC_STRING,  /**< A runtime loader string. */
+  RTEMS_RTL_ALLOC_OBJECT,  /**< An RTL object. */
+  RTEMS_RTL_ALLOC_MODULE   /**< The module's code, data and bss memory. */
+};
+
+typedef enum rtems_rtl_alloc_tags_e rtems_rtl_alloc_tag_t;
+
+/**
+ * Allocator handler handles all RTL allocations. It can be hooked and
+ * overridded for customised allocation schemes or memory maps.
+ *
+ * @param allocation If true the request is to allocate memory else free.
+ * @param tag The type of allocation request.
+ * @param address Pointer to the memory address. If an allocation the value is
+ *                unspecific on entry and the allocated address or NULL on
+ *                exit. The NULL value means the allocation failed. If a delete
+ *                or free request the memory address is the block to free. A
+ *                free request of NULL is silently ignored.
+ * @param size The size of the allocation if an allocation request and
+ *             not used if deleting or freeing a previous allocation.
+ */
+typedef void (*rtems_rtl_allocator_t)(bool                  allocate,
+                                      rtems_rtl_alloc_tag_t tag,
+                                      void**                address,
+                                      size_t                size);
+
+/**
+ * The Runtime Loader allocator new allocates new memory.
+ *
+ * @param tag The type of allocation request.
+ * @param size The size of the allocation.
+ * @return void* The memory address or NULL is not memory available.
+ */
+void* rtems_rtl_alloc_new(rtems_rtl_alloc_tag_t tag, size_t size);
+
+/**
+ * The Runtime Loader allocator delete deletes allocated memory.
+ *
+ * @param tag The type of allocation request.
+ * @param address The memory address to delete. A NULL is ignored.
+ */
+void rtems_rtl_alloc_del(rtems_rtl_alloc_tag_t tag, void* address);
+
+/**
+ * Hook the Runtime Loader allocatior. A handler can call the previous handler
+ * in the chain to use it for specific tags. The default handler uses the
+ * system heap. Do not unhook your handler if memory it allocates has not been
+ * returned.
+ *
+ * @param handler The handler to use as the allocator.
+ * @return rtems_rtl_alloc_handler_t The previous handler.
+ */
+rtems_rtl_allocator_t rtems_rtl_alloc_hook(rtems_rtl_allocator_t handler);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif