1 files changed, 110 insertions, 0 deletions
diff --git a/lib/wrappers/libffi/common/malloc_closure.c b/lib/wrappers/libffi/common/malloc_closure.c
new file mode 100644
index 000000000..5b33aa4ca
--- /dev/null
+++ b/lib/wrappers/libffi/common/malloc_closure.c
@@ -0,0 +1,110 @@
+#include <ffi.h>
+#ifdef MS_WIN32
+#include <windows.h>
+#else
+#include <sys/mman.h>
+#include <unistd.h>
+# if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
+#  define MAP_ANONYMOUS MAP_ANON
+# endif
+#endif
+#include "ctypes.h"
+
+/* BLOCKSIZE can be adjusted.  Larger blocksize will take a larger memory
+   overhead, but allocate less blocks from the system.  It may be that some
+   systems have a limit of how many mmap'd blocks can be open.
+*/
+
+#define BLOCKSIZE _pagesize
+
+/* #define MALLOC_CLOSURE_DEBUG */ /* enable for some debugging output */
+
+/******************************************************************/
+
+typedef union _tagITEM {
+    ffi_closure closure;
+    union _tagITEM *next;
+} ITEM;
+
+static ITEM *free_list;
+static int _pagesize;
+
+static void more_core(void)
+{
+    ITEM *item;
+    int count, i;
+
+/* determine the pagesize */
+#ifdef MS_WIN32
+    if (!_pagesize) {
+        SYSTEM_INFO systeminfo;
+        GetSystemInfo(&systeminfo);
+        _pagesize = systeminfo.dwPageSize;
+    }
+#else
+    if (!_pagesize) {
+#ifdef _SC_PAGESIZE
+        _pagesize = sysconf(_SC_PAGESIZE);
+#else
+        _pagesize = getpagesize();
+#endif
+    }
+#endif
+
+    /* calculate the number of nodes to allocate */
+    count = BLOCKSIZE / sizeof(ITEM);
+
+    /* allocate a memory block */
+#ifdef MS_WIN32
+    item = (ITEM *)VirtualAlloc(NULL,
+                                           count * sizeof(ITEM),
+                                           MEM_COMMIT,
+                                           PAGE_EXECUTE_READWRITE);
+    if (item == NULL)
+        return;
+#else
+    item = (ITEM *)mmap(NULL,
+                        count * sizeof(ITEM),
+                        PROT_READ | PROT_WRITE | PROT_EXEC,
+                        MAP_PRIVATE | MAP_ANONYMOUS,
+                        -1,
+                        0);
+    if (item == (void *)MAP_FAILED)
+        return;
+#endif
+
+#ifdef MALLOC_CLOSURE_DEBUG
+    printf("block at %p allocated (%d bytes), %d ITEMs\n",
+           item, count * sizeof(ITEM), count);
+#endif
+    /* put them into the free list */
+    for (i = 0; i < count; ++i) {
+        item->next = free_list;
+        free_list = item;
+        ++item;
+    }
+}
+
+/******************************************************************/
+
+/* put the item back into the free list */
+void ffi_closure_free(void *p)
+{
+    ITEM *item = (ITEM *)p;
+    item->next = free_list;
+    free_list = item;
+}
+
+/* return one item from the free list, allocating more if needed */
+void *ffi_closure_alloc(size_t ignored, void** codeloc)
+{
+    ITEM *item;
+    if (!free_list)
+        more_core();
+    if (!free_list)
+        return NULL;
+    item = free_list;
+    free_list = item->next;
+    *codeloc = (void *)item;
+    return (void *)item;
+}