import winsup-2000-02-17 snapshot

winsup/cygwin/malloc_wrapper.cc

@@ -0,0 +1,221 @@
+/* malloc.cc for WIN32.
+
+   Copyright 1996, 1997, 1998 Cygnus Solutions.
+
+   Written by Steve Chamberlain of Cygnus Support
+   sac@cygnus.com
+
+This file is part of Cygwin.
+
+This software is a copyrighted work licensed under the terms of the
+Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
+details. */
+
+#include "winsup.h"
+#include <stdlib.h>
+
+/* we provide these stubs to call into a user's
+   provided malloc if there is one - otherwise
+   functions we provide - like strdup will cause
+   problems if malloced on our heap and free'd on theirs.
+*/
+
+static int export_malloc_called = 0;
+static int use_internal_malloc = 1;
+
+#undef in
+#undef out
+#define in(x)
+#define out(x)
+
+#ifdef MALLOC_DEBUG
+extern "C" void * _sbrk (size_t incr_arg);
+
+#if 0
+extern "C" void *
+_sbrk_r (struct _reent *, size_t incr_arg)
+{
+  return _sbrk (incr_arg);
+}
+#endif
+
+extern "C" void *
+_malloc_r (struct _reent *, size_t size)
+{
+  export_malloc_called = 1;
+  return malloc (size);
+}
+#undef malloc
+
+extern "C" void *
+_calloc_r (struct _reent *, size_t nmemb, size_t size)
+{
+  export_malloc_called = 1;
+  return calloc (nmemb, size);
+}
+#undef calloc
+
+extern "C" void
+_free_r (struct _reent *, void *p)
+{
+  export_malloc_called = 1;
+  free (p);
+}
+#undef free
+
+extern "C" void *
+_realloc_r (struct _reent *, void *p, size_t size)
+{
+  export_malloc_called = 1;
+  return realloc (p, size);
+}
+#undef realloc
+
+extern "C" char *
+strdup_dbg (const char *s, const char *file, int line)
+{
+  char    *p;
+  export_malloc_called = 1;
+  if ((p = (char *) malloc_dbg (strlen (s) + 1, file, line)) != NULL)
+      strcpy (p, s);
+  return p;
+}
+
+#undef strdup
+extern "C" char *
+strdup (const char *s)
+{
+  return strdup_dbg (s, __FILE__, __LINE__);
+}
+#else
+/* Call though the application pointer,
+   which either points to export_malloc, or the application's
+   own version. */
+
+void *
+malloc (size_t size)
+{
+  void *res;
+  res = user_data->malloc (size);
+  return res;
+}
+
+void
+free (void *p)
+{
+  user_data->free (p);
+}
+
+void *
+realloc (void *p, size_t size)
+{
+  void *res;
+  res = user_data->realloc (p, size);
+  return res;
+}
+
+void *
+calloc (size_t nmemb, size_t size)
+{
+  void *res;
+  res = user_data->calloc (nmemb, size);
+  return res;
+}
+#endif
+
+/* These routines are used by the application if it
+   doesn't provide its own malloc. */
+
+extern "C"
+void
+export_free (void *p)
+{
+  malloc_printf ("(%p), called by %x", p, ((int *)&p)[-1]);
+  if (use_internal_malloc)
+    _free_r (_impure_ptr, p);
+  else
+    user_data->free (p);
+}
+
+extern "C"
+void *
+export_malloc (int size)
+{
+  void *res;
+  export_malloc_called = 1;
+  if (use_internal_malloc)
+    res = _malloc_r (_impure_ptr, size);
+  else
+    res = user_data->malloc (size);
+  malloc_printf ("(%d) = %x, called by %x", size, res, ((int *)&size)[-1]);
+  return res;
+}
+
+extern "C"
+void *
+export_realloc (void *p, int size)
+{
+  void *res;
+  if (use_internal_malloc)
+    res = _realloc_r (_impure_ptr, p, size);
+  else
+    res = user_data->realloc (p, size);
+  malloc_printf ("(%x, %d) = %x, called by %x", p, size, res, ((int *)&p)[-1]);
+  return res;
+}
+
+extern "C"
+void *
+export_calloc (size_t nmemb, size_t size)
+{
+  void *res;
+  if (use_internal_malloc)
+    res = _calloc_r (_impure_ptr, nmemb, size);
+  else
+    res = user_data->calloc (nmemb, size);
+  malloc_printf ("(%d, %d) = %x, called by %x", nmemb, size, res, ((int *)&nmemb)[-1]);
+  return res;
+}
+
+/* We use a critical section to lock access to the malloc data
+   structures.  This permits malloc to be called from different
+   threads.  Note that it does not make malloc reentrant, and it does
+   not permit a signal handler to call malloc.  The malloc code in
+   newlib will call __malloc_lock and __malloc_unlock at appropriate
+   times.  */
+
+static NO_COPY CRITICAL_SECTION malloc_critical_section;
+
+void
+malloc_init ()
+{
+  InitializeCriticalSection (&malloc_critical_section);
+  /* Check if mallock is provided by application. If so, redirect all
+     calls to export_malloc/free/realloc to application provided. This may
+     happen if some other dll calls cygwin's malloc, but main code provides
+     its own malloc */
+  if (!user_data->forkee)
+    {
+#ifdef MALLOC_DEBUG
+      _free_r (NULL, _malloc_r (NULL, 16));
+#else
+      free (malloc (16));
+#endif
+      if (!export_malloc_called)
+	use_internal_malloc = 0;
+    }
+}
+
+extern "C"
+void
+__malloc_lock (struct _reent *ptr)
+{
+  SetResourceLock(LOCK_MEMORY_LIST,WRITE_LOCK|READ_LOCK," __malloc_lock");
+}
+
+extern "C"
+void
+__malloc_unlock (struct _reent *ptr)
+{
+  ReleaseResourceLock(LOCK_MEMORY_LIST,WRITE_LOCK|READ_LOCK," __malloc_unlock");
+}