Initial Contribution

libc/unistd/sbrk.c

@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+#include <unistd.h>
+#include <errno.h>
+
+
+#define  SBRK_ALIGN  32
+
+/* shared with brk() implementation */
+char*   __bionic_brk;
+
+void *sbrk(ptrdiff_t increment)
+{
+    char*  start;
+    char*  end;
+    char*  new_brk;
+  
+    if ( !__bionic_brk)
+        __bionic_brk = __brk((void*)0);
+
+    start = (char*)(((long)__bionic_brk + SBRK_ALIGN-1) & ~(SBRK_ALIGN-1));
+  end   = start + increment;
+
+  new_brk = __brk(end);
+    if (new_brk == (void*)-1)
+        return new_brk;
+    else if (new_brk < end)
+    {
+    errno = ENOMEM;
+        return (void*)-1;
+  }
+
+    __bionic_brk = new_brk;
+  return start;
+}