From 354bb40e75d94466e91fe6960523612c9d17ccfb Mon Sep 17 00:00:00 2001
From: Karen Arutyunov <karen@codesynthesis.com>
Date: Thu, 2 Nov 2017 23:11:29 +0300
Subject: Add implementation

---
 mysql/mysys/my_once.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 120 insertions(+)
 create mode 100644 mysql/mysys/my_once.c

(limited to 'mysql/mysys/my_once.c')

diff --git a/mysql/mysys/my_once.c b/mysql/mysys/my_once.c
new file mode 100644
index 0000000..b0938f0
--- /dev/null
+++ b/mysql/mysys/my_once.c
@@ -0,0 +1,120 @@
+/* Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
+
+/* Not MT-SAFE */
+
+#include "mysys_priv.h"
+#include "my_static.h"
+#include "mysys_err.h"
+#include <m_string.h>
+#include "my_thread_local.h"
+
+/*
+  Alloc for things we don't nend to free run-time (that only
+  should be free'd on exit)
+
+  SYNOPSIS
+    my_once_alloc()
+      Size
+      MyFlags
+
+  NOTES
+    No DBUG_ENTER... here to get smaller dbug-startup 
+*/
+
+void* my_once_alloc(size_t Size, myf MyFlags)
+{
+  size_t get_size, max_left;
+  uchar* point;
+  USED_MEM *next;
+  USED_MEM **prev;
+
+  Size= ALIGN_SIZE(Size);
+  prev= &my_once_root_block;
+  max_left=0;
+  for (next=my_once_root_block ; next && next->left < Size ; next= next->next)
+  {
+    if (next->left > max_left)
+      max_left=next->left;
+    prev= &next->next;
+  }
+  if (! next)
+  {						/* Time to alloc new block */
+    get_size= Size+ALIGN_SIZE(sizeof(USED_MEM));
+    if (max_left*4 < my_once_extra && get_size < my_once_extra)
+      get_size=my_once_extra;			/* Normal alloc */
+
+    if ((next = (USED_MEM*) malloc(get_size)) == 0)
+    {
+      set_my_errno(errno);
+      if (MyFlags & (MY_FAE+MY_WME))
+	my_error(EE_OUTOFMEMORY, MYF(ME_FATALERROR), get_size);
+      return((uchar*) 0);
+    }
+    DBUG_PRINT("test",("my_once_malloc %lu byte malloced", (ulong) get_size));
+    next->next= 0;
+    next->size= (uint)get_size;
+    next->left= (uint)(get_size-ALIGN_SIZE(sizeof(USED_MEM)));
+    *prev=next;
+  }
+  point= (uchar*) ((char*) next+ (next->size-next->left));
+  next->left-= (uint)Size;
+
+  if (MyFlags & MY_ZEROFILL)
+    memset(point, 0, Size);
+  return((void*) point);
+} /* my_once_alloc */
+
+
+char *my_once_strdup(const char *src,myf myflags)
+{
+  size_t len= strlen(src)+1;
+  uchar *dst= my_once_alloc(len, myflags);
+  if (dst)
+    memcpy(dst, src, len);
+  return (char*) dst;
+}
+
+
+void *my_once_memdup(const void *src, size_t len, myf myflags)
+{
+  uchar *dst= my_once_alloc(len, myflags);
+  if (dst)
+    memcpy(dst, src, len);
+  return dst;
+}
+
+
+/*
+  Deallocate everything that was allocated with my_once_alloc
+
+  SYNOPSIS
+    my_once_free()
+*/
+
+void my_once_free(void)
+{
+  USED_MEM *next,*old;
+  DBUG_ENTER("my_once_free");
+
+  for (next=my_once_root_block ; next ; )
+  {
+    old=next; next= next->next ;
+    free((uchar*) old);
+  }
+  my_once_root_block=0;
+
+  DBUG_VOID_RETURN;
+} /* my_once_free */
-- 
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