xpcom/tests/TestOOM.cpp

   1 /* ***** BEGIN LICENSE BLOCK *****
   2  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   3  *
   4  * The contents of this file are subject to the Mozilla Public License Version
   5  * 1.1 (the "License"); you may not use this file except in compliance with
   6  * the License. You may obtain a copy of the License at
   7  * http://www.mozilla.org/MPL/
   8  *
   9  * Software distributed under the License is distributed on an "AS IS" basis,
  10  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  11  * for the specific language governing rights and limitations under the
  12  * License.
  13  *
  14  * The Original Code is a simple OOM Test.
  15  *
  16  * The Initial Developer of the Original Code is
  17  * Mozilla Corporation.
  18  * Portions created by the Initial Developer are Copyright (C) 2008
  19  * the Initial Developer. All Rights Reserved.
  20  *
  21  * Contributor(s):
  22  *   Doug Turner <dougt@meer.net>
  23  *
  24  * Alternatively, the contents of this file may be used under the terms of
  25  * either the GNU General Public License Version 2 or later (the "GPL"), or
  26  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  27  * in which case the provisions of the GPL or the LGPL are applicable instead
  28  * of those above. If you wish to allow use of your version of this file only
  29  * under the terms of either the GPL or the LGPL, and not to allow others to
  30  * use your version of this file under the terms of the MPL, indicate your
  31  * decision by deleting the provisions above and replace them with the notice
  32  * and other provisions required by the GPL or the LGPL. If you do not delete
  33  * the provisions above, a recipient may use your version of this file under
  34  * the terms of any one of the MPL, the GPL or the LGPL.
  35  *
  36  * ***** END LICENSE BLOCK ***** */
  37
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <math.h>
  41
  42 #include "nsXPCOM.h"
  43 #include "nsISupportsUtils.h"
  44 #include "nsCOMPtr.h"
  45 #include "nsIMemory.h"
  46
  47 int main(int argc, char **argv)
  48 {
  49   nsCOMPtr<nsIMemory> mem;
  50   nsresult rv = NS_GetMemoryManager(getter_AddRefs(mem));
  51
  52   if (!mem || NS_FAILED(rv))
  53   {
  54     printf("Could not get the memory manager\n");
  55     return -1;
  56   }
  57
  58   // allocation note.  don't use nsIMemory to allocate,
  59   // because we want to test the isLowMemory predicate
  60   // without regard for the nsIMemory impelmentation (the
  61   // implementation might count bytes handed out.  however,
  62   // the predicate should work with out having to rely on
  63   // that.
  64   void *big_alloc = malloc(1024 * 1024 * 16);
  65
  66   const int highpower = 500000;
  67
  68   char* buffers[highpower];
  69   for (int i=0; i<highpower; i++)
  70     buffers[i] = nsnull;
  71
  72   for (int i=0; i<highpower; i++)
  73   {
  74     PRBool lowMem = PR_FALSE;
  75     size_t s = 4096; //pow(2,i);
  76     buffers[i] = (char*) malloc(s);
  77
  78     // You have to touch the buffer
  79     if (!buffers[i])
  80       printf("Could not allocate a buffer of size %ld\n", s);
  81     else
  82     {
  83       for (int j=0; j<s; j++)
  84         buffers[i][j] = 'a';
  85     }
  86
  87     PRIntervalTime start = PR_IntervalNow();
  88     mem->IsLowMemory(&lowMem);
  89     PRIntervalTime cost = PR_IntervalNow() - start;
  90
  91
  92     printf("Total Allocated: %ld. \tLow Memory now?  %s\t Took (%d)\n",
  93            s*i,
  94            lowMem ? "Yes" : "No",
  95            PR_IntervalToMilliseconds(cost));
  96
  97     if (lowMem)
  98       break;
  99   }
 100
 101   for(int i=0; i<highpower; i++)
 102   {
 103     if (buffers[i])
 104       free(buffers[i]);
 105   }
 106   return 0;
 107 }