Bug 451672 - Fix nsIMemory::IsLowMemory on Maemo. r=stuart

xpcom/base/nsMemoryImpl.cpp

@@ -55,6 +55,8 @@
 #if defined(XP_WIN)
 #include <windows.h>
 #define NS_MEMORY_FLUSHER
+#elif defined (NS_OSSO)
+#include <osso-mem.h>
 #else
 // Need to implement the nsIMemory::IsLowMemory() predicate
 #undef NS_MEMORY_FLUSHER
@@ -189,6 +191,16 @@ nsMemoryImpl::IsLowMemory(PRBool *result)
     MEMORYSTATUS stat;
     GlobalMemoryStatus(&stat);
     *result = ((float)stat.dwAvailPageFile / stat.dwTotalPageFile) < 0.1;
+#elif defined(NS_OSSO)
+    osso_mem_usage_t usage;
+    osso_mem_get_usage(&usage);
+    
+    // According to the docs, low memory limit isn't set if it is
+    // zero, or if it is greater than 100%.
+    if (usage.low == 0 || usage.low > usage.total)
+      *result = PR_FALSE;
+    else
+      *result = (PRBool) usage.low <= usage.used;
 #else
     *result = PR_FALSE;
 #endif

xpcom/tests/Makefile.in

@@ -81,6 +81,7 @@ CPPSRCS		= \
 		TestProxies.cpp \
 		TestThreadPoolListener.cpp \
 		TestTimers.cpp \
+		TestOOM.cpp \
 		$(NULL)
 
 ifndef MOZ_ENABLE_LIBXUL

xpcom/tests/TestOOM.cpp

@@ -0,0 +1,107 @@
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is a simple OOM Test.
+ *
+ * The Initial Developer of the Original Code is
+ * Mozilla Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 2008
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Doug Turner <dougt@meer.net>
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+
+#include "nsXPCOM.h"
+#include "nsISupportsUtils.h"
+#include "nsCOMPtr.h"
+#include "nsIMemory.h"
+
+int main(int argc, char **argv)
+{
+  nsCOMPtr<nsIMemory> mem;
+  nsresult rv = NS_GetMemoryManager(getter_AddRefs(mem));
+
+  if (!mem || NS_FAILED(rv))
+  {
+    printf("Could not get the memory manager\n");
+    return -1;
+  }
+
+  // allocation note.  don't use nsIMemory to allocate,
+  // because we want to test the isLowMemory predicate
+  // without regard for the nsIMemory impelmentation (the
+  // implementation might count bytes handed out.  however,
+  // the predicate should work with out having to rely on
+  // that.
+  void *big_alloc = malloc(1024 * 1024 * 16);
+
+  const int highpower = 500000;
+  
+  char* buffers[highpower];
+  for (int i=0; i<highpower; i++)
+    buffers[i] = nsnull;
+  
+  for (int i=0; i<highpower; i++)
+  {
+    PRBool lowMem = PR_FALSE;
+    size_t s = 4096; //pow(2,i);
+    buffers[i] = (char*) malloc(s);
+    
+    // You have to touch the buffer
+    if (!buffers[i])
+      printf("Could not allocate a buffer of size %ld\n", s);
+    else
+    {
+      for (int j=0; j<s; j++)
+        buffers[i][j] = 'a';
+    }
+   
+    PRIntervalTime start = PR_IntervalNow();
+    mem->IsLowMemory(&lowMem);
+    PRIntervalTime cost = PR_IntervalNow() - start;
+    
+    
+    printf("Total Allocated: %ld. \tLow Memory now?  %s\t Took (%d)\n",
+           s*i,
+	   lowMem ? "Yes" : "No",
+	   PR_IntervalToMilliseconds(cost));
+  
+    if (lowMem)
+      break;
+  }
+
+  for(int i=0; i<highpower; i++)
+  {
+    if (buffers[i])
+      free(buffers[i]);
+  }
+  return 0;
+}