#i101955# new osl_File_MapFlag_WillNeed (honored on MACOSX and SOLARIS for now)

1 files changed, 23 insertions, 0 deletions

diff --git a/sal/osl/unx/file.cxx b/sal/osl/unx/file.cxx
index bd5b54a6d8c3..ef6dc601b53d 100644
--- a/sal/osl/unx/file.cxx
+++ b/sal/osl/unx/file.cxx
@@ -1297,6 +1297,29 @@ SAL_CALL osl_mapFile (
             }
         }
     }
+    if (uFlags & osl_File_MapFlag_WillNeed)
+    {
+        // On Linux, madvise(..., MADV_WILLNEED) appears to have the undesirable
+        // effect of not returning until the data has actually been paged in, so
+        // that its net effect would typically be to slow down the process
+        // (which could start processing at the beginning of the data while the
+        // OS simultaneously pages in the rest); on other platforms, it remains
+        // to be evaluated whether madvise or equivalent is available and
+        // actually useful:
+#if defined MACOSX
+        int e = posix_madvise(p, nLength, POSIX_MADV_WILLNEED);
+        if (e != 0)
+        {
+            OSL_TRACE(
+                "posix_madvise(..., POSIX_MADV_WILLNEED) failed with %d", e);
+        }
+#elif defined SOLARIS
+        if (madvise(static_cast< caddr_t >(p), nLength, MADV_WILLNEED) != 0)
+        {
+            OSL_TRACE("madvise(..., MADV_WILLNEED) failed with %d", errno);
+        }
+#endif
+    }
     return osl_File_E_None;
 }