SERVER-7404 Link to posix_fadvise at runtime for Solaris

For the Solaris/SmartOS build, do not make direct calls to posix_fadvise,
which is present in Solaris 11 but not in Solaris 10.  Instead, see if
it is available in a loaded library (which will be libc.so.1) at runtime
and either call it or call an emulation.  The emulation is a no-op.

3 files changed, 98 insertions, 0 deletions

diff --git a/src/mongo/platform/SConscript b/src/mongo/platform/SConscript
index 0c668a4e436..4a81a31d9cb 100644
--- a/src/mongo/platform/SConscript
+++ b/src/mongo/platform/SConscript
@@ -3,6 +3,7 @@
 Import("env")
 
 env.Library('platform', [
+        'posix_fadvise.cpp',
         'process_id.cpp',
         'random.cpp',
         'strcasestr.cpp',
diff --git a/src/mongo/platform/posix_fadvise.cpp b/src/mongo/platform/posix_fadvise.cpp
new file mode 100644
index 00000000000..3053b02fbec
--- /dev/null
+++ b/src/mongo/platform/posix_fadvise.cpp
@@ -0,0 +1,56 @@
+/*    Copyright 2013 10gen Inc.
+ *
+ *    Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+#if defined(__sunos__)
+
+#include "mongo/platform/posix_fadvise.h"
+
+#include <dlfcn.h>
+
+#include "mongo/base/init.h"
+#include "mongo/base/status.h"
+
+namespace mongo {
+namespace pal {
+
+    int posix_fadvise_emulation(int fd, off_t offset, off_t len, int advice) {
+        return 0;
+    }
+
+    typedef int (*PosixFadviseFunc)(int fd, off_t offset, off_t len, int advice);
+    static PosixFadviseFunc posix_fadvise_switcher = mongo::pal::posix_fadvise_emulation;
+
+    int posix_fadvise(int fd, off_t offset, off_t len, int advice) {
+        return posix_fadvise_switcher(fd, offset, len, advice);
+    }
+
+} // namespace pal
+
+    // 'posix_fadvise()' on Solaris will call the emulation if the symbol is not found
+    //
+    MONGO_INITIALIZER_GENERAL(SolarisPosixFadvise,
+                              MONGO_NO_PREREQUISITES,
+                              ("default"))(InitializerContext* context) {
+        void* functionAddress = dlsym(RTLD_DEFAULT, "posix_fadvise");
+        if (functionAddress != NULL) {
+            mongo::pal::posix_fadvise_switcher =
+                    reinterpret_cast<mongo::pal::PosixFadviseFunc>(functionAddress);
+        }
+        return Status::OK();
+    }
+
+} // namespace mongo
+
+#endif // #if defined(__sunos__)
diff --git a/src/mongo/platform/posix_fadvise.h b/src/mongo/platform/posix_fadvise.h
new file mode 100644
index 00000000000..117b6b917f4
--- /dev/null
+++ b/src/mongo/platform/posix_fadvise.h
@@ -0,0 +1,41 @@
+/*    Copyright 2013 10gen Inc.
+ *
+ *    Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+ *
+ *    Unless required by applicable law or agreed to in writing, software
+ *    distributed under the License is distributed on an "AS IS" BASIS,
+ *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *    See the License for the specific language governing permissions and
+ *    limitations under the License.
+ */
+
+#pragma once
+
+#if !defined(_WIN32)
+
+#include <fcntl.h>
+
+#if defined(__sunos__)
+
+#include <sys/types.h>
+
+namespace mongo {
+    namespace pal {
+        int posix_fadvise(int fd, off_t offset, off_t len, int advice);
+    } // namespace pal
+    using pal::posix_fadvise;
+} // namespace mongo
+
+#elif defined(POSIX_FADV_DONTNEED)
+
+namespace mongo {
+    using ::posix_fadvise;
+} // namespace mongo
+
+#endif
+
+#endif