syscall_emul: [patch 10/22] refactor fdentry and add fdarray class

Several large changes happen in this patch.

The FDEntry class is rewritten so that file descriptors now correspond to
types: 'File' which is normal file-backed file with the file open on the
host machine, 'Pipe' which is a pipe that has been opened on the host machine,
and 'Device' which does not have an open file on the host yet acts as a pseudo
device with which to issue ioctls. Other types which might be added in the
future are directory entries and sockets (off the top of my head).

The FDArray class was create to hold most of the file descriptor handling
that was stuffed into the Process class. It uses shared pointers and
the std::array type to hold the FDEntries mentioned above.

The changes to these two classes needed to be propagated out to the rest
of the code so there were quite a few changes for that. Also, comments were
added where I thought they were needed to help others and extend our
DOxygen coverage.

1 files changed, 71 insertions, 62 deletions

diff --git a/src/sim/fd_entry.cc b/src/sim/fd_entry.cc
index 72975a7a6..65bf7a81c 100644
--- a/src/sim/fd_entry.cc
+++ b/src/sim/fd_entry.cc
@@ -1,91 +1,100 @@
 /*
- * Copyright (c) 2015 Advanced Micro Devices, Inc.
- * Copyright (c) 2001-2005 The Regents of The University of Michigan
+ * Copyright (c) 2016 Advanced Micro Devices, Inc.
+ * All rights reserved.
+ *
+ * For use for simulation and test purposes only
  *
  * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met: redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer;
- * redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution;
- * neither the name of the copyright holders nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
  *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived from this
+ * software without specific prior written permission.
  *
- * Authors: Nathan Binkert
- *          Steve Reinhardt
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Author: Brandon Potter
  */
 
-#include "base/misc.hh"
-#include "fd_entry.hh"
+#include "sim/fd_entry.hh"
 
-using namespace std;
+#include "sim/serialize.hh"
 
 void
 FDEntry::serialize(CheckpointOut &cp) const
 {
-    SERIALIZE_SCALAR(fd);
-    if (fd != -1) {
-        SERIALIZE_SCALAR(mode);
-        SERIALIZE_SCALAR(flags);
-        SERIALIZE_SCALAR(isPipe);
-        SERIALIZE_SCALAR(readPipeSource);
-        SERIALIZE_SCALAR(fileOffset);
-        SERIALIZE_SCALAR(filename);
-    }
-    if (driver)
-        warn("EmulatedDriver objects do not currently support checkpoints");
+    SERIALIZE_SCALAR(_closeOnExec);
 }
 
 void
 FDEntry::unserialize(CheckpointIn &cp)
 {
-    UNSERIALIZE_SCALAR(fd);
-    if (fd != -1) {
-        UNSERIALIZE_SCALAR(mode);
-        UNSERIALIZE_SCALAR(flags);
-        UNSERIALIZE_SCALAR(isPipe);
-        UNSERIALIZE_SCALAR(readPipeSource);
-        UNSERIALIZE_SCALAR(fileOffset);
-        UNSERIALIZE_SCALAR(filename);
-    }
-    driver = NULL;
+    UNSERIALIZE_SCALAR(_closeOnExec);
 }
 
-bool
-FDEntry::isFree()
+void
+FileFDEntry::serialize(CheckpointOut &cp) const
+{
+    SERIALIZE_SCALAR(_closeOnExec);
+    SERIALIZE_SCALAR(_flags);
+    SERIALIZE_SCALAR(_fileName);
+    SERIALIZE_SCALAR(_fileOffset);
+}
+
+void
+FileFDEntry::unserialize(CheckpointIn &cp)
+{
+    UNSERIALIZE_SCALAR(_closeOnExec);
+    UNSERIALIZE_SCALAR(_flags);
+    UNSERIALIZE_SCALAR(_fileName);
+    UNSERIALIZE_SCALAR(_fileOffset);
+}
+
+void
+PipeFDEntry::serialize(CheckpointOut &cp) const
+{
+    SERIALIZE_SCALAR(_closeOnExec);
+    SERIALIZE_SCALAR(_flags);
+    //SERIALIZE_SCALAR(_pipeEndType);
+}
+
+void
+PipeFDEntry::unserialize(CheckpointIn &cp)
 {
-    return (fd == -1 && driver == NULL);
+    UNSERIALIZE_SCALAR(_closeOnExec);
+    UNSERIALIZE_SCALAR(_flags);
+    //UNSERIALIZE_SCALAR(_pipeEndType);
 }
 
 void
-FDEntry::set(int sim_fd, const string name, int flags, int mode, bool pipe)
+DeviceFDEntry::serialize(CheckpointOut &cp) const
 {
-    fd = sim_fd;
-    filename = name;
-    this->flags = flags;
-    this->mode = mode;
-    isPipe = pipe;
-    fileOffset = 0;
-    readPipeSource = 0;
-    driver = NULL;
+    SERIALIZE_SCALAR(_closeOnExec);
+    //SERIALIZE_SCALAR(_driver);
+    SERIALIZE_SCALAR(_fileName);
 }
 
 void
-FDEntry::reset()
+DeviceFDEntry::unserialize(CheckpointIn &cp)
 {
-    set(-1, "", 0, 0, false);
+    UNSERIALIZE_SCALAR(_closeOnExec);
+    //UNSERIALIZE_SCALAR(_driver);
+    UNSERIALIZE_SCALAR(_fileName);
 }