1 files changed, 197 insertions, 0 deletions
diff --git a/gnuradio-runtime/lib/gr_vmcircbuf_mmap_tmpfile.cc b/gnuradio-runtime/lib/gr_vmcircbuf_mmap_tmpfile.cc
new file mode 100644
index 0000000000..35de64699e
--- /dev/null
+++ b/gnuradio-runtime/lib/gr_vmcircbuf_mmap_tmpfile.cc
@@ -0,0 +1,197 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2003,2011 Free Software Foundation, Inc.
+ *
+ * This file is part of GNU Radio
+ *
+ * GNU Radio is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3, or (at your option)
+ * any later version.
+ *
+ * GNU Radio is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Radio; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include <gr_vmcircbuf_mmap_tmpfile.h>
+#include <stdexcept>
+#include <assert.h>
+#include <unistd.h>
+#include <stdlib.h>
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif
+#include <fcntl.h>
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <gr_pagesize.h>
+#include <gr_sys_paths.h>
+
+gr_vmcircbuf_mmap_tmpfile::gr_vmcircbuf_mmap_tmpfile (int size)
+  : gr_vmcircbuf (size)
+{
+#if !defined(HAVE_MMAP)
+  fprintf (stderr, "gr_vmcircbuf_mmap_tmpfile: mmap or mkstemp is not available\n");
+  throw std::runtime_error ("gr_vmcircbuf_mmap_tmpfile");
+#else
+
+  if (size <= 0 || (size % gr_pagesize ()) != 0){
+    fprintf (stderr, "gr_vmcircbuf_mmap_tmpfile: invalid size = %d\n", size);
+    throw std::runtime_error ("gr_vmcircbuf_mmap_tmpfile");
+  }
+
+  int	seg_fd = -1;
+  char	seg_name[1024];
+
+  static int s_seg_counter = 0;
+
+
+  // open a temporary file that we'll map in a bit later
+
+  while (1){
+    snprintf (seg_name, sizeof (seg_name),
+	      "%s/gnuradio-%d-%d-XXXXXX", gr_tmp_path (), getpid (), s_seg_counter);
+    s_seg_counter++;
+
+    seg_fd = open (seg_name, O_RDWR | O_CREAT | O_EXCL, 0600);
+    if (seg_fd == -1){
+      if (errno == EEXIST)	// File already exists (shouldn't happen).  Try again
+	continue;
+
+      char msg[1024];
+      snprintf (msg, sizeof (msg),
+		"gr_vmcircbuf_mmap_tmpfile: open [%s]", seg_name);
+      perror (msg);
+      throw std::runtime_error ("gr_vmcircbuf_mmap_tmpfile");
+    }
+    break;
+  }
+
+  if (unlink (seg_name) == -1){
+    perror ("gr_vmcircbuf_mmap_tmpfile: unlink");
+    throw std::runtime_error ("gr_vmcircbuf_mmap_tmpfile");
+  }
+
+  // We've got a valid file descriptor to a tmp file.
+  // Now set it's length to 2x what we really want and mmap it in.
+
+  if (ftruncate (seg_fd, (off_t) 2 * size) == -1){
+    close (seg_fd);						// cleanup
+    perror ("gr_vmcircbuf_mmap_tmpfile: ftruncate (1)");
+    throw std::runtime_error ("gr_vmcircbuf_mmap_tmpfile");
+  }
+
+  void *first_copy = mmap (0, 2 * size,
+			   PROT_READ | PROT_WRITE, MAP_SHARED,
+			   seg_fd, (off_t) 0);
+
+  if (first_copy == MAP_FAILED){
+    close (seg_fd);						// cleanup
+    perror ("gr_vmcircbuf_mmap_tmpfile: mmap (1)");
+    throw std::runtime_error ("gr_vmcircbuf_mmap_tmpfile");
+  }
+
+  // unmap the 2nd half
+  if (munmap ((char *) first_copy + size, size) == -1){
+    close (seg_fd);						// cleanup
+    perror ("gr_vmcircbuf_mmap_tmpfile: munmap (1)");
+    throw std::runtime_error ("gr_vmcircbuf_mmap_tmpfile");
+  }
+
+  // map the first half into the now available hole where the
+  // second half used to be.
+
+  void *second_copy = mmap ((char *) first_copy + size, size,
+			    PROT_READ | PROT_WRITE, MAP_SHARED,
+			    seg_fd, (off_t) 0);
+
+  if (second_copy == MAP_FAILED){
+    munmap(first_copy, size);					// cleanup
+    close (seg_fd);
+    perror ("gr_vmcircbuf_mmap_tmpfile: mmap (2)");
+    throw std::runtime_error ("gr_vmcircbuf_mmap_tmpfile");
+  }
+
+  // check for contiguity
+  if ((char *) second_copy != (char *) first_copy + size){
+    munmap(first_copy, size);					// cleanup
+    munmap(second_copy, size);
+    close (seg_fd);
+    perror ("gr_vmcircbuf_mmap_tmpfile: non-contiguous second copy");
+    throw std::runtime_error ("gr_vmcircbuf_mmap_tmpfile");
+  }
+
+  // cut the tmp file down to size
+  if (ftruncate (seg_fd, (off_t) size) == -1){
+    munmap(first_copy, size);					// cleanup
+    munmap(second_copy, size);
+    close (seg_fd);
+    perror ("gr_vmcircbuf_mmap_tmpfile: ftruncate (2)");
+    throw std::runtime_error ("gr_vmcircbuf_mmap_tmpfile");
+  }
+
+  close (seg_fd);	// fd no longer needed.  The mapping is retained.
+
+  // Now remember the important stuff
+
+  d_base = (char *) first_copy;
+  d_size = size;
+#endif
+}
+
+gr_vmcircbuf_mmap_tmpfile::~gr_vmcircbuf_mmap_tmpfile ()
+{
+#if defined(HAVE_MMAP)
+  if (munmap (d_base, 2 * d_size) == -1){
+    perror ("gr_vmcircbuf_mmap_tmpfile: munmap (2)");
+  }
+#endif
+}
+
+// ----------------------------------------------------------------
+//			The factory interface
+// ----------------------------------------------------------------
+
+
+gr_vmcircbuf_factory *gr_vmcircbuf_mmap_tmpfile_factory::s_the_factory = 0;
+
+gr_vmcircbuf_factory *
+gr_vmcircbuf_mmap_tmpfile_factory::singleton ()
+{
+  if (s_the_factory)
+    return s_the_factory;
+
+  s_the_factory = new gr_vmcircbuf_mmap_tmpfile_factory ();
+  return s_the_factory;
+}
+
+int
+gr_vmcircbuf_mmap_tmpfile_factory::granularity ()
+{
+  return gr_pagesize ();
+}
+
+gr_vmcircbuf *
+gr_vmcircbuf_mmap_tmpfile_factory::make (int size)
+{
+  try {
+    return new gr_vmcircbuf_mmap_tmpfile (size);
+  }
+  catch (...){
+    return 0;
+  }
+}