1 files changed, 205 insertions, 0 deletions
diff --git a/gnuradio-runtime/lib/gr_vmcircbuf_mmap_shm_open.cc b/gnuradio-runtime/lib/gr_vmcircbuf_mmap_shm_open.cc
new file mode 100644
index 0000000000..3d170081d0
--- /dev/null
+++ b/gnuradio-runtime/lib/gr_vmcircbuf_mmap_shm_open.cc
@@ -0,0 +1,205 @@
+/* -*- 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_shm_open.h>
+#include <stdexcept>
+#include <assert.h>
+#include <unistd.h>
+#include <fcntl.h>
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_MMAN_H
+#include <sys/mman.h>
+#endif
+#include <errno.h>
+#include <stdio.h>
+#include <gr_pagesize.h>
+#include <gr_sys_paths.h>
+
+
+gr_vmcircbuf_mmap_shm_open::gr_vmcircbuf_mmap_shm_open (int size)
+  : gr_vmcircbuf (size)
+{
+#if !defined(HAVE_MMAP) || !defined(HAVE_SHM_OPEN)
+  fprintf (stderr, "gr_vmcircbuf_mmap_shm_open: mmap or shm_open is not available\n");
+  throw std::runtime_error ("gr_vmcircbuf_mmap_shm_open");
+#else
+  static int s_seg_counter = 0;
+
+  if (size <= 0 || (size % gr_pagesize ()) != 0){
+    fprintf (stderr, "gr_vmcircbuf_mmap_shm_open: invalid size = %d\n", size);
+    throw std::runtime_error ("gr_vmcircbuf_mmap_shm_open");
+  }
+
+  int		shm_fd = -1;
+  char	 	seg_name[1024];
+  static bool	portable_format = true;
+
+  // open a new named shared memory segment
+
+  while (1){
+    if (portable_format){
+
+      // This is the POSIX recommended "portable format".
+      // Of course the "portable format" doesn't work on some systems...
+
+      snprintf (seg_name, sizeof (seg_name),
+		"/gnuradio-%d-%d", getpid (), s_seg_counter);
+    }
+    else {
+
+      // Where the "portable format" doesn't work, we try building
+      // a full filesystem pathname pointing into a suitable temporary directory.
+
+      snprintf (seg_name, sizeof (seg_name),
+		"%s/gnuradio-%d-%d", gr_tmp_path (), getpid (), s_seg_counter);
+    }
+
+    shm_fd = shm_open (seg_name, O_RDWR | O_CREAT | O_EXCL, 0600);
+    if (shm_fd == -1 && errno == EACCES && portable_format){
+      portable_format = false;
+      continue;			// try again using "non-portable format"
+    }
+
+    s_seg_counter++;
+
+    if (shm_fd == -1){
+      if (errno == EEXIST)	// Named segment already exists (shouldn't happen).  Try again
+	continue;
+
+      char msg[1024];
+      snprintf (msg, sizeof (msg), "gr_vmcircbuf_mmap_shm_open: shm_open [%s]", seg_name);
+      perror (msg);
+      throw std::runtime_error ("gr_vmcircbuf_mmap_shm_open");
+    }
+    break;
+  }
+
+  // We've got a new shared memory segment fd open.
+  // Now set it's length to 2x what we really want and mmap it in.
+
+  if (ftruncate (shm_fd, (off_t) 2 * size) == -1){
+    close (shm_fd);						// cleanup
+    perror ("gr_vmcircbuf_mmap_shm_open: ftruncate (1)");
+    throw std::runtime_error ("gr_vmcircbuf_mmap_shm_open");
+  }
+
+  void *first_copy = mmap (0, 2 * size,
+			   PROT_READ | PROT_WRITE, MAP_SHARED,
+			   shm_fd, (off_t) 0);
+
+  if (first_copy == MAP_FAILED){
+    close (shm_fd);						// cleanup
+    perror ("gr_vmcircbuf_mmap_shm_open: mmap (1)");
+    throw std::runtime_error ("gr_vmcircbuf_mmap_shm_open");
+  }
+
+  // unmap the 2nd half
+  if (munmap ((char *) first_copy + size, size) == -1){
+    close (shm_fd);						// cleanup
+    perror ("gr_vmcircbuf_mmap_shm_open: munmap (1)");
+    throw std::runtime_error ("gr_vmcircbuf_mmap_shm_open");
+  }
+
+  // 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,
+			    shm_fd, (off_t) 0);
+
+  if (second_copy == MAP_FAILED){
+    close (shm_fd);						// cleanup
+    perror ("gr_vmcircbuf_mmap_shm_open: mmap (2)");
+    throw std::runtime_error ("gr_vmcircbuf_mmap_shm_open");
+  }
+
+#if 0  // OS/X doesn't allow you to resize the segment
+
+  // cut the shared memory segment down to size
+  if (ftruncate (shm_fd, (off_t) size) == -1){
+    close (shm_fd);						// cleanup
+    perror ("gr_vmcircbuf_mmap_shm_open: ftruncate (2)");
+    throw std::runtime_error ("gr_vmcircbuf_mmap_shm_open");
+  }
+#endif
+
+  close (shm_fd);	// fd no longer needed.  The mapping is retained.
+
+  if (shm_unlink (seg_name) == -1){	// unlink the seg_name.
+    perror ("gr_vmcircbuf_mmap_shm_open: shm_unlink");
+    throw std::runtime_error ("gr_vmcircbuf_mmap_shm_open");
+  }
+
+  // Now remember the important stuff
+
+  d_base = (char *) first_copy;
+  d_size = size;
+#endif
+}
+
+gr_vmcircbuf_mmap_shm_open::~gr_vmcircbuf_mmap_shm_open ()
+{
+#if defined(HAVE_MMAP)
+  if (munmap (d_base, 2 * d_size) == -1){
+    perror ("gr_vmcircbuf_mmap_shm_open: munmap (2)");
+  }
+#endif
+}
+
+// ----------------------------------------------------------------
+//			The factory interface
+// ----------------------------------------------------------------
+
+
+gr_vmcircbuf_factory *gr_vmcircbuf_mmap_shm_open_factory::s_the_factory = 0;
+
+gr_vmcircbuf_factory *
+gr_vmcircbuf_mmap_shm_open_factory::singleton ()
+{
+  if (s_the_factory)
+    return s_the_factory;
+
+  s_the_factory = new gr_vmcircbuf_mmap_shm_open_factory ();
+  return s_the_factory;
+}
+
+int
+gr_vmcircbuf_mmap_shm_open_factory::granularity ()
+{
+  return gr_pagesize ();
+}
+
+gr_vmcircbuf *
+gr_vmcircbuf_mmap_shm_open_factory::make (int size)
+{
+  try {
+    return new gr_vmcircbuf_mmap_shm_open (size);
+  }
+  catch (...){
+    return 0;
+  }
+}