common/server_shm.hpp

   1 //  shared memory interface to the supercollider server
   2 //  Copyright (C) 2011 Tim Blechmann
   3 //  Copyright (C) 2011 Jakob Leben
   4 //
   5 //  This program is free software; you can redistribute it and/or modify
   6 //  it under the terms of the GNU General Public License as published by
   7 //  the Free Software Foundation; either version 2 of the License, or
   8 //  (at your option) any later version.
   9 //
  10 //  This program is distributed in the hope that it will be useful,
  11 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 //  GNU General Public License for more details.
  14 //
  15 //  You should have received a copy of the GNU General Public License
  16 //  along with this program; see the file COPYING.  If not, write to
  17 //  the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18 //  Boston, MA 02111-1307, USA.
  19
  20 #ifndef SERVER_SHM_HPP
  21 #define SERVER_SHM_HPP
  22
  23 #include "scope_buffer.hpp"
  24
  25 #include <boost/foreach.hpp>
  26 #include <boost/ref.hpp>
  27 #include <boost/lexical_cast.hpp>
  28 #include <boost/interprocess/managed_shared_memory.hpp>
  29 #include <boost/interprocess/containers/vector.hpp>
  30 #include <boost/atomic.hpp>
  31
  32 namespace detail_server_shm {
  33
  34 using std::string; using std::pair;
  35
  36 using boost::ref;
  37
  38 namespace bi = boost::interprocess;
  39 using bi::managed_shared_memory; using bi::shared_memory_object;
  40
  41 static inline string make_shmem_name(unsigned int port_number)
  42 {
  43         return string("SuperColliderServer_") + boost::lexical_cast<string>(port_number);
  44 }
  45
  46 struct server_shared_memory
  47 {
  48         typedef offset_ptr<float> sh_float_ptr;
  49         typedef offset_ptr<scope_buffer> scope_buffer_ptr;
  50
  51         typedef bi::allocator<scope_buffer_ptr, managed_shared_memory::segment_manager> scope_buffer_ptr_allocator;
  52         typedef bi::vector<scope_buffer_ptr, scope_buffer_ptr_allocator> scope_buffer_vector;
  53
  54         server_shared_memory(managed_shared_memory & segment, int control_busses, int num_scope_buffers = 128):
  55                 num_control_busses(control_busses),
  56
  57                 scope_buffers(scope_buffer_ptr_allocator(segment.get_segment_manager()))
  58         {
  59                 control_busses_ = (float*)segment.allocate(control_busses * sizeof(float));
  60                 std::fill(control_busses_.get(), control_busses_.get() + control_busses, 0);
  61
  62                 for (int i = 0; i != num_scope_buffers; ++i) {
  63                         scope_buffer * raw_scope_ptr = (scope_buffer*)segment.allocate(sizeof(scope_buffer));
  64                         new(raw_scope_ptr) scope_buffer();
  65                         scope_buffer_ptr buf = raw_scope_ptr;
  66                         scope_buffers.push_back(buf);
  67                 }
  68         }
  69
  70         void destroy(managed_shared_memory & segment)
  71         {
  72                 segment.deallocate(control_busses_.get());
  73
  74                 for (int i = 0; i != scope_buffers.size(); ++i)
  75                         segment.deallocate(scope_buffers[i].get());
  76         }
  77
  78         void set_control_bus(int bus, float value)
  79         {
  80                 // TODO: we need to set the control busses via a work queue
  81         }
  82
  83         float * get_control_busses(void)
  84         {
  85                 return control_busses_.get();
  86         }
  87
  88         scope_buffer * get_scope_buffer(unsigned int index)
  89         {
  90                 if (index < scope_buffers.size())
  91                         return scope_buffers[index].get();
  92                 else
  93                         return 0;
  94         }
  95
  96 private:
  97         string shmem_name;
  98         int num_control_busses;
  99         sh_float_ptr control_busses_; // control busses
 100         scope_buffer_vector scope_buffers;
 101 };
 102
 103 class server_shared_memory_creator
 104 {
 105 public:
 106         server_shared_memory_creator(unsigned int port_number, unsigned int control_busses):
 107                 shmem_name(detail_server_shm::make_shmem_name(port_number)),
 108                 segment(bi::open_or_create, shmem_name.c_str(), 8192 * 1024)
 109         {
 110                 segment.flush();
 111
 112                 const int num_scope_buffers = 128;
 113                 size_t scope_pool_size = num_scope_buffers * sizeof(float) * 8192; // pessimize, about 4 MB
 114                 void * memory_for_scope_pool = segment.allocate(scope_pool_size);
 115                 scope_pool.init(memory_for_scope_pool, scope_pool_size);
 116
 117                 shm = segment.construct<server_shared_memory>(shmem_name.c_str())(ref(segment), control_busses,
 118                                                                                                                                                   num_scope_buffers);
 119         }
 120
 121         static void cleanup(unsigned int port_number)
 122         {
 123                 shared_memory_object::remove(detail_server_shm::make_shmem_name(port_number).c_str());
 124         }
 125
 126         ~server_shared_memory_creator(void)
 127         {
 128                 shm->destroy(segment);
 129                 segment.destroy<server_shared_memory>(shmem_name.c_str());
 130                 shared_memory_object::remove(shmem_name.c_str());
 131         }
 132
 133         float * get_control_busses(void)
 134         {
 135                 return shm->get_control_busses();
 136         }
 137
 138         scope_buffer_writer get_scope_buffer_writer(unsigned int index, unsigned int channels, unsigned int size)
 139         {
 140                 scope_buffer *buf = shm->get_scope_buffer(index);
 141                 if (buf)
 142                         return scope_buffer_writer(buf, scope_pool, channels, size);
 143                 else
 144                         return scope_buffer_writer();
 145         }
 146
 147         void release_scope_buffer_writer( scope_buffer_writer & writer )
 148         {
 149                 writer.release( scope_pool );
 150         }
 151
 152 private:
 153         string shmem_name;
 154         managed_shared_memory segment;
 155         scope_buffer_pool scope_pool;
 156
 157 protected:
 158         server_shared_memory * shm;
 159 };
 160
 161
 162 class server_shared_memory_client
 163 {
 164 public:
 165         server_shared_memory_client(unsigned int port_number):
 166                 shmem_name(detail_server_shm::make_shmem_name(port_number)),
 167                 segment(bi::open_only, shmem_name.c_str())
 168         {
 169                 pair<server_shared_memory*, size_t> res = segment.find<server_shared_memory> (shmem_name.c_str());
 170                 if (res.second != 1)
 171                         throw std::runtime_error("Cannot connect to shared memory");
 172                 shm = res.first;
 173         }
 174
 175         float * get_control_busses(void)
 176         {
 177                 return shm->get_control_busses();
 178         }
 179
 180         scope_buffer_reader get_scope_buffer_reader(unsigned int index)
 181         {
 182                 scope_buffer *buf = shm->get_scope_buffer(index);
 183                 return scope_buffer_reader(buf);
 184         }
 185
 186 private:
 187         string shmem_name;
 188         managed_shared_memory segment;
 189         server_shared_memory * shm;
 190 };
 191
 192 }
 193
 194 using detail_server_shm::server_shared_memory_client;
 195 using detail_server_shm::server_shared_memory_creator;
 196 using detail_server_shm::scope_buffer_writer;
 197 using detail_server_shm::scope_buffer_reader;
 198 using detail_server_shm::scope_buffer;
 199
 200 #endif /* SERVER_SHM_HPP */