include/shm/SharedMemoryHeader.h

   1 /**
   2         Aesalon, a tool to visualize a program's behaviour at run-time.
   3         Copyright (C) 2010, Aesalon Development Team.
   4
   5         Aesalon is distributed under the terms of the GNU GPLv3. For more
   6         licensing information, see the file LICENSE included with the distribution.
   7
   8         @file include/shm/SharedMemoryHeader.h
   9
  10 */
  11
  12 #ifndef AesalonSHM_SharedMemoryHeader_H
  13 #define AesalonSHM_SharedMemoryHeader_H
  14
  15 #include <stdint.h>
  16 #include <semaphore.h>
  17
  18 typedef struct SharedMemoryHeader_t SharedMemoryHeader_t;
  19 struct SharedMemoryHeader_t {
  20         /** Overall size of SHM in pages. */
  21         uint32_t shmSize;
  22
  23         /** The size of the configuration data (in pages). */
  24         uint32_t configDataSize;
  25
  26         /** The number of pages to use to store zone usage data in. */
  27         uint32_t zoneUsagePages;
  28
  29         /** The page offset that zones are created starting at. */
  30         uint32_t zonePageOffset;
  31
  32         /** The size of a zone, in pages. */
  33         uint32_t zoneSize;
  34
  35         /** The number of zones currently in use. */
  36         uint32_t zoneCount;
  37
  38         /** The number of zones that memory has been allocated for. */
  39         uint32_t zonesAllocated;
  40
  41         /** Packet semaphore: incremented when a packet is available for reading. */
  42         sem_t packetSemaphore;
  43
  44         /** Resizing semaphore; locked when a thread is resizing the SHM. */
  45         sem_t resizeSemaphore;
  46
  47         /** The last process ID; used to assign 4-byte thread IDs dynamically.
  48         */
  49         uint32_t lastProcessID;
  50
  51         /** The last thread ID; used to assign 4-byte thread IDs dynamically.
  52         */
  53         uint32_t lastThreadID;
  54 };
  55
  56 #endif