ACE/ace/System_Time.h

   1 // -*- C++ -*-
   2
   3 //=============================================================================
   4 /**
   5  *  @file    System_Time.h
   6  *
   7  *  @author Prashant Jain
   8  *  @author Tim H. Harrison
   9  *  @author Douglas C. Schmidt
  10  */
  11 //=============================================================================
  12
  13 #ifndef ACE_SYSTEM_TIME_H
  14 #define ACE_SYSTEM_TIME_H
  15 #include /**/ "ace/pre.h"
  16
  17 #include /**/ "ace/config-all.h"
  18
  19 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  20 # pragma once
  21 #endif /* ACE_LACKS_PRAGMA_ONCE */
  22
  23 #include "ace/Global_Macros.h"
  24 #include "ace/os_include/os_time.h"  /* For time_t. */
  25 #include "ace/os_include/os_limits.h"  /* For MAXPATHLEN. */
  26 #include "ace/MMAP_Memory_Pool.h"
  27
  28 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  29
  30 template<ACE_MEM_POOL_1, class ACE_LOCK> class ACE_Malloc;
  31 template<class MALLOC> class ACE_Allocator_Adapter;
  32
  33 class ACE_Null_Mutex;
  34 class ACE_Time_Value;
  35 class ACE_MMAP_Memory_Pool;
  36
  37 /**
  38  * @class ACE_System_Time
  39  *
  40  * @brief Defines the timer services of the OS interface to access the
  41  * system time either on the local host or on the central time
  42  * server in the network.
  43  */
  44 class ACE_Export ACE_System_Time
  45 {
  46 public:
  47   /**
  48    * Enumeration types to specify mode of synchronization with master
  49    * clock.  Jump will set local system time directly (thus possibly
  50    * producing time gaps or ambiguous local system times.  Adjust will
  51    * smoothly slow down or speed up the local system clock to reach
  52    * the system time of the master clock.
  53    */
  54   enum Sync_Mode { Jump, Adjust };
  55
  56   /// Default constructor.
  57   ACE_System_Time (const ACE_TCHAR *poolname = 0);
  58
  59   /// Default destructor.
  60   ~ACE_System_Time ();
  61
  62   /// Get the local system time, i.e., the value returned by
  63   /// ACE_OS::time().
  64   static int get_local_system_time (time_t & time_out);
  65
  66   /// Get the local system time, i.e., the value returned by
  67   /// ACE_OS::time().
  68   static int get_local_system_time (ACE_Time_Value &time_out);
  69
  70   /// Get the system time of the central time server.
  71   int get_master_system_time (time_t & time_out);
  72
  73   /// Get the system time of the central time server.
  74   int get_master_system_time (ACE_Time_Value &time_out);
  75
  76   /// Synchronize local system time with the central time server using
  77   /// specified mode.
  78   int sync_local_system_time (ACE_System_Time::Sync_Mode mode);
  79
  80 private:
  81   typedef ACE_Malloc<ACE_MMAP_MEMORY_POOL, ACE_Null_Mutex> MALLOC;
  82   typedef ACE_Allocator_Adapter<MALLOC> ALLOCATOR;
  83
  84   /// Our allocator (used for obtaining system time from shared memory).
  85   ALLOCATOR * shmem_;
  86
  87   /// The name of the pool used by the allocator.
  88   ACE_TCHAR poolname_[MAXPATHLEN + 1];
  89
  90   /// Pointer to delta time kept in shared memory.
  91   long * delta_time_;
  92 };
  93
  94 ACE_END_VERSIONED_NAMESPACE_DECL
  95
  96 #include /**/ "ace/post.h"
  97 #endif /* ACE_SYSTEM_TIME_H */