ACE/ace/SUN_Proactor.h

   1 // -*- C++ -*-
   2
   3 //=============================================================================
   4 /**
   5  *  @file    SUN_Proactor.h
   6  *
   7  *  @author Alexander Libman <alibman@baltimore.com>
   8  */
   9 //=============================================================================
  10
  11 #ifndef ACE_SUN_PROACTOR_H
  12 #define ACE_SUN_PROACTOR_H
  13
  14 #include /**/ "ace/config-all.h"
  15
  16 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  17 # pragma once
  18 #endif /* ACE_LACKS_PRAGMA_ONCE */
  19
  20 #if defined (ACE_HAS_AIO_CALLS) && defined (sun)
  21
  22 #include "ace/POSIX_Proactor.h"
  23 #include /**/ <sys/asynch.h>    // Sun native aio calls
  24
  25 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  26
  27 /**
  28  * @class ACE_SUN_Proactor
  29  *
  30  * @brief Implementation of the fast and reliable Proactor
  31  * for SunOS 5.6, 5.7, etc.
  32  *
  33  * This proactor, based on ACE_POSIX_AIOCB_Proactor,
  34  * works with Sun native interface for aio calls.
  35  * POSIX_API          Native SUN_API
  36  * aio_read           aioread
  37  * aio_write          aiowrite
  38  * aio_suspend        aiowait
  39  * aio_error          aio_result_t.errno
  40  * aio_return         aio_result_t.return
  41  * On Solaris, the Sun <aio*()> native implementation is more
  42  * reliable and efficient than POSIX <aio_*()> implementation.
  43  * There is a problem of lost RT signals with POSIX, if we start
  44  * more than SIGQUEUEMAX asynchronous operations at the same
  45  * time.
  46  * The Sun <aiocb> it is not the standard POSX <aiocb>, instead,
  47  * it has the following structure:
  48  * typedef struct aiocb
  49  * {
  50  * int          aio_fildes;     File descriptor
  51  * void         *aio_buf;       buffer location
  52  * size_t       aio_nbytes;     length of transfer
  53  * off_t        aio_offset;     file offset
  54  * int          aio_reqprio;    request priority offset
  55  * sigevent     aio_sigevent;   signal number and offset
  56  * int          aio_lio_opcode; listio operation
  57  * aio_result_t aio_resultp;    results
  58  * int          aio_state;      state flag for List I/O
  59  * int          aio__pad[1];    extension padding
  60  * };
  61  */
  62 class ACE_Export ACE_SUN_Proactor : public ACE_POSIX_AIOCB_Proactor
  63 {
  64 public:
  65   virtual Proactor_Type get_impl_type (void);
  66
  67   /// Destructor.
  68   virtual ~ACE_SUN_Proactor (void);
  69
  70   /// Constructor defines max number asynchronous operations that can
  71   /// be started at the same time.
  72   ACE_SUN_Proactor (size_t max_aio_operations = ACE_AIO_DEFAULT_SIZE);
  73
  74 protected:
  75   /**
  76    * Dispatch a single set of events.  If @a wait_time elapses before
  77    * any events occur, return 0.  Return 1 on success i.e., when a
  78    * completion is dispatched, non-zero (-1) on errors and errno is
  79    * set accordingly.
  80    */
  81   virtual int handle_events (ACE_Time_Value &wait_time);
  82
  83   /**
  84    * Block indefinitely until at least one event is dispatched.
  85    * Dispatch a single set of events. Return 1 on success i.e., when a
  86    * completion is dispatched, non-zero (-1) on errors and errno is
  87    * set accordingly.
  88    */
  89   virtual int handle_events (void);
  90
  91   /// Internal completion detection and dispatching.
  92   int handle_events_i (ACE_Time_Value *delta);
  93
  94   /// Initiate an aio operation.
  95   virtual int start_aio_i (ACE_POSIX_Asynch_Result *result);
  96
  97   /// Check AIO for completion, error and result status
  98   /// Return: 1 - AIO completed , 0 - not completed yet
  99   virtual int get_result_status (ACE_POSIX_Asynch_Result* asynch_result,
 100                                  int &error_status,
 101                                  size_t &transfer_count);
 102
 103   /// Extract the results of aio.
 104   ACE_POSIX_Asynch_Result *find_completed_aio (aio_result_t *result,
 105                                                int &error_status,
 106                                                size_t &transfer_count);
 107
 108   /// From ACE_POSIX_AIOCB_Proactor.
 109   /// Attempt to cancel running request
 110   virtual int cancel_aiocb (ACE_POSIX_Asynch_Result *result);
 111
 112   /// Specific Sun aiowait
 113   int wait_for_start (ACE_Time_Value * abstime);
 114
 115   /// Condition variable .
 116   /// used to wait the first AIO start
 117   ACE_SYNCH_CONDITION condition_;
 118 };
 119
 120 ACE_END_VERSIONED_NAMESPACE_DECL
 121
 122 #endif /* ACE_HAS_AIO_CALLS && sun */
 123 #endif /* ACE_SUN_PROACTOR_H*/