/* <code/event.h> -- Event Logging Interface
 *
 * Copyright (c) 2001 Ravenbrook Limited.  See end of file for license.
 * $Id$
 *
 * READERSHIP
 *
 * .readership: MPS developers.
 *
 * DESIGN
 *
 * .design: <design/telemetry/>.
 */

#ifndef event_h
#define event_h

#include "eventcom.h"
#include "mpm.h"


extern Res EventSync(void);
extern Res EventInit(void);
extern void EventFinish(void);
extern Word EventControl(Word, Word);
extern Word EventInternString(const char *);
extern Word EventInternGenString(size_t, const char *);
extern void EventLabelAddr(Addr, Word);


#ifdef EVENT


extern Res EventFlush(void);


/* Event Kinds --- see <design/telemetry/>
 *
 * All events are classified as being of one event type.
 * They are small enough to be able to be used as shifts within a word.
 */

#define EventKindArena      ((EventKind)0) /* Per space or arena */
#define EventKindPool       ((EventKind)1) /* Per pool */
#define EventKindTrace      ((EventKind)2) /* Per trace or scan */
#define EventKindSeg        ((EventKind)3) /* Per seg */
#define EventKindRef        ((EventKind)4) /* Per ref or fix */
#define EventKindObject     ((EventKind)5) /* Per alloc or object */
#define EventKindUser       ((EventKind)6) /* User-invoked */

#define EventKindNumber     ((Count)7) /* Number of event kinds */


/* Event type definitions
 *
 * Define various constants for each event type to describe them.
 */

/* Note that enum values can be up to fifteen bits long portably. */
#define RELATION(type, code, always, kind, format) \
  enum { \
    Event##type##High = ((code >> 8) & 0xFF), \
    Event##type##Low = (code & 0xFF), \
    Event##type##Always = always, \
    Event##type##Kind = EventKind##kind, \
    Event##type##Format = EventFormat##format \
  };
 
#include "eventdef.h"

#undef RELATION


/* Event writing support */

extern EventUnion EventMould;
extern char *EventNext, *EventLimit;
extern Word EventKindControl;

#define EVENT_BEGIN(type) \
  BEGIN \
    if(BS_IS_MEMBER(EventKindControl, ((Index)Event##type##Kind))) { \
      size_t _length;

#define EVENT_END(type, format, length) \
      AVER(EventFormat##format == Event##type##Format); \
      /* @@@@ As an interim measure, send the old event codes */ \
      EventMould.any.code = Event##type; \
      EventMould.any.clock = mps_clock(); \
      AVER(EventNext <= EventLimit); \
      _length = size_tAlignUp(length, sizeof(Word)); \
      if(_length > (size_t)(EventLimit - EventNext)) \
        EventFlush(); /* @@@@ should pass length */ \
      AVER(_length <= (size_t)(EventLimit - EventNext)); \
      mps_lib_memcpy(EventNext, &EventMould, _length); \
      EventNext += _length; \
    } \
  END


#else /* EVENT not */


#define EventInit()            NOOP
#define EventFinish()          NOOP
#define EventControl(r, f)     (UNUSED(r), UNUSED(f), (Word)0)
#define EventInternString(s)   (UNUSED(s), (Word)0)
#define EventInternGenString(l, s) (UNUSED(l), UNUSED(s), (Word)0)
#define EventLabelAddr(a, i)   BEGIN UNUSED(a); UNUSED(i); END


#endif /* EVENT */


#endif /* event_h */


/* C. COPYRIGHT AND LICENSE
 *
 * Copyright (C) 2001-2002 Ravenbrook Limited <http://www.ravenbrook.com/>.
 * All rights reserved.  This is an open source license.  Contact
 * Ravenbrook for commercial licensing options.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 
 * 3. Redistributions in any form must be accompanied by information on how
 * to obtain complete source code for this software and any accompanying
 * software that uses this software.  The source code must either be
 * included in the distribution or be available for no more than the cost
 * of distribution plus a nominal fee, and must be freely redistributable
 * under reasonable conditions.  For an executable file, complete source
 * code means the source code for all modules it contains. It does not
 * include source code for modules or files that typically accompany the
 * major components of the operating system on which the executable file
 * runs.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE, OR NON-INFRINGEMENT, ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */