monitor.h

《移动Agent技术》一书的所有章节源代码。

/*
 * @(#)monitor.h	1.34 97/10/07
 *
 * Copyright (c) 1995, 1996 Sun Microsystems, Inc. All Rights Reserved.
 *
 * This software is the confidential and proprietary information of Sun
 * Microsystems, Inc. ("Confidential Information").  You shall not
 * disclose such Confidential Information and shall use it only in
 * accordance with the terms of the license agreement you entered into
 * with Sun.
 *
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE
 * SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR ANY DAMAGES
 * SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING
 * THIS SOFTWARE OR ITS DERIVATIVES.
 *
 * CopyrightVersion 1.1_beta
 *
 */

/* dfb modifications (MON_FLAT)
 *   1: move MSB to high bit
 *   2: parameterize monitor shape sense (SHAPE_TID/SHAPE_MID)
 *   3: reverse sense of monitor shape bit (MSB)
 *   4: start short count at 0 instead of 1.
 *   5: inline monitorEnterQuicker, convert ATOMIC_ADD to "+"
 *   6: inline monitorExitQuicker
 *   7: remove multi-level macros
 *   8: use inlining names compatible with asm code
 *  10: pre-shifted thread index
 *  11: update inlined enter/exit code: remove redundant mask, adjust countmax
 */

/*
 * Monitor interface
 */

#ifndef	_MONITOR_H_
#define	_MONITOR_H_

#include "sys_api.h"

#ifdef MON_FLAT/* ibm.3740 */
#include "atomic_md.h"
#if !defined(IBM_OS2) && !defined(IBM_WIN32)                            /*ibm.5421*/
#include "../native_threads/include/monitor_md.h"
#endif
#if defined(IBM_WIN32)                                                  /*ibm.5421*/
#include "monitor_md.h"
#endif                                                                  /*ibm.5421*/

#define MAKE_MASK(nbits, shift) (((1<<nbits)-1)<<shift)
#define GET_VALUE(word,mask,shift) (((word) & mask) >> shift)

#define FlatLockBits 24
#define FlatLockShift 8
#define FlatLockMask MAKE_MASK(FlatLockBits, FlatLockShift)

#define ShapeShift 31
#define ShapeMask (1<<ShapeShift)

#define MonitorBits 23
#define MonitorShift 8
#define MonitorMask MAKE_MASK(MonitorBits, MonitorShift)

#define ThreadBits 15
#define ThreadShift 16
#define ThreadMask MAKE_MASK(ThreadBits, ThreadShift)

#define CountBits 8
#define CountShift 8
#define CountMask MAKE_MASK(CountBits, CountShift)
#define CountIncrement (1<<CountShift)

#define monword(obj) (obj->locknflags)
#define monaddr(obj) (& monword(obj))

#if defined(DEBUG) || (!defined(IBM_AIX) && !defined(IBM_OS2) && !defined(IBM_4690)) /* ibm.3867 *//*ibm.8015*/
#  define MONITOR_ENTER_QUICKER(obj,ee) monitorEnterQuicker(obj,ee)
#  define MONITOR_EXIT_QUICKER(obj,ee) monitorExitQuicker(obj,ee)
#else  /* ! DEBUG && (IBM_AIX || IBM_OS2)*/
#  define MONITOR_ENTER_QUICKER(obj,ee) monitorEnterAsm(obj,ee)
#  define MONITOR_EXIT_QUICKER(obj,ee) monitorExitAsm(obj,ee)
#endif


/* Test if monitor is inflated */
#define monword_inflated_p(_word) (((iatomic_t) _word) < 0)
#define monitor_inflated_p(_obj) (monword_inflated_p(monword(_obj)))

/* Test if monitor is not inflated and locked by the given thread */
#define flat_locked(_obj,__tid__) \
  ((monword(_obj) & (ThreadMask | ShapeMask)) == (__tid__))

/* Get the number of times we've locked this flat-locked object */
#define monitor_get_entrycount(_obj) \
  (GET_VALUE(monword(_obj), CountMask, CountShift)+1)

/* Get the pointer to the inflated monitor, or NULL if it is not inflated */
#define monitor_infl(_obj) \
  (! (monitor_inflated_p(_obj)) ? NULL : \
   monitorIndexToMonitor(GET_VALUE(monword(_obj), MonitorMask, MonitorShift)))

/* Calculate the new monword for the object given the monitor index */
#define SET_MON_MIDX(obj, midx) \
  ((monword(obj) & ~FlatLockMask) | (midx << MonitorShift) | ShapeMask)

typedef struct infl_mon {	/* an inflated monitor */
  struct infl_mon *next;
  int index;
  struct sys_mon _sysmon;
} infl_mon_t, *infl_mon_id;

#else /* ibm.3740 */

/*
 * Used by the monitor caching machanism to mark monitors as being
 * in-use.
 */
#define MON_LOCAL_CACHE_REF		(1 << 0)

/*
 * The monitor data structure:
 *
 * The use_count field counts the number of createMonitor calls yet
 * unmatched by monitorExit calls; that is, it is a count of outstanding
 * monitor entries of all threads regardless of whether those threads
 * own the monitor or are waiting on it.
 *
 * Note that because the mid[] array will hold the system-specific
 * sys_mon_t, it needs to start on a four-byte boundary lest the fields
 * of the sys_mon_t aren't properly aligned.  Otherwise the flags field
 * would be shorter than a long.
 */
typedef struct monitor_t {
    unsigned int	key;		/* Monitor hash key */
    struct monitor_t   *next;
    char		mid[1];		/* The sys_mon_t */
} monitor_t, *MID;

/* A macro for accessing the sys_mon_t from the monitor_t */
#define sysmon(m)   (*(sys_mon_t *) m->mid)
#endif /* ibm.3411 */

typedef struct reg_mon_t {
    sys_mon_t *mid;
    char *name;
    struct reg_mon_t *next;
} reg_mon_t;

/*
 * Macros
 */
#define MID_NULL 	    ((MID) 0)
#define TIMEOUT_INFINITY    -1

/*
 * Support for the monitor registry
 */
extern sys_mon_t *_registry_lock;

#define REGISTRY_LOCK_INIT()    monitorRegister(_registry_lock, \
						"Monitor registry")
#define REGISTRY_LOCK()	  	sysMonitorEnter(_registry_lock)
#define REGISTRY_LOCKED()	sysMonitorEntered(_registry_lock)
#define REGISTRY_UNLOCK()	sysMonitorExit(_registry_lock)

/*
 * External routines.
 */
#ifdef MON_FLAT /* ibm.3740 */
struct Hjava_lang_Object;
struct execenv; /* ibm.3796 */
#endif

/*
 * Synchronization interface
 */
void monitorCacheInit(void);
#ifdef MON_FLAT /* ibm.3740 */
void monitorDeflate(struct Hjava_lang_Object *);
void monitorEnter(struct Hjava_lang_Object *);
void monitorExit(struct Hjava_lang_Object *);
void monitorWait(struct Hjava_lang_Object *, int);
void monitorNotify(struct Hjava_lang_Object *);
void monitorNotifyAll(struct Hjava_lang_Object *);
void monitorEnterQuicker(struct Hjava_lang_Object *, struct execenv *); /* ibm.3796 */
void monitorExitQuicker(struct Hjava_lang_Object *, struct execenv *); /* ibm.3796 */
void monitorEnterAsm(struct Hjava_lang_Object *, struct execenv *); /* ibm.3796 */
void monitorExitAsm(struct Hjava_lang_Object *, struct execenv *); /* ibm.3796 */
void monitorExitError(struct Hjava_lang_Object *, struct execenv *); /* ibm.3796 */
void inflMonitorInit(infl_mon_t *);
#else
void monitorInit(monitor_t *mon);
void monitorEnter(unsigned int);
void monitorExit(unsigned int);
void monitorWait(unsigned int, int);
void monitorNotify(unsigned int);
void monitorNotifyAll(unsigned int);
#if (defined(IBM_AIX) || defined(IBM_4690)) /* ibm.3812 *//*ibm.7306*/
void monitorEnterQuicker(unsigned int, struct execenv * );
void monitorExitQuicker(unsigned int, struct execenv *);
#endif /* ibm.3812 */

#endif /* ibm.3411 */

/* Registry of static monitors */
extern reg_mon_t *MonitorRegistry;

void monitorRegistryInit(void);
void monitorRegister(sys_mon_t *, char *);
void monitorUnregister(sys_mon_t *);
void registeredEnumerate(void (*)(reg_mon_t *, void *), void *);
void registeredEnumerate_unlocked(void (*)(reg_mon_t *, void *), void *);


/*
 * Random non-local locks without obviously better homes
 */

/* The class loading lock */
extern sys_mon_t *_loadclass_lock;
#define LOADCLASS_LOCK_INIT() \
    monitorRegister(_loadclass_lock, "Class loading lock")
#define LOADCLASS_LOCK()     sysMonitorEnter(_loadclass_lock)
#define LOADCLASS_LOCKED()   sysMonitorEntered(_loadclass_lock)
#define LOADCLASS_UNLOCK()   sysMonitorExit(_loadclass_lock)

/* The global class table (binclasses) lock */
extern sys_mon_t *_binclass_lock;
#define BINCLASS_LOCK_INIT() monitorRegister(_binclass_lock, "BinClass lock")
#define BINCLASS_LOCK()	     sysMonitorEnter(_binclass_lock)
#define BINCLASS_LOCKED()    sysMonitorEntered(_binclass_lock)
#define BINCLASS_UNLOCK()    sysMonitorExit(_binclass_lock)

/* Locks on the interned string hash table */

extern sys_mon_t *_stringhash_lock;
#define STRINGHASH_INIT()    monitorRegister(_stringhash_lock, \
					     "String intern lock")
#define STRINGHASH_LOCK()    sysMonitorEnter(_stringhash_lock)
#define STRINGHASH_LOCKED()  sysMonitorEntered(_stringhash_lock)
#define STRINGHASH_UNLOCK()  sysMonitorExit(_stringhash_lock)

/* Locks on the method info (name and signature) hash table */

extern sys_mon_t *_nametypehash_lock;
#define NAMETYPEHASH_INIT()   monitorRegister(_nametypehash_lock, \
					      "Name and type hash table lock")
#define NAMETYPEHASH_LOCK()   sysMonitorEnter(_nametypehash_lock)
#define NAMETYPEHASH_LOCKED() sysMonitorEntered(_nametypehash_lock)
#define NAMETYPEHASH_UNLOCK() sysMonitorExit(_nametypehash_lock)

/* JNI global reference locks */

extern sys_mon_t *_globalref_lock;
#define GLOBALREF_LOCK_INIT() \
          monitorRegister(_globalref_lock, "JNI global reference lock")
#define GLOBALREF_LOCK()	    sysMonitorEnter(_globalref_lock)
#define GLOBALREF_LOCKED()	    sysMonitorEntered(_globalref_lock)
#define GLOBALREF_UNLOCK()	    sysMonitorExit(_globalref_lock)

#endif	/* !_MONITOR_H_ */