mutex.h

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
    1 /*-
    2  * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
    3  *
    4  * Redistribution and use in source and binary forms, with or without
    5  * modification, are permitted provided that the following conditions
    6  * are met:
    7  * 1. Redistributions of source code must retain the above copyright
    8  *    notice, this list of conditions and the following disclaimer.
    9  * 2. Redistributions in binary form must reproduce the above copyright
   10  *    notice, this list of conditions and the following disclaimer in the
   11  *    documentation and/or other materials provided with the distribution.
   12  * 3. Berkeley Software Design Inc's name may not be used to endorse or
   13  *    promote products derived from this software without specific prior
   14  *    written permission.
   15  *
   16  * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
   17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   19  * ARE DISCLAIMED.  IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
   20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   26  * SUCH DAMAGE.
   27  *
   28  *      from BSDI $Id: mutex.h,v 2.7.2.35 2000/04/27 03:10:26 cp Exp $
   29  * $FreeBSD: releng/5.2/sys/sys/mutex.h 122152 2003-11-05 23:42:51Z sam $
   30  */
   31 
   32 #ifndef _SYS_MUTEX_H_
   33 #define _SYS_MUTEX_H_
   34 
   35 #ifndef LOCORE
   36 #include <sys/queue.h>
   37 #include <sys/_lock.h>
   38 #include <sys/_mutex.h>
   39 
   40 #ifdef _KERNEL
   41 #include <sys/pcpu.h>
   42 #include <machine/atomic.h>
   43 #include <machine/cpufunc.h>
   44 #endif  /* _KERNEL_ */
   45 #endif  /* !LOCORE */
   46 
   47 #include <machine/mutex.h>
   48 
   49 #ifdef _KERNEL
   50 
   51 /*
   52  * Mutex types and options passed to mtx_init().  MTX_QUIET can also be
   53  * passed in.
   54  */
   55 #define MTX_DEF         0x00000000      /* DEFAULT (sleep) lock */ 
   56 #define MTX_SPIN        0x00000001      /* Spin lock (disables interrupts) */
   57 #define MTX_RECURSE     0x00000004      /* Option: lock allowed to recurse */
   58 #define MTX_NOWITNESS   0x00000008      /* Don't do any witness checking. */
   59 #define MTX_DUPOK       0x00000020      /* Don't log a duplicate acquire */
   60 
   61 /*
   62  * Option flags passed to certain lock/unlock routines, through the use
   63  * of corresponding mtx_{lock,unlock}_flags() interface macros.
   64  */
   65 #define MTX_QUIET       LOP_QUIET       /* Don't log a mutex event */
   66 
   67 /*
   68  * State bits kept in mutex->mtx_lock, for the DEFAULT lock type. None of this,
   69  * with the exception of MTX_UNOWNED, applies to spin locks.
   70  */
   71 #define MTX_RECURSED    0x00000001      /* lock recursed (for MTX_DEF only) */
   72 #define MTX_CONTESTED   0x00000002      /* lock contested (for MTX_DEF only) */
   73 #define MTX_UNOWNED     0x00000004      /* Cookie for free mutex */
   74 #define MTX_FLAGMASK    ~(MTX_RECURSED | MTX_CONTESTED)
   75 
   76 #endif  /* _KERNEL */
   77 
   78 #ifndef LOCORE
   79 
   80 /*
   81  * XXX: Friendly reminder to fix things in MP code that is presently being
   82  * XXX: worked on.
   83  */
   84 #define mp_fixme(string)
   85 
   86 #ifdef _KERNEL
   87 
   88 /*
   89  * Prototypes
   90  *
   91  * NOTE: Functions prepended with `_' (underscore) are exported to other parts
   92  *       of the kernel via macros, thus allowing us to use the cpp LOCK_FILE
   93  *       and LOCK_LINE. These functions should not be called directly by any
   94  *       code using the API. Their macros cover their functionality.
   95  *
   96  * [See below for descriptions]
   97  *
   98  */
   99 void    mtx_init(struct mtx *m, const char *name, const char *type, int opts);
  100 void    mtx_destroy(struct mtx *m);
  101 void    mtx_sysinit(void *arg);
  102 void    mutex_init(void);
  103 void    _mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line);
  104 void    _mtx_unlock_sleep(struct mtx *m, int opts, const char *file, int line);
  105 void    _mtx_lock_spin(struct mtx *m, int opts, const char *file, int line);
  106 void    _mtx_unlock_spin(struct mtx *m, int opts, const char *file, int line);
  107 int     _mtx_trylock(struct mtx *m, int opts, const char *file, int line);
  108 void    _mtx_lock_flags(struct mtx *m, int opts, const char *file, int line);
  109 void    _mtx_unlock_flags(struct mtx *m, int opts, const char *file, int line);
  110 void    _mtx_lock_spin_flags(struct mtx *m, int opts, const char *file,
  111                              int line);
  112 void    _mtx_unlock_spin_flags(struct mtx *m, int opts, const char *file,
  113                              int line);
  114 #ifdef INVARIANT_SUPPORT
  115 void    _mtx_assert(struct mtx *m, int what, const char *file, int line);
  116 #endif
  117 
  118 /*
  119  * We define our machine-independent (unoptimized) mutex micro-operations
  120  * here, if they are not already defined in the machine-dependent mutex.h 
  121  */
  122 
  123 /* Actually obtain mtx_lock */
  124 #ifndef _obtain_lock
  125 #define _obtain_lock(mp, tid)                                           \
  126         atomic_cmpset_acq_ptr(&(mp)->mtx_lock, (void *)MTX_UNOWNED, (tid))
  127 #endif
  128 
  129 /* Actually release mtx_lock */
  130 #ifndef _release_lock
  131 #define _release_lock(mp, tid)                                          \
  132         atomic_cmpset_rel_ptr(&(mp)->mtx_lock, (tid), (void *)MTX_UNOWNED)
  133 #endif
  134 
  135 /* Actually release mtx_lock quickly, assuming we own it. */
  136 #ifndef _release_lock_quick
  137 #define _release_lock_quick(mp)                                         \
  138         atomic_store_rel_ptr(&(mp)->mtx_lock, (void *)MTX_UNOWNED)
  139 #endif
  140 
  141 /*
  142  * Obtain a sleep lock inline, or call the "hard" function if we can't get it
  143  * easy.
  144  */
  145 #ifndef _get_sleep_lock
  146 #define _get_sleep_lock(mp, tid, opts, file, line) do {                 \
  147         if (!_obtain_lock((mp), (tid)))                                 \
  148                 _mtx_lock_sleep((mp), (opts), (file), (line));          \
  149 } while (0)
  150 #endif
  151 
  152 /*
  153  * Obtain a spin lock inline, or call the "hard" function if we can't get it
  154  * easy. For spinlocks, we handle recursion inline (it turns out that function
  155  * calls can be significantly expensive on some architectures).
  156  * Since spin locks are not _too_ common, inlining this code is not too big 
  157  * a deal.
  158  */
  159 #ifndef _get_spin_lock
  160 #define _get_spin_lock(mp, tid, opts, file, line) do {                  \
  161         critical_enter();                                               \
  162         if (!_obtain_lock((mp), (tid))) {                               \
  163                 if ((mp)->mtx_lock == (uintptr_t)(tid))                 \
  164                         (mp)->mtx_recurse++;                            \
  165                 else                                                    \
  166                         _mtx_lock_spin((mp), (opts), (file), (line));   \
  167         }                                                               \
  168 } while (0)
  169 #endif
  170 
  171 /*
  172  * Release a sleep lock inline, or call the "hard" function if we can't do it
  173  * easy.
  174  */
  175 #ifndef _rel_sleep_lock
  176 #define _rel_sleep_lock(mp, tid, opts, file, line) do {                 \
  177         if (!_release_lock((mp), (tid)))                                \
  178                 _mtx_unlock_sleep((mp), (opts), (file), (line));        \
  179 } while (0)
  180 #endif
  181 
  182 /*
  183  * For spinlocks, we can handle everything inline, as it's pretty simple and
  184  * a function call would be too expensive (at least on some architectures).
  185  * Since spin locks are not _too_ common, inlining this code is not too big 
  186  * a deal.
  187  *
  188  * Since we always perform a critical_enter() when attempting to acquire a
  189  * spin lock, we need to always perform a matching critical_exit() when
  190  * releasing a spin lock.  This includes the recursion cases.
  191  */
  192 #ifndef _rel_spin_lock
  193 #define _rel_spin_lock(mp) do {                                         \
  194         if (mtx_recursed((mp)))                                         \
  195                 (mp)->mtx_recurse--;                                    \
  196         else                                                            \
  197                 _release_lock_quick((mp));                              \
  198         critical_exit();                                        \
  199 } while (0)
  200 #endif
  201 
  202 /*
  203  * Exported lock manipulation interface.
  204  *
  205  * mtx_lock(m) locks MTX_DEF mutex `m'
  206  *
  207  * mtx_lock_spin(m) locks MTX_SPIN mutex `m'
  208  *
  209  * mtx_unlock(m) unlocks MTX_DEF mutex `m'
  210  *
  211  * mtx_unlock_spin(m) unlocks MTX_SPIN mutex `m'
  212  *
  213  * mtx_lock_spin_flags(m, opts) and mtx_lock_flags(m, opts) locks mutex `m'
  214  *     and passes option flags `opts' to the "hard" function, if required.
  215  *     With these routines, it is possible to pass flags such as MTX_QUIET
  216  *     to the appropriate lock manipulation routines.
  217  *
  218  * mtx_trylock(m) attempts to acquire MTX_DEF mutex `m' but doesn't sleep if
  219  *     it cannot. Rather, it returns 0 on failure and non-zero on success.
  220  *     It does NOT handle recursion as we assume that if a caller is properly
  221  *     using this part of the interface, he will know that the lock in question
  222  *     is _not_ recursed.
  223  *
  224  * mtx_trylock_flags(m, opts) is used the same way as mtx_trylock() but accepts
  225  *     relevant option flags `opts.'
  226  *
  227  * mtx_initialized(m) returns non-zero if the lock `m' has been initialized.
  228  *
  229  * mtx_owned(m) returns non-zero if the current thread owns the lock `m'
  230  *
  231  * mtx_recursed(m) returns non-zero if the lock `m' is presently recursed.
  232  */ 
  233 #define mtx_lock(m)             mtx_lock_flags((m), 0)
  234 #define mtx_lock_spin(m)        mtx_lock_spin_flags((m), 0)
  235 #define mtx_trylock(m)          mtx_trylock_flags((m), 0)
  236 #define mtx_unlock(m)           mtx_unlock_flags((m), 0)
  237 #define mtx_unlock_spin(m)      mtx_unlock_spin_flags((m), 0)
  238 
  239 struct mtx_pool;
  240 
  241 struct mtx_pool *mtx_pool_create(const char *mtx_name, int pool_size, int opts);
  242 void mtx_pool_destroy(struct mtx_pool **poolp);
  243 struct mtx *mtx_pool_find(struct mtx_pool *pool, void *ptr);
  244 struct mtx *mtx_pool_alloc(struct mtx_pool *pool);
  245 #define mtx_pool_lock(pool, ptr)                                        \
  246         mtx_lock(mtx_pool_find((pool), (ptr)))
  247 #define mtx_pool_lock_spin(pool, ptr)                                   \
  248         mtx_lock_spin(mtx_pool_find((pool), (ptr)))
  249 #define mtx_pool_unlock(pool, ptr)                                      \
  250         mtx_unlock(mtx_pool_find((pool), (ptr)))
  251 #define mtx_pool_unlock_spin(pool, ptr)                                 \
  252         mtx_unlock_spin(mtx_pool_find((pool), (ptr)))
  253 
  254 /*
  255  * mtxpool_lockbuilder is a pool of sleep locks that is not witness
  256  * checked and should only be used for building higher level locks.
  257  *
  258  * mtxpool_sleep is a general purpose pool of sleep mutexes.
  259  */
  260 extern struct mtx_pool *mtxpool_lockbuilder;
  261 extern struct mtx_pool *mtxpool_sleep;
  262 
  263 #ifndef LOCK_DEBUG
  264 #error LOCK_DEBUG not defined, include <sys/lock.h> before <sys/mutex.h>
  265 #endif
  266 #if LOCK_DEBUG > 0 || defined(MUTEX_NOINLINE)
  267 #define mtx_lock_flags(m, opts)                                         \
  268         _mtx_lock_flags((m), (opts), LOCK_FILE, LOCK_LINE)
  269 #define mtx_unlock_flags(m, opts)                                       \
  270         _mtx_unlock_flags((m), (opts), LOCK_FILE, LOCK_LINE)
  271 #define mtx_lock_spin_flags(m, opts)                                    \
  272         _mtx_lock_spin_flags((m), (opts), LOCK_FILE, LOCK_LINE)
  273 #define mtx_unlock_spin_flags(m, opts)                                  \
  274         _mtx_unlock_spin_flags((m), (opts), LOCK_FILE, LOCK_LINE)
  275 #else   /* LOCK_DEBUG == 0 && !MUTEX_NOINLINE */
  276 #define mtx_lock_flags(m, opts)                                         \
  277         _get_sleep_lock((m), curthread, (opts), LOCK_FILE, LOCK_LINE)
  278 #define mtx_unlock_flags(m, opts)                                       \
  279         _rel_sleep_lock((m), curthread, (opts), LOCK_FILE, LOCK_LINE)
  280 #ifndef SMPnotyet
  281 #define mtx_lock_spin_flags(m, opts)                                    \
  282         _get_spin_lock((m), curthread, (opts), LOCK_FILE, LOCK_LINE)
  283 #define mtx_unlock_spin_flags(m, opts)                                  \
  284         _rel_spin_lock((m))
  285 #else   /* SMP */
  286 #define mtx_lock_spin_flags(m, opts)    critical_enter()
  287 #define mtx_unlock_spin_flags(m, opts)  critical_exit()
  288 #endif  /* SMP */
  289 #endif  /* LOCK_DEBUG > 0 || MUTEX_NOINLINE */
  290 
  291 #define mtx_trylock_flags(m, opts)                                      \
  292         _mtx_trylock((m), (opts), LOCK_FILE, LOCK_LINE)
  293 
  294 #define mtx_initialized(m)      ((m)->mtx_object.lo_flags & LO_INITIALIZED)
  295 
  296 #define mtx_owned(m)    (((m)->mtx_lock & MTX_FLAGMASK) == (uintptr_t)curthread)
  297 
  298 #define mtx_recursed(m) ((m)->mtx_recurse != 0)
  299 
  300 #define mtx_name(m)     ((m)->mtx_object.lo_name)
  301 
  302 /*
  303  * Global locks.
  304  */
  305 extern struct mtx sched_lock;
  306 extern struct mtx Giant;
  307 
  308 /*
  309  * Giant lock manipulation and clean exit macros.
  310  * Used to replace return with an exit Giant and return.
  311  *
  312  * Note that DROP_GIANT*() needs to be paired with PICKUP_GIANT() 
  313  * The #ifndef is to allow lint-like tools to redefine DROP_GIANT.
  314  */
  315 #ifndef DROP_GIANT
  316 #define DROP_GIANT()                                                    \
  317 do {                                                                    \
  318         int _giantcnt;                                                  \
  319         WITNESS_SAVE_DECL(Giant);                                       \
  320                                                                         \
  321         if (mtx_owned(&Giant))                                          \
  322                 WITNESS_SAVE(&Giant.mtx_object, Giant);                 \
  323         for (_giantcnt = 0; mtx_owned(&Giant); _giantcnt++)             \
  324                 mtx_unlock(&Giant)
  325 
  326 #define PICKUP_GIANT()                                                  \
  327         mtx_assert(&Giant, MA_NOTOWNED);                                \
  328         while (_giantcnt--)                                             \
  329                 mtx_lock(&Giant);                                       \
  330         if (mtx_owned(&Giant))                                          \
  331                 WITNESS_RESTORE(&Giant.mtx_object, Giant);              \
  332 } while (0)
  333 
  334 #define PARTIAL_PICKUP_GIANT()                                          \
  335         mtx_assert(&Giant, MA_NOTOWNED);                                \
  336         while (_giantcnt--)                                             \
  337                 mtx_lock(&Giant);                                       \
  338         if (mtx_owned(&Giant))                                          \
  339                 WITNESS_RESTORE(&Giant.mtx_object, Giant)
  340 #endif
  341 
  342 /*
  343  * Network MPSAFE temporary workarounds.  When debug_mpsafenet
  344  * is 1 the network is assumed to operate without Giant on the
  345  * input path and protocols that require Giant must collect it
  346  * on entry.  When 0 Giant is grabbed in the network interface
  347  * ISR's and in the netisr path and there is no need to grab
  348  * the Giant lock.
  349  *
  350  * This mechanism is intended as temporary until everything of
  351  * importance is properly locked.
  352  */
  353 extern  int debug_mpsafenet;            /* defined in net/netisr.c */
  354 #define NET_PICKUP_GIANT() do {                                         \
  355         if (debug_mpsafenet)                                            \
  356                 mtx_lock(&Giant);                                       \
  357 } while (0)
  358 #define NET_DROP_GIANT() do {                                           \
  359         if (debug_mpsafenet)                                            \
  360                 mtx_unlock(&Giant);                                     \
  361 } while (0)
  362 
  363 #define UGAR(rval) do {                                                 \
  364         int _val = (rval);                                              \
  365         mtx_unlock(&Giant);                                             \
  366         return (_val);                                                  \
  367 } while (0)
  368 
  369 struct mtx_args {
  370         struct mtx      *ma_mtx;
  371         const char      *ma_desc;
  372         int              ma_opts;
  373 };
  374 
  375 #define MTX_SYSINIT(name, mtx, desc, opts)                              \
  376         static struct mtx_args name##_args = {                          \
  377                 (mtx),                                                  \
  378                 (desc),                                                 \
  379                 (opts)                                                  \
  380         };                                                              \
  381         SYSINIT(name##_mtx_sysinit, SI_SUB_LOCK, SI_ORDER_MIDDLE,       \
  382             mtx_sysinit, &name##_args)
  383 
  384 /*
  385  * The INVARIANTS-enabled mtx_assert() functionality.
  386  *
  387  * The constants need to be defined for INVARIANT_SUPPORT infrastructure
  388  * support as _mtx_assert() itself uses them and the latter implies that
  389  * _mtx_assert() must build.
  390  */
  391 #ifdef INVARIANT_SUPPORT
  392 #define MA_OWNED        0x01
  393 #define MA_NOTOWNED     0x02
  394 #define MA_RECURSED     0x04
  395 #define MA_NOTRECURSED  0x08
  396 #endif /* INVARIANT_SUPPORT */
  397 
  398 #ifdef INVARIANTS
  399 #define mtx_assert(m, what)                                             \
  400         _mtx_assert((m), (what), __FILE__, __LINE__)
  401 
  402 #define GIANT_REQUIRED  mtx_assert(&Giant, MA_OWNED)
  403 
  404 #else   /* INVARIANTS */
  405 #define mtx_assert(m, what)
  406 #define GIANT_REQUIRED
  407 #endif  /* INVARIANTS */
  408 
  409 /*
  410  * Common lock type names.
  411  */
  412 #define MTX_NETWORK_LOCK        "network driver"
  413 
  414 #endif  /* _KERNEL */
  415 #endif  /* !LOCORE */
  416 #endif  /* _SYS_MUTEX_H_ */
Cache object: 042b97778001ecc43c8a1cf8fd83f4a7
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.
FreeBSD/Linux Kernel Cross Reference sys/sys/mutex.h

FreeBSD/Linux Kernel Cross Reference
sys/sys/mutex.h
