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    1: 
    2: /*
    3:  * Copyright (c) 2001-2002 Packet Design, LLC.
    4:  * All rights reserved.
    5:  * 
    6:  * Subject to the following obligations and disclaimer of warranty,
    7:  * use and redistribution of this software, in source or object code
    8:  * forms, with or without modifications are expressly permitted by
    9:  * Packet Design; provided, however, that:
   10:  * 
   11:  *    (i)  Any and all reproductions of the source or object code
   12:  *         must include the copyright notice above and the following
   13:  *         disclaimer of warranties; and
   14:  *    (ii) No rights are granted, in any manner or form, to use
   15:  *         Packet Design trademarks, including the mark "PACKET DESIGN"
   16:  *         on advertising, endorsements, or otherwise except as such
   17:  *         appears in the above copyright notice or in the software.
   18:  * 
   19:  * THIS SOFTWARE IS BEING PROVIDED BY PACKET DESIGN "AS IS", AND
   20:  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, PACKET DESIGN MAKES NO
   21:  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING
   22:  * THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED
   23:  * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE,
   24:  * OR NON-INFRINGEMENT.  PACKET DESIGN DOES NOT WARRANT, GUARANTEE,
   25:  * OR MAKE ANY REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS
   26:  * OF THE USE OF THIS SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY,
   27:  * RELIABILITY OR OTHERWISE.  IN NO EVENT SHALL PACKET DESIGN BE
   28:  * LIABLE FOR ANY DAMAGES RESULTING FROM OR ARISING OUT OF ANY USE
   29:  * OF THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY DIRECT,
   30:  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, PUNITIVE, OR CONSEQUENTIAL
   31:  * DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, LOSS OF
   32:  * USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY THEORY OF
   33:  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   34:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
   35:  * THE USE OF THIS SOFTWARE, EVEN IF PACKET DESIGN IS ADVISED OF
   36:  * THE POSSIBILITY OF SUCH DAMAGE.
   37:  *
   38:  * Author: Archie Cobbs <archie@freebsd.org>
   39:  */
   40: 
   41: #ifndef _PDEL_UTIL_TINFO_H_
   42: #define _PDEL_UTIL_TINFO_H_
   43: 
   44: /*
   45:  * Support for generic per-thread data described by a structs type.
   46:  */
   47: 
   48: struct tinfo;
   49: 
   50: /*
   51:  * Optional user-supplied initialization routine. The routine should
   52:  * initialize the memory pointed to by "data" as an instance of the
   53:  * structs type for this tinfo data (i.e., t->type). If this method
   54:  * is not supplied (i.e., NULL), then structs_init() is invoked instead.
   55:  */
   56: typedef int	tinfo_init_t(struct tinfo *t, void *data);
   57: 
   58: /* User-supplied data structure for a tinfo variable */
   59: struct tinfo {
   60: 	const struct structs_type	*const type;	/* type for data */
   61: 	const char			*const mtype;	/* typed mem string */
   62: 	pthread_key_t			pkey;		/* per-thread var */
   63: 	tinfo_init_t			*init;		/* initialize data */
   64: };
   65: 
   66: /* Invalid key value */
   67: #define TINFO_KEY_INIT		(-1)			/* XXX not portable */
   68: 
   69: /* Always use this macro to initialize a struct tinfo */
   70: #define TINFO_INIT(type, mtype, init)	{ type, mtype, TINFO_KEY_INIT, init }
   71: 
   72: __BEGIN_DECLS
   73: 
   74: /*
   75:  * Get thread-local variable.
   76:  *
   77:  * If the variable has not been initialized, a new one is instantiated
   78:  * using the t->type's init method, and t->init is called (if not NULL).
   79:  *
   80:  * The caller should NOT free the returned value, but may modify it
   81:  * in a way consistent with its structs type (i.e., t->type).
   82:  */
   83: extern void	*tinfo_get(struct tinfo *t);
   84: 
   85: /*
   86:  * Set thread-local variable by copying "data".
   87:  *
   88:  * The "data" pointer must point to an object having structs type t->type.
   89:  * The data is copied using structs_get(). Any previous thread-local
   90:  * value is free'd and replaced.
   91:  *
   92:  * If "data" is NULL, then any existing information is free'd, so that
   93:  * the next call to tinfo_get() will cause the init routine to be called
   94:  * again.
   95:  */
   96: extern int	tinfo_set(struct tinfo *t, const void *data);
   97: 
   98: /*
   99:  * Set thread-local variable to "data".
  100:  *
  101:  * This sets the thread-local variable to "data" without copying it.
  102:  * "data" must point to memory allocated with type t->mtype.
  103:  * Any previous thread-local value is free'd and replaced.
  104:  *
  105:  * The caller should not reference "data" if this function returns
  106:  * successfully.
  107:  */
  108: extern int	tinfo_set_nocopy(struct tinfo *t, void *data);
  109: 
  110: __END_DECLS
  111: 
  112: #endif	/* _PDEL_UTIL_TINFO_H_ */
  113: