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150 lines
4 KiB
C
150 lines
4 KiB
C
/* Copyright (C) 1995,1996 Free Software Foundation, Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this software; see the file COPYING. If not, write to
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* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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* As a special exception, the Free Software Foundation gives permission
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* for additional uses of the text contained in its release of GUILE.
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*
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* The exception is that, if you link the GUILE library with other files
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* to produce an executable, this does not by itself cause the
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* resulting executable to be covered by the GNU General Public License.
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* Your use of that executable is in no way restricted on account of
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* linking the GUILE library code into it.
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*
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* This exception does not however invalidate any other reasons why
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* the executable file might be covered by the GNU General Public License.
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*
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* This exception applies only to the code released by the
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* Free Software Foundation under the name GUILE. If you copy
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* code from other Free Software Foundation releases into a copy of
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* GUILE, as the General Public License permits, the exception does
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* not apply to the code that you add in this way. To avoid misleading
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* anyone as to the status of such modified files, you must delete
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* this exception notice from them.
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*
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* If you write modifications of your own for GUILE, it is your choice
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* whether to permit this exception to apply to your modifications.
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* If you do not wish that, delete this exception notice.
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*/
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#include <stdio.h>
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#include "_scm.h"
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/* {Arbiters}
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*
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* These procedures implement synchronization primitives. Processors
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* with an atomic test-and-set instruction can use it here (and not
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* SCM_DEFER_INTS).
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*/
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static long scm_tc16_arbiter;
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#ifdef __STDC__
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static int
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prinarb (SCM exp, SCM port, int writing)
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#else
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static int
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prinarb (exp, port, writing)
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SCM exp;
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SCM port;
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int writing;
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#endif
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{
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scm_gen_puts (scm_regular_string, "#<arbiter ", port);
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if (SCM_CAR (exp) & (1L << 16))
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scm_gen_puts (scm_regular_string, "locked ", port);
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scm_iprin1 (SCM_CDR (exp), port, writing);
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scm_gen_putc ('>', port);
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return !0;
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}
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static scm_smobfuns arbsmob =
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{
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scm_markcdr, scm_free0, prinarb, 0
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};
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SCM_PROC(s_make_arbiter, "make-arbiter", 1, 0, 0, scm_make_arbiter);
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#ifdef __STDC__
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SCM
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scm_make_arbiter (SCM name)
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#else
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SCM
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scm_make_arbiter (name)
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SCM name;
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#endif
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{
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register SCM z;
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SCM_NEWCELL (z);
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SCM_CDR (z) = name;
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SCM_CAR (z) = scm_tc16_arbiter;
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return z;
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}
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SCM_PROC(s_try_arbiter, "try-arbiter", 1, 0, 0, scm_try_arbiter);
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#ifdef __STDC__
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SCM
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scm_try_arbiter (SCM arb)
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#else
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SCM
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scm_try_arbiter (arb)
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SCM arb;
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#endif
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{
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SCM_ASSERT ((SCM_TYP16 (arb) == scm_tc16_arbiter), arb, SCM_ARG1, s_try_arbiter);
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SCM_DEFER_INTS;
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if (SCM_CAR (arb) & (1L << 16))
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arb = SCM_BOOL_F;
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else
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{
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SCM_CAR (arb) = scm_tc16_arbiter | (1L << 16);
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arb = SCM_BOOL_T;
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}
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SCM_ALLOW_INTS;
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return arb;
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}
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SCM_PROC(s_release_arbiter, "release-arbiter", 1, 0, 0, scm_release_arbiter);
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#ifdef __STDC__
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SCM
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scm_release_arbiter (SCM arb)
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#else
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SCM
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scm_release_arbiter (arb)
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SCM arb;
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#endif
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{
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SCM_ASSERT ((SCM_TYP16 (arb) == scm_tc16_arbiter), arb, SCM_ARG1, s_release_arbiter);
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if (!(SCM_CAR (arb) & (1L << 16)))
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return SCM_BOOL_F;
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SCM_CAR (arb) = scm_tc16_arbiter;
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return SCM_BOOL_T;
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}
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#ifdef __STDC__
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void
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scm_init_arbiters (void)
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#else
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void
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scm_init_arbiters ()
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#endif
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{
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scm_tc16_arbiter = scm_newsmob (&arbsmob);
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#include "arbiters.x"
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}
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