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https://github.com/Zenithsiz/ftmemsim-valgrind.git
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9cb0696641
module-local, use the new ML_ prefix instead of VG_. This makes it trivial to see which names are those exported from public module interfaces: precisely those using VG_. /* VG_ is for symbols exported from modules. ML_ (module-local) is for symbols which are not intended to be visible outside modules, but which cannot be declared as C 'static's since they need to be visible across C files within a given module. It is a mistake for a ML_ name to appear in a pub_core_*.h or pub_tool_*.h file. Likewise it is a mistake for a VG_ name to appear in a priv_*.h file. */ git-svn-id: svn://svn.valgrind.org/valgrind/trunk@4000
101 lines
2.7 KiB
C
101 lines
2.7 KiB
C
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/*--------------------------------------------------------------------*/
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/*--- Semaphore stuff. sema.c ---*/
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/*--------------------------------------------------------------------*/
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/*
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This file is part of Valgrind, a dynamic binary instrumentation
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framework.
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Copyright (C) 2000-2005 Julian Seward
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jseward@acm.org
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307, USA.
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The GNU General Public License is contained in the file COPYING.
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*/
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#include "pub_core_basics.h"
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#include "pub_core_libcassert.h"
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#include "pub_core_libcfile.h"
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#include "pub_core_libcproc.h" // For VG_(gettid)()
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#include "priv_sema.h"
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/*
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Slower (than the removed futex-based sema scheme) but more portable
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pipe-based token passing scheme.
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*/
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void ML_(sema_init)(vg_sema_t *sema)
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{
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VG_(pipe)(sema->pipe);
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sema->pipe[0] = VG_(safe_fd)(sema->pipe[0]);
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sema->pipe[1] = VG_(safe_fd)(sema->pipe[1]);
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sema->owner_thread = -1;
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/* create initial token */
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VG_(write)(sema->pipe[1], "T", 1);
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}
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void ML_(sema_deinit)(vg_sema_t *sema)
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{
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VG_(close)(sema->pipe[0]);
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VG_(close)(sema->pipe[1]);
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sema->pipe[0] = sema->pipe[1] = -1;
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}
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/* get a token */
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void ML_(sema_down)(vg_sema_t *sema)
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{
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Char buf[2] = { 'x' };
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Int ret;
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Int lwpid = VG_(gettid)();
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vg_assert(sema->owner_thread != lwpid); /* can't have it already */
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again:
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ret = VG_(read)(sema->pipe[0], buf, 2);
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if (ret == -VKI_EINTR)
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goto again;
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vg_assert(ret == 1); /* should get exactly 1 token */
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vg_assert(buf[0] == 'T');
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sema->owner_thread = lwpid;
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}
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/* put token back */
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void ML_(sema_up)(vg_sema_t *sema)
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{
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Int ret;
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vg_assert(sema->owner_thread == VG_(gettid)()); /* must have it */
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sema->owner_thread = 0;
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ret = VG_(write)(sema->pipe[1], "T", 1);
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vg_assert(ret == 1);
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}
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/*--------------------------------------------------------------------*/
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/*--- end ---*/
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/*--------------------------------------------------------------------*/
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