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/* |
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* Copyright (c) 2001-2006 Marc Alexander Lehmann <schmorp@schmorp.de> |
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* |
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* Redistribution and use in source and binary forms, with or without modifica- |
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* tion, are permitted provided that the following conditions are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright notice, |
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* this list of conditions and the following disclaimer. |
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* |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* |
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* 3. The name of the author may not be used to endorse or promote products |
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* derived from this software without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- |
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* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO |
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* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- |
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* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH- |
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* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
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* OF THE POSSIBILITY OF SUCH DAMAGE. |
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* |
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* This library is modelled strictly after Ralf S. Engelschalls article at |
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* http://www.gnu.org/software/pth/rse-pmt.ps. So most of the credit must |
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* go to Ralf S. Engelschall <rse@engelschall.com>. |
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* |
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* This coroutine library is very much stripped down. You should either |
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* build your own process abstraction using it or - better - just use GNU |
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* Portable Threads, http://www.gnu.org/software/pth/. |
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* |
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*/ |
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|
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/* |
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* 2006-10-26 Include stddef.h on OS X to work around one of its bugs. |
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* Reported by Michael_G_Schwern. |
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* 2006-11-26 Use _setjmp instead of setjmp on GNU/Linux. |
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*/ |
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|
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#ifndef CORO_H |
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#define CORO_H |
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|
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#define CORO_VERSION 2 |
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|
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/* |
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* Changes since API version 1: |
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* replaced bogus -DCORO_LOOSE with gramatically more correct -DCORO_LOSER |
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*/ |
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|
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/* |
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* This library consists of only three files |
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* coro.h, coro.c and LICENSE (and optionally README) |
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* |
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* It implements what is known as coroutines, in a hopefully |
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* portable way. At the moment you have to define which kind |
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* of implementation flavour you want: |
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* |
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* -DCORO_UCONTEXT |
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* |
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* This flavour uses SUSv2's get/set/swap/makecontext functions that |
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* unfortunately only newer unices support. |
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* Use this for GNU/Linux + glibc-2.2.3 and possibly higher. |
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* |
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* -DCORO_SJLJ |
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* |
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* This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to |
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* do it's job. Coroutine creation is much slower than UCONTEXT, but |
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* context switching is often a bit cheaper. It should work on almost |
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* all unices. Use this for GNU/Linux + glibc-2.2. glibc-2.1 and below |
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* do not work with any sane model (neither sigaltstack nor context |
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* functions are implemented) |
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* |
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* -DCORO_LINUX |
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* |
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* Old GNU/Linux systems (<= glibc-2.1) work with this implementation |
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* (it is very fast and therefore recommended over other methods). |
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* |
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* -DCORO_LOSER |
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* |
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* Microsoft's highly proprietary platform doesn't support sigaltstack, and |
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* this automatically selects a suitable workaround for this platform. |
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* (untested) |
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* |
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* -DCORO_IRIX |
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* |
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* SGI's version of Microsoft's NT ;) |
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* |
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* If you define neither of these symbols, coro.h will try to autodetect |
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* the model. This currently works for CORO_LOSER only. For the other |
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* alternatives you should check (e.g. using autoconf) and define the |
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* following symbols: HAVE_UCONTEXT_H / HAVE_SETJMP_H / HAVE_SIGALTSTACK. |
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*/ |
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|
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/* |
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* This is the type for the initialization function of a new coroutine. |
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*/ |
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typedef void (*coro_func)(void *); |
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|
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/* |
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* A coroutine state is saved in the following structure. Treat it as an |
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* opaque type. errno and sigmask might be saved, but don't rely on it, |
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* implement your own switching primitive if you need that. |
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*/ |
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typedef struct coro_context coro_context; |
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|
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/* |
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* This function creates a new coroutine. Apart from a pointer to an |
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* uninitialised coro_context, it expects a pointer to the entry function |
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* and the single pointer value that is given to it as argument. |
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* |
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* Allocating/deallocating the stack is your own responsibility, so there is |
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* no coro_destroy function. |
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*/ |
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void coro_create (coro_context *ctx, /* an uninitialised coro_context */ |
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coro_func coro, /* the coroutine code to be executed */ |
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void *arg, /* a single pointer passed to the coro */ |
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void *sptr, /* start of stack area */ |
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long ssize); /* size of stack area */ |
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|
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/* |
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* The following prototype defines the coroutine switching function. It is |
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* usually implemented as a macro, so watch out. |
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* |
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void coro_transfer(coro_context *prev, coro_context *next); |
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*/ |
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|
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/* |
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* That was it. No other user-visible functions are implemented here. |
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*/ |
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|
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/*****************************************************************************/ |
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|
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#if !defined(CORO_LOSER) && !defined(CORO_UCONTEXT) \ |
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&& !defined(CORO_SJLJ) && !defined(CORO_LINUX) \ |
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&& !defined(CORO_IRIX) |
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# if defined(WINDOWS) |
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# define CORO_LOSER 1 /* you don't win with windoze */ |
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# elif defined(__linux) && defined(__x86) |
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# elif defined(HAVE_UCONTEXT_H) |
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# define CORO_UCONTEXT 1 |
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# elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK) |
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# define CORO_SJLJ 1 |
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# else |
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error unknown or unsupported architecture |
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# endif |
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#endif |
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|
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/*****************************************************************************/ |
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|
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#if CORO_UCONTEXT |
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|
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#include <ucontext.h> |
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|
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struct coro_context { |
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ucontext_t uc; |
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}; |
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|
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#define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc)) |
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|
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#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX |
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|
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#if defined(CORO_LINUX) && !defined(_GNU_SOURCE) |
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# define _GNU_SOURCE /* for linux libc */ |
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#endif |
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|
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#include <setjmp.h> |
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|
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struct coro_context { |
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jmp_buf env; |
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}; |
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|
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#if CORO_LINUX |
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# define coro_transfer(p,n) do { if (!_setjmp ((p)->env)) _longjmp ((n)->env, 1); } while (0) |
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#else |
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# define coro_transfer(p,n) do { if (!setjmp ((p)->env)) longjmp ((n)->env, 1); } while (0) |
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#endif |
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|
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#endif |
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|
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#endif |
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|
