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/* |
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* Copyright (c) 2001 Marc Alexander Lehmann <pcg@goof.com> |
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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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|
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#include "coro.h" |
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|
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#if CORO_LOOSE || CORO_SJLJ |
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|
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#include <signal.h> |
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|
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static volatile coro_func coro_init_func; |
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static volatile void *coro_init_arg; |
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static volatile coro_context *new_coro, *create_coro; |
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|
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static void |
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coro_init (void) |
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{ |
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volatile coro_func func = coro_init_func; |
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volatile void *arg = coro_init_arg; |
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|
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coro_transfer (new_coro, create_coro); |
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|
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func (arg); |
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|
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/* the new coro returned. bad. just abort() for now */ |
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abort (); |
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} |
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|
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# if CORO_SJLJ |
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# define coro_save(ctx) (void)setjmp((ctx)->env) |
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|
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static volatile int trampoline_count; |
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|
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/* trampoline signal handler */ |
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static void |
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trampoline(int sig) |
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{ |
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if (setjmp (&(new_coro->env))) |
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coro_init (); /* start it */ |
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else |
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trampoline_count++; |
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} |
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|
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# endif |
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|
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#elif CORO_UCONTEXT |
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# define coro_save(ctx) getcontext(&((ctx)->uc)) |
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#endif |
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|
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/* initialize a machine state */ |
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void coro_create(coro_context *ctx, |
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coro_func coro, void *arg, |
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void *sptr, long ssize) |
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{ |
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#if CORO_UCONTEXT |
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|
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getcontext (&(ctx->uc)); |
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|
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ctx->uc.uc_link = 0; |
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ctx->uc.uc_stack.ss_sp = sptr; |
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ctx->uc.uc_stack.ss_size = (size_t) ssize; |
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ctx->uc.uc_stack.ss_flags = 0; |
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|
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makecontext (&(ctx->uc), (void (*)()) coro, 1, arg); |
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|
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#elif CORO_SJLJ || CORO_LOOSE |
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|
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# if CORO_SJLJ |
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stack_t ostk, nstk; |
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struct sigaction osa, nsa; |
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sigset_t nsig, osig; |
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# endif |
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coro_context nctx; |
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|
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coro_init_func = coro; |
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coro_init_arg = arg; |
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|
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new_coro = ctx; |
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create_coro = &nctx; |
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|
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# if CORO_SJLJ |
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/* we use SIGUSR2. first block it, then fiddle with it. */ |
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|
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sigemptyset (&nsig); |
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sigaddset (&nsig, SIGUSR2); |
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sigprocmask (SIG_BLOCK, &nsig, &osig); |
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|
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nsa.sa_handler = trampoline; |
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sigemptyset (&nsa.sa_mask); |
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nsa.sa_flags = SA_ONSTACK; |
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|
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if (sigaction (SIGUSR2, &nsa, &osa)) |
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perror ("sigaction"); |
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|
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/* set the new stack */ |
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nstk.ss_sp = sptr; |
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nstk.ss_size = ssize; |
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nstk.ss_flags = 0; |
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|
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if (sigaltstack (&nstk, &ostk) < 0) |
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perror ("sigaltstack"); |
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|
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trampoline_count = 0; |
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kill (getpid (), SIGUSR2); |
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sigfillset (&nsig); sigdelset (&nsig, SIGUSR2); |
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|
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while (!trampoline_count) |
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sigsuspend (&nsig); |
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|
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sigaltstack (0, &nstk); |
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nstk.ss_flags = SS_DISABLE; |
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if (sigaltstack (&nstk, 0) < 0) |
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perror ("sigaltstack"); |
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|
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sigaltstack (0, &nstk); |
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if (~nstk.ss_flags & SS_DISABLE) |
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abort (); |
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|
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if (~ostk.ss_flags & SS_DISABLE) |
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sigaltstack (&ostk, 0); |
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|
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sigaction (SIGUSR1, &osa, 0); |
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|
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sigprocmask (SIG_SETMASK, &osig, 0); |
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|
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# elif MS_LOOSE |
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|
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coro_save (ctx); |
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ctx->env[7] = (int)((char *)sptr + ssize); |
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ctx->env[8] = (int)coro; |
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|
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# endif |
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|
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coro_transfer (create_coro, new_coro); |
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|
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#else |
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error unsupported architecture |
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#endif |
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} |
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|
