libcoro/coro.c

/*
 * Copyright (c) 2001 Marc Alexander Lehmann <pcg@goof.com>
 * 
 * Redistribution and use in source and binary forms, with or without modifica-
 * tion, are permitted provided that the following conditions are met:
 * 
 *   1.  Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 * 
 *   2.  Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 * 
 *   3.  The name of the author may not be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This library is modelled strictly after Ralf S. Engelschalls article at
 * http://www.gnu.org/software/pth/rse-pmt.ps.  So most of the credit must
 * go to Ralf S. Engelschall <rse@engelschall.com>.
 */

#include "coro.h"

#if !defined(STACK_ADJUST_PTR)
/* IRIX is decidedly NON-unix */
# if __sgi
#  define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
#  define STACK_ADJUST_SIZE(sp,ss) ((ss) - 8)
# elif __i386__ && CORO_LINUX
#  define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss))
#  define STACK_ADJUST_SIZE(sp,ss) (ss)
# else
#  define STACK_ADJUST_PTR(sp,ss) (sp)
#  define STACK_ADJUST_SIZE(sp,ss) (ss)
# endif
#endif

#if CORO_SJLJ || CORO_LOOSE || CORO_LINUX || CORO_IRIX

#include <signal.h>

static volatile coro_func coro_init_func;
static volatile void *coro_init_arg;
static volatile coro_context *new_coro, *create_coro;

static void
coro_init (void)
{
  volatile coro_func func = coro_init_func;
  volatile void *arg = coro_init_arg;

  coro_transfer ((coro_context *)new_coro, (coro_context *)create_coro);

  func ((void *)arg);

  /* the new coro returned. bad. just abort() for now */
  abort ();
}

# if CORO_SJLJ

static volatile int trampoline_count;

/* trampoline signal handler */
static void
trampoline(int sig)
{
  if (setjmp (((coro_context *)new_coro)->env))
    coro_init (); /* start it */
  else
    trampoline_count++;
}

# endif

#endif

/* initialize a machine state */
void coro_create(coro_context *ctx,
                 coro_func coro, void *arg,
                 void *sptr, long ssize)
{
#if CORO_UCONTEXT

  getcontext (&(ctx->uc));

  ctx->uc.uc_link           =  0;
  ctx->uc.uc_stack.ss_sp    = STACK_ADJUST_PTR (sptr,ssize);
  ctx->uc.uc_stack.ss_size  = (size_t) STACK_ADJUST_SIZE (sptr,ssize);
  ctx->uc.uc_stack.ss_flags = 0;

  makecontext (&(ctx->uc), (void (*)()) coro, 1, arg);

#elif CORO_SJLJ || CORO_LOOSE || CORO_LINUX || CORO_IRIX

# if CORO_SJLJ
  stack_t ostk, nstk;
  struct sigaction osa, nsa;
  sigset_t nsig, osig;
# endif
  coro_context nctx;

  coro_init_func = coro;
  coro_init_arg  = arg;

  new_coro    = ctx;
  create_coro = &nctx;

# if CORO_SJLJ
  /* we use SIGUSR2. first block it, then fiddle with it. */

  sigemptyset (&nsig);
  sigaddset (&nsig, SIGUSR2);
  sigprocmask (SIG_BLOCK, &nsig, &osig);

  nsa.sa_handler = trampoline;
  sigemptyset (&nsa.sa_mask);
  nsa.sa_flags = SA_ONSTACK;

  if (sigaction (SIGUSR2, &nsa, &osa))
    perror ("sigaction");

  /* set the new stack */
  nstk.ss_sp    = STACK_ADJUST_PTR (sptr,ssize); /* yes, some platforms (IRIX) get this wrong. */
  nstk.ss_size  = STACK_ADJUST_SIZE (sptr,ssize);
  nstk.ss_flags = 0;

  if (sigaltstack (&nstk, &ostk) < 0)
    perror ("sigaltstack");

  trampoline_count = 0;
  kill (getpid (), SIGUSR2);
  sigfillset (&nsig); sigdelset (&nsig, SIGUSR2);

  while (!trampoline_count)
    sigsuspend (&nsig);

  sigaltstack (0, &nstk);
  nstk.ss_flags = SS_DISABLE;
  if (sigaltstack (&nstk, 0) < 0)
    perror ("sigaltstack");

  sigaltstack (0, &nstk);
  if (~nstk.ss_flags & SS_DISABLE)
    abort ();

  if (~ostk.ss_flags & SS_DISABLE)
    sigaltstack (&ostk, 0);

  sigaction (SIGUSR1, &osa, 0);

  sigprocmask (SIG_SETMASK, &osig, 0);

# elif CORO_LOOSE

  setjmp (ctx->env);
  ctx->env[7] = (int)((char *)sptr + ssize);
  ctx->env[8] = (int)coro_init;

# elif CORO_LINUX

  setjmp (ctx->env);
#if defined(__GLIBC__) && defined(__GLIBC_MINOR__) \
    && __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined(JB_PC) && defined(JB_SP)
  ctx->env[0].__jmpbuf[JB_PC] = (int)coro_init;
  ctx->env[0].__jmpbuf[JB_SP] = (int)STACK_ADJUST_PTR (sptr,ssize);
#elif defined(__GLIBC__) && defined(__GLIBC_MINOR__) \
    && __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined(__mc68000__)
  ctx->env[0].__jmpbuf[0].__aregs[0] = (long int)coro_init;
  ctx->env[0].__jmpbuf[0].__sp = (int *)((char *)sptr + ssize);
#elif defined(__GNU_LIBRARY__) && defined(__i386__)
  ctx->env[0].__jmpbuf[0].__pc = (char *)coro_init;
  ctx->env[0].__jmpbuf[0].__sp = (void *)((char *)sptr + ssize);
#else
#error "linux libc or architecture not supported"
#endif

# elif CORO_IRIX

  setjmp (ctx->env);
  ctx->env[JB_PC] = (__uint64_t)coro_init;
  ctx->env[JB_SP] = (__uint64_t)STACK_ADJUST_PTR (sptr,ssize);

# endif

  coro_transfer ((coro_context *)create_coro, (coro_context *)new_coro);

#else
error unsupported architecture
#endif
}

Revision:	1.9
Committed:	Tue Nov 6 20:34:11 2001 UTC (24 years, 10 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.8:	+4 -4 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2			* Copyright (c) 2001 Marc Alexander Lehmann <pcg@goof.com>
3			*
4			* Redistribution and use in source and binary forms, with or without modifica-
5			* tion, are permitted provided that the following conditions are met:
6			*
7			* 1. Redistributions of source code must retain the above copyright notice,
8			* this list of conditions and the following disclaimer.
9			*
10			* 2. Redistributions in binary form must reproduce the above copyright
11			* notice, this list of conditions and the following disclaimer in the
12			* documentation and/or other materials provided with the distribution.
13			*
14			* 3. The name of the author may not be used to endorse or promote products
15			* derived from this software without specific prior written permission.
16			*
17			* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
18			* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
19			* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
20			* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
21			* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22			* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23			* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24			* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
25			* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
26			* OF THE POSSIBILITY OF SUCH DAMAGE.
27			*
28			* This library is modelled strictly after Ralf S. Engelschalls article at
29			* http://www.gnu.org/software/pth/rse-pmt.ps. So most of the credit must
30			* go to Ralf S. Engelschall <rse@engelschall.com>.
31			*/
32
33			#include "coro.h"
34
35	root	1.8	#if !defined(STACK_ADJUST_PTR)
36	root	1.5	/* IRIX is decidedly NON-unix */
37	root	1.8	# if __sgi
38			# define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
39			# define STACK_ADJUST_SIZE(sp,ss) ((ss) - 8)
40			# elif __i386__ && CORO_LINUX
41			# define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss))
42			# define STACK_ADJUST_SIZE(sp,ss) (ss)
43			# else
44			# define STACK_ADJUST_PTR(sp,ss) (sp)
45			# define STACK_ADJUST_SIZE(sp,ss) (ss)
46			# endif
47	root	1.5	#endif
48	root	1.7
49			#if CORO_SJLJ \|\| CORO_LOOSE \|\| CORO_LINUX \|\| CORO_IRIX
50	root	1.1
51			#include <signal.h>
52
53			static volatile coro_func coro_init_func;
54			static volatile void *coro_init_arg;
55			static volatile coro_context new_coro, create_coro;
56
57			static void
58			coro_init (void)
59			{
60			volatile coro_func func = coro_init_func;
61			volatile void *arg = coro_init_arg;
62
63	root	1.2	coro_transfer ((coro_context )new_coro, (coro_context )create_coro);
64	root	1.1
65	root	1.3	func ((void *)arg);
66	root	1.1
67			/* the new coro returned. bad. just abort() for now */
68			abort ();
69			}
70
71			# if CORO_SJLJ
72
73			static volatile int trampoline_count;
74
75			/* trampoline signal handler */
76			static void
77			trampoline(int sig)
78			{
79	root	1.3	if (setjmp (((coro_context *)new_coro)->env))
80	root	1.1	coro_init (); /* start it */
81			else
82			trampoline_count++;
83			}
84
85			# endif
86
87			#endif
88
89			/* initialize a machine state */
90			void coro_create(coro_context *ctx,
91			coro_func coro, void *arg,
92			void *sptr, long ssize)
93			{
94			#if CORO_UCONTEXT
95
96			getcontext (&(ctx->uc));
97
98	root	1.5	ctx->uc.uc_link = 0;
99	root	1.9	ctx->uc.uc_stack.ss_sp = STACK_ADJUST_PTR (sptr,ssize);
100	root	1.8	ctx->uc.uc_stack.ss_size = (size_t) STACK_ADJUST_SIZE (sptr,ssize);
101	root	1.1	ctx->uc.uc_stack.ss_flags = 0;
102
103			makecontext (&(ctx->uc), (void (*)()) coro, 1, arg);
104
105	root	1.5	#elif CORO_SJLJ \|\| CORO_LOOSE \|\| CORO_LINUX \|\| CORO_IRIX
106	root	1.1
107			# if CORO_SJLJ
108			stack_t ostk, nstk;
109			struct sigaction osa, nsa;
110			sigset_t nsig, osig;
111			# endif
112			coro_context nctx;
113
114			coro_init_func = coro;
115			coro_init_arg = arg;
116
117			new_coro = ctx;
118			create_coro = &nctx;
119
120			# if CORO_SJLJ
121			/* we use SIGUSR2. first block it, then fiddle with it. */
122
123			sigemptyset (&nsig);
124			sigaddset (&nsig, SIGUSR2);
125			sigprocmask (SIG_BLOCK, &nsig, &osig);
126
127			nsa.sa_handler = trampoline;
128			sigemptyset (&nsa.sa_mask);
129			nsa.sa_flags = SA_ONSTACK;
130
131			if (sigaction (SIGUSR2, &nsa, &osa))
132			perror ("sigaction");
133
134			/* set the new stack */
135	root	1.9	nstk.ss_sp = STACK_ADJUST_PTR (sptr,ssize); /* yes, some platforms (IRIX) get this wrong. */
136	root	1.8	nstk.ss_size = STACK_ADJUST_SIZE (sptr,ssize);
137	root	1.1	nstk.ss_flags = 0;
138
139			if (sigaltstack (&nstk, &ostk) < 0)
140			perror ("sigaltstack");
141
142			trampoline_count = 0;
143			kill (getpid (), SIGUSR2);
144			sigfillset (&nsig); sigdelset (&nsig, SIGUSR2);
145
146			while (!trampoline_count)
147			sigsuspend (&nsig);
148
149			sigaltstack (0, &nstk);
150			nstk.ss_flags = SS_DISABLE;
151			if (sigaltstack (&nstk, 0) < 0)
152			perror ("sigaltstack");
153
154			sigaltstack (0, &nstk);
155			if (~nstk.ss_flags & SS_DISABLE)
156			abort ();
157
158			if (~ostk.ss_flags & SS_DISABLE)
159			sigaltstack (&ostk, 0);
160
161			sigaction (SIGUSR1, &osa, 0);
162
163			sigprocmask (SIG_SETMASK, &osig, 0);
164
165	root	1.4	# elif CORO_LOOSE
166	root	1.1
167	root	1.4	setjmp (ctx->env);
168	root	1.1	ctx->env[7] = (int)((char *)sptr + ssize);
169	root	1.4	ctx->env[8] = (int)coro_init;
170
171			# elif CORO_LINUX
172
173			setjmp (ctx->env);
174			#if defined(__GLIBC__) && defined(__GLIBC_MINOR__) \
175			&& __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined(JB_PC) && defined(JB_SP)
176			ctx->env[0].__jmpbuf[JB_PC] = (int)coro_init;
177	root	1.9	ctx->env[0].__jmpbuf[JB_SP] = (int)STACK_ADJUST_PTR (sptr,ssize);
178	root	1.4	#elif defined(__GLIBC__) && defined(__GLIBC_MINOR__) \
179			&& __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined(__mc68000__)
180			ctx->env[0].__jmpbuf[0].__aregs[0] = (long int)coro_init;
181			ctx->env[0].__jmpbuf[0].__sp = (int )((char )sptr + ssize);
182			#elif defined(__GNU_LIBRARY__) && defined(__i386__)
183			ctx->env[0].__jmpbuf[0].__pc = (char *)coro_init;
184			ctx->env[0].__jmpbuf[0].__sp = (void )((char )sptr + ssize);
185			#else
186	root	1.5	#error "linux libc or architecture not supported"
187	root	1.4	#endif
188	root	1.5
189			# elif CORO_IRIX
190
191			setjmp (ctx->env);
192	root	1.6	ctx->env[JB_PC] = (__uint64_t)coro_init;
193	root	1.9	ctx->env[JB_SP] = (__uint64_t)STACK_ADJUST_PTR (sptr,ssize);
194	root	1.1
195			# endif
196
197	root	1.2	coro_transfer ((coro_context )create_coro, (coro_context )new_coro);
198	root	1.1
199			#else
200			error unsupported architecture
201			#endif
202			}
203