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 CORO_SJLJ || CORO_LOOSE || CORO_LINUX || CORO_IRIX

/* IRIX is decidedly NON-unix */
#if __sgi
# define STACK_ADJUST(sp,ss) ((ss) - 8 + (char *)(sp))
#else
# define STACK_ADJUST(sp,ss) (ss)
#endif

#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(sptr,ssize);
  ctx->uc.uc_stack.ss_size  = (size_t) 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(sptr,ssize); /* yes, some platforms (IRIX) get this wrong. */
  nstk.ss_size  = 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)((char *)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(sptr,ssize);

# endif

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

#else
error unsupported architecture
#endif
}

Revision:	1.6
Committed:	Mon Sep 3 03:36:00 2001 UTC (22 years, 8 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.5:	+3 -3 lines
Log Message:	* empty log message *
#	Content
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	#if CORO_SJLJ \|\| CORO_LOOSE \|\| CORO_LINUX \|\| CORO_IRIX
36
37	/* IRIX is decidedly NON-unix */
38	#if __sgi
39	# define STACK_ADJUST(sp,ss) ((ss) - 8 + (char *)(sp))
40	#else
41	# define STACK_ADJUST(sp,ss) (ss)
42	#endif
43
44	#include <signal.h>
45
46	static volatile coro_func coro_init_func;
47	static volatile void *coro_init_arg;
48	static volatile coro_context new_coro, create_coro;
49
50	static void
51	coro_init (void)
52	{
53	volatile coro_func func = coro_init_func;
54	volatile void *arg = coro_init_arg;
55
56	coro_transfer ((coro_context )new_coro, (coro_context )create_coro);
57
58	func ((void *)arg);
59
60	/* the new coro returned. bad. just abort() for now */
61	abort ();
62	}
63
64	# if CORO_SJLJ
65
66	static volatile int trampoline_count;
67
68	/* trampoline signal handler */
69	static void
70	trampoline(int sig)
71	{
72	if (setjmp (((coro_context *)new_coro)->env))
73	coro_init (); /* start it */
74	else
75	trampoline_count++;
76	}
77
78	# endif
79
80	#endif
81
82	/* initialize a machine state */
83	void coro_create(coro_context *ctx,
84	coro_func coro, void *arg,
85	void *sptr, long ssize)
86	{
87	#if CORO_UCONTEXT
88
89	getcontext (&(ctx->uc));
90
91	ctx->uc.uc_link = 0;
92	ctx->uc.uc_stack.ss_sp = STACK_ADJUST(sptr,ssize);
93	ctx->uc.uc_stack.ss_size = (size_t) ssize;
94	ctx->uc.uc_stack.ss_flags = 0;
95
96	makecontext (&(ctx->uc), (void (*)()) coro, 1, arg);
97
98	#elif CORO_SJLJ \|\| CORO_LOOSE \|\| CORO_LINUX \|\| CORO_IRIX
99
100	# if CORO_SJLJ
101	stack_t ostk, nstk;
102	struct sigaction osa, nsa;
103	sigset_t nsig, osig;
104	# endif
105	coro_context nctx;
106
107	coro_init_func = coro;
108	coro_init_arg = arg;
109
110	new_coro = ctx;
111	create_coro = &nctx;
112
113	# if CORO_SJLJ
114	/* we use SIGUSR2. first block it, then fiddle with it. */
115
116	sigemptyset (&nsig);
117	sigaddset (&nsig, SIGUSR2);
118	sigprocmask (SIG_BLOCK, &nsig, &osig);
119
120	nsa.sa_handler = trampoline;
121	sigemptyset (&nsa.sa_mask);
122	nsa.sa_flags = SA_ONSTACK;
123
124	if (sigaction (SIGUSR2, &nsa, &osa))
125	perror ("sigaction");
126
127	/* set the new stack */
128	nstk.ss_sp = STACK_ADJUST(sptr,ssize); /* yes, some platforms (IRIX) get this wrong. */
129	nstk.ss_size = ssize;
130	nstk.ss_flags = 0;
131
132	if (sigaltstack (&nstk, &ostk) < 0)
133	perror ("sigaltstack");
134
135	trampoline_count = 0;
136	kill (getpid (), SIGUSR2);
137	sigfillset (&nsig); sigdelset (&nsig, SIGUSR2);
138
139	while (!trampoline_count)
140	sigsuspend (&nsig);
141
142	sigaltstack (0, &nstk);
143	nstk.ss_flags = SS_DISABLE;
144	if (sigaltstack (&nstk, 0) < 0)
145	perror ("sigaltstack");
146
147	sigaltstack (0, &nstk);
148	if (~nstk.ss_flags & SS_DISABLE)
149	abort ();
150
151	if (~ostk.ss_flags & SS_DISABLE)
152	sigaltstack (&ostk, 0);
153
154	sigaction (SIGUSR1, &osa, 0);
155
156	sigprocmask (SIG_SETMASK, &osig, 0);
157
158	# elif CORO_LOOSE
159
160	setjmp (ctx->env);
161	ctx->env[7] = (int)((char *)sptr + ssize);
162	ctx->env[8] = (int)coro_init;
163
164	# elif CORO_LINUX
165
166	setjmp (ctx->env);
167	#if defined(__GLIBC__) && defined(__GLIBC_MINOR__) \
168	&& __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined(JB_PC) && defined(JB_SP)
169	ctx->env[0].__jmpbuf[JB_PC] = (int)coro_init;
170	ctx->env[0].__jmpbuf[JB_SP] = (int)((char *)sptr + ssize);
171	#elif defined(__GLIBC__) && defined(__GLIBC_MINOR__) \
172	&& __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined(__mc68000__)
173	ctx->env[0].__jmpbuf[0].__aregs[0] = (long int)coro_init;
174	ctx->env[0].__jmpbuf[0].__sp = (int )((char )sptr + ssize);
175	#elif defined(__GNU_LIBRARY__) && defined(__i386__)
176	ctx->env[0].__jmpbuf[0].__pc = (char *)coro_init;
177	ctx->env[0].__jmpbuf[0].__sp = (void )((char )sptr + ssize);
178	#else
179	#error "linux libc or architecture not supported"
180	#endif
181
182	# elif CORO_IRIX
183
184	setjmp (ctx->env);
185	ctx->env[JB_PC] = (__uint64_t)coro_init;
186	ctx->env[JB_SP] = (__uint64_t)STACK_ADJUST(sptr,ssize);
187
188	# endif
189
190	coro_transfer ((coro_context )create_coro, (coro_context )new_coro);
191
192	#else
193	error unsupported architecture
194	#endif
195	}
196