thr_init.c revision 39807 
1/*
2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
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 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by John Birrell.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 */
33
34/* Allocate space for global thread variables here: */
35#define GLOBAL_PTHREAD_PRIVATE
36
37#include <errno.h>
38#include <stdlib.h>
39#include <string.h>
40#include <fcntl.h>
41#include <paths.h>
42#include <unistd.h>
43#include <sys/time.h>
44#include <sys/ttycom.h>
45#ifdef _THREAD_SAFE
46#include <machine/reg.h>
47#include <pthread.h>
48#include "pthread_private.h"
49
50#ifdef GCC_2_8_MADE_THREAD_AWARE
51typedef void *** (*dynamic_handler_allocator)();
52extern void __set_dynamic_handler_allocator(dynamic_handler_allocator);
53
54static pthread_key_t except_head_key;
55
56typedef struct {
57  void **__dynamic_handler_chain;
58  void *top_elt[2];
59} except_struct;
60
61static void ***dynamic_allocator_handler_fn()
62{
63	except_struct *dh = (except_struct *)pthread_getspecific(except_head_key);
64
65	if(dh == NULL) {
66		dh = (except_struct *)malloc( sizeof(except_struct) );
67		memset(dh, '\0', sizeof(except_struct));
68		dh->__dynamic_handler_chain= dh->top_elt;
69		pthread_setspecific(except_head_key, (void *)dh);
70	}
71	return &dh->__dynamic_handler_chain;
72}
73#endif /* GCC_2_8_MADE_THREAD_AWARE */
74
75/*
76 * Threaded process initialization
77 */
78void
79_thread_init(void)
80{
81	int		fd;
82	int             flags;
83	int             i;
84	struct sigaction act;
85
86	/* Check if this function has already been called: */
87	if (_thread_initial)
88		/* Only initialise the threaded application once. */
89		return;
90
91	/*
92	 * Check for the special case of this process running as
93	 * or in place of init as pid = 1:
94	 */
95	if (getpid() == 1) {
96		/*
97		 * Setup a new session for this process which is
98		 * assumed to be running as root.
99		 */
100    		if (setsid() == -1)
101			PANIC("Can't set session ID");
102    		if (revoke(_PATH_CONSOLE) != 0)
103			PANIC("Can't revoke console");
104    		if ((fd = _thread_sys_open(_PATH_CONSOLE, O_RDWR)) < 0)
105			PANIC("Can't open console");
106    		if (setlogin("root") == -1)
107			PANIC("Can't set login to root");
108    		if (_thread_sys_ioctl(fd,TIOCSCTTY, (char *) NULL) == -1)
109			PANIC("Can't set controlling terminal");
110    		if (_thread_sys_dup2(fd,0) == -1 ||
111    		    _thread_sys_dup2(fd,1) == -1 ||
112    		    _thread_sys_dup2(fd,2) == -1)
113			PANIC("Can't dup2");
114	}
115
116	/* Get the standard I/O flags before messing with them : */
117	for (i = 0; i < 3; i++)
118		if ((_pthread_stdio_flags[i] =
119		    _thread_sys_fcntl(i,F_GETFL, NULL)) == -1)
120			PANIC("Cannot get stdio flags");
121
122	/*
123	 * Create a pipe that is written to by the signal handler to prevent
124	 * signals being missed in calls to _select:
125	 */
126	if (_thread_sys_pipe(_thread_kern_pipe) != 0) {
127		/* Cannot create pipe, so abort: */
128		PANIC("Cannot create kernel pipe");
129	}
130	/* Get the flags for the read pipe: */
131	else if ((flags = _thread_sys_fcntl(_thread_kern_pipe[0], F_GETFL, NULL)) == -1) {
132		/* Abort this application: */
133		PANIC("Cannot get kernel read pipe flags");
134	}
135	/* Make the read pipe non-blocking: */
136	else if (_thread_sys_fcntl(_thread_kern_pipe[0], F_SETFL, flags | O_NONBLOCK) == -1) {
137		/* Abort this application: */
138		PANIC("Cannot make kernel read pipe non-blocking");
139	}
140	/* Get the flags for the write pipe: */
141	else if ((flags = _thread_sys_fcntl(_thread_kern_pipe[1], F_GETFL, NULL)) == -1) {
142		/* Abort this application: */
143		PANIC("Cannot get kernel write pipe flags");
144	}
145	/* Make the write pipe non-blocking: */
146	else if (_thread_sys_fcntl(_thread_kern_pipe[1], F_SETFL, flags | O_NONBLOCK) == -1) {
147		/* Abort this application: */
148		PANIC("Cannot get kernel write pipe flags");
149	}
150	/* Allocate memory for the thread structure of the initial thread: */
151	else if ((_thread_initial = (pthread_t) malloc(sizeof(struct pthread))) == NULL) {
152		/*
153		 * Insufficient memory to initialise this application, so
154		 * abort:
155		 */
156		PANIC("Cannot allocate memory for initial thread");
157	} else {
158		/* Zero the global kernel thread structure: */
159		memset(&_thread_kern_thread, 0, sizeof(struct pthread));
160		memset(_thread_initial, 0, sizeof(struct pthread));
161
162		/* Default the priority of the initial thread: */
163		_thread_initial->pthread_priority = PTHREAD_DEFAULT_PRIORITY;
164
165		/* Initialise the state of the initial thread: */
166		_thread_initial->state = PS_RUNNING;
167
168		/* Initialise the queue: */
169		_thread_queue_init(&(_thread_initial->join_queue));
170
171		/* Initialise the rest of the fields: */
172		_thread_initial->specific_data = NULL;
173		_thread_initial->cleanup = NULL;
174		_thread_initial->queue = NULL;
175		_thread_initial->qnxt = NULL;
176		_thread_initial->nxt = NULL;
177		_thread_initial->flags = 0;
178		_thread_initial->error = 0;
179		_thread_link_list = _thread_initial;
180		_thread_run = _thread_initial;
181
182		/* Initialise the global signal action structure: */
183		sigfillset(&act.sa_mask);
184		act.sa_handler = (void (*) ()) _thread_sig_handler;
185		act.sa_flags = 0;
186
187		/* Enter a loop to get the existing signal status: */
188		for (i = 1; i < NSIG; i++) {
189			/* Check for signals which cannot be trapped: */
190			if (i == SIGKILL || i == SIGSTOP) {
191			}
192
193			/* Get the signal handler details: */
194			else if (_thread_sys_sigaction(i, NULL,
195			    &_thread_sigact[i - 1]) != 0) {
196				/*
197				 * Abort this process if signal
198				 * initialisation fails:
199				 */
200				PANIC("Cannot read signal handler info");
201			}
202		}
203
204		/*
205		 * Install the signal handler for the most important
206		 * signals that the user-thread kernel needs. Actually
207		 * SIGINFO isn't really needed, but it is nice to have.
208		 */
209		if (_thread_sys_sigaction(SIGVTALRM, &act, NULL) != 0 ||
210		    _thread_sys_sigaction(SIGINFO  , &act, NULL) != 0 ||
211		    _thread_sys_sigaction(SIGCHLD  , &act, NULL) != 0) {
212			/*
213			 * Abort this process if signal initialisation fails:
214			 */
215			PANIC("Cannot initialise signal handler");
216		}
217
218		/* Get the table size: */
219		if ((_thread_dtablesize = getdtablesize()) < 0) {
220			/*
221			 * Cannot get the system defined table size, so abort
222			 * this process.
223			 */
224			PANIC("Cannot get dtablesize");
225		}
226		/* Allocate memory for the file descriptor table: */
227		if ((_thread_fd_table = (struct fd_table_entry **) malloc(sizeof(struct fd_table_entry *) * _thread_dtablesize)) == NULL) {
228			/*
229			 * Cannot allocate memory for the file descriptor
230			 * table, so abort this process.
231			 */
232			PANIC("Cannot allocate memory for file descriptor table");
233		} else {
234			/*
235			 * Enter a loop to initialise the file descriptor
236			 * table:
237			 */
238			for (i = 0; i < _thread_dtablesize; i++) {
239				/* Initialise the file descriptor table: */
240				_thread_fd_table[i] = NULL;
241			}
242		}
243	}
244
245#ifdef GCC_2_8_MADE_THREAD_AWARE
246	/* Create the thread-specific data for the exception linked list. */
247	if(pthread_key_create(&except_head_key, NULL) != 0)
248        	PANIC("Failed to create thread specific execption head");
249
250	/* Setup the gcc exception handler per thread. */
251	__set_dynamic_handler_allocator( dynamic_allocator_handler_fn );
252#endif /* GCC_2_8_MADE_THREAD_AWARE */
253
254	/* Initialise the garbage collector mutex and condition variable. */
255	if (pthread_mutex_init(&_gc_mutex,NULL) != 0 ||
256	    pthread_cond_init(&_gc_cond,NULL) != 0)
257		PANIC("Failed to initialise garbage collector mutex or condvar");
258
259	return;
260}
261
262/*
263 * Special start up code for NetBSD/Alpha
264 */
265#if	defined(__NetBSD__) && defined(__alpha__)
266int
267main(int argc, char *argv[], char *env);
268
269int
270_thread_main(int argc, char *argv[], char *env)
271{
272	_thread_init();
273	return (main(argc, argv, env));
274}
275#endif
276#else
277/*
278 * A stub for non-threaded programs.
279 */
280void
281_thread_init(void)
282{
283}
284#endif
285