root / prex-0.9.0 / usr / lib / posix / process / waitpid.c @ 03e9c04a
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1 | 03e9c04a | Brad Neuman | /*
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2 | * Copyright (c) 2005, Kohsuke Ohtani
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3 | * All rights reserved.
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4 | *
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5 | * Redistribution and use in source and binary forms, with or without
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6 | * modification, are permitted provided that the following conditions
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7 | * are met:
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8 | * 1. Redistributions of source code must retain the above copyright
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9 | * notice, this list of conditions and the following disclaimer.
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10 | * 2. Redistributions in binary form must reproduce the above copyright
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11 | * notice, this list of conditions and the following disclaimer in the
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12 | * documentation and/or other materials provided with the distribution.
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13 | * 3. Neither the name of the author nor the names of any co-contributors
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14 | * may be used to endorse or promote products derived from this software
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15 | * without specific prior written permission.
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16 | *
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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27 | * SUCH DAMAGE.
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28 | */
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29 | |||
30 | #include <sys/prex.h> |
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31 | #include <sys/posix.h> |
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32 | #include <ipc/proc.h> |
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33 | #include <ipc/ipc.h> |
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34 | #include <sys/wait.h> |
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35 | |||
36 | #include <stddef.h> |
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37 | #include <errno.h> |
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38 | |||
39 | /*
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40 | * If the target child task calls exit() just after we
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41 | * send PS_WAITPID message, a process server will send an
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42 | * exception to us. But, we can not catch the exception
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43 | * before calling exception_wait().
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44 | */
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45 | pid_t |
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46 | waitpid(pid_t pid, int *status, int options) |
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47 | { |
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48 | struct msg m;
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49 | pid_t child; |
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50 | int sig, error;
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51 | thread_t self; |
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52 | int pri;
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53 | |||
54 | /* Boost current priority */
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55 | self = thread_self(); |
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56 | thread_getpri(self, &pri); |
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57 | thread_setpri(self, pri - 1);
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58 | for (;;) {
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59 | m.hdr.code = PS_WAITPID; |
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60 | m.data[0] = pid;
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61 | m.data[1] = options;
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62 | error = msg_send(__proc_obj, &m, sizeof(m));
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63 | if (error == EINTR)
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64 | continue;
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65 | |||
66 | if (m.hdr.status) {
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67 | errno = m.hdr.status; |
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68 | return -1; |
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69 | } |
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70 | child = m.data[0];
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71 | if (child != 0 || options & WNOHANG) |
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72 | break;
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73 | |||
74 | error = exception_wait(&sig); |
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75 | if (error == EINTR) {
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76 | errno = EINTR; |
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77 | break;
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78 | } |
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79 | } |
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80 | /* Restore priority */
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81 | thread_setpri(self, pri); |
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82 | if (status != NULL) |
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83 | *status = m.data[1];
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84 | return child;
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85 | } |