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1 | .\" Copyright (c) 2002, 2011 Michael Kerrisk <mtk.manpages@gmail.com> |
2 | .\" | |
3 | .\" Permission is granted to make and distribute verbatim copies of this | |
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9 | .\" entire resulting derived work is distributed under the terms of a | |
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12 | .\" Since the Linux kernel and libraries are constantly changing, this | |
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22 | .\" | |
23 | .TH RT_SIGQUEUEINFO 2 2011-09-18 "Linux" "Linux Programmer's Manual" | |
24 | .SH NAME | |
25 | rt_sigqueueinfo, rt_tgsigqueueinfo \- queue a signal and data | |
26 | .SH SYNOPSIS | |
27 | .nf | |
28 | .BI "int rt_sigqueueinfo(pid_t " tgid ", int " sig ", siginfo_t *" uinfo ); | |
29 | .sp | |
30 | .BI "int rt_tgsigqueueinfo(pid_t " tgid ", pid_t " tid ", int " sig , | |
31 | .BI " siginfo_t *" uinfo ); | |
32 | .fi | |
33 | .SH DESCRIPTION | |
34 | The | |
b18e759d | 35 | .BR rt_sigqueueinfo () |
23f438b5 | 36 | and |
b18e759d | 37 | .BR rt_tgsigqueueinfo () |
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38 | system calls are the low-level interfaces used to send a signal plus data |
39 | to a process or thread. | |
40 | The receiver of the signal can obtain the accompanying data | |
41 | by establishing a signal handler with the | |
42 | .BR sigaction (2) | |
43 | .B SA_SIGINFO | |
44 | flag. | |
45 | ||
46 | These system calls are not intended for direct application use; | |
47 | they are provided to allow the implementation of | |
485ab701 | 48 | .BR sigqueue (3) |
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49 | and |
50 | .BR pthread_sigqueue (3). | |
51 | ||
52 | The | |
b18e759d | 53 | .BR rt_sigqueueinfo () |
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54 | system call sends the signal |
55 | .I sig | |
56 | to the thread group with the ID | |
57 | .IR tgid . | |
8be77077 | 58 | (The term "thread group" is synonymous with "process", and |
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59 | .I tid |
60 | corresponds to the traditional UNIX process ID.) | |
61 | The signal will be delivered to an arbitrary member of the thread group | |
62 | (i.e., one of the threads that is not currently blocking the signal). | |
63 | ||
64 | The | |
65 | .I uinfo | |
66 | argument specifies the data to accompany the signal. | |
67 | This argument is a pointer to a structure of type | |
68 | .IR siginfo_t , | |
69 | described in | |
70 | .BR sigaction (2) | |
71 | (and defined by including | |
72 | .IR <sigaction.h> ). | |
73 | The caller should set the following fields in this structure: | |
74 | .TP | |
75 | .I si_code | |
76 | This must be one of the | |
77 | .B SI_* | |
78 | codes in the kernel source file | |
79 | .IR include/asm-generic/siginfo.h , | |
80 | with the restriction that the code must be negative | |
81 | (i.e., cannot be | |
82 | .BR SI_USER , | |
83 | which is used by the kernel to indicate a signal sent by | |
84 | .BR kill (2)) | |
85 | and cannot (since Linux 2.6.39) be | |
86 | .BR SI_TKILL | |
87 | (which is used by the kernel to indicate a signal sent using | |
88 | .\" tkill(2) or | |
89 | .BR tgkill (2)). | |
90 | .TP | |
91 | .I si_pid | |
92 | This should be set to a process ID, | |
93 | typically the process ID of the sender. | |
94 | .TP | |
95 | .I si_uid | |
96 | This should be set to a user ID, | |
97 | typically the real user ID of the sender. | |
98 | .TP | |
99 | .I si_value | |
100 | This field contains the user data to accompany the signal. | |
1976f57a | 101 | For more information, see the description of the last |
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102 | .RI ( "union sigval" ) |
103 | argument of | |
485ab701 | 104 | .BR sigqueue (3). |
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105 | .PP |
106 | Internally, the kernel sets the | |
107 | .I si_signo | |
1976f57a | 108 | field to the value specified in |
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109 | .IR sig , |
110 | so that the receiver of the signal can also obtain | |
111 | the signal number via that field. | |
112 | ||
113 | The | |
3ba9126c | 114 | .BR rt_tgsigqueueinfo () |
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115 | system call is like |
116 | .BR rt_sigueueinfo (), | |
117 | but sends the signal and data to the single thread | |
118 | specified by the combination of | |
119 | .IR tgid , | |
120 | a thread group ID, | |
121 | and | |
122 | .IR tid , | |
123 | a thread in that thread group. | |
124 | .SH "RETURN VALUE" | |
125 | On success, these system calls return 0. | |
126 | On error, they return \-1 and | |
127 | .I errno | |
128 | is set to indicate the error. | |
129 | .SH ERRORS | |
130 | .TP | |
131 | .B EAGAIN | |
132 | The limit of signals which may be queued has been reached. | |
133 | (See | |
134 | .BR signal (7) | |
135 | for further information.) | |
136 | .TP | |
137 | .B EINVAL | |
138 | .IR sig , | |
139 | .IR tgid , | |
140 | or | |
141 | .IR tid | |
142 | was invalid. | |
143 | .TP | |
144 | .B EPERM | |
145 | The caller does not have permission to send the signal to the target. | |
146 | For the required permissions, see | |
147 | .BR kill (2). | |
148 | Or: | |
149 | .I uinfo->si_code | |
150 | is invalid. | |
151 | .TP | |
152 | .B ESRCH | |
153 | .BR rt_sigqueinfo (): | |
154 | No thread group matching | |
155 | .I tgid | |
156 | was found. | |
157 | .br | |
158 | .BR rt_rtsigqueinfo (): | |
159 | No thread matching | |
160 | .I tgid | |
161 | and | |
162 | .I tid | |
163 | was found. | |
164 | .SH VERSIONS | |
165 | The | |
166 | .BR rt_sigqueueinfo () | |
167 | system call was added to Linux in version 2.2. | |
168 | The | |
169 | .BR rt_tgsigqueueinfo () | |
170 | system call was added to Linux in version 2.6.31. | |
171 | .SH "CONFORMING TO" | |
172 | These system calls are Linux-specific. | |
173 | .SH NOTES | |
174 | Since these system calls are not intended for application use, | |
175 | there are no glibc wrapper functions; use | |
176 | .BR syscall (2) | |
177 | in the unlikely case that you want to call them directly. | |
178 | ||
179 | As with | |
180 | .BR kill (2), | |
181 | the null signal (0) can be used to check if the specified process | |
182 | or thread exists. | |
183 | .SH "SEE ALSO" | |
184 | .BR kill (2), | |
185 | .BR sigaction (2), | |
186 | .BR sigprocmask (2), | |
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187 | .BR tgkill (2), |
188 | .BR pthread_sigqueue (3), | |
485ab701 | 189 | .BR sigqueue (3), |
23f438b5 | 190 | .BR signal (7) |