Asterisk - The Open Source Telephony Project GIT-master-27fb039
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Functions
alertpipe.c File Reference

Alert Pipe API. More...

#include "asterisk.h"
#include <unistd.h>
#include <fcntl.h>
#include <sys/eventfd.h>
#include "asterisk/alertpipe.h"
#include "asterisk/logger.h"
Include dependency graph for alertpipe.c:

Go to the source code of this file.

Functions

void ast_alertpipe_close (int alert_pipe[2])
 Close an alert pipe.
 
ast_alert_status_t ast_alertpipe_flush (int alert_pipe[2])
 Consume all alerts written to the alert pipe.
 
int ast_alertpipe_init (int alert_pipe[2])
 Initialize an alert pipe.
 
ast_alert_status_t ast_alertpipe_read (int alert_pipe[2])
 Read an event from an alert pipe.
 
ssize_t ast_alertpipe_write (int alert_pipe[2])
 Write an event to an alert pipe.
 

Detailed Description

Alert Pipe API.

Author
Sean Bright

Definition in file alertpipe.c.

Function Documentation

◆ ast_alertpipe_close()

void ast_alertpipe_close ( int  alert_pipe[2])

Close an alert pipe.

Since
13.16.0
Parameters
alert_pipea two-element containing the alert pipe's file descriptors

Definition at line 79 of file alertpipe.c.

80{
81#ifdef HAVE_EVENTFD
82
83 if (alert_pipe[0] == alert_pipe[1]) {
84 if (alert_pipe[0] > -1) {
85 close(alert_pipe[0]);
86 ast_alertpipe_clear(alert_pipe);
87 }
88 return;
89 }
90
91#endif
92
93 if (alert_pipe[0] > -1) {
94 close(alert_pipe[0]);
95 }
96 if (alert_pipe[1] > -1) {
97 close(alert_pipe[1]);
98 }
99 ast_alertpipe_clear(alert_pipe);
100}
ast_alertpipe_clear
void ast_alertpipe_clear(int alert_pipe[2])
Sets the alert pipe file descriptors to default values.
Definition alertpipe.h:98
alert_pipe
int alert_pipe[2]
Definition res_corosync.c:276

References alert_pipe, and ast_alertpipe_clear().

Referenced by ast_alertpipe_init(), ast_channel_internal_alertpipe_close(), bridge_channel_destroy(), dealloc_signal(), and really_quit().

◆ ast_alertpipe_flush()

ast_alert_status_t ast_alertpipe_flush ( int  alert_pipe[2])

Consume all alerts written to the alert pipe.

Since
13.16.0
Parameters
alert_pipea two-element array containing the alert pipe's file descriptors
Return values
AST_ALERT_READ_SUCCESSon success
AST_ALERT_NOT_READABLEif the alert pipe is not readable
AST_ALERT_READ_FATALif the alert pipe's file descriptors are in blocking mode, or a read error occurs.

Definition at line 134 of file alertpipe.c.

135{
136 int bytes_read;
137 uint64_t tmp[16];
138
139 if (!ast_alertpipe_readable(alert_pipe)) {
140 return AST_ALERT_NOT_READABLE;
141 }
142
143 /* Read the alertpipe until it is exhausted. */
144 for (;;) {
145 bytes_read = read(alert_pipe[0], tmp, sizeof(tmp));
146 if (bytes_read < 0) {
147 if (errno == EINTR) {
148 continue;
149 }
150 if (errno == EAGAIN || errno == EWOULDBLOCK) {
151 /*
152 * Would block so nothing left to read.
153 * This is the normal loop exit.
154 */
155 break;
156 }
157 ast_log(LOG_WARNING, "read() failed flushing alertpipe: %s\n",
158 strerror(errno));
159 return AST_ALERT_READ_FAIL;
160 }
161 if (!bytes_read) {
162 /* Read nothing so we are done */
163 break;
164 }
165 }
166
167 return AST_ALERT_READ_SUCCESS;
168}
ast_alertpipe_readable
int attribute_pure ast_alertpipe_readable(int alert_pipe[2])
Determine if the alert pipe is readable.
Definition alertpipe.h:114
AST_ALERT_READ_FAIL
@ AST_ALERT_READ_FAIL
Definition alertpipe.h:27
AST_ALERT_READ_SUCCESS
@ AST_ALERT_READ_SUCCESS
Definition alertpipe.h:25
AST_ALERT_NOT_READABLE
@ AST_ALERT_NOT_READABLE
Definition alertpipe.h:26
ast_log
#define ast_log
Definition astobj2.c:42
LOG_WARNING
#define LOG_WARNING
Definition include/asterisk/logger.h:280
errno
int errno

References alert_pipe, AST_ALERT_NOT_READABLE, AST_ALERT_READ_FAIL, AST_ALERT_READ_SUCCESS, ast_alertpipe_readable(), ast_log, errno, and LOG_WARNING.

Referenced by ast_channel_internal_alert_flush().

◆ ast_alertpipe_init()

int ast_alertpipe_init ( int  alert_pipe[2])

Initialize an alert pipe.

Since
13.16.0
Parameters
alert_pipea two-element array to hold the alert pipe's file descriptors
Return values
non-zeroif a failure occurred.
zerootherwise.

Definition at line 38 of file alertpipe.c.

39{
40#ifdef HAVE_EVENTFD
41
42 int fd = eventfd(0, EFD_NONBLOCK | EFD_SEMAPHORE);
43 if (fd > -1) {
44 alert_pipe[0] = alert_pipe[1] = fd;
45 return 0;
46 }
47
48 ast_log(LOG_WARNING, "Failed to create alert pipe with eventfd(), falling back to pipe(): %s\n",
49 strerror(errno));
50 ast_alertpipe_clear(alert_pipe);
51
52#endif
53
54#ifdef HAVE_PIPE2
55
56 if (pipe2(alert_pipe, O_NONBLOCK)) {
57 ast_log(LOG_WARNING, "Failed to create alert pipe: %s\n", strerror(errno));
58 return -1;
59 }
60
61#else
62
63 if (pipe(alert_pipe)) {
64 ast_log(LOG_WARNING, "Failed to create alert pipe: %s\n", strerror(errno));
65 return -1;
66 } else {
67 if (ast_fd_set_flags(alert_pipe[0], O_NONBLOCK)
68 || ast_fd_set_flags(alert_pipe[1], O_NONBLOCK)) {
69 ast_alertpipe_close(alert_pipe);
70 return -1;
71 }
72 }
73
74#endif
75
76 return 0;
77}
ast_alertpipe_close
void ast_alertpipe_close(int alert_pipe[2])
Close an alert pipe.
Definition alertpipe.c:79
ast_fd_set_flags
#define ast_fd_set_flags(fd, flags)
Set flags on the given file descriptor.
Definition utils.h:1079

References alert_pipe, ast_alertpipe_clear(), ast_alertpipe_close(), ast_fd_set_flags, ast_log, errno, and LOG_WARNING.

Referenced by alloc_signal(), ast_channel_internal_alertpipe_init(), asterisk_daemon(), and bridge_channel_internal_alloc().

◆ ast_alertpipe_read()

ast_alert_status_t ast_alertpipe_read ( int  alert_pipe[2])

Read an event from an alert pipe.

Since
13.16.0
Parameters
alert_pipea two-element array containing the alert pipe's file descriptors
Return values
AST_ALERT_READ_SUCCESSon success
AST_ALERT_NOT_READABLEif the alert pipe is not readable
AST_ALERT_READ_FATALif the alert pipe's file descriptors are in blocking mode, or a read error occurs.

Definition at line 102 of file alertpipe.c.

103{
104 uint64_t tmp;
105
106 if (!ast_alertpipe_readable(alert_pipe)) {
107 return AST_ALERT_NOT_READABLE;
108 }
109
110 if (read(alert_pipe[0], &tmp, sizeof(tmp)) < 0) {
111 if (errno != EINTR && errno != EAGAIN) {
112 ast_log(LOG_WARNING, "read() failed: %s\n", strerror(errno));
113 return AST_ALERT_READ_FAIL;
114 }
115 }
116
117 return AST_ALERT_READ_SUCCESS;
118}

References alert_pipe, AST_ALERT_NOT_READABLE, AST_ALERT_READ_FAIL, AST_ALERT_READ_SUCCESS, ast_alertpipe_readable(), ast_log, errno, and LOG_WARNING.

Referenced by ast_channel_internal_alert_read(), bridge_channel_handle_write(), monitor_sig_flags(), and wait_for_signal_or_hangup().

◆ ast_alertpipe_write()

ssize_t ast_alertpipe_write ( int  alert_pipe[2])

Write an event to an alert pipe.

Since
13.16.0
Parameters
alert_pipea two-element array containing the alert pipe's file descriptors
Return values
0Success
1Failure

Definition at line 120 of file alertpipe.c.

121{
122 uint64_t tmp = 1;
123
124 if (!ast_alertpipe_writable(alert_pipe)) {
125 errno = EBADF;
126 return 0;
127 }
128
129 /* preset errno in case returned size does not match */
130 errno = EPIPE;
131 return write(alert_pipe[1], &tmp, sizeof(tmp)) != sizeof(tmp);
132}
ast_alertpipe_writable
int attribute_pure ast_alertpipe_writable(int alert_pipe[2])
Determine if the alert pipe is writable.
Definition alertpipe.h:130

References alert_pipe, ast_alertpipe_writable(), and errno.

Referenced by __quit_handler(), _hup_handler(), ast_bridge_channel_queue_frame(), ast_channel_alert_write(), send_signal(), and wait_for_signal_or_hangup().

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