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131 | .\} |
131 | .\} |
132 | .rm #[ #] #H #V #F C |
132 | .rm #[ #] #H #V #F C |
133 | .\" ======================================================================== |
133 | .\" ======================================================================== |
134 | .\" |
134 | .\" |
135 | .IX Title "LIBEV 3" |
135 | .IX Title "LIBEV 3" |
136 | .TH LIBEV 3 "2019-12-20" "libev-4.27" "libev - high performance full featured event loop" |
136 | .TH LIBEV 3 "2020-01-22" "libev-4.31" "libev - high performance full featured event loop" |
137 | .\" For nroff, turn off justification. Always turn off hyphenation; it makes |
137 | .\" For nroff, turn off justification. Always turn off hyphenation; it makes |
138 | .\" way too many mistakes in technical documents. |
138 | .\" way too many mistakes in technical documents. |
139 | .if n .ad l |
139 | .if n .ad l |
140 | .nh |
140 | .nh |
141 | .SH "NAME" |
141 | .SH "NAME" |
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593 | threads that are not interested in handling them. |
593 | threads that are not interested in handling them. |
594 | .Sp |
594 | .Sp |
595 | Signalfd will not be used by default as this changes your signal mask, and |
595 | Signalfd will not be used by default as this changes your signal mask, and |
596 | there are a lot of shoddy libraries and programs (glib's threadpool for |
596 | there are a lot of shoddy libraries and programs (glib's threadpool for |
597 | example) that can't properly initialise their signal masks. |
597 | example) that can't properly initialise their signal masks. |
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598 | .ie n .IP """EVFLAG_NOSIGMASK""" 4 |
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599 | .el .IP "\f(CWEVFLAG_NOSIGMASK\fR" 4 |
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600 | .IX Item "EVFLAG_NOSIGMASK" |
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601 | When this flag is specified, then libev will avoid to modify the signal |
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602 | mask. Specifically, this means you have to make sure signals are unblocked |
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603 | when you want to receive them. |
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604 | .Sp |
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605 | This behaviour is useful when you want to do your own signal handling, or |
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606 | want to handle signals only in specific threads and want to avoid libev |
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607 | unblocking the signals. |
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608 | .Sp |
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609 | It's also required by \s-1POSIX\s0 in a threaded program, as libev calls |
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610 | \&\f(CW\*(C`sigprocmask\*(C'\fR, whose behaviour is officially unspecified. |
598 | .ie n .IP """EVFLAG_NOTIMERFD""" 4 |
611 | .ie n .IP """EVFLAG_NOTIMERFD""" 4 |
599 | .el .IP "\f(CWEVFLAG_NOTIMERFD\fR" 4 |
612 | .el .IP "\f(CWEVFLAG_NOTIMERFD\fR" 4 |
600 | .IX Item "EVFLAG_NOTIMERFD" |
613 | .IX Item "EVFLAG_NOTIMERFD" |
601 | When this flag is specified, the libev will avoid using a \f(CW\*(C`timerfd\*(C'\fR to |
614 | When this flag is specified, the libev will avoid using a \f(CW\*(C`timerfd\*(C'\fR to |
602 | detect time jumps. It will still be able to detect time jumps, but takes |
615 | detect time jumps. It will still be able to detect time jumps, but takes |
603 | longer and has a lower accuracy in doing so, but saves a file descriptor |
616 | longer and has a lower accuracy in doing so, but saves a file descriptor |
604 | per loop. |
617 | per loop. |
605 | .ie n .IP """EVFLAG_NOSIGMASK""" 4 |
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606 | .el .IP "\f(CWEVFLAG_NOSIGMASK\fR" 4 |
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607 | .IX Item "EVFLAG_NOSIGMASK" |
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608 | When this flag is specified, then libev will avoid to modify the signal |
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609 | mask. Specifically, this means you have to make sure signals are unblocked |
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610 | when you want to receive them. |
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611 | .Sp |
618 | .Sp |
612 | This behaviour is useful when you want to do your own signal handling, or |
619 | The current implementation only tries to use a \f(CW\*(C`timerfd\*(C'\fR when the first |
613 | want to handle signals only in specific threads and want to avoid libev |
620 | \&\f(CW\*(C`ev_periodic\*(C'\fR watcher is started and falls back on other methods if it |
614 | unblocking the signals. |
621 | cannot be created, but this behaviour might change in the future. |
615 | .Sp |
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616 | It's also required by \s-1POSIX\s0 in a threaded program, as libev calls |
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617 | \&\f(CW\*(C`sigprocmask\*(C'\fR, whose behaviour is officially unspecified. |
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618 | .Sp |
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619 | This flag's behaviour will become the default in future versions of libev. |
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620 | .ie n .IP """EVBACKEND_SELECT"" (value 1, portable select backend)" 4 |
622 | .ie n .IP """EVBACKEND_SELECT"" (value 1, portable select backend)" 4 |
621 | .el .IP "\f(CWEVBACKEND_SELECT\fR (value 1, portable select backend)" 4 |
623 | .el .IP "\f(CWEVBACKEND_SELECT\fR (value 1, portable select backend)" 4 |
622 | .IX Item "EVBACKEND_SELECT (value 1, portable select backend)" |
624 | .IX Item "EVBACKEND_SELECT (value 1, portable select backend)" |
623 | This is your standard \fBselect\fR\|(2) backend. Not \fIcompletely\fR standard, as |
625 | This is your standard \fBselect\fR\|(2) backend. Not \fIcompletely\fR standard, as |
624 | libev tries to roll its own fd_set with no limits on the number of fds, |
626 | libev tries to roll its own fd_set with no limits on the number of fds, |
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1765 | .IX Header "WATCHER TYPES" |
1767 | .IX Header "WATCHER TYPES" |
1766 | This section describes each watcher in detail, but will not repeat |
1768 | This section describes each watcher in detail, but will not repeat |
1767 | information given in the last section. Any initialisation/set macros, |
1769 | information given in the last section. Any initialisation/set macros, |
1768 | functions and members specific to the watcher type are explained. |
1770 | functions and members specific to the watcher type are explained. |
1769 | .PP |
1771 | .PP |
1770 | Members are additionally marked with either \fI[read\-only]\fR, meaning that, |
1772 | Most members are additionally marked with either \fI[read\-only]\fR, meaning |
1771 | while the watcher is active, you can look at the member and expect some |
1773 | that, while the watcher is active, you can look at the member and expect |
1772 | sensible content, but you must not modify it (you can modify it while the |
1774 | some sensible content, but you must not modify it (you can modify it while |
1773 | watcher is stopped to your hearts content), or \fI[read\-write]\fR, which |
1775 | the watcher is stopped to your hearts content), or \fI[read\-write]\fR, which |
1774 | means you can expect it to have some sensible content while the watcher |
1776 | means you can expect it to have some sensible content while the watcher |
1775 | is active, but you can also modify it. Modifying it may not do something |
1777 | is active, but you can also modify it. Modifying it may not do something |
1776 | sensible or take immediate effect (or do anything at all), but libev will |
1778 | sensible or take immediate effect (or do anything at all), but libev will |
1777 | not crash or malfunction in any way. |
1779 | not crash or malfunction in any way. |
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1780 | .PP |
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1781 | In any case, the documentation for each member will explain what the |
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1782 | effects are, and if there are any additional access restrictions. |
1778 | .ie n .SS """ev_io"" \- is this file descriptor readable or writable?" |
1783 | .ie n .SS """ev_io"" \- is this file descriptor readable or writable?" |
1779 | .el .SS "\f(CWev_io\fP \- is this file descriptor readable or writable?" |
1784 | .el .SS "\f(CWev_io\fP \- is this file descriptor readable or writable?" |
1780 | .IX Subsection "ev_io - is this file descriptor readable or writable?" |
1785 | .IX Subsection "ev_io - is this file descriptor readable or writable?" |
1781 | I/O watchers check whether a file descriptor is readable or writable |
1786 | I/O watchers check whether a file descriptor is readable or writable |
1782 | in each iteration of the event loop, or, more precisely, when reading |
1787 | in each iteration of the event loop, or, more precisely, when reading |
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1950 | .IX Item "ev_io_set (ev_io *, int fd, int events)" |
1955 | .IX Item "ev_io_set (ev_io *, int fd, int events)" |
1951 | .PD |
1956 | .PD |
1952 | Configures an \f(CW\*(C`ev_io\*(C'\fR watcher. The \f(CW\*(C`fd\*(C'\fR is the file descriptor to |
1957 | Configures an \f(CW\*(C`ev_io\*(C'\fR watcher. The \f(CW\*(C`fd\*(C'\fR is the file descriptor to |
1953 | receive events for and \f(CW\*(C`events\*(C'\fR is either \f(CW\*(C`EV_READ\*(C'\fR, \f(CW\*(C`EV_WRITE\*(C'\fR or |
1958 | receive events for and \f(CW\*(C`events\*(C'\fR is either \f(CW\*(C`EV_READ\*(C'\fR, \f(CW\*(C`EV_WRITE\*(C'\fR or |
1954 | \&\f(CW\*(C`EV_READ | EV_WRITE\*(C'\fR, to express the desire to receive the given events. |
1959 | \&\f(CW\*(C`EV_READ | EV_WRITE\*(C'\fR, to express the desire to receive the given events. |
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1960 | .IP "ev_io_modify (ev_io *, int events)" 4 |
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1961 | .IX Item "ev_io_modify (ev_io *, int events)" |
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1962 | Similar to \f(CW\*(C`ev_io_set\*(C'\fR, but only changes the event mask. Using this might |
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1963 | be faster with some backends, as libev can assume that the \f(CW\*(C`fd\*(C'\fR still |
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1964 | refers to the same underlying file description, something it cannot do |
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1965 | when using \f(CW\*(C`ev_io_set\*(C'\fR. |
1955 | .IP "int fd [read\-only]" 4 |
1966 | .IP "int fd [no\-modify]" 4 |
1956 | .IX Item "int fd [read-only]" |
1967 | .IX Item "int fd [no-modify]" |
1957 | The file descriptor being watched. |
1968 | The file descriptor being watched. While it can be read at any time, you |
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1969 | must not modify this member even when the watcher is stopped \- always use |
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1970 | \&\f(CW\*(C`ev_io_set\*(C'\fR for that. |
1958 | .IP "int events [read\-only]" 4 |
1971 | .IP "int events [no\-modify]" 4 |
1959 | .IX Item "int events [read-only]" |
1972 | .IX Item "int events [no-modify]" |
1960 | The events being watched. |
1973 | The set of events being watched, among other flags. This field is a |
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1974 | bit set \- to test for \f(CW\*(C`EV_READ\*(C'\fR, use \f(CW\*(C`w\->events & EV_READ\*(C'\fR, and |
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1975 | similarly for \f(CW\*(C`EV_WRITE\*(C'\fR. |
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1976 | .Sp |
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1977 | As with \f(CW\*(C`fd\*(C'\fR, you must not modify this member even when the watcher is |
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1978 | stopped, always use \f(CW\*(C`ev_io_set\*(C'\fR or \f(CW\*(C`ev_io_modify\*(C'\fR for that. |
1961 | .PP |
1979 | .PP |
1962 | \fIExamples\fR |
1980 | \fIExamples\fR |
1963 | .IX Subsection "Examples" |
1981 | .IX Subsection "Examples" |
1964 | .PP |
1982 | .PP |
1965 | Example: Call \f(CW\*(C`stdin_readable_cb\*(C'\fR when \s-1STDIN_FILENO\s0 has become, well |
1983 | Example: Call \f(CW\*(C`stdin_readable_cb\*(C'\fR when \s-1STDIN_FILENO\s0 has become, well |