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| author | Michael Kerrisk <mtk.manpages@gmail.com> | 2008-07-07 04:16:16 +0000 |
|---|---|---|
| committer | Michael Kerrisk <mtk.manpages@gmail.com> | 2008-07-07 04:16:16 +0000 |
| commit | 72710182cda805bd1279098b3442572c536eda0b (patch) | |
| tree | 845950a1356e025189dbadc9c6a505994ed2ded5 /man7/signal.7 | |
| parent | dcb28126b1c122c83480c6f241432a4370548624 (diff) | |
| download | man-pages-72710182cda805bd1279098b3442572c536eda0b.tar.gz | |
tweaks
Diffstat (limited to 'man7/signal.7')
| -rw-r--r-- | man7/signal.7 | 36 |
1 files changed, 19 insertions, 17 deletions
diff --git a/man7/signal.7 b/man7/signal.7 index 9739047931..e12f43afee 100644 --- a/man7/signal.7 +++ b/man7/signal.7 @@ -40,7 +40,7 @@ .\" Added section on system call restarting (SA_RESTART) .\" Added section on stop/cont signals interrupting syscalls. .\" -.TH SIGNAL 7 2008-07-04 "Linux" "Linux Programmer's Manual" +.TH SIGNAL 7 2008-07-07 "Linux" "Linux Programmer's Manual" .SH NAME signal \- list of available signals .SH DESCRIPTION @@ -481,25 +481,27 @@ write() .fi .in .SS Interruption of System Calls and Library Functions by Signal Handlers -If a signal handler is invoked while a system call or library function -call is blocked, then the call may fail with the error +If a signal handler is invoked while a system call or library +function call is blocked, then either: +.IP * 2 +the call is automatically restarted after the signal handler returns; or +.IP * +the call fails with the error .BR EINTR . -The details depend on the interface -(in particular, whether the genealogy of the interface is System V or BSD) -and whether or not the signal handler was established using the +.PP +Which of these two behaviors occurs depends on the interface and +whether or not the signal handler was established using the .BR SA_RESTART flag (see .BR sigaction (2)). The details vary across Unix systems; below, are the details for Linux. -For the following interfaces, -if the +If a blocked call to one of the following interfaces is interrupted +by a signal handler, then the call will be automatically restarted +after the signal handler returns if the .BR SA_RESTART -flag was used, -then a blocked call will be restarted after being interrupted -by a signal handler; -otherwise the call will fail with the error +flag was used; otherwise the call will fail with the error .BR EINTR : .\" The following system calls use ERESTARTSYS, .\" so that they are restartable @@ -512,11 +514,11 @@ otherwise the call will fail with the error and .BR ioctl (2) calls on "slow" devices. -A "slow" device is one where the I/O call may block for an indefinite time, -for example, a terminal, pipe, or socket. +A "slow" device is one where the I/O call may block for an +indefinite time, for example, a terminal, pipe, or socket. (A disk is not a slow device according to this definition.) -If an I/O call on a slow device has already transferred some data by the -time it is interrupted by a signal handler, +If an I/O call on a slow device has already transferred some +data by the time it is interrupted by a signal handler, then the call will return a success status (normally, the number of bytes transferred). .IP * @@ -532,7 +534,7 @@ and .BR waitpid (2). .IP * Socket interfaces: -.\" If a timeout i(setsockopt()) is in effect on the socket, then these +.\" If a timeout (setsockopt()) is in effect on the socket, then these .\" system calls switch to using EINTR. Consequently, they and are not .\" automatically restarted, and they show the stop/cont behavior .\" described below. (Verified from 2.6.26 source, and by experiment; mtk) |