(split) LDP: Update original to LDP v3.41.

[linuxjm/LDP_man-pages.git] / original / man2 / poll.2

diff --git a/original/man2/poll.2 b/original/man2/poll.2
index 2ceb738..87905e8 100644 (file)
--- a/original/man2/poll.2
+++ b/original/man2/poll.2
@@ -28,7 +28,7 @@
 .\" 2006-07-01, mtk, Added POLLRDHUP + various other wording and
 .\"    formatting changes.
 .\"
-.TH POLL 2 2012-04-15 "Linux" "Linux Programmer's Manual"
+.TH POLL 2 2012-05-05 "Linux" "Linux Programmer's Manual"
 .SH NAME
 poll, ppoll \- wait for some event on a file descriptor
 .SH SYNOPSIS
@@ -122,12 +122,20 @@ blocks until one of the events occurs.
 
 The
 .I timeout
-argument specifies an upper limit on the time for which
+argument specifies the minimum number of milliseconds that
 .BR poll ()
-will block, in milliseconds.
+will block.
+(This interval will be rounded up to the system clock granularity,
+and kernel scheduling delays mean that the blocking interval
+may overrun by a small amount.)
 Specifying a negative value in
 .I timeout
 means an infinite timeout.
+Specifying a
+.I timeout
+of zero causes
+.BR poll ()
+to return immediately, even if no file descriptors are ready.
 
 The bits that may be set/returned in
 .I events
@@ -305,15 +313,12 @@ There was no space to allocate file descriptor tables.
 The
 .BR poll ()
 system call was introduced in Linux 2.1.23.
-The
+On older kernels that lack this system call,
+.\" library call was introduced in libc 5.4.28
+the glibc (and the old Linux libc)
 .BR poll ()
-library call was introduced in libc 5.4.28
-(and provides emulation using
-.BR select (2)
-if your kernel does not
-have a
-.BR poll ()
-system call).
+wrapper function provides emulation using
+.BR select (2).
 
 The
 .BR ppoll ()