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authorJoel Sherrill <joel.sherrill@OARcorp.com>2004-01-09 23:39:14 +0000
committerJoel Sherrill <joel.sherrill@OARcorp.com>2004-01-09 23:39:14 +0000
commit2e83792c7555c93c250c69c4ffa2d0c1482d1bbc (patch)
tree7c9a9029685f7ce169e3b293b09ab25e5e35a039 /doc/posix_users/signal.t
parent234f7adb59e1d55116ad6dfd26ef65d1f31ac658 (diff)
downloadrtems-2e83792c7555c93c250c69c4ffa2d0c1482d1bbc.tar.bz2
2004-01-09 Joel Sherrill <joel@OARcorp.com>
PR 464/doc * clock.t, signal.t: Add documentation for usleep() and ualarm(). Also fixed a couple of calls which have the wrong .h files per the OpenGroup site documentation.
Diffstat (limited to '')
-rw-r--r--doc/posix_users/signal.t68
1 files changed, 65 insertions, 3 deletions
diff --git a/doc/posix_users/signal.t b/doc/posix_users/signal.t
index b56d325422..933faa56c0 100644
--- a/doc/posix_users/signal.t
+++ b/doc/posix_users/signal.t
@@ -35,6 +35,7 @@ The directives provided by the signal manager are:
@item @code{sigtimedwait} - Synchronously Accept a Signal with Timeout
@item @code{sigqueue} - Queue a Signal to a Process
@item @code{alarm} - Schedule Alarm
+@item @code{ualarm} - Schedule Alarm in Microseconds
@end itemize
@section Background
@@ -860,7 +861,7 @@ NONE
@subheading CALLING SEQUENCE:
@example
-#include <signal.h>
+#include <unistd.h>
unsigned int alarm(
unsigned int seconds
@@ -871,13 +872,74 @@ unsigned int alarm(
This call always succeeds.
+If there was a previous @code{alarm()} request with time remaining,
+then this routine returns the number of seconds until that outstanding
+alarm would have fired. If no previous @code{alarm()} request was
+outstanding, then zero is returned.
+
@subheading DESCRIPTION:
-If there was a previous @code{alarm()} request with time remaining,
+The @code{alarm()} service causes the @code{SIGALRM} signal to
+be generated after the number of seconds specified by
+@code{seconds} has elapsed.
+
+@subheading NOTES:
+
+Alarm requests do not queue. If @code{alarm} is called while
+a previous request is outstanding, the call will result in
+rescheduling the time at which the @code{SIGALRM} signal
+will be generated.
+
+If the notification signal, @code{SIGALRM}, is not caught or ignored, the
+calling process is terminated.
+
+@c
+@c
+@c
+@page
+@subsection ualarm - Schedule Alarm in Microseconds
+
+@findex alarm
+@findex microseonds alarm
+@findex usecs alarm
+@cindex schedule alarm in microseonds
+
+@subheading CALLING SEQUENCE:
+
+@example
+#include <unistd.h>
+
+useconds_t ualarm(
+ useconds_t useconds,
+ useconds_t interval
+);
+@end example
+
+@subheading STATUS CODES:
+
+This call always succeeds.
+
+If there was a previous @code{ualarm()} request with time remaining,
then this routine returns the number of seconds until that outstanding
alarm would have fired. If no previous @code{alarm()} request was
outstanding, then zero is returned.
+@subheading DESCRIPTION:
+
+The @code{ualarm()} service causes the @code{SIGALRM} signal to
+be generated after the number of microseconds specified by
+@code{useconds} has elapsed.
+
+When @code{interval} is non-zero, repeated timeout notification occurs
+with a period in microseconds specified by @code{interval}.
+
@subheading NOTES:
-NONE
+Alarm requests do not queue. If @code{alarm} is called while
+a previous request is outstanding, the call will result in
+rescheduling the time at which the @code{SIGALRM} signal
+will be generated.
+
+If the notification signal, @code{SIGALRM}, is not caught or ignored, the
+calling process is terminated.
+