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posix/src/nanosleep.c: Address issue when delay is longer than desired

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This resulted in the elapsed time going below 0 and an arbitrarily large
number returned as the time remaining.

closes #2296.
This commit is contained in:
Joel Sherrill
2015-03-11 15:53:44 -05:00
parent b0f8bb4eec
commit d937d364af
1 changed files with 29 additions and 18 deletions
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27
cpukit/posix/src/nanosleep.c
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@@ -1,12 +1,12 @@
/**
* @file
*
* @brief Suspends Execution of calling thread until Time elaps
* @brief Suspends Execution of calling thread until Time elapses
* @ingroup POSIXAPI
*/
/*
* COPYRIGHT (c) 1989-2007.
* COPYRIGHT (c) 1989-2015.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
@@ -29,7 +29,6 @@
/*
* 14.2.5 High Resolution Sleep, P1003.1b-1993, p. 269
*/
int nanosleep(
const struct timespec *rqtp,
struct timespec *rmtp
@@ -42,6 +41,7 @@ int nanosleep(
Thread_Control *executing;
Watchdog_Interval ticks;
Watchdog_Interval elapsed;
/*
@@ -53,6 +53,9 @@ int nanosleep(
if ( !_Timespec_Is_valid( rqtp ) )
rtems_set_errno_and_return_minus_one( EINVAL );
/*
* Convert the timespec delay into the appropriate number of clock ticks.
*/
ticks = _Timespec_To_ticks( rqtp );
/*
@@ -60,7 +63,6 @@ int nanosleep(
* This behavior is also beyond the POSIX specification but is
* consistent with the RTEMS API and yields desirable behavior.
*/
if ( !ticks ) {
_Thread_Disable_dispatch();
executing = _Thread_Executing;
@@ -91,12 +93,22 @@ int nanosleep(
_Watchdog_Insert_ticks( &executing->Timer, ticks );
_Thread_Enable_dispatch();
/* calculate time remaining */
/*
* Calculate the time that passed while we were sleeping and how
* much remains from what we requested.
*/
elapsed = executing->Timer.stop_time - executing->Timer.start_time;
if ( elapsed >= ticks )
ticks = 0;
else
ticks -= elapsed;
/*
* If the user wants the time remaining, do the conversion.
*/
if ( rmtp ) {
ticks -= executing->Timer.stop_time - executing->Timer.start_time;
_Timespec_From_ticks( ticks, rmtp );
}
/*
* Only when POSIX is enabled, can a sleep be interrupted.
@@ -108,7 +120,6 @@ int nanosleep(
if ( ticks )
rtems_set_errno_and_return_minus_one( EINTR );
#endif
}
return 0;
}