1 files changed, 104 insertions, 0 deletions
diff --git a/cpukit/posix/src/adjtime.c b/cpukit/posix/src/adjtime.c
new file mode 100644
index 0000000000..89ccd7950d
--- /dev/null
+++ b/cpukit/posix/src/adjtime.c
@@ -0,0 +1,104 @@
+/*
+ *  adjime() function
+ *
+ *  This method was initially added as part of porting NTP to RTEMS.
+ *  It is a BSD compatability function and now is available on
+ *  GNU/Linux.
+ */
+
+/*
+ *  COPYRIGHT (c) 1989-2007.
+ *  On-Line Applications Research Corporation (OAR).
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ *
+ *  $Id$
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <time.h>
+#include <sys/time.h>
+#include <errno.h>
+
+#include <rtems/system.h>
+#include <rtems/config.h>
+#include <rtems/seterr.h>
+#include <rtems/score/tod.h>
+#include <rtems/posix/time.h>
+#include <rtems/score/thread.h>
+#include <rtems/score/timespec.h>
+
+/*
+ *  At one point there was a static variable named adjustment
+ *  used by this implementation.  I don't see any reason for it
+ *  to be here based upon the GNU/Linux documentation.
+ */
+
+int  adjtime(
+  struct timeval *delta,
+  struct timeval *olddelta
+)
+{
+  struct timespec ts;
+  long   adjustment;
+
+  /*
+   * Simple validations
+   */
+  if ( !delta )
+    rtems_set_errno_and_return_minus_one( EINVAL );
+
+  if ( delta->tv_usec >= TOD_MICROSECONDS_PER_SECOND )
+    rtems_set_errno_and_return_minus_one( EINVAL );
+
+  if ( olddelta ) {
+    olddelta->tv_sec  = 0;
+    olddelta->tv_usec = 0;
+  }
+
+  /* convert delta to microseconds */
+  adjustment  = (delta->tv_sec * TOD_MICROSECONDS_PER_SECOND);
+  adjustment += delta->tv_usec;
+
+  /* too small to account for */
+  if ( adjustment < rtems_configuration_get_microseconds_per_tick() )
+    return 0;
+
+  /*
+   * This prevents context switches while we are adjusting the TOD
+   */
+
+  _Thread_Disable_dispatch();
+
+    _TOD_Get( &ts );
+
+    ts.tv_sec  += delta->tv_sec;
+    ts.tv_nsec += delta->tv_usec * TOD_NANOSECONDS_PER_MICROSECOND;
+
+    /* if adjustment is too much positive */
+    while ( ts.tv_nsec >= TOD_NANOSECONDS_PER_SECOND ) {
+      ts.tv_nsec -= TOD_NANOSECONDS_PER_SECOND;
+      ts.tv_sec++;
+    }
+
+    /* if adjustment is too much negative */
+    while ( ts.tv_nsec <= (-1 * TOD_NANOSECONDS_PER_SECOND) ) {
+      ts.tv_nsec += TOD_NANOSECONDS_PER_SECOND;
+      ts.tv_sec--;
+    }
+
+    _TOD_Set( &ts );
+
+  _Thread_Enable_dispatch();
+
+  /* set the user's output */
+  if ( olddelta )
+    *olddelta = *delta;
+
+  return 0;
+}