WebSVN – HelenOS – Diff – /trunk/uspace/lib/libc/generic/time.c

 /*
  * Copyright (c) 2006 Ondrej Palkovsky
  * All rights reserved.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
+ *
  * - Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  * - Redistributions in binary form must reproduce the above copyright
  *   notice, this list of conditions and the following disclaimer in the
  *   documentation and/or other materials provided with the distribution.
  * - The name of the author may not be used to endorse or promote products
  *   derived from this software without specific prior written permission.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 /** @addtogroup libc
  * @{
  */
 /** @file
  */
 #include <sys/time.h>
 #include <unistd.h>
 #include <ipc/ipc.h>
 #include <stdio.h>
 #include <arch/barrier.h>
 #include <unistd.h>
 #include <atomic.h>
 #include <futex.h>
 #include <sysinfo.h>
 #include <ipc/services.h>
 #include <sysinfo.h>
 #include <as.h>
 #include <ddi.h>
 /* Pointers to public variables with time */
 struct {
     volatile sysarg_t seconds1;
     volatile sysarg_t useconds;
     volatile sysarg_t seconds2;
 } *ktime = NULL;
+/** Add microseconds to given timeval.
+ *
+ * @param tv        Destination timeval.
+ * @param usecs     Number of microseconds to add.
+ */
+void tv_add(struct timeval *tv, suseconds_t usecs)
+{
+    tv->tv_sec += usecs / 1000000;
+    tv->tv_usec += usecs % 1000000;
+    if (tv->tv_usec > 1000000) {
+        tv->tv_sec++;
+        tv->tv_usec -= 1000000;
+    }
+}
+/** Subtract two timevals.
+ *
+ * @param tv1       First timeval.
+ * @param tv2       Second timeval.
+ *
+ * @return      Return difference between tv1 and tv2 (tv1 - tv2) in
+ *          microseconds.
+ */
+suseconds_t tv_sub(struct timeval *tv1, struct timeval *tv2)
+{
+    suseconds_t result;
+    result = tv1->tv_usec - tv2->tv_usec;
+    result += (tv1->tv_sec - tv2->tv_sec) * 1000000;
+    return result;
+}
+/** Decide if one timeval is greater than the other.
+ *
+ * @param t1        First timeval.
+ * @param t2        Second timeval.
+ *
+ * @return      Return true tv1 is greater than tv2. Otherwise return
+ *          false.
+ */
+int tv_gt(struct timeval *tv1, struct timeval *tv2)
+{
+    if (tv1->tv_sec > tv2->tv_sec)
+        return 1;
+    if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec > tv2->tv_usec)
+        return 1;
+    return 0;
+}
+/** Decide if one timeval is greater than or equal to the other.
+ *
+ * @param tv1       First timeval.
+ * @param tv2       Second timeval.
+ *
+ * @return      Return true if tv1 is greater than or equal to tv2.
+ *          Otherwise return false.
+ */
+int tv_gteq(struct timeval *tv1, struct timeval *tv2)
+{
+    if (tv1->tv_sec > tv2->tv_sec)
+        return 1;
+    if (tv1->tv_sec == tv2->tv_sec && tv1->tv_usec >= tv2->tv_usec)
+        return 1;
+    return 0;
+}
 /** POSIX gettimeofday
+ *
  * The time variables are memory mapped(RO) from kernel, which updates
  * them periodically. As it is impossible to read 2 values atomically, we
  * use a trick: First read a seconds, then read microseconds, then
  * read seconds again. If a second elapsed in the meantime, set it to zero.
  * This provides assurance, that at least the
  * sequence of subsequent gettimeofday calls is ordered.
  */
 int gettimeofday(struct timeval *tv, struct timezone *tz)
+{
     void *mapping;
     sysarg_t s1, s2;
     sysarg_t rights;
     int res;
     if (!ktime) {
         mapping = as_get_mappable_page(PAGE_SIZE);
         /* Get the mapping of kernel clock */
         res = ipc_call_sync_3(PHONE_NS, IPC_M_AS_AREA_RECV,
             (sysarg_t) mapping, PAGE_SIZE, SERVICE_MEM_REALTIME, NULL,
             &rights, NULL);
         if (res) {
             printf("Failed to initialize timeofday memarea\n");
             _exit(1);
+        }
         if (! (rights & AS_AREA_READ)) {
             printf("Received bad rights on time area: %X\n",
                    rights);
             as_area_destroy(mapping);
             _exit(1);
+        }
         ktime = mapping;
+    }
     if (tz) {
         tz->tz_minuteswest = 0;
         tz->tz_dsttime = DST_NONE;
+    }
     s2 = ktime->seconds2;
     read_barrier();
     tv->tv_usec = ktime->useconds;
     read_barrier();
     s1 = ktime->seconds1;
     if (s1 != s2) {
         tv->tv_usec = 0;
         tv->tv_sec = s1 > s2 ? s1 : s2;
     } else
         tv->tv_sec = s1;
     return 0;
+}
 /** Wait unconditionally for specified number of microseconds */
 void usleep(unsigned long usec)
+{
     atomic_t futex = FUTEX_INITIALIZER;
     futex_initialize(&futex, 0);
     futex_down_timeout(&futex, usec, 0);
+}
 /** Wait unconditionally for specified number of seconds */
 unsigned int sleep(unsigned int seconds)
+{
     atomic_t futex = FUTEX_INITIALIZER;
     futex_initialize(&futex, 0);
     /* Sleep in 1000 second steps to support
        full argument range */
     while (seconds > 0) {
         unsigned int period = (seconds > 1000) ? 1000 : seconds;
         futex_down_timeout(&futex, period * 1000000, 0);
         seconds -= period;
+    }
+}
 /** @}
  */

Subversion Repositories HelenOS

(root)/trunk/uspace/lib/libc/generic/time.c – Rev 2479 → 2486