Changes in uspace/lib/c/generic/time.c [2c577e0b:63f8966] in mainline

File:

• uspace/lib/c/generic/time.c (modified) (6 diffs)

uspace/lib/c/generic/time.c

@@ -35 +35 @@
 #include <sys/time.h>
 #include <unistd.h>
-#include <bool.h>
-#include <ipc/ns.h>
+#include <ipc/ipc.h>
+#include <stdio.h>
 #include <arch/barrier.h>
-#include <macros.h>
+#include <unistd.h>
+#include <atomic.h>
+#include <sysinfo.h>
+#include <ipc/services.h>
 #include <libc.h>
+
+#include <sysinfo.h>
+#include <as.h>
+#include <ddi.h>
+
 #include <time.h>
 
-/** Pointer to kernel shared variables with time */
+/* Pointers to public variables with time */
 struct {
         volatile sysarg_t seconds1;
@@ -51 +59 @@
 /** Add microseconds to given timeval.
  *
- * @param tv    Destination timeval.
- * @param usecs Number of microseconds to add.
- *
+ * @param tv            Destination timeval.
+ * @param usecs         Number of microseconds to add.
  */
 void tv_add(struct timeval *tv, suseconds_t usecs)
@@ -59 +66 @@
         tv->tv_sec += usecs / 1000000;
         tv->tv_usec += usecs % 1000000;
-        
         if (tv->tv_usec > 1000000) {
                 tv->tv_sec++;
@@ -68 +74 @@
 /** Subtract two timevals.
  *
- * @param tv1 First timeval.
- * @param tv2 Second timeval.
- *
- * @return Difference between tv1 and tv2 (tv1 - tv2) in
- *         microseconds.
- *
+ * @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)
 {
-        return (tv1->tv_usec - tv2->tv_usec) +
-            ((tv1->tv_sec - tv2->tv_sec) * 1000000);
+        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 True if tv1 is greater than tv2.
- * @return False otherwise.
- *
+ * @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 true;
-        
-        if ((tv1->tv_sec == tv2->tv_sec) && (tv1->tv_usec > tv2->tv_usec))
-                return true;
-        
-        return false;
+                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 True if tv1 is greater than or equal to tv2.
- * @return False otherwise.
- *
+ * @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 true;
-        
-        if ((tv1->tv_sec == tv2->tv_sec) && (tv1->tv_usec >= tv2->tv_usec))
-                return true;
-        
-        return false;
-}
-
-/** Get time of day
- *
- * The time variables are memory mapped (read-only) from kernel which
- * updates them periodically.
- *
- * As it is impossible to read 2 values atomically, we use a trick:
- * First we read the seconds, then we read the microseconds, then we
- * read the seconds again. If a second elapsed in the meantime, set
- * the microseconds to zero.
- *
- * This assures that the values returned by two subsequent calls
- * to gettimeofday() are monotonous.
- *
+                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;
+        int rights;
+        int res;
+
         if (!ktime) {
-                ktime = service_realtime_share_in();
-                if (!ktime)
-                        return -1;
-        }
-        
+                mapping = as_get_mappable_page(PAGE_SIZE);
+                /* Get the mapping of kernel clock */
+                res = ipc_share_in_start_1_1(PHONE_NS, mapping, PAGE_SIZE,
+                    SERVICE_MEM_REALTIME, &rights);
+                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;
         }
-        
-        sysarg_t s2 = ktime->seconds2;
-        
+
+        s2 = ktime->seconds2;
         read_barrier();
         tv->tv_usec = ktime->useconds;
-        
         read_barrier();
-        sysarg_t s1 = ktime->seconds1;
-        
+        s1 = ktime->seconds1;
         if (s1 != s2) {
-                tv->tv_sec = max(s1, s2);
                 tv->tv_usec = 0;
+                tv->tv_sec = s1 > s2 ? s1 : s2;
         } else
                 tv->tv_sec = s1;
-        
+
         return 0;
 }
@@ -168 +180 @@
 {
         struct timeval tv;
+
         if (gettimeofday(&tv, NULL))
                 return (time_t) -1;
-        
         if (tloc)
                 *tloc = tv.tv_sec;
-        
         return tv.tv_sec;
 }
 
-/** Wait unconditionally for specified number of microseconds
- *
- */
+/** Wait unconditionally for specified number of microseconds */
 int usleep(useconds_t usec)
 {
@@ -186 +195 @@
 }
 
-/** Wait unconditionally for specified number of seconds
- *
- */
+/** Wait unconditionally for specified number of seconds */
 unsigned int sleep(unsigned int sec)
 {
-        /*
-         * Sleep in 1000 second steps to support
-         * full argument range
-         */
-        
+        /* Sleep in 1000 second steps to support
+           full argument range */
         while (sec > 0) {
                 unsigned int period = (sec > 1000) ? 1000 : sec;
-                
+        
                 usleep(period * 1000000);
                 sec -= period;
         }
-        
         return 0;
 }