Changeset 8b655705 in mainline for uspace/lib/c/generic/time.c

Timestamp:

2011-04-15T19:38:07Z (13 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

9dd730d1

Parents:

6b9e85b (diff), b2fb47f (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge mainline changes.

File:

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

uspace/lib/c/generic/time.c

@@ -34 +34 @@
 
 #include <sys/time.h>
-#include <unistd.h>
-#include <ipc/ipc.h>
-#include <stdio.h>
+#include <time.h>
+#include <bool.h>
 #include <arch/barrier.h>
-#include <unistd.h>
-#include <atomic.h>
-#include <sysinfo.h>
-#include <ipc/services.h>
-#include <libc.h>
-
+#include <macros.h>
+#include <errno.h>
 #include <sysinfo.h>
 #include <as.h>
 #include <ddi.h>
-
-#include <time.h>
-
-/* Pointers to public variables with time */
+#include <libc.h>
+
+/** Pointer to kernel shared variables with time */
 struct {
         volatile sysarg_t seconds1;
@@ -59 +53 @@
 /** 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)
@@ -66 +61 @@
         tv->tv_sec += usecs / 1000000;
         tv->tv_usec += usecs % 1000000;
+        
         if (tv->tv_usec > 1000000) {
                 tv->tv_sec++;
@@ -74 +70 @@
 /** Subtract two timevals.
  *
- * @param tv1           First timeval.
- * @param tv2           Second timeval.
- *
- * @return              Return difference between tv1 and tv2 (tv1 - tv2) in
- *                      microseconds.
+ * @param tv1 First timeval.
+ * @param tv2 Second timeval.
+ *
+ * @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;
+        return (tv1->tv_usec - tv2->tv_usec) +
+            ((tv1->tv_sec - tv2->tv_sec) * 1000000);
 }
 
 /** 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.
+ * @param t1 First timeval.
+ * @param t2 Second timeval.
+ *
+ * @return True if tv1 is greater than tv2.
+ * @return False otherwise.
+ *
  */
 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;
+                return true;
+        
+        if ((tv1->tv_sec == tv2->tv_sec) && (tv1->tv_usec > tv2->tv_usec))
+                return true;
+        
+        return false;
 }
 
 /** 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.
+ * @param tv1 First timeval.
+ * @param tv2 Second timeval.
+ *
+ * @return True if tv1 is greater than or equal to tv2.
+ * @return False otherwise.
+ *
  */
 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.
+                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.
+ *
  */
 int gettimeofday(struct timeval *tv, struct timezone *tz)
 {
-        void *mapping;
-        sysarg_t s1, s2;
-        int rights;
-        int res;
-
-        if (!ktime) {
-                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 (ktime == NULL) {
+                uintptr_t faddr;
+                int rc = sysinfo_get_value("clock.faddr", &faddr);
+                if (rc != EOK) {
+                        errno = rc;
+                        return -1;
                 }
-                if (!(rights & AS_AREA_READ)) {
-                        printf("Received bad rights on time area: %X\n",
-                            rights);
-                        as_area_destroy(mapping);
-                        _exit(1);
+                
+                void *addr = as_get_mappable_page(PAGE_SIZE);
+                if (addr == NULL) {
+                        errno = ENOMEM;
+                        return -1;
                 }
-                ktime = mapping;
-        }
+                
+                rc = physmem_map((void *) faddr, addr, 1,
+                    AS_AREA_READ | AS_AREA_CACHEABLE);
+                if (rc != EOK) {
+                        as_area_destroy(addr);
+                        errno = rc;
+                        return -1;
+                }
+                
+                ktime = addr;
+        }
+        
         if (tz) {
                 tz->tz_minuteswest = 0;
                 tz->tz_dsttime = DST_NONE;
         }
-
-        s2 = ktime->seconds2;
+        
+        sysarg_t s2 = ktime->seconds2;
+        
         read_barrier();
         tv->tv_usec = ktime->useconds;
+        
         read_barrier();
-        s1 = ktime->seconds1;
+        sysarg_t 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;
 }
@@ -180 +189 @@
 {
         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)
 {
@@ -195 +207 @@
 }
 
-/** 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;
 }