Adds trunk/talk folder of revision 359 from libjingles google code to
trunk/talk


git-svn-id: http://webrtc.googlecode.com/svn/trunk@4318 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/talk/base/timeutils.cc b/talk/base/timeutils.cc
new file mode 100644
index 0000000..66b9bf2
--- /dev/null
+++ b/talk/base/timeutils.cc
@@ -0,0 +1,201 @@
+/*
+ * libjingle
+ * Copyright 2004--2005, Google Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *  2. 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.
+ *  3. 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.
+ */
+
+#ifdef POSIX
+#include <sys/time.h>
+#if defined(OSX) || defined(IOS)
+#include <mach/mach_time.h>
+#endif
+#endif
+
+#ifdef WIN32
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#include <mmsystem.h>
+#endif
+
+#include "talk/base/common.h"
+#include "talk/base/timeutils.h"
+
+#define EFFICIENT_IMPLEMENTATION 1
+
+namespace talk_base {
+
+const uint32 LAST = 0xFFFFFFFF;
+const uint32 HALF = 0x80000000;
+
+uint64 TimeNanos() {
+  int64 ticks = 0;
+#if defined(OSX) || defined(IOS)
+  static mach_timebase_info_data_t timebase;
+  if (timebase.denom == 0) {
+    // Get the timebase if this is the first time we run.
+    // Recommended by Apple's QA1398.
+    VERIFY(KERN_SUCCESS == mach_timebase_info(&timebase));
+  }
+  // Use timebase to convert absolute time tick units into nanoseconds.
+  ticks = mach_absolute_time() * timebase.numer / timebase.denom;
+#elif defined(POSIX)
+  struct timespec ts;
+  // TODO: Do we need to handle the case when CLOCK_MONOTONIC
+  // is not supported?
+  clock_gettime(CLOCK_MONOTONIC, &ts);
+  ticks = kNumNanosecsPerSec * static_cast<int64>(ts.tv_sec) +
+      static_cast<int64>(ts.tv_nsec);
+#elif defined(WIN32)
+  static volatile LONG last_timegettime = 0;
+  static volatile int64 num_wrap_timegettime = 0;
+  volatile LONG* last_timegettime_ptr = &last_timegettime;
+  DWORD now = timeGetTime();
+  // Atomically update the last gotten time
+  DWORD old = InterlockedExchange(last_timegettime_ptr, now);
+  if (now < old) {
+    // If now is earlier than old, there may have been a race between
+    // threads.
+    // 0x0fffffff ~3.1 days, the code will not take that long to execute
+    // so it must have been a wrap around.
+    if (old > 0xf0000000 && now < 0x0fffffff) {
+      num_wrap_timegettime++;
+    }
+  }
+  ticks = now + (num_wrap_timegettime << 32);
+  // TODO: Calculate with nanosecond precision.  Otherwise, we're just
+  // wasting a multiply and divide when doing Time() on Windows.
+  ticks = ticks * kNumNanosecsPerMillisec;
+#endif
+  return ticks;
+}
+
+uint32 Time() {
+  return static_cast<uint32>(TimeNanos() / kNumNanosecsPerMillisec);
+}
+
+#if defined(WIN32)
+static const uint64 kFileTimeToUnixTimeEpochOffset = 116444736000000000ULL;
+
+struct timeval {
+  long tv_sec, tv_usec;  // NOLINT
+};
+
+// Emulate POSIX gettimeofday().
+// Based on breakpad/src/third_party/glog/src/utilities.cc
+static int gettimeofday(struct timeval *tv, void *tz) {
+  // FILETIME is measured in tens of microseconds since 1601-01-01 UTC.
+  FILETIME ft;
+  GetSystemTimeAsFileTime(&ft);
+
+  LARGE_INTEGER li;
+  li.LowPart = ft.dwLowDateTime;
+  li.HighPart = ft.dwHighDateTime;
+
+  // Convert to seconds and microseconds since Unix time Epoch.
+  int64 micros = (li.QuadPart - kFileTimeToUnixTimeEpochOffset) / 10;
+  tv->tv_sec = static_cast<long>(micros / kNumMicrosecsPerSec);  // NOLINT
+  tv->tv_usec = static_cast<long>(micros % kNumMicrosecsPerSec); // NOLINT
+
+  return 0;
+}
+
+// Emulate POSIX gmtime_r().
+static struct tm *gmtime_r(const time_t *timep, struct tm *result) {
+  // On Windows, gmtime is thread safe.
+  struct tm *tm = gmtime(timep);  // NOLINT
+  if (tm == NULL) {
+    return NULL;
+  }
+  *result = *tm;
+  return result;
+}
+#endif  // WIN32
+
+void CurrentTmTime(struct tm *tm, int *microseconds) {
+  struct timeval timeval;
+  if (gettimeofday(&timeval, NULL) < 0) {
+    // Incredibly unlikely code path.
+    timeval.tv_sec = timeval.tv_usec = 0;
+  }
+  time_t secs = timeval.tv_sec;
+  gmtime_r(&secs, tm);
+  *microseconds = timeval.tv_usec;
+}
+
+uint32 TimeAfter(int32 elapsed) {
+  ASSERT(elapsed >= 0);
+  ASSERT(static_cast<uint32>(elapsed) < HALF);
+  return Time() + elapsed;
+}
+
+bool TimeIsBetween(uint32 earlier, uint32 middle, uint32 later) {
+  if (earlier <= later) {
+    return ((earlier <= middle) && (middle <= later));
+  } else {
+    return !((later < middle) && (middle < earlier));
+  }
+}
+
+bool TimeIsLaterOrEqual(uint32 earlier, uint32 later) {
+#if EFFICIENT_IMPLEMENTATION
+  int32 diff = later - earlier;
+  return (diff >= 0 && static_cast<uint32>(diff) < HALF);
+#else
+  const bool later_or_equal = TimeIsBetween(earlier, later, earlier + HALF);
+  return later_or_equal;
+#endif
+}
+
+bool TimeIsLater(uint32 earlier, uint32 later) {
+#if EFFICIENT_IMPLEMENTATION
+  int32 diff = later - earlier;
+  return (diff > 0 && static_cast<uint32>(diff) < HALF);
+#else
+  const bool earlier_or_equal = TimeIsBetween(later, earlier, later + HALF);
+  return !earlier_or_equal;
+#endif
+}
+
+int32 TimeDiff(uint32 later, uint32 earlier) {
+#if EFFICIENT_IMPLEMENTATION
+  return later - earlier;
+#else
+  const bool later_or_equal = TimeIsBetween(earlier, later, earlier + HALF);
+  if (later_or_equal) {
+    if (earlier <= later) {
+      return static_cast<long>(later - earlier);
+    } else {
+      return static_cast<long>(later + (LAST - earlier) + 1);
+    }
+  } else {
+    if (later <= earlier) {
+      return -static_cast<long>(earlier - later);
+    } else {
+      return -static_cast<long>(earlier + (LAST - later) + 1);
+    }
+  }
+#endif
+}
+
+} // namespace talk_base