From 08e55d81ef1ca4a540345964e8d1f464a88957b7 Mon Sep 17 00:00:00 2001
From: Copybara-Service <copybara-worker@google.com>
Date: Wed, 23 Oct 2024 15:22:22 -0700
Subject: [PATCH] Merge pull request #1794 from
 stevemayhew:p-fix-ntp-time-update-main

PiperOrigin-RevId: 689121191
(cherry picked from commit b5615d5e919b297def6450b45320a3165c34548c)
---
 RELEASENOTES.md                               |  4 +++
 .../media3/exoplayer/util/SntpClient.java     | 30 +++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 1c5da6be41..5cb14f1565 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -7,6 +7,10 @@
 This release includes the following changes since the
 [1.5.0-beta01 release](#150-beta01-2024-10-30):
 
+*   ExoPlayer:
+    *   Add a setter to `SntpClient` to set the max elapsed time since the last
+        update after which the client is re-initialized
+        ([#1794](https://github.com/androidx/media/pull/1794)).
 *   Extractors:
     *   Fix media duration parsing in `mdhd` box of MP4 files to handle `-1`
         values ([#1819](https://github.com/androidx/media/issues/1819)).
diff --git a/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/util/SntpClient.java b/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/util/SntpClient.java
index df8010c75f..db84e8494d 100644
--- a/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/util/SntpClient.java
+++ b/libraries/exoplayer/src/main/java/androidx/media3/exoplayer/util/SntpClient.java
@@ -96,6 +96,12 @@ public final class SntpClient {
   @GuardedBy("valueLock")
   private static int timeoutMs = DEFAULT_TIMEOUT_MS;
 
+  @GuardedBy("valueLock")
+  private static long maxElapsedTimeUntilUpdateMs = C.TIME_UNSET;
+
+  @GuardedBy("valueLock")
+  private static long lastUpdateElapsedRealtime = C.TIME_UNSET;
+
   private SntpClient() {}
 
   /** Returns the NTP host address used to retrieve {@link #getElapsedRealtimeOffsetMs()}. */
@@ -148,6 +154,24 @@ public final class SntpClient {
     }
   }
 
+  /**
+   * Sets the maximum time to elapse until the client is re-initialized, in milliseconds.
+   *
+   * <p>The default is {@link C#TIME_UNSET} to never re-initialize.
+   */
+  public static void setMaxElapsedTimeUntilUpdateMs(long maxElapsedTimeUntilUpdateMs) {
+    synchronized (valueLock) {
+      SntpClient.maxElapsedTimeUntilUpdateMs = maxElapsedTimeUntilUpdateMs;
+    }
+  }
+
+  /** Returns the maximum time to elapse until the client is re-initialized, in milliseconds. */
+  public static long getMaxElapsedTimeUntilUpdateMs() {
+    synchronized (valueLock) {
+      return maxElapsedTimeUntilUpdateMs;
+    }
+  }
+
   /**
    * Returns whether the device time offset has already been loaded.
    *
@@ -156,6 +180,11 @@ public final class SntpClient {
    */
   public static boolean isInitialized() {
     synchronized (valueLock) {
+      if (lastUpdateElapsedRealtime != C.TIME_UNSET
+          && maxElapsedTimeUntilUpdateMs != C.TIME_UNSET) {
+        long deltaLastUpdate = SystemClock.elapsedRealtime() - lastUpdateElapsedRealtime;
+        isInitialized = isInitialized && deltaLastUpdate < maxElapsedTimeUntilUpdateMs;
+      }
       return isInitialized;
     }
   }
@@ -353,6 +382,7 @@ public final class SntpClient {
         }
         long offsetMs = loadNtpTimeOffsetMs();
         synchronized (valueLock) {
+          lastUpdateElapsedRealtime = SystemClock.elapsedRealtime();
           elapsedRealtimeOffsetMs = offsetMs;
           isInitialized = true;
         }