commit 43550eee5bfeaf7832487a2285ae86be0f7ce561
author Jeff Brown <jeffbrown@google.com> Thu Mar 17 01:34:19 2011 -0700
committer Alex Ray <aray@google.com> Tue Jul 30 13:56:56 2013 -0700
tree 416b1750a40bced1f92c0d6025b7ca95755eed3e
parent 7c123375ffee76d6e15b611e8146c13bb67a8c9f

Refactor how timeouts are calculated.

Added a timeout mechanism to EventHub and InputReader so that
InputMappers can request timeouts to perform delayed processing of
input when needed.

Change-Id: Iec2045baaf4e67690b15eef3c09a58d5cac76897

include/utils/Timers.h

diff --git a/include/utils/Timers.h b/include/utils/Timers.h
index 9a9e07c..8b4d322 100644
--- a/include/utils/Timers.h
+++ b/include/utils/Timers.h
@@ -88,6 +88,16 @@
 nsecs_t systemTime(int clock);
 #endif // def __cplusplus
 
+/**
+ * Returns the number of milliseconds to wait between the reference time and the timeout time.
+ * If the timeout is in the past relative to the reference time, returns 0.
+ * If the timeout is more than INT_MAX milliseconds in the future relative to the reference time,
+ * such as when timeoutTime == LLONG_MAX, returns -1 to indicate an infinite timeout delay.
+ * Otherwise, returns the difference between the reference time and timeout time
+ * rounded up to the next millisecond.
+ */
+int toMillisecondTimeoutDelay(nsecs_t referenceTime, nsecs_t timeoutTime);
+
 #ifdef __cplusplus
 } // extern "C"
 #endif

libs/utils/Looper.cpp

diff --git a/libs/utils/Looper.cpp b/libs/utils/Looper.cpp
index 18f858b..d5dd126 100644
--- a/libs/utils/Looper.cpp
+++ b/libs/utils/Looper.cpp
@@ -218,14 +218,10 @@
     // Adjust the timeout based on when the next message is due.
     if (timeoutMillis != 0 && mNextMessageUptime != LLONG_MAX) {
         nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
-        if (mNextMessageUptime <= now) {
-            timeoutMillis = 0;
-        } else {
-            uint64_t delay = (mNextMessageUptime - now + 999999LL) / 1000000LL;
-            if (delay < INT_MAX
-                    && (timeoutMillis < 0 || int(delay) < timeoutMillis)) {
-                timeoutMillis = int(delay);
-            }
+        int messageTimeoutMillis = toMillisecondTimeoutDelay(now, mNextMessageUptime);
+        if (messageTimeoutMillis >= 0
+                && (timeoutMillis < 0 || messageTimeoutMillis < timeoutMillis)) {
+            timeoutMillis = messageTimeoutMillis;
         }
 #if DEBUG_POLL_AND_WAKE
         LOGD("%p ~ pollOnce - next message in %lldns, adjusted timeout: timeoutMillis=%d",
@@ -444,12 +440,11 @@
                 return result;
             }
 
-            nsecs_t timeoutNanos = endTime - systemTime(SYSTEM_TIME_MONOTONIC);
-            if (timeoutNanos <= 0) {
+            nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
+            timeoutMillis = toMillisecondTimeoutDelay(now, endTime);
+            if (timeoutMillis == 0) {
                 return ALOOPER_POLL_TIMEOUT;
             }
-
-            timeoutMillis = int(nanoseconds_to_milliseconds(timeoutNanos + 999999LL));
         }
     }
 }

libs/utils/Timers.cpp

diff --git a/libs/utils/Timers.cpp b/libs/utils/Timers.cpp
index 784f035..64a29f5 100644
--- a/libs/utils/Timers.cpp
+++ b/libs/utils/Timers.cpp
@@ -26,6 +26,7 @@
 #include <sys/time.h>
 #include <time.h>
 #include <errno.h>
+#include <limits.h>
 
 #ifdef HAVE_WIN32_THREADS
 #include <windows.h>
@@ -53,6 +54,23 @@
 #endif
 }
 
+int toMillisecondTimeoutDelay(nsecs_t referenceTime, nsecs_t timeoutTime)
+{
+    int timeoutDelayMillis;
+    if (timeoutTime > referenceTime) {
+        uint64_t timeoutDelay = uint64_t(timeoutTime - referenceTime);
+        if (timeoutDelay > uint64_t((INT_MAX - 1) * 1000000LL)) {
+            timeoutDelayMillis = -1;
+        } else {
+            timeoutDelayMillis = (timeoutDelay + 999999LL) / 1000000LL;
+        }
+    } else {
+        timeoutDelayMillis = 0;
+    }
+    return timeoutDelayMillis;
+}
+
+
 /*
  * ===========================================================================
  *      DurationTimer