Fix the problem of slow exit of boot animation

When desc.txt configuration interval is very long, it leads to too long sleep time, which affects the execution frequency of checkExit and leads to untimely exit of boot animation.

For example:
1080 2400 5
p 0 5 part0

Change-Id: I9806a934189642a31ceb72cbf35c3ff07fe6b7d8
Signed-off-by: niuwenchao <niuwenchao@xiaomi.com>
diff --git a/cmds/bootanimation/BootAnimation.cpp b/cmds/bootanimation/BootAnimation.cpp
index 6b6bc97..27dadda 100644
--- a/cmds/bootanimation/BootAnimation.cpp
+++ b/cmds/bootanimation/BootAnimation.cpp
@@ -107,6 +107,7 @@
 static const char DISPLAYS_PROP_NAME[] = "persist.service.bootanim.displays";
 static const char CLOCK_ENABLED_PROP_NAME[] = "persist.sys.bootanim.clock.enabled";
 static const int ANIM_ENTRY_NAME_MAX = ANIM_PATH_MAX + 1;
+static const int MAX_CHECK_EXIT_INTERVAL_US = 50000;
 static constexpr size_t TEXT_POS_LEN_MAX = 16;
 static const int DYNAMIC_COLOR_COUNT = 4;
 static const char U_TEXTURE[] = "uTexture";
@@ -1680,7 +1681,17 @@
                 checkExit();
             }
 
-            usleep(part.pause * ns2us(frameDuration));
+            int pauseDuration = part.pause * ns2us(frameDuration);
+            while(pauseDuration > 0 && !exitPending()){
+                if (pauseDuration > MAX_CHECK_EXIT_INTERVAL_US) {
+                    usleep(MAX_CHECK_EXIT_INTERVAL_US);
+                    pauseDuration -= MAX_CHECK_EXIT_INTERVAL_US;
+                } else {
+                    usleep(pauseDuration);
+                    break;
+                }
+                checkExit();
+            }
 
             if (exitPending() && !part.count && mCurrentInset >= mTargetInset &&
                 !part.hasFadingPhase()) {