关于Navigator STK例子的一个问题

在 Navigator STK 里的MNav_test.c 里：
/*poll the packet descriptor in destination queue*/
do
[
/*received packet number should equal to channel number
since each channel transfer on packet*/
uiEntryCount= KeyStone_GetQueueEntryCount(PKT_DMA_TEST_DST_Q);
]while(uiEntryCount cycles= TSC_count_cycle_from(cycles);
printf("Packet DMA achieves %4lld MB/s when transfer %5d bytes ",
(unsigned long long)uiNumCh*uiByteCount*gDSP_Core_Speed_Hz/cycles/1000000,
uiByteCount);
问题：
uiEntryCount= KeyStone_GetQueueEntryCount(PKT_DMA_TEST_DST_Q);是什么意思呢
uiEntryCount 表示的到底是什么呢 ？
谢谢～