dpdk_read_with_timeout() non-blocking, blocking with timeout read

diff --git a/pcap-dpdk.c b/pcap-dpdk.c
index 285a63ab68e663b25b18f6b8aa0fee2eb5d7c148..824a5de079c43daa95009ad9d914a4acd734ff78 100644 (file)
--- a/pcap-dpdk.c
+++ b/pcap-dpdk.c
@@ -124,7 +124,7 @@ static int is_dpdk_pre_inited=0;
 #define DPDK_DEV_NAME_MAX 32
 #define DPDK_DEV_DESC_MAX 512 
 #define DPDK_CFG_ENV_NAME "DPDK_CFG"
-#define DPDK_DEF_MIN_SLEEP_MS 100
+#define DPDK_DEF_MIN_SLEEP_MS 1
 static char dpdk_cfg_buf[DPDK_CFG_MAX_LEN];
 #define DPDK_MAC_ADDR_SIZE 32
 #define DPDK_DEF_MAC_ADDR "00:00:00:00:00:00"
@@ -215,11 +215,40 @@ static uint32_t dpdk_gather_data(unsigned char *data, int len, struct rte_mbuf *
        return total_len;
 }
 
+
+static int dpdk_read_with_timeout(pcap_t *p, uint16_t portid, uint16_t queueid,struct rte_mbuf **pkts_burst, const uint16_t burst_cnt){
+       struct pcap_dpdk *pd = (struct pcap_dpdk*)(p->priv);
+       int nb_rx = 0;  
+       int timeout_ms = p->opt.timeout;
+       int sleep_ms = 0;
+       if (pd->nonblock){
+               // In non-blocking mode, just read once, no mater how many packets are captured.
+               nb_rx = (int)rte_eth_rx_burst(pd->portid, 0, pkts_burst, burst_cnt);
+       }else{
+               // In blocking mode, read many times until packets are captured or timeout or break_loop is setted.     
+               // if timeout_ms == 0, it may be blocked forever.
+               while (timeout_ms == 0 || sleep_ms < timeout_ms){
+                       nb_rx = (int)rte_eth_rx_burst(pd->portid, 0, pkts_burst, burst_cnt);
+                       if (nb_rx){ // got packets within timeout_ms
+                               break;  
+                       }else{ // no packet arrives at this round.
+                               if (p->break_loop){
+                                       break;
+                               }
+                               // sleep for a very short while, but do not block CPU.
+                               rte_delay_us_block(DPDK_DEF_MIN_SLEEP_MS*1000);
+                               sleep_ms += DPDK_DEF_MIN_SLEEP_MS;
+                       }
+               }
+       }
+       return nb_rx;
+}
+
 static int pcap_dpdk_dispatch(pcap_t *p, int max_cnt, pcap_handler cb, u_char *cb_arg)
 {
        struct pcap_dpdk *pd = (struct pcap_dpdk*)(p->priv);
        int burst_cnt = 0;
-       int nb_rx=0;
+       int nb_rx = 0;
        struct rte_mbuf *pkts_burst[MAX_PKT_BURST];
        struct rte_mbuf *m;
        struct pcap_pkthdr pcap_header;
@@ -233,7 +262,8 @@ static int pcap_dpdk_dispatch(pcap_t *p, int max_cnt, pcap_handler cb, u_char *c
        int pkt_cnt = 0;
        int is_accepted=0;
        u_char *large_buffer=NULL;
-       
+       int timeout_ms = p->opt.timeout;
+
        pd->rx_pkts = 0;
        if ( !PACKET_COUNT_IS_UNLIMITED(max_cnt) && max_cnt < MAX_PKT_BURST){
                burst_cnt = max_cnt;
@@ -243,9 +273,27 @@ static int pcap_dpdk_dispatch(pcap_t *p, int max_cnt, pcap_handler cb, u_char *c
 
        while( PACKET_COUNT_IS_UNLIMITED(max_cnt) || pkt_cnt < max_cnt){
                if (p->break_loop){
-                       break;
+                       p->break_loop = 1;
+                       return PCAP_ERROR_BREAK;
+               }
+               // read once in non-blocking mode, or try many times waiting for timeout_ms.
+               // if timeout_ms == 0, it will be blocked until one packet arrives or break_loop is setted.
+               nb_rx = dpdk_read_with_timeout(p, portid, 0, pkts_burst, burst_cnt);
+               if (nb_rx == 0){ 
+                       if (pd->nonblock){
+                               RTE_LOG(DEBUG, USER1, "dpdk: no packets available in non-blocking mode.\n");
+                       }else{
+                               if (p->break_loop){
+                                       RTE_LOG(DEBUG, USER1, "dpdk: no packets available and break_loop is setted in blocking mode.\n");
+                                       p->break_loop = 1;
+                                       return PCAP_ERROR_BREAK;
+
+                               }
+                               RTE_LOG(DEBUG, USER1, "dpdk: no packets available for timeout %d ms in blocking mode.\n", timeout_ms);
+                       }
+                       // break if dpdk reads 0 packet, no matter in blocking(timeout) or non-blocking mode.
+                       break;  
                }
-               nb_rx = (int)rte_eth_rx_burst(portid, 0, pkts_burst, burst_cnt);
                pkt_cnt += nb_rx;
                for ( i = 0; i < nb_rx; i++) {
                        m = pkts_burst[i];