Add API: ff_gettimeofday.

Since f-stack run with polling mode, nginx will call gettimeofday every loop, and cost a lot.
With this commit, f-stack will update current timespec periodically in
ff_hardclock_job. And ff_gettimeofday will get this value.
In nginx, hijack gettimeofday to call ff_gettimeofday.

app/nginx-1.11.10/src/event/modules/ngx_ff_module.c

@@ -332,3 +332,10 @@ kevent(int kq, const struct kevent *changelist, int nchanges,
 {
     return ff_kevent(kq, changelist, nchanges, eventlist, nevents, timeout);
 }
+
+int
+gettimeofday(struct timeval *tv, struct timezone *tz)
+{
+    return ff_gettimeofday(tv, tz);
+}
+

lib/ff_api.h

@@ -34,6 +34,7 @@ extern "C" {
 #include <sys/select.h>
 #include <sys/poll.h>
 #include <netinet/in.h>
+#include <sys/time.h>
 
 #include "ff_event.h"
 #include "ff_errno.h"
@@ -106,6 +107,8 @@ int ff_kevent_do_each(int kq, const struct kevent *changelist, int nchanges,
     void *eventlist, int nevents, const struct timespec *timeout, 
     void (*do_each)(void **, struct kevent *));
 
+int ff_gettimeofday(struct timeval *tv, struct timezone *tz);
+
 /* route api begin */
 enum FF_ROUTE_CTL {
     FF_ROUTE_ADD,

lib/ff_api.symlist

@@ -40,4 +40,4 @@ ff_mbuf_copydata
 ff_mbuf_tx_offload
 ff_route_ctl
 ff_rtioctl
-
+ff_gettimeofday

lib/ff_dpdk_if.c

@@ -182,9 +182,10 @@ static struct ff_dpdk_if_context *veth_ctx[RTE_MAX_ETHPORTS];
 extern void ff_hardclock(void);
 
 static void
-freebsd_hardclock_job(__rte_unused struct rte_timer *timer,
+ff_hardclock_job(__rte_unused struct rte_timer *timer,
     __rte_unused void *arg) {
     ff_hardclock();
+    ff_update_current_ts();
 }
 
 struct ff_dpdk_if_context *
@@ -773,11 +774,15 @@ init_port_start(void)
         }
     }
 
+    if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
+        check_all_ports_link_status();
+    }
+
     return 0;
 }
 
 static int
-init_freebsd_clock(void)
+init_clock(void)
 {
     rte_timer_subsystem_init();
     uint64_t hz = rte_get_timer_hz();
@@ -786,7 +791,9 @@ init_freebsd_clock(void)
 
     rte_timer_init(&freebsd_clock);
     rte_timer_reset(&freebsd_clock, tsc, PERIODICAL,
-        rte_lcore_id(), &freebsd_hardclock_job, NULL);
+        rte_lcore_id(), &ff_hardclock_job, NULL);
+
+    ff_update_current_ts();
 
     return 0;
 }
@@ -827,9 +834,7 @@ ff_dpdk_init(int argc, char **argv)
         rte_exit(EXIT_FAILURE, "init_port_start failed\n");
     }
 
-    check_all_ports_link_status();
-
-    init_freebsd_clock();
+    init_clock();
 
     return 0;
 }

lib/ff_host_interface.c

@@ -45,6 +45,8 @@
 #include "ff_host_interface.h"
 #include "ff_errno.h"
 
+static struct timespec current_ts;
+
 void *
 ff_mmap(void *addr, uint64_t len, int prot, int flags, int fd, uint64_t offset)
 {
@@ -171,28 +173,18 @@ ff_clock_gettime_ns(int id)
     return ((uint64_t)sec * ff_NSEC_PER_SEC + nsec);
 }
 
-/*
- *  Sleeps for at least the given number of nanoseconds and returns 0,
- *  unless there is a non-EINTR failure, in which case a non-zero value is
- *  returned.
- */
-int
-ff_nanosleep(uint64_t nsecs)
+void
+ff_get_current_time(time_t *sec, long *nsec)
 {
-    struct timespec ts;
-    struct timespec rts;
-    int rv;
-
-    ts.tv_sec = nsecs / ff_NSEC_PER_SEC;
-    ts.tv_nsec = nsecs % ff_NSEC_PER_SEC;
-    while ((-1 == (rv = nanosleep(&ts, &rts))) && (EINTR == errno)) {
-        ts = rts;
-    }
-    if (-1 == rv) {
-        rv = errno;
+    *sec = current_ts.tv_sec;
+    *nsec = current_ts.tv_nsec;
 }
 
-    return (rv);
+void
+ff_update_current_ts()
+{
+    int rv = clock_gettime(CLOCK_MONOTONIC, &current_ts);
+    assert(rv == 0);
 }
 
 void

lib/ff_host_interface.h

@@ -56,7 +56,9 @@ void ff_free(void *p);
 
 void ff_clock_gettime(int id, int64_t *sec, long *nsec);
 uint64_t ff_clock_gettime_ns(int id);
-int ff_nanosleep(uint64_t nsecs);
+
+void ff_get_current_time(int64_t *sec, long *nsec);
+void ff_update_current_ts(void);
 
 typedef void * ff_mutex_t;
 typedef void * ff_cond_t;

lib/ff_syscall_wrapper.c

@@ -1025,6 +1025,15 @@ ff_kevent(int kq, const struct kevent *changelist, int nchanges,
     return ff_kevent_do_each(kq, changelist, nchanges, eventlist, nevents, timeout, NULL);
 }
 
+int
+ff_gettimeofday(struct timeval *tv, struct timezone *tz)
+{
+    long nsec;
+    ff_get_current_time(&(tv->tv_sec), &nsec);
+    tv->tv_usec = nsec/1000;
+    return 0;
+}
+
 int
 ff_route_ctl(enum FF_ROUTE_CTL req, enum FF_ROUTE_FLAG flag,
     struct linux_sockaddr *dst, struct linux_sockaddr *gw,