安装libevent报错

   
[dudu@localhost libevent-1.3]# make
make  all-recursive
make[1]: 进入目录“/tmp/libevent-1.3”
Making all in .
make[2]: 进入目录“/tmp/libevent-1.3”
/bin/sh ./libtool --tag=CC --mode=compile gcc -DHAVE_CONFIG_H -I. -I. -I. -Icompat     -g -O2 -Wall -c -o event.lo event.c
mkdir .libs
gcc -DHAVE_CONFIG_H -I. -I. -I. -Icompat -g -O2 -Wall -c event.c  -fPIC -DPIC -o .libs/event.o
event.c: In function 'gettime':
event.c:156:2: warning: implicit declaration of function 'clock_gettime' [-Wimplicit-function-declaration]
  if (clock_gettime(CLOCK_REALTIME, &ts) == -1)
  ^
event.c:156:20: error: 'CLOCK_REALTIME' undeclared (first use in this function)
  if (clock_gettime(CLOCK_REALTIME, &ts) == -1)
                    ^
event.c:156:20: note: each undeclared identifier is reported only once for each function it appears in
make[2]: *** [event.lo] 错误 1
make[2]: 离开目录“/tmp/libevent-1.3”
make[1]: *** [all-recursive] 错误 1
make[1]: 离开目录“/tmp/libevent-1.3”
make: *** [all] 错误 2