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我正在運行Linux,並有這段代碼片斷,我想用它來操縱C中的一個定時器,每40ms觸發一個函數。到目前爲止,我只試圖運行創建並啓動新計時器的部分。然而,我收到以下錯誤:在C中初始化定時器
/tmp/ccA7MbyS.o: In function `main':
server.c:(.text+0x69e): undefined reference to `timer_create'
server.c:(.text+0x6be): undefined reference to `timer_settime'
collect2: ld returned 1 exit status
如果我註釋這些方法代碼編譯罰款。有任何想法嗎?
#include <sys/time.h>
#include <signal.h>
#include <time.h>
// This struct is created to save information that will be needed by the timer,
// such as socket file descriptors, frame numbers and video captures.
struct send_frame_data {
int socket_fd;
// other fields
};
// This function will be called when the timer ticks
void send_frame(union sigval sv_data) {
struct send_frame_data *data = (struct send_frame_data *) sv_data.sival_ptr;
// You may retrieve information from the caller using data->field_name
// ...
}
// ...
// The following snippet is used to create and start a new timer that runs
// every 40 ms.
struct send_frame_data data; // Set fields as necessary
struct sigevent play_event;
timer_t play_timer;
struct itimerspec play_interval;
memset(&play_event, 0, sizeof(play_event));
play_event.sigev_notify = SIGEV_THREAD;
play_event.sigev_value.sival_ptr = &data;
play_event.sigev_notify_function = send_frame;
play_interval.it_interval.tv_sec = 0;
play_interval.it_interval.tv_nsec = 40 * 1000000; // 40 ms in ns
play_interval.it_value.tv_sec = 0;
play_interval.it_value.tv_nsec = 1; // can't be zero
timer_create(CLOCK_REALTIME, &play_event, &play_timer);
timer_settime(play_timer, 0, &play_interval, NULL);
// The following snippet is used to stop a currently running timer. The current
// task is not interrupted, only future tasks are stopped.
play_interval.it_interval.tv_sec = 0;
play_interval.it_interval.tv_nsec = 0;
play_interval.it_value.tv_sec = 0;
play_interval.it_value.tv_nsec = 0;
timer_settime(play_timer, 0, &play_interval, NULL);
// The following line is used to delete a timer.
timer_delete(play_timer);
我一直在掙扎整天跟這和解決方案是如此簡單,哈哈,感謝的人。 – 2013-04-04 01:05:16
@PatricioJerí適合我們所有人:)很高興我能提供幫助。 – 2013-04-04 01:05:28
''lrt'記錄在'clock_gettime'的'man'頁面中......請**閱讀'man'頁面**(例如在您的終端中鍵入'man clock_gettime'),它們幫助很大。 – 2013-04-04 05:19:50