我让我的记录处理程序在 strace 下运行了几分钟。
这表明在这几分钟内有超过 200 000 000 个呼叫stat("/etc/localtime",..)
这听起来有点过分而且没有必要。
strace 输出如下所示:
write(1, "C137015 393393093052629137110 47"..., 16384) = 16384
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2225, ...}) = 0
read(0, "\224q\1\207\0\0\202\1\4\203\1\4\204\1\1\205\1\1\206\1\7\207\1\6\211\1\22\212\1\22\213\1"..., 16384) = 16384
本质上,它是对处理的每条记录进行 1 次 stat() 调用,而罪魁祸首就是这行非常普通的代码
strftime(call->date_time,DATELEN,"%Y%m%d %H%M%S",&tm_buf);
那么 - 如何避免 strftime() 在每次调用时调用 stat(/etc/localtime) ?