ssize_t readn(int fd, void *buf, size_t n);
ssize_t writen(int fd, const void *buf, size_t n);
+ssize_t preadn(int fd, void *buf, size_t n, off_t offs);
+
#endif /* __LIBPERF_INTERNAL_CPUMAP_H */
return ion(true, fd, buf, n);
}
+ssize_t preadn(int fd, void *buf, size_t n, off_t offs)
+{
+ size_t left = n;
+
+ while (left) {
+ ssize_t ret = pread(fd, buf, left, offs);
+
+ if (ret < 0 && errno == EINTR)
+ continue;
+ if (ret <= 0)
+ return ret;
+
+ left -= ret;
+ buf += ret;
+ offs += ret;
+ }
+
+ return n;
+}
+
/*
* Write exactly 'n' bytes or return an error.
*/