Android adb TEMP_FAILURE_RETRY

stdio.c

//bionic/libc/stdio/stdio.c
int
__sread(void *cookie, char *buf, int n)
{
	FILE *fp = cookie;
	int ret;
	
	ret = TEMP_FAILURE_RETRY(read(fp->_file, buf, n));
	/* if the read succeeded, update the current offset */
	if (ret >= 0)
		fp->_offset += ret;
	else
		fp->_flags &= ~__SOFF;	/* paranoia */
	return (ret);
}

sysdeps.h

//system/core/adb/sysdeps.h
//Also see https://stackoverflow.com/questions/12081502/typeof-operator-in-c
//https://gustedt.wordpress.com/2011/01/09/dont-be-afraid-of-variably-modified-types/
/*
 * TEMP_FAILURE_RETRY is defined by some, but not all, versions of
 * <unistd.h>. (Alas, it is not as standard as we'd hoped!) So, if it's
 * not already defined, then define it here.
 */
#ifndef TEMP_FAILURE_RETRY
/* Used to retry syscalls that can return EINTR. */
#define TEMP_FAILURE_RETRY(exp) ({         \
    typeof (exp) _rc;                      \
    do {                                   \
        _rc = (exp);                       \
    } while (_rc == -1 && errno == EINTR); \
    _rc; })
#endif

static __inline__  int  adb_read(int  fd, void*  buf, size_t  len)
{
    return TEMP_FAILURE_RETRY( read( fd, buf, len ) );
}