through a temporary buffer instead of one character at a time. The old
method takes about 6 usec/char on a 486DX2/66. This is larger than than
the combined interrupt and PIO overhead for a 16550!
This change was first implemented in 1.1.5. It was rewritten for 2.1.
The clist access functions allow a simpler implementation at some cost
in correctness and speed. There needs to be an ungetc() function to
recover from EFAULT, and it wastes time to copy through a temporary
buffer.
Don't snoop on single characters that weren't read due to EFAULT.
Rewrite a snoop comment in my approximation to English.
Undo bogus exportation of ttnread().
3431d053fa