+ /* Make sure the input buffer is big enough to hold "needed" bytes.
+ * Also make sure it will fit in the free space at the end, or
+ * else we need to shift some bytes. */
+ if (needed && iobuf.in.size < needed) {
+ if (!(iobuf.in.buf = realloc_array(iobuf.in.buf, char, needed)))
+ out_of_memory("perform_io");
+ if (DEBUG_GTE(IO, 4)) {
+ rprintf(FINFO, "[%s] resized input buffer from %ld to %ld bytes.\n",
+ who_am_i(), (long)iobuf.in.size, (long)needed);
+ }
+ iobuf.in.size = needed;
+ }
+ if (iobuf.in.size - iobuf.in.pos < needed
+ || (iobuf.in.len < needed && iobuf.in.len < 1024
+ && iobuf.in.size - (iobuf.in.pos + iobuf.in.len) < 1024)) {
+ memmove(iobuf.in.buf, iobuf.in.buf + iobuf.in.pos, iobuf.in.len);
+ if (DEBUG_GTE(IO, 4)) {
+ rprintf(FINFO,
+ "[%s] moved %ld bytes from %ld to 0 in the input buffer (size=%ld, needed=%ld).\n",
+ who_am_i(), (long)iobuf.in.len, (long)iobuf.in.pos, (long)iobuf.in.size, (long)needed);
+ }
+ if (iobuf.raw_input_ends_before)
+ iobuf.raw_input_ends_before -= iobuf.in.pos;
+ iobuf.in.pos = 0;
+ }
+ break;
+
+ case PIO_NEED_OUTROOM:
+ /* We never resize the circular output buffer. */
+ if (iobuf.out.size - iobuf.out_empty_len < needed) {
+ fprintf(stderr, "need to write %ld bytes, iobuf.out.buf is only %ld bytes.\n",
+ (long)needed, (long)(iobuf.out.size - iobuf.out_empty_len));
+ exit_cleanup(RERR_PROTOCOL);
+ }
+
+ if (DEBUG_GTE(IO, 3)) {
+ rprintf(FINFO, "[%s] perform_io(%ld, outroom) needs to flush %ld\n",
+ who_am_i(), (long)needed,
+ iobuf.out.len + needed > iobuf.out.size
+ ? (long)(iobuf.out.len + needed - iobuf.out.size) : 0L);
+ }
+ break;
+
+ case PIO_NEED_MSGROOM:
+ /* We never resize the circular message buffer. */
+ if (iobuf.msg.size < needed) {
+ fprintf(stderr, "need to write %ld bytes, iobuf.msg.buf is only %ld bytes.\n",
+ (long)needed, (long)iobuf.msg.size);
+ exit_cleanup(RERR_PROTOCOL);
+ }
+
+ if (DEBUG_GTE(IO, 3)) {
+ rprintf(FINFO, "[%s] perform_io(%ld, msgroom) needs to flush %ld\n",
+ who_am_i(), (long)needed,
+ iobuf.msg.len + needed > iobuf.msg.size
+ ? (long)(iobuf.msg.len + needed - iobuf.msg.size) : 0L);
+ }
+ break;
+
+ case 0:
+ if (DEBUG_GTE(IO, 3))
+ rprintf(FINFO, "[%s] perform_io(%ld, %d)\n", who_am_i(), (long)needed, flags);
+ break;
+
+ default:
+ exit_cleanup(RERR_UNSUPPORTED);
+ }
+
+ while (1) {
+ switch (flags & PIO_NEED_FLAGS) {
+ case PIO_NEED_INPUT:
+ if (iobuf.in.len >= needed)
+ goto double_break;
+ break;
+ case PIO_NEED_OUTROOM:
+ /* Note that iobuf.out_empty_len doesn't factor into this check
+ * because iobuf.out.len already holds any needed header len. */
+ if (iobuf.out.len + needed <= iobuf.out.size)
+ goto double_break;
+ break;
+ case PIO_NEED_MSGROOM:
+ if (iobuf.msg.len + needed <= iobuf.msg.size)
+ goto double_break;
+ break;
+ }
+
+ max_fd = -1;