From fb5dd968ec23014d25f694c2e88604f14578e68f Mon Sep 17 00:00:00 2001 From: ocean Date: Sat, 17 Sep 2005 21:44:24 +0000 Subject: * win32/win32.c (rb_w32_select): documented problem. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@9208 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- win32/win32.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) (limited to 'win32') diff --git a/win32/win32.c b/win32/win32.c index da0fa3c069..df97a39da6 100644 --- a/win32/win32.c +++ b/win32/win32.c @@ -2064,6 +2064,12 @@ rb_w32_select(int nfds, fd_set *rd, fd_set *wr, fd_set *ex, StartSockets(); } + // assume else_{rd,wr} (other than socket, pipe reader, console reader) + // are always readable/writable. but this implementation still has + // problem. if pipe's buffer is full, writing to pipe will block + // until some data is read from pipe. but ruby is single threaded system, + // so whole system will be blocked forever. + else_rd.fd_count = 0; nonsock += extract_fd(&else_rd, rd, is_not_socket); @@ -2100,17 +2106,18 @@ rb_w32_select(int nfds, fd_set *rd, fd_set *wr, fd_set *ex, struct timeval zero; if (timeout) rest = *timeout; wait.tv_sec = 0; wait.tv_usec = 10 * 1000; // 10ms - zero.tv_sec = 0; zero.tv_usec = 0; // poling + zero.tv_sec = 0; zero.tv_usec = 0; // 0ms do { - // this is safe because handle is moved, function returns anway. + // modifying {else,pipe,cons}_rd is safe because + // if they are modified, function returns immediately. extract_fd(&else_rd, &pipe_rd, is_readable_pipe); extract_fd(&else_rd, &cons_rd, is_readable_console); if (else_rd.fd_count || else_wr.fd_count) { - r = do_select(nfds, rd, wr, ex, &zero); + r = do_select(nfds, rd, wr, ex, &zero); // polling if (r < 0) break; // XXX: should I ignore error and return signaled handles? - r += extract_fd(rd, &else_rd, NULL); - r += extract_fd(wr, &else_wr, NULL); + r += extract_fd(rd, &else_rd, NULL); // move all + r += extract_fd(wr, &else_wr, NULL); // move all break; } else { @@ -2121,7 +2128,7 @@ rb_w32_select(int nfds, fd_set *rd, fd_set *wr, fd_set *ex, if (wr) orig_wr = *wr; if (ex) orig_ex = *ex; r = do_select(nfds, rd, wr, ex, &wait); - if (r) break; // signaled or error + if (r != 0) break; // signaled or error if (rd) *rd = orig_rd; if (wr) *wr = orig_wr; if (ex) *ex = orig_ex; -- cgit v1.2.3