From ab087e0aa4bd9f12a73ca0b248f02d8a22d49e46 Mon Sep 17 00:00:00 2001 From: Andreas Schwab Date: Sat, 19 Jan 2013 17:18:47 +0100 Subject: Avoid busy loop in wordexp when substituted command closed its stdout --- posix/wordexp.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'posix') diff --git a/posix/wordexp.c b/posix/wordexp.c index bf49baab9c..96ce8a4b17 100644 --- a/posix/wordexp.c +++ b/posix/wordexp.c @@ -953,7 +953,12 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, if ((buflen = TEMP_FAILURE_RETRY (__read (fildes[0], buffer, bufsize))) < 1) { - if (TEMP_FAILURE_RETRY (__waitpid (pid, &status, WNOHANG)) == 0) + /* If read returned 0 then the process has closed its + stdout. Don't use WNOHANG in that case to avoid busy + looping until the process eventually exits. */ + if (TEMP_FAILURE_RETRY (__waitpid (pid, &status, + buflen == 0 ? 0 : WNOHANG)) + == 0) continue; if ((buflen = TEMP_FAILURE_RETRY (__read (fildes[0], buffer, bufsize))) < 1) @@ -983,7 +988,12 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, if ((buflen = TEMP_FAILURE_RETRY (__read (fildes[0], buffer, bufsize))) < 1) { - if (TEMP_FAILURE_RETRY (__waitpid (pid, &status, WNOHANG)) == 0) + /* If read returned 0 then the process has closed its + stdout. Don't use WNOHANG in that case to avoid busy + looping until the process eventually exits. */ + if (TEMP_FAILURE_RETRY (__waitpid (pid, &status, + buflen == 0 ? 0 : WNOHANG)) + == 0) continue; if ((buflen = TEMP_FAILURE_RETRY (__read (fildes[0], buffer, bufsize))) < 1) -- cgit 1.4.1