diff options
| author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2012-12-17 00:05:04 +0100 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2012-12-17 00:14:36 +0100 |
| commit | cbe6f88b5ee7fa3394e916a8a7fe893066923b73 (patch) | |
| tree | 218060794f87c0fbaa0a9b2f34ca322acf3598a8 /trans/fifo.c | |
| parent | 23c9bbee12b08bcbc82188dabe3bf8135756c183 (diff) | |
Make io_select return errors
instead of returning 0 and make clients have to actually read the error.
This makes implementing "poll" much easier.
Based on Svante Signell's patch.
* pflocal/io.c (S_io_select): Return error returned by pipe_wait_readable or
pipe_wait_writable.
* trans/fifo.c (trivfs_S_io_select): Return error returned by
pipe_wait_readable or pipe_wait_writable. Return EBADF on bogus access mode.
* trans/new-fifo.c (trivfs_S_io_select): Likewise.
Diffstat (limited to 'trans/fifo.c')
| -rw-r--r-- | trans/fifo.c | 27 |
1 files changed, 21 insertions, 6 deletions
diff --git a/trans/fifo.c b/trans/fifo.c index 4fe999dd..b40a50d1 100644 --- a/trans/fifo.c +++ b/trans/fifo.c @@ -424,12 +424,21 @@ trivfs_S_io_select (struct trivfs_protid *cred, if (cred->po->openmodes & O_READ) { pthread_mutex_lock (&pipe->lock); - if (pipe_wait_readable (pipe, 1, 1) != EWOULDBLOCK) - ready |= SELECT_READ; /* Data immediately readable (or error). */ + err = pipe_wait_readable (pipe, 1, 1); + if (err == EWOULDBLOCK) + err = 0; /* Not readable, actually not an error. */ + else + ready |= SELECT_READ; /* Data immediately readable (or error). */ pthread_mutex_unlock (&pipe->lock); } else - ready |= SELECT_READ; /* Error immediately available... */ + { + err = EBADF; + ready |= SELECT_READ; /* Error immediately available... */ + } + if (err) + /* Prevent write test from overwriting err. */ + *select_type &= ~SELECT_WRITE; } if (*select_type & SELECT_WRITE) @@ -437,12 +446,18 @@ trivfs_S_io_select (struct trivfs_protid *cred, if (cred->po->openmodes & O_WRITE) { pthread_mutex_lock (&pipe->lock); - if (pipe_wait_writable (pipe, 1) != EWOULDBLOCK) - ready |= SELECT_WRITE; /* Data immediately writable (or error). */ + err = pipe_wait_writable (pipe, 1); + if (err == EWOULDBLOCK) + err = 0; /* Not writable, actually not an error. */ + else + ready |= SELECT_WRITE; /* Data immediately writable (or error). */ pthread_mutex_unlock (&pipe->lock); } else - ready |= SELECT_WRITE; /* Error immediately available... */ + { + err = EBADF; + ready |= SELECT_WRITE; /* Error immediately available... */ + } } if (ready) |