From 7350d1d3b2ec940c89a2b20f9d09985d9fd9e9d7 Mon Sep 17 00:00:00 2001 From: julian Date: Tue, 20 Aug 1996 08:22:01 +0000 Subject: Submitted by: John Birrell Here are the diffs for libc_r to get it one step closer to P1003.1c These make most of the thread/mutex/condvar structures opaque to the user. There are three functions which have been renamed with _np suffixes because they are extensions to P1003.1c (I did them for JAVA, which needs to suspend/resume threads and also start threads suspended). I've created a new header (pthread_np.h) for the non-POSIX stuff. The egrep tags stuff in /usr/src/lib/libc_r/Makefile that I uncommented doesn't work. I think its best to delete it. I don't think libc_r needs tags anyway, 'cause most of the source is in libc which does have tags. also: Here's the first batch of man pages for the thread functions. The diff to /usr/src/lib/libc_r/Makefile removes some stuff that was inherited from /usr/src/lib/libc/Makefile that should only be done with libc. also: I should have sent this diff with the pthread(3) man page. It allows people to type make -DWANT_LIBC_R world to get libc_r built with the rest of the world. I put this in the pthread(3) man page. The default is still not to build libc_r. also: The diff attached adds a pthread(3) man page to /usr/src/share/man/man3. The idea is that without libc_r installed, this man page will give people enough info to know that they have to build libc_r. --- lib/libc_r/uthread/uthread_close.c | 52 ++++++++++++++++++++++++++++++++++++-- 1 file changed, 50 insertions(+), 2 deletions(-) (limited to 'lib/libc_r/uthread/uthread_close.c') diff --git a/lib/libc_r/uthread/uthread_close.c b/lib/libc_r/uthread/uthread_close.c index f98e056..26a8fbf 100644 --- a/lib/libc_r/uthread/uthread_close.c +++ b/lib/libc_r/uthread/uthread_close.c @@ -30,7 +30,10 @@ * SUCH DAMAGE. * */ +#include #include +#include +#include #ifdef _THREAD_SAFE #include #include "pthread_private.h" @@ -38,10 +41,55 @@ int close(int fd) { - int ret; + int flags; + int ret; + int status; + struct stat sb; + + /* Lock the file descriptor while the file is closed: */ if ((ret = _thread_fd_lock(fd, FD_RDWR, NULL, __FILE__, __LINE__)) == 0) { + /* Block signals: */ + _thread_kern_sig_block(&status); + + /* Get file descriptor status. */ + fstat(fd, &sb); + + /* + * Check if the file should be left as blocking. + * + * This is so that the file descriptors shared with a parent + * process aren't left set to non-blocking if the child + * closes them prior to exit. An example where this causes + * problems with /bin/sh is when a child closes stdin. + * + * Setting a file as blocking causes problems if a threaded + * parent accesses the file descriptor before the child exits. + * Once the threaded parent receives a SIGCHLD then it resets + * all of its files to non-blocking, and so it is then safe + * to access them. + * + * Pipes are not set to blocking when they are closed, as + * the parent and child will normally close the file + * descriptor of the end of the pipe that they are not + * using, which would then cause any reads to block + * indefinitely. + */ + if ((S_ISREG(sb.st_mode) || S_ISCHR(sb.st_mode)) && (_thread_fd_table[fd]->flags & O_NONBLOCK) == 0) { + /* Get the current flags: */ + flags = _thread_sys_fcntl(fd, F_GETFL, NULL); + /* Clear the nonblocking file descriptor flag: */ + _thread_sys_fcntl(fd, F_SETFL, flags & ~O_NONBLOCK); + } + + /* Close the file descriptor: */ ret = _thread_sys_close(fd); - _thread_fd_unlock(fd, FD_RDWR); + + /* Free the file descriptor table entry: */ + free(_thread_fd_table[fd]); + _thread_fd_table[fd] = NULL; + + /* Unblock signals again: */ + _thread_kern_sig_unblock(status); } return (ret); } -- cgit v1.1