> Now that people are able to build libc, I'd like somebody to try out
> my posix_spawn implementation. Plop this into sysdeps/mach/hurd/spawni.c,
> rebuild libc, and then try the `tst-spawn' test in posix. Then you get to
> debug it for me. As described in the comments, I will probably rewrite
> parts of this to do something more hairy (and more robust). But I'd like
> to get this code tested and debugged first.
Roland, it is a pleasure debugging your code: I always learn so much.
Anyway, three small bugs:
o We need <spin-lock.h> for the declaration of spin_lock_locked.
o Anything allocated with alloca is freed when the stack frame is
destroy, i.e. we cannot expand local arrays using a nested
function; I have changed this to a macro in the included patch.
o You forgot to clear the corresponding dtable_cell when setting
dtable to a raw port in the spawn_do_open action. This was causing
a core dump in the clean up code.
The code with this patch passes Ulrich's test plus a few personal
additions.
2001-12-16 Neal H Walfield <[EMAIL PROTECTED]>
* sysdeps/mach/hurd/spawni.c: Include <spin-lock.h> for the
spin_lock_locked declaration.
(__spawni:expand_dtable): Change this from a function . . .
(EXPAND_DTABLE): . . . to a macro.
(GROW_TABLE): New macro.
(__spawni): When setting an element of DTABLE to a raw port,
be sure to clear the corresponding element in DTABLE_CELLS.
--- libc/sysdeps/mach/hurd/spawni.c Sun Dec 16 22:31:41 2001
+++ libc/sysdeps/mach/hurd/spawni.c.new Sun Dec 16 22:27:16 2001
@@ -32,6 +32,7 @@
#include <hurd/resource.h>
#include <assert.h>
#include <argz.h>
+#include <spin-lock.h>
#include "spawn_int.h"
/* Spawn a new process executing PATH with the attributes describes in *ATTRP.
@@ -386,24 +387,28 @@ __spawni (pid_t *pid, const char *file,
}
/* Make sure the dtable can hold NEWFD. */
- error_t expand_dtable (int newfd)
- {
- if ((unsigned int)newfd >= dtablesize
- && newfd < _hurd_rlimits[RLIMIT_OFILE].rlim_cur)
- {
- /* We need to expand the dtable for the child. */
-#define NEW(x) \
- do { __typeof (x) new_##x = __alloca ((newfd + 1) * sizeof (x[0])); \
- memcpy (new_##x, x, dtablesize * sizeof (x[0])); \
- memset (&new_##x[dtablesize], 0, (newfd + 1 - dtablesize) * sizeof (x[0])); \
- x = new_##x; } while (0)
- NEW (dtable);
- NEW (ulink_dtable);
- NEW (dtable_cells);
-#undef NEW
- }
- return ((unsigned int)newfd < dtablesize ? 0 : EMFILE);
- }
+#define GROW_TABLE(x, newfd) \
+ do \
+ { \
+ __typeof (x) new_##x = __alloca ((newfd + 1) * sizeof (x[0])); \
+ memcpy (new_##x, x, dtablesize * sizeof (x[0])); \
+ memset (&new_##x[dtablesize], 0, \
+ (newfd + 1 - dtablesize) * sizeof (x[0])); \
+ x = new_##x; \
+ } \
+ while (0)
+#define EXPAND_DTABLE(newfd) \
+ ({ if ((unsigned int)newfd >= dtablesize \
+ && newfd < _hurd_rlimits[RLIMIT_OFILE].rlim_cur) \
+ { \
+ /* We need to expand the dtable for the child. */ \
+ GROW_TABLE (dtable, newfd); \
+ GROW_TABLE (ulink_dtable, newfd); \
+ GROW_TABLE (dtable_cells, newfd); \
+ dtablesize = newfd + 1; \
+ } \
+ ((unsigned int)newfd < dtablesize ? 0 : EMFILE); \
+ })
struct __spawn_action *action = &file_actions->__actions[i];
@@ -425,7 +430,7 @@ __spawni (pid_t *pid, const char *file,
if (fd == newfd)
// Same is same as same was.
break;
- err = expand_dtable (newfd);
+ err = EXPAND_DTABLE (newfd);
if (!err)
{
/* Close the old NEWFD and replace it with FD's
@@ -464,7 +469,7 @@ __spawni (pid_t *pid, const char *file,
do_close (fd);
if (fd < orig_dtablesize)
dtable_cloexec[fd] = 0;
- err = expand_dtable (fd);
+ err = EXPAND_DTABLE (fd);
if (err)
break;
@@ -472,6 +477,7 @@ __spawni (pid_t *pid, const char *file,
action->action.open_action.oflag,
action->action.open_action.mode,
&dtable[fd]);
+ dtable_cells[fd] = NULL;
break;
}
}
_______________________________________________
Bug-hurd mailing list
[EMAIL PROTECTED]
http://mail.gnu.org/mailman/listinfo/bug-hurd
