On Tue, 31 May 2016, Ed Schouten wrote:
Log:
Improve POSIX conformance of <signal.h>.
- This header file has always depended on pthread_t, pthread_attr_t,
struct timespec, size_t and uid_t. Only as of POSIX 2008, these
dependencies have been states explicitly. They should now be defined.
Not always. POSIX didn't have pthreads or timespecs before about 1993.
- In our implementation, struct sigevent::sigev_notify_attributes has
type "void *" instead of "pthread_attr_t *". My guess is that this was
done to prevent pulling in the pthread types, but this can easily be
avoided by using the underlying structure types.
Not easily, since the tags of the underlying struct types are in the
application namespace, at least up to POSIX 2001.
Modified:
head/sys/sys/signal.h
Modified: head/sys/sys/signal.h
==============================================================================
--- head/sys/sys/signal.h Tue May 31 18:45:52 2016 (r301070)
+++ head/sys/sys/signal.h Tue May 31 19:05:41 2016 (r301071)
@@ -45,6 +45,23 @@
#include <machine/_limits.h> /* __MINSIGSTKSZ */
#include <machine/signal.h> /* sig_atomic_t; trap codes; sigcontext */
+#if __POSIX_VISIBLE >= 200809
+
+#include <sys/_pthreadtypes.h>
This gives the following pollution (which breaks almost everything since
<sys/types.h> includes this header:
- struct tag names pthread*
- struct member names state and mutex
POSIX could reasonably be unimproved by reserving pthread* but not ordinary
identifiers like state and mutex.
...
@@ -160,6 +177,9 @@ union sigval {
#endif
#if __POSIX_VISIBLE >= 199309
+
+struct pthread_attr;
+
The 1993 version certainly doesn't reserve pthread*.
The 1996 version has a nice table of reserved symbols for every header.
For signal.h, they are just ones with a prefix of sa_, si_, sigev_
and sival_ (these shall not be declared or #defined by the application),
and SIG_, SA_, SI_ and SIGEV_ (these may be used by the application iff
they are #undef'ed before use). This doesn't proprtly separate optional
things.
A draft 2001 version as a not so nice table. The rules are now too
tangled to present in a single table, so there are several tables that
are hard to parse. The first table has sa_, uc_ (new), SIG[A-Z]
(stronger), SIG_[A-Z] (weaker). Then it has ss_ (new) and sv_ (new)
for XSI only. Then it has si_, SI_, sigev_, SIGEV_ and sival_ for
RTS only. The second table has SA_, SIG_[0-9a-z_] (different/weaker),
then massive pollution: BUS_, CLD_, FPE_, ILL_, POLL_, SEGV_, SI_
(now in both tables), SS_, SV_ and TRAP_.
A draft 2007 version is like the 2001 version. It fixes the sorting
of uc_ and makes RTS non-optional. In the second table, it moves SS_,
SV_ and TRAP_ under XSI, and moves POLL_ under OBS XSR.
I think pthread is not reserved since it is not in these tables. Later
versions of POSIX were broken to allow <signal.h> to be pollutied
with all the symbols in <time.h>, but I don't want to check what
is in that now. <time.h> is slightly simpler in POSIX but much
more polluted than <signal.h> in FreeBSD.
struct sigevent {
int sigev_notify; /* Notification type */
int sigev_signo; /* Signal number */
@@ -168,7 +188,7 @@ struct sigevent {
__lwpid_t _threadid;
Names like _threadid are bogus. sigev is reserved for uses like this.
Noy using a prefix makes the namespace random.
struct {
void (*_function)(union sigval);
- void *_attribute; /* pthread_attr_t * */
+ struct pthread_attr **_attribute;
pthread is not reserved. pthread*_t is only reserved by the general
rule that everything ending in _t is reserved.
This also has indentation errors.
} _sigev_thread;
unsigned short _kevent_flags;
Further bogus names. At least they use a prefix.
long __spare__[8];
A more bogus name.
@@ -190,6 +210,7 @@ struct sigevent {
#define SIGEV_KEVENT 3 /* Generate a kevent. */
#define SIGEV_THREAD_ID 4 /* Send signal to a kernel thread. */
It is correct to used the reserved prefix for our extensions, but this style
is inconsistent with old parts of the file. In the old parts, we ifdef
out extensions to a fault. This makes the code hard to read but provides
good documentation of what is portable.
#endif
+
#endif /* __POSIX_VISIBLE >= 199309 */
#if __POSIX_VISIBLE >= 199309 || __XSI_VISIBLE
Bruce
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