This is the mail archive of the cygwin mailing list for the Cygwin project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Support for ITIMER_PROF?


On 6/22/2015 9:25 AM, Corinna Vinschen wrote:
On Jun 22 08:05, Ken Brown wrote:
According to the Cygwin API documentation
(https://cygwin.com/cygwin-api/std-notes.html), "getitimer and setitimer
only support ITIMER_REAL for now."  I'm wondering whether there's any chance
that support for ITIMER_PROF might be added.  I have no idea what the
obstacles are.

My reason for asking is that emacs has a CPU profiling function, which
doesn't work on Cygwin because it relies on ITIMER_PROF.  (There's an
alternative implementation, but it requires timer_getoverrun, also not
available in Cygwin.)

Both very tricky.  Given the description of timer_getoverrun and how
this stuff is implemented in Cygwin, you might get away with

   #ifdef __CYGWIN__
   #define timer_getoverrun(x)	0
   #endif

indepedently of using SIGEV_SIGNAL or SIGEV_THREAD.

This seems to work.  Thanks!

One question: It seems that SIGEV_SIGNAL and friends are defined as macros on Linux (or at least on the one Linux distribution I looked at), but on Cygwin they're only enum constants. And emacs expects them to be defined as macros. Would something like the following be reasonable for the sake of compatibility?

--- a/winsup/cygwin/include/cygwin/signal.h
+++ b/winsup/cygwin/include/cygwin/signal.h
@@ -311,6 +311,10 @@ enum
                                           perform notification */
 };

+#define SIGEV_SIGNAL SIGEV_SIGNAL
+#define SIGEV_NONE   SIGEV_NONE
+#define SIGEV_THREAD SIGEV_THREAD
+
 #if __WORDSIZE == 64
 typedef __uint64_t sigset_t;
 #else


Ken
Ken

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]