Swimming, 1st May 2017

The pool was fairly busy today and quite a few people were lane-swimming so I stuck to front crawl. My plan was to do 2.5km, but when I’d done that I felt good for another 500m and after that I decided I’d do the extra eight lengths to make the distance up to two miles. Doubtless there will be payback tomorrow, but that’s another day. Takes a good chunk out of the distance I’m behind target for the year, too.

Total distance for the month: 3,200m
Total distance for this year: 150,600m
Distance compared to annual target: 21,400m under

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OSX compile problem understood

Understood, but no solution is in sight unfortunately.

It turns out that configure doesn’t play nicely with -Werror and whilst my code still compiles and works on Linux when compiled that way it’s mostly luck. OSX does not (in my house at least) come with such a large dollop of good fortune.

Were it not for the fact that I have code for other projects that will fail to build with -Werror embedded in my code tree there was a possibility that adding the following to the top level Makefile.am would have helped:

WARNINGS = -Werror -O2 -g

warnings:
        $(MAKE) V=0 CFLAGS='$(WARNINGS)' CXXFLAGS='$(WARNINGS)'
        $(MAKE) V=0 CFLAGS='$(WARNINGS)' CXXFLAGS='$(WARNINGS)' $(check_PROGRAMS)

allowing me to run

  $ make warnings

to build the system where warnings cause a compile error. In my case I don’t unfortunately see such a handy workaround.

On the positive side, I did at the same time discover that the option

  AM_SILENT_RULES([yes])

in configure.ac significantly decreases the verbosity of the compilation process, so I shall tuck that one behind my ear for later.

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Swimming, 28th April 2017

My last swim of this month unless something unexpected happens at the weekend. And a hideous fight it was, too. After 1km of front crawl I was pretty much running on empty. I even started to get the shakes because I had so little energy left. I pressed on to 2.2km, all front crawl, but there was no real joy in it. I think my efforts with the Swimfit session earlier in the week really just took too much out of me.

Still, an acceptable total for me for this month and I’ve improved my position compared with my annual target by a whole 400m.

Total distance for the month: 40,400m
Total distance for this year: 147,400m
Distance compared to annual target: 22,600m under

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Swimming, 27th April 2017

One more go at the Swimfit session for this week, made up to 2.6km with front crawl. It was a bit of a struggle to be honest. I just didn’t seem to have the energy any more.

Total distance for the month: 38,200m
Total distance for this year: 145,200m
Distance compared to annual target: 22,800m under

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Further frustrations with OSX…

Recent versions of the command line tools for Xcode appear to have changed the way the -pthread argument to the compiler is handled such that it generates a warning if used in a call to the compiler that actually only links existing objects into an executable. When used to compile C or C++ into .o files it’s fine.

This wouldn’t be a big deal but for the fact (as stated elsewhere) that I compile my own code with -Wall -Werror. The warning then causes the link stage to fail. Unfortunately fixing this is not a simple case of removing -pthread from my link command because it isn’t me who puts it there. In fact that flag is added by libtool as it is also used during the compilation of one of the third-party libraries I’m linking against, libhidapi.

I thought salvation had come my way last night when I discovered that clang on OSX has another flag, -Qunused-arguments, which is supposed to prevent the compiler issuing warnings about unused command line arguments. But here’s where I am now:

If I build the project as normal, with -Wall -Werror, all the code compiles happily but fails at the link stage because of the -pthread warning. If I repeat the command manually without that flag then the link stage works.

If I build the project only changing CFLAGS to add -Qunused-arguments then compilation again completes happily, but the link stage this time fails with hundreds of duplicate symbols, many of which appear to be inline functions from the libm. Linking manually removing both this and the -pthread flag fails the same way.

I can only assume that -Qunused-arguments is causing some other side-effect, perhaps when configure is run, but at the moment I just can’t find it.

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Swimming, 26th April 2017

Yes, that session again 🙂 This time made up to 2.7km with front crawl.

It was very tough today and my legs felt like jelly by halfway through the session, but it does feel as though my breaststroke (particularly) and backstroke are slowly improving. Somewhat oddly I’ve noticed that I tend to close my eyes whilst my head is under water when I’m swimming breaststroke. I don’t know if that’s because I’m trying to concentrate so hard on what’s happening, but it does mean I tend to drift off the centre line a bit.

Had the pool pretty much to myself for the entire session too, which was quite pleasant.

Total distance for the month: 35,600m
Total distance for this year: 142,600m
Distance compared to annual target: 23,400m under

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Swimming, 25th April 2017

Being something of a glutton for punishment (or as some might put it, “unbelievably pig-headed” 🙂 I repeated my current Swimfit session for the umpteenth time, with much the same result as yesterday. For some reason despite feeling rather tired on my way to the pool I’m in quite a positive frame of mind about it today. I’m getting the distance done that I intended so I stay in touch with my target for the year and it does mean I’m getting practice in on my breaststroke and backstroke which I really do need.

Breaststroke is supposed to have a certain amount of undulation in the stroke and I think my body is too rigid in the water. Today I tried to be a bit more flexible and relaxed, stopping my hips being permanently low in the water, and to achieve a good streamline position with my upper body before starting the kick. It also occurred to me to question exactly how the “A-pull” might be performed. Naively perhaps, I’ve always done it with my arms starting in a streamline position and my hands describing an arc in the horizontal plane back to my hips. I wonder though if it might not produce more forward motion if it were performed more like a butterfly pull, with the hands and forearms dropping to the vertical near the front of the pull to catch the water, then rotating the arms backwards to the body around the shoulder, keeping the elbows high. Experimenting over the course of a few lengths it seems to me that the pressure wave I feel along my lower legs when doing the pull this way is far stronger than if I do it the original way. I’m not sure about the legality of it so I’ll have to check that. I should have a look at what Maglischo might have to say about the breaststroke transition too. One of the dangers I’ve already discovered, especially in relatively shallow water, is that it’s quite easy to have a downwards component to the pull, thereby bringing the body closer to the surface. I didn’t find it such a problem at the deep end though.

As for backstroke, I think first I need to work on getting better longitudinal rotation of my body and a wider entry position for my arms so I can get into a proper catch more quickly. An interesting apparent side-effect of the rotation I’ve discovered is that it means I’m effectively not having to lift my recovering arm out of the water. Instead it rotates out with the body taking much less effort.

For today at least I feel as though I could repeat the session every day until I do hit that target time. Of course tomorrow I might feel utterly sick of it and want to move on again.

Anyhow, after the main session I made the distance up to 2.6km with some front crawl. Last one out of the pool again 😀

Total distance for the month: 32,900m
Total distance for this year: 139,900m
Distance compared to annual target: 24,100m under

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Well that’s not going to work then

A short while ago I posted about the problems when combining Xcode’s -Wall and -Werror flags with pkg-config to get include directory flags.

I’ve just been through my configure script doing the necessary work to replace the -I flags with -isystem. In the end it turned out to be fairly straightforward to do it in just for OSX. But there are unintended consequences…

The application uses Qt to build the user interface and as part of the build uses Qt’s moc to generate some intermediate sources. moc needs to be passed the C/C++ preprocessor flags, but it only recognises -I, not -isystem and therefore throws an error.

It looks as though what I’ll need to do is maintain two separate copies of the flags, one for compiling code and one for moc. Fairly hideous, but at the moment I see no other choice.

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Swimming, 24th April 2017

As I don’t swim at the weekend I thought I’d give the latest Swimfit session another crack first thing this week:

12 lengths front crawl
8 lengths breaststroke
4 lengths backstroke
1 minute rest
2 x ( 2 lengths each of front crawl, backstroke, breaststroke ) 15 sec rest after each length
8 x ( 1 length each of front crawl, backstroke, breaststroke, 30 sec rest )
10 lengths fast front crawl, 30 seconds rest every 2 lengths
8 lengths easy front crawl

I still can’t do it in the expected 55 minutes. I think my breaststroke and backstroke just aren’t fast enough. By my reckoning in the above set there are ten and a half minutes rest, leaving forty-four and a half minutes swimming for seventy-eight lengths which is just over 34 seconds per length. I can’t do that in breaststroke and backstroke. In fact, covering 1950m at 34 seconds per length is a pretty reasonable pace (for me, at least) just sticking to front crawl.

For the previous session the timing was sixty minutes for three quarters the distance, mostly in front crawl and the session before that allowed seventy minutes for seventy-four lengths, again mostly front crawl though there were four lengths of kick. On the other hand the next session asks for about sixty lengths in twenty-seven minutes (with rest time on top). I just can’t see that happening in the near future. Perhaps I need some other guide as to when to move on to the next session.

Anyhow, having done the session I made the distance up to 2,700m with front crawl, until I was kicked out of the lane to make room for a swimming lesson 🙂

Total distance for the month: 30,300m
Total distance for this year: 137,300m
Distance compared to annual target: 24,700m under

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A different sort of MOAB

Over the winter we had a few trees in our hedges decide that they couldn’t stand life any longer and fell into part of the orchard. Over the last week or so I’ve been out there with the chainsaw, removing what would be suitable for the log-burner this winter (or even in the chiminea over the summer) and stacking what was left (including some savage bits of blackthorn) around a large old sycamore stump. Eventually I ended up with a heap about three to four metres across and perhaps five metres tall.

Very little effort was required to get a fire started and I was amazed how fast it got going. At one point we had flames that were getting close to ten metres high. Of course I forgot to take pictures, but my daughter appears to be permanently attached to her phone these days and she has some videos. I shall try to get a copy of them from her. Once it had died back a bit both my son and daughter toasted marsh mallows on the end of some sticks of green willow. I remember when we had bonfires in my own childhood my parents used to wrap up potatoes in baking foil and put them in the hot ashes to cook once the fire had died back. I really must try that again one day.

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