[PATCH 1/2] fix compilation with --disable-pthreads

[PATCH 1/2] fix compilation with --disable-pthreads

[Etienne Buira]

Signed-off-by: Etienne Buira <etienne.buira@gmail.com>
---
 builtin/index-pack.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index eebf1a8..0f88f4b 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -185,6 +185,9 @@ static void cleanup_thread(void)
 #define deepest_delta_lock()
 #define deepest_delta_unlock()
 
+#define type_cas_lock()
+#define type_cas_unlock()
+
 #endif
 
 
-- 
1.8.5.5

[PATCH 2/2] Remove spurious 'no threads support' warnings

[Etienne Buira]

Threads count being defaulted to 0 (autodetect), and --disable-pthreads
build checking that thread count==1, there were spurious warnings about
threads being ignored, despite not specified on command line/conf.

Fixes tests 5521 and 5526 that were broken in --disable-pthreads builds
because of those warnings.

Signed-off-by: Etienne Buira <etienne.buira@gmail.com>
---
 builtin/pack-objects.c | 2 +-
 thread-utils.h         | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index b59f5d8..7b51453 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -51,7 +51,7 @@ static int progress = 1;
 static int window = 10;
 static unsigned long pack_size_limit;
 static int depth = 50;
-static int delta_search_threads;
+static int delta_search_threads = THREAD_COMPAT_DEFAULT_THREAD_NBR;
 static int pack_to_stdout;
 static int num_preferred_base;
 static struct progress *progress_state;
diff --git a/thread-utils.h b/thread-utils.h
index 6fb98c3..4f5e802 100644
--- a/thread-utils.h
+++ b/thread-utils.h
@@ -7,5 +7,8 @@
 extern int online_cpus(void);
 extern int init_recursive_mutex(pthread_mutex_t*);
 
+#define THREAD_COMPAT_DEFAULT_THREAD_NBR 0
+#else
+#define THREAD_COMPAT_DEFAULT_THREAD_NBR 1
 #endif
 #endif /* THREAD_COMPAT_H */
-- 
1.8.5.5

Re: [PATCH 2/2] Remove spurious 'no threads support' warnings

[Junio C Hamano]

Etienne Buira <etienne.buira@gmail.com> writes:

> Threads count being defaulted to 0 (autodetect), and --disable-pthreads
> build checking that thread count==1, there were spurious warnings about
> threads being ignored, despite not specified on command line/conf.
>
> Fixes tests 5521 and 5526 that were broken in --disable-pthreads builds
> because of those warnings.
>
> Signed-off-by: Etienne Buira <etienne.buira@gmail.com>
> ---

I am not sure if this is the right fix.

Shouldn't a --threads=0 from the command line (when there is a
pack.threads configuration hardcoding some number to override it)
give a chance to the auto detection codepath to ask online_cpus()
and receive 1 on NO_PTHREADS build to avoid triggering the same
warning you are squelching with this patch?

That is, something like this instead, perhaps?

-- >8 --
Subject: [PATCH] pack-objects: set number of threads before checking and warning

Under NO_PTHREADS build, we warn when delta_search_threads is not
set to 1, because that is the only sensible value on a single
threaded build.

However, the auto detection that kicks in when that variable is set
to 0 (e.g. there is no configuration variable or command line option,
or an explicit --threads=0 is given from the command line to override
the pack.threads configuration to force auto-detection) was not done
before the condition to issue this warning was tested.

Move the auto-detection code and place it at an appropriate spot.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/pack-objects.c | 6 ++++--
 thread-utils.h         | 4 ++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index d391934..a715237 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -1972,8 +1972,6 @@ static void ll_find_deltas(struct object_entry **list, unsigned list_size,
 
 	init_threaded_search();
 
-	if (!delta_search_threads)	/* --threads=0 means autodetect */
-		delta_search_threads = online_cpus();
 	if (delta_search_threads <= 1) {
 		find_deltas(list, &list_size, window, depth, processed);
 		cleanup_threaded_search();
@@ -2685,6 +2683,10 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 		pack_compression_level = Z_DEFAULT_COMPRESSION;
 	else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
 		die("bad pack compression level %d", pack_compression_level);
+
+	if (!delta_search_threads)	/* --threads=0 means autodetect */
+		delta_search_threads = online_cpus();
+
 #ifdef NO_PTHREADS
 	if (delta_search_threads != 1)
 		warning("no threads support, ignoring --threads");
diff --git a/thread-utils.h b/thread-utils.h
index 6fb98c3..d9a769d 100644
--- a/thread-utils.h
+++ b/thread-utils.h
@@ -7,5 +7,9 @@
 extern int online_cpus(void);
 extern int init_recursive_mutex(pthread_mutex_t*);
 
+#else
+
+#define online_cpus() 1
+
 #endif
 #endif /* THREAD_COMPAT_H */
-- 
2.1.2-468-g1a77c5b

Re: [PATCH 2/2] Remove spurious 'no threads support' warnings

[Etienne Buira]

On Mon, Oct 13, 2014 at 9:54 PM, Junio C Hamano <gitster@pobox.com> wrote:
> Etienne Buira <etienne.buira@gmail.com> writes:
>
>> Threads count being defaulted to 0 (autodetect), and --disable-pthreads
>> build checking that thread count==1, there were spurious warnings about
>> threads being ignored, despite not specified on command line/conf.
>>
>> Fixes tests 5521 and 5526 that were broken in --disable-pthreads builds
>> because of those warnings.
>>
>> Signed-off-by: Etienne Buira <etienne.buira@gmail.com>
>> ---
>
> I am not sure if this is the right fix.
>
> Shouldn't a --threads=0 from the command line (when there is a
> pack.threads configuration hardcoding some number to override it)
> give a chance to the auto detection codepath to ask online_cpus()
> and receive 1 on NO_PTHREADS build to avoid triggering the same
> warning you are squelching with this patch?
>
> That is, something like this instead, perhaps?

Indeed, your patch is better.

> -- >8 --
> Subject: [PATCH] pack-objects: set number of threads before checking and warning
>
> Under NO_PTHREADS build, we warn when delta_search_threads is not
> set to 1, because that is the only sensible value on a single
> threaded build.
>
> However, the auto detection that kicks in when that variable is set
> to 0 (e.g. there is no configuration variable or command line option,
> or an explicit --threads=0 is given from the command line to override
> the pack.threads configuration to force auto-detection) was not done
> before the condition to issue this warning was tested.
>
> Move the auto-detection code and place it at an appropriate spot.
>
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> ---
>  builtin/pack-objects.c | 6 ++++--
>  thread-utils.h         | 4 ++++
>  2 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
> index d391934..a715237 100644
> --- a/builtin/pack-objects.c
> +++ b/builtin/pack-objects.c
> @@ -1972,8 +1972,6 @@ static void ll_find_deltas(struct object_entry **list, unsigned list_size,
>
>         init_threaded_search();
>
> -       if (!delta_search_threads)      /* --threads=0 means autodetect */
> -               delta_search_threads = online_cpus();
>         if (delta_search_threads <= 1) {
>                 find_deltas(list, &list_size, window, depth, processed);
>                 cleanup_threaded_search();
> @@ -2685,6 +2683,10 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
>                 pack_compression_level = Z_DEFAULT_COMPRESSION;
>         else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
>                 die("bad pack compression level %d", pack_compression_level);
> +
> +       if (!delta_search_threads)      /* --threads=0 means autodetect */
> +               delta_search_threads = online_cpus();
> +
>  #ifdef NO_PTHREADS
>         if (delta_search_threads != 1)
>                 warning("no threads support, ignoring --threads");
> diff --git a/thread-utils.h b/thread-utils.h
> index 6fb98c3..d9a769d 100644
> --- a/thread-utils.h
> +++ b/thread-utils.h
> @@ -7,5 +7,9 @@
>  extern int online_cpus(void);
>  extern int init_recursive_mutex(pthread_mutex_t*);
>
> +#else
> +
> +#define online_cpus() 1
> +
>  #endif
>  #endif /* THREAD_COMPAT_H */
> --
> 2.1.2-468-g1a77c5b
>

Re: [PATCH 1/2] fix compilation with --disable-pthreads

[Junio C Hamano]

Etienne Buira <etienne.buira@gmail.com> writes:

> Subject: Re: [PATCH 1/2] fix compilation with --disable-pthreads

That probably is a typo of "NO_PTHREADS=NoThanks" or something.
Thanks.

Just out of curiosity, are you porting to some exotic platforms?

> Signed-off-by: Etienne Buira <etienne.buira@gmail.com>
> ---
>  builtin/index-pack.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/builtin/index-pack.c b/builtin/index-pack.c
> index eebf1a8..0f88f4b 100644
> --- a/builtin/index-pack.c
> +++ b/builtin/index-pack.c
> @@ -185,6 +185,9 @@ static void cleanup_thread(void)
>  #define deepest_delta_lock()
>  #define deepest_delta_unlock()
>  
> +#define type_cas_lock()
> +#define type_cas_unlock()
> +
>  #endif