On Sun, 5 Feb 2012, Jilles Tjoelker wrote:
On Sun, Feb 05, 2012 at 01:32:42PM -0500, Daniel Eischen wrote:
On Sun, 5 Feb 2012, Ivan Voras wrote:
On 5 February 2012 11:44, Garrett Cooper <[email protected]> wrote:
'make MAKE_JOBS_NUMBER=1' is the workground used right now..
David Xu suggested that it is a bug in Python - it doesn't set
process-shared attribute when it calls sem_init(), but i've tried
patching it (replacing the port patchfile file the one I've attached)
and I still get the hang.
I don't understand how process shared semaphores can work. Perhaps
I'm dumb and ignorant, but a sem_id_t is an allocated struct. The
actual kernel sem_id is inside the struct. Isn't this the same
reason pthread_mutex_t and pthread_cond_t cannot be process-shared?
That's how the old implementation works. It does not support
process-shared semaphores although they may happen to work in some
specific cases.
However, in 9.0, sem_t works differently and contains the actual lock
word directly, so that process-shared semaphores work. The
implementation is in lib/libc/gen/sem_new.c. The pshared flag to
sem_init() is not a no-op because it tells the kernel to allow for use
from multiple processes.
Note that the old implementation is still present as well, for
compatibility with old binaries.
Ahh, okay, I was looking at the old implementation in libc.
--
DE
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