[PATCH] Cygwin: af_unix_spinlock_t: add initializer

[Ken Brown]

On 1/10/2019 1:02 PM, Corinna Vinschen wrote:
> On Jan 10 17:56, Ken Brown wrote:
>> Also fix a typo.
>> ---
>>   winsup/cygwin/fhandler.h | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/winsup/cygwin/fhandler.h b/winsup/cygwin/fhandler.h
>> index d02b9a913..7e460701c 100644
>> --- a/winsup/cygwin/fhandler.h
>> +++ b/winsup/cygwin/fhandler.h
>> @@ -832,9 +832,10 @@ class fhandler_socket_local: public fhandler_socket_wsock
>>   /* Sharable spinlock with low CPU profile.  These locks are NOT recursive! */
>>   class af_unix_spinlock_t
>>   {
>> -  LONG  locked;          /* 0 oder 1 */
>> +  LONG  locked;          /* 0 or 1 */
> 
> Huh.
> 
>>   public:
>> +  af_unix_spinlock_t () : locked (0) {}
> 
> Why do we need that?  The spinlock is created as part of a shared mem
> region which gets initialized to all zero, no?  Or do you plan to use it
> outside of this scenario?

At the moment I'm using it in the new FIFO code, and I'm not sure yet whether it 
will eventually be in shared memory.  (Until I get things working, I'm 
postponing thinking about whether I need shared memory.)

Would it be better to use some other kind of spinlock until I know for sure that 
I need shared memory?  My only reason for choosing af_unix_spinlock_t is that I 
was copying code from fhandler_socket_unix, and this saved me the trouble of 
learning about other kinds of spinlocks.

Ken