Re: Using a latch between a background worker process and a thread

On Tue, Nov 1, 2016 at 12:35 PM, Abbas Butt <abbas.butt@enterprisedb.com> wrote:
> Hi,
> Consider this situation:
> 1. I have a background worker process.
> 2. The process creates a latch, initializes it using InitLatch & resets it.
> 3. It then creates a thread and passes the latch created in step 2 to it.
>     To pass it, the process uses the last argument of pthread_create.
> 4. The thread blocks by calling WaitLatch.
> 5. The process after some time sets the latch using SetLatch.
>
> The thread does not notice that the latch has been set and keeps waiting.
>
> My question is:
> Are latches supposed to work between a process and a thread created by that
> process?

Nothing in the entire backend is guaranteed to work if you spawn
multiple threads within the same process.

Including this.

-- 
Robert Haas
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