[Threads-devel] pthreads_rwlock vs shared_mutex

Subject: [Threads-devel] pthreads_rwlock vs shared_mutex
From: Nathan Rosenblum (flander_at_[hidden])
Date: 2014-02-03 12:33:10

Apologies if this is a question that gets asked ad nauseum on this list,
but why is the shared_mutex implementation not a wrapper for pthread_rwlock
on pthreads-based systems? I observe significantly better performance under
concurrent reader access when using the pthreads implementation compared to
acquiring a reader lock on shared_mutex, particularly on OSX where the cost
of a contended pthread_mutex is extremely high (a short-hold,
high-utilization, mostly-read shared_mutex on that platform effectively
serializes access).

Best,

--nate