rename io::PortableSpinLock to SpinLock
Summary:
folly::io::PortableSpinLock seems generally useful outside of the io
code. This moves it into the base folly namespace, and renames it from
PortableSpinLock to just SpinLock.
For most users, the main difference between MicroSpinLock and SpinLock
is that SpinLock provides a constructor that does the right thing, while
MicroSpinLock has to be explicitly initialized.
Test Plan:
Added some new unit tests, and tested both the MicroSpinLock and
pthread_spinlock_t implementations. I didn't test the Mac OS version,
although that code remains unchanged.
Reviewed By: seanc@fb.com
Subscribers: trunkagent, doug, net-systems@, exa, folly-diffs@
FB internal diff:
D1734632
Signature: t1:
1734632:
1418394033:
99f6fbe73b485a1d631a2ef7d1b39ea6f49ecb0b