Adding portability to gating PicoSpinLock.

Summary:PicoSpinLock only works on x86_64, Arm64, and ppc64 (i.e.,
not 32-bit).  Add a bit of gating so we can continue to run tests and
use headers when compiling for i386.

Reviewed By: yfeldblum

Differential Revision: D2991328

fb-gh-sync-id: b0d0c229508f65dff62b24fdd9d80c799cd97935
shipit-source-id: b0d0c229508f65dff62b24fdd9d80c799cd97935

folly/PicoSpinLock.h

@@ -31,6 +31,7 @@
  */
 
 #pragma once
+#define FOLLY_PICO_SPIN_LOCK_H_
 
 /*
  * @author Keith Adams <kma@fb.com>
@@ -38,16 +39,16 @@
  */
 
 #include <array>
+#include <atomic>
 #include <cinttypes>
-#include <type_traits>
 #include <cstdlib>
-#include <pthread.h>
+#include <folly/Portability.h>
 #include <mutex>
-#include <atomic>
+#include <pthread.h>
+#include <type_traits>
 
 #include <glog/logging.h>
 #include <folly/detail/Sleeper.h>
-#include <folly/Portability.h>
 
 #if !FOLLY_X64 && !FOLLY_A64 && !FOLLY_PPC64
 # error "PicoSpinLock.h is currently x64, aarch64 and ppc64 only."

folly/SmallLocks.h

@@ -36,6 +36,10 @@
 
 #include <folly/MicroLock.h>
 #include <folly/MicroSpinLock.h>
+
+#include <folly/Portability.h>
+#if FOLLY_X64 || FOLLY_A64 || FOLLY_PPC64
 #include <folly/PicoSpinLock.h>
+#endif
 
 #endif

folly/test/SmallLocksTest.cpp

@@ -34,9 +34,12 @@
 using folly::MSLGuard;
 using folly::MicroLock;
 using folly::MicroSpinLock;
-using folly::PicoSpinLock;
 using std::string;
 
+#ifdef FOLLY_PICO_SPIN_LOCK_H_
+using folly::PicoSpinLock;
+#endif
+
 namespace {
 
 struct LockedVal {
@@ -53,10 +56,12 @@ struct LockedVal {
 // these classes are POD).
 FOLLY_PACK_PUSH
 struct ignore1 { MicroSpinLock msl; int16_t foo; } FOLLY_PACK_ATTR;
-struct ignore2 { PicoSpinLock<uint32_t> psl; int16_t foo; } FOLLY_PACK_ATTR;
 static_assert(sizeof(ignore1) == 3, "Size check failed");
-static_assert(sizeof(ignore2) == 6, "Size check failed");
 static_assert(sizeof(MicroSpinLock) == 1, "Size check failed");
+#ifdef FOLLY_PICO_SPIN_LOCK_H_
+struct ignore2 { PicoSpinLock<uint32_t> psl; int16_t foo; } FOLLY_PACK_ATTR;
+static_assert(sizeof(ignore2) == 6, "Size check failed");
+#endif
 FOLLY_PACK_POP
 
 LockedVal v;
@@ -78,6 +83,7 @@ void splock_test() {
   }
 }
 
+#ifdef FOLLY_PICO_SPIN_LOCK_H_
 template<class T> struct PslTest {
   PicoSpinLock<T> lock;
 
@@ -109,6 +115,7 @@ void doPslTest() {
     t.join();
   }
 }
+#endif
 
 struct TestClobber {
   TestClobber() {
@@ -141,6 +148,7 @@ TEST(SmallLocks, SpinLockCorrectness) {
   }
 }
 
+#ifdef FOLLY_PICO_SPIN_LOCK_H_
 TEST(SmallLocks, PicoSpinCorrectness) {
   doPslTest<int16_t>();
   doPslTest<uint16_t>();
@@ -164,6 +172,7 @@ TEST(SmallLocks, PicoSpinSigned) {
   }
   EXPECT_EQ(val.getData(), -8);
 }
+#endif
 
 TEST(SmallLocks, RegClobber) {
   TestClobber().go();