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authorChris Mumford <cmumford@chromium.org>2014-09-16 14:19:52 -0700
committerChris Mumford <cmumford@chromium.org>2014-09-16 14:19:52 -0700
commit803d69203a62faf50f1b77897310a3a1fcae712b (patch)
tree7d35750580d36d88ee8d6dee4d497e990a125aeb /port/atomic_pointer.h
parente353fbc7ea81f12a5694991b708f8f45343594b1 (diff)
downloadleveldb-1.18.tar.gz
leveldb-1.18.zip
Release 1.18v1.18
Changes are: * Update version number to 1.18 * Replace the basic fprintf call with a call to fwrite in order to work around the apparent compiler optimization/rewrite failure that we are seeing with the new toolchain/iOS SDKs provided with Xcode6 and iOS8. * Fix ALL the header guards. * Createed a README.md with the LevelDB project description. * A new CONTRIBUTING file. * Don't implicitly convert uint64_t to size_t or int. Either preserve it as uint64_t, or explicitly cast. This fixes MSVC warnings about possible value truncation when compiling this code in Chromium. * Added a DumpFile() library function that encapsulates the guts of the "leveldbutil dump" command. This will allow clients to dump data to their log files instead of stdout. It will also allow clients to supply their own environment. * leveldb: Remove unused function 'ConsumeChar'. * leveldbutil: Remove unused member variables from WriteBatchItemPrinter. * OpenBSD, NetBSD and DragonflyBSD have _LITTLE_ENDIAN, so define PLATFORM_IS_LITTLE_ENDIAN like on FreeBSD. This fixes: * issue #143 * issue #198 * issue #249 * Switch from <cstdatomic> to <atomic>. The former never made it into the standard and doesn't exist in modern gcc versions at all. The later contains everything that leveldb was using from the former. This problem was noticed when porting to Portable Native Client where no memory barrier is defined. The fact that <cstdatomic> is missing normally goes unnoticed since memory barriers are defined for most architectures. * Make Hash() treat its input as unsigned. Before this change LevelDB files from platforms with different signedness of char were not compatible. This change fixes: issue #243 * Verify checksums of index/meta/filter blocks when paranoid_checks set. * Invoke all tools for iOS with xcrun. (This was causing problems with the new XCode 5.1.1 image on pulse.) * include <sys/stat.h> only once, and fix the following linter warning: "Found C system header after C++ system header" * When encountering a corrupted table file, return Status::Corruption instead of Status::InvalidArgument. * Support cygwin as build platform, patch is from https://code.google.com/p/leveldb/issues/detail?id=188 * Fix typo, merge patch from https://code.google.com/p/leveldb/issues/detail?id=159 * Fix typos and comments, and address the following two issues: * issue #166 * issue #241 * Add missing db synchronize after "fillseq" in the benchmark. * Removed unused variable in SeekRandom: value (issue #201)
Diffstat (limited to 'port/atomic_pointer.h')
-rw-r--r--port/atomic_pointer.h21
1 files changed, 10 insertions, 11 deletions
diff --git a/port/atomic_pointer.h b/port/atomic_pointer.h
index a9866b2..9bf091f 100644
--- a/port/atomic_pointer.h
+++ b/port/atomic_pointer.h
@@ -5,14 +5,13 @@
// AtomicPointer provides storage for a lock-free pointer.
// Platform-dependent implementation of AtomicPointer:
// - If the platform provides a cheap barrier, we use it with raw pointers
-// - If cstdatomic is present (on newer versions of gcc, it is), we use
-// a cstdatomic-based AtomicPointer. However we prefer the memory
+// - If <atomic> is present (on newer versions of gcc, it is), we use
+// a <atomic>-based AtomicPointer. However we prefer the memory
// barrier based version, because at least on a gcc 4.4 32-bit build
-// on linux, we have encountered a buggy <cstdatomic>
-// implementation. Also, some <cstdatomic> implementations are much
-// slower than a memory-barrier based implementation (~16ns for
-// <cstdatomic> based acquire-load vs. ~1ns for a barrier based
-// acquire-load).
+// on linux, we have encountered a buggy <atomic> implementation.
+// Also, some <atomic> implementations are much slower than a memory-barrier
+// based implementation (~16ns for <atomic> based acquire-load vs. ~1ns for
+// a barrier based acquire-load).
// This code is based on atomicops-internals-* in Google's perftools:
// http://code.google.com/p/google-perftools/source/browse/#svn%2Ftrunk%2Fsrc%2Fbase
@@ -20,8 +19,8 @@
#define PORT_ATOMIC_POINTER_H_
#include <stdint.h>
-#ifdef LEVELDB_CSTDATOMIC_PRESENT
-#include <cstdatomic>
+#ifdef LEVELDB_ATOMIC_PRESENT
+#include <atomic>
#endif
#ifdef OS_WIN
#include <windows.h>
@@ -126,7 +125,7 @@ class AtomicPointer {
};
// AtomicPointer based on <cstdatomic>
-#elif defined(LEVELDB_CSTDATOMIC_PRESENT)
+#elif defined(LEVELDB_ATOMIC_PRESENT)
class AtomicPointer {
private:
std::atomic<void*> rep_;
@@ -207,7 +206,7 @@ class AtomicPointer {
inline void NoBarrier_Store(void* v) { rep_ = v; }
};
-// We have neither MemoryBarrier(), nor <cstdatomic>
+// We have neither MemoryBarrier(), nor <atomic>
#else
#error Please implement AtomicPointer for this platform.