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Remove static initializer; fix endian-ness detection; fix build on

various platforms; improve android port speed.

Avoid static initializer by using a new portability interface for
thread-safe lazy initialization.  Custom ports will need to be
extended to implement InitOnce/OnceType/LEVELDB_ONCE_INIT.

Fix endian-ness detection (fixes Powerpc builds).

Build related fixes:
- Support platforms that have unversioned shared libraries.
- Fix IOS build rules.

Android improvements
- Speed up atomic pointers
- Share more code with port_posix.

Do not spin in a tight loop attempting compactions if the file system
is inaccessible (e.g., if kerberos tickets have expired or if it is out
of space).
ld
Sanjay Ghemawat 12 years ago
parent
commit
075a35a6d3
18 changed files with 283 additions and 62 deletions
  1. +18
    -9
      Makefile
  2. +28
    -9
      build_detect_platform
  3. +10
    -1
      db/c_test.c
  4. +9
    -1
      db/db_bench.cc
  5. +19
    -4
      db/db_impl.cc
  6. +1
    -1
      db/db_impl.h
  7. +54
    -9
      db/db_test.cc
  8. +2
    -2
      db/version_set.cc
  9. +9
    -0
      db/version_set.h
  10. +25
    -3
      doc/bench/db_bench_sqlite3.cc
  11. +26
    -4
      doc/bench/db_bench_tree_db.cc
  12. +13
    -5
      port/atomic_pointer.h
  13. +0
    -2
      port/port.h
  14. +10
    -0
      port/port_example.h
  15. +4
    -0
      port/port_posix.cc
  16. +24
    -9
      port/port_posix.h
  17. +23
    -0
      util/coding_test.cc
  18. +8
    -3
      util/comparator.cc

+ 18
- 9
Makefile View File

@ -3,8 +3,6 @@
# found in the LICENSE file. See the AUTHORS file for names of contributors.
# Inherit some settings from environment variables, if available
CXX ?= g++
CC ?= gcc
INSTALL_PATH ?= $(CURDIR)
#-----------------------------------------------
@ -63,6 +61,13 @@ default: all
# Should we build shared libraries?
ifneq ($(PLATFORM_SHARED_EXT),)
ifneq ($(PLATFORM_SHARED_VERSIONED),true)
SHARED1 = libleveldb.$(PLATFORM_SHARED_EXT)
SHARED2 = $(SHARED1)
SHARED3 = $(SHARED1)
SHARED = $(SHARED1)
else
# Update db.h if you change these.
SHARED_MAJOR = 1
SHARED_MINOR = 4
@ -70,14 +75,17 @@ SHARED1 = libleveldb.$(PLATFORM_SHARED_EXT)
SHARED2 = $(SHARED1).$(SHARED_MAJOR)
SHARED3 = $(SHARED1).$(SHARED_MAJOR).$(SHARED_MINOR)
SHARED = $(SHARED1) $(SHARED2) $(SHARED3)
$(SHARED3):
$(CXX) $(LDFLAGS) $(PLATFORM_SHARED_LDFLAGS)$(INSTALL_PATH)/$(SHARED2) $(CXXFLAGS) $(PLATFORM_SHARED_CFLAGS) $(SOURCES) -o $(SHARED3)
$(SHARED2): $(SHARED3)
ln -fs $(SHARED3) $(SHARED2)
$(SHARED1): $(SHARED3)
ln -fs $(SHARED3) $(SHARED1)
$(SHARED2): $(SHARED3)
ln -fs $(SHARED3) $(SHARED2)
endif
$(SHARED3):
$(CXX) $(LDFLAGS) $(PLATFORM_SHARED_LDFLAGS)$(SHARED2) $(CXXFLAGS) $(PLATFORM_SHARED_CFLAGS) $(SOURCES) -o $(SHARED3)
endif # PLATFORM_SHARED_EXT
all: $(SHARED) $(LIBRARY)
check: all $(PROGRAMS) $(TESTS)
@ -164,9 +172,10 @@ memenv_test : helpers/memenv/memenv_test.o $(MEMENVLIBRARY) $(LIBRARY) $(TESTHAR
ifeq ($(PLATFORM), IOS)
# For iOS, create universal object files to be used on both the simulator and
# a device.
SIMULATORROOT=/Developer/Platforms/iPhoneSimulator.platform/Developer
DEVICEROOT=/Developer/Platforms/iPhoneOS.platform/Developer
IOSVERSION=$(shell defaults read /Developer/Platforms/iPhoneOS.platform/version CFBundleShortVersionString)
PLATFORMSROOT=/Applications/Xcode.app/Contents/Developer/Platforms
SIMULATORROOT=$(PLATFORMSROOT)/iPhoneSimulator.platform/Developer
DEVICEROOT=$(PLATFORMSROOT)/iPhoneOS.platform/Developer
IOSVERSION=$(shell defaults read $(PLATFORMSROOT)/iPhoneOS.platform/version CFBundleShortVersionString)
.cc.o:
mkdir -p ios-x86/$(dir $@)

+ 28
- 9
build_detect_platform View File

@ -4,18 +4,27 @@
# argument, which in turn gets read while processing Makefile.
#
# The output will set the following variables:
# CC C Compiler path
# CXX C++ Compiler path
# PLATFORM_LDFLAGS Linker flags
# PLATFORM_SHARED_EXT Extension for shared libraries
# PLATFORM_SHARED_LDFLAGS Flags for building shared library
# PLATFORM_SHARED_CFLAGS Flags for compiling objects for shared library
# PLATFORM_CCFLAGS C compiler flags
# PLATFORM_CXXFLAGS C++ compiler flags. Will contain:
# -DLEVELDB_PLATFORM_POSIX if cstdatomic is present
# -DLEVELDB_PLATFORM_NOATOMIC if it is not
# PLATFORM_SHARED_VERSIONED Set to 'true' if platform supports versioned
# shared libraries, empty otherwise.
#
# The PLATFORM_CCFLAGS and PLATFORM_CXXFLAGS might include the following:
#
# -DLEVELDB_CSTDATOMIC_PRESENT if <cstdatomic> is present
# -DLEVELDB_PLATFORM_POSIX for Posix-based platforms
# -DSNAPPY if the Snappy library is present
#
OUTPUT=$1
if test -z "$OUTPUT"; then
echo "usage: $0 <output-filename>"
echo "usage: $0 <output-filename>" >&2
exit 1
fi
@ -23,6 +32,10 @@ fi
rm -f $OUTPUT
touch $OUTPUT
if test -z "$CC"; then
CC=cc
fi
if test -z "$CXX"; then
CXX=g++
fi
@ -33,12 +46,14 @@ if test -z "$TARGET_OS"; then
fi
COMMON_FLAGS=
CROSS_COMPILE=
PLATFORM_CCFLAGS=
PLATFORM_CXXFLAGS=
PLATFORM_LDFLAGS=
PLATFORM_SHARED_EXT="so"
PLATFORM_SHARED_LDFLAGS="-shared -Wl,-soname -Wl,"
PLATFORM_SHARED_CFLAGS="-fPIC"
PLATFORM_SHARED_VERSIONED=true
# On GCC, we pick libc's memcmp over GCC's memcmp via -fno-builtin-memcmp
case "$TARGET_OS" in
@ -86,13 +101,14 @@ case "$TARGET_OS" in
PORT_FILE=port/port_posix.cc
;;
OS_ANDROID_CROSSCOMPILE)
PLATFORM="$TARGET_OS"
COMMON_FLAGS=""
PLATFORM_LDFLAGS=""
PORT_FILE=port/port_android.cc
PLATFORM=OS_ANDROID
COMMON_FLAGS="-fno-builtin-memcmp -D_REENTRANT -DOS_ANDROID -DLEVELDB_PLATFORM_POSIX"
PLATFORM_LDFLAGS="" # All pthread features are in the Android C library
PORT_FILE=port/port_posix.cc
CROSS_COMPILE=true
;;
*)
echo "Unknown platform!"
echo "Unknown platform!" >&2
exit 1
esac
@ -112,7 +128,7 @@ set +f # re-enable globbing
echo "SOURCES=$PORTABLE_FILES $PORT_FILE" >> $OUTPUT
echo "MEMENV_SOURCES=helpers/memenv/memenv.cc" >> $OUTPUT
if [ "$PLATFORM" = "OS_ANDROID_CROSSCOMPILE" ]; then
if [ "$CROSS_COMPILE" = "true" ]; then
# Cross-compiling; do not try any compilation tests.
true
else
@ -151,6 +167,8 @@ fi
PLATFORM_CCFLAGS="$PLATFORM_CCFLAGS $COMMON_FLAGS"
PLATFORM_CXXFLAGS="$PLATFORM_CXXFLAGS $COMMON_FLAGS"
echo "CC=$CC" >> $OUTPUT
echo "CXX=$CXX" >> $OUTPUT
echo "PLATFORM=$PLATFORM" >> $OUTPUT
echo "PLATFORM_LDFLAGS=$PLATFORM_LDFLAGS" >> $OUTPUT
echo "PLATFORM_CCFLAGS=$PLATFORM_CCFLAGS" >> $OUTPUT
@ -158,3 +176,4 @@ echo "PLATFORM_CXXFLAGS=$PLATFORM_CXXFLAGS" >> $OUTPUT
echo "PLATFORM_SHARED_CFLAGS=$PLATFORM_SHARED_CFLAGS" >> $OUTPUT
echo "PLATFORM_SHARED_EXT=$PLATFORM_SHARED_EXT" >> $OUTPUT
echo "PLATFORM_SHARED_LDFLAGS=$PLATFORM_SHARED_LDFLAGS" >> $OUTPUT
echo "PLATFORM_SHARED_VERSIONED=$PLATFORM_SHARED_VERSIONED" >> $OUTPUT

+ 10
- 1
db/c_test.c View File

@ -19,6 +19,13 @@ static void StartPhase(const char* name) {
phase = name;
}
static const char* GetTempDir(void) {
const char* ret = getenv("TEST_TMPDIR");
if (ret == NULL || ret[0] == '\0')
ret = "/tmp";
return ret;
}
#define CheckNoError(err) \
if ((err) != NULL) { \
fprintf(stderr, "%s:%d: %s: %s\n", __FILE__, __LINE__, phase, (err)); \
@ -158,7 +165,9 @@ int main(int argc, char** argv) {
char* err = NULL;
int run = -1;
snprintf(dbname, sizeof(dbname), "/tmp/leveldb_c_test-%d",
snprintf(dbname, sizeof(dbname),
"%s/leveldb_c_test-%d",
GetTempDir(),
((int) geteuid()));
StartPhase("create_objects");

+ 9
- 1
db/db_bench.cc View File

@ -100,7 +100,7 @@ static int FLAGS_bloom_bits = -1;
static bool FLAGS_use_existing_db = false;
// Use the db with the following name.
static const char* FLAGS_db = "/tmp/dbbench";
static const char* FLAGS_db = NULL;
namespace leveldb {
@ -925,6 +925,7 @@ class Benchmark {
int main(int argc, char** argv) {
FLAGS_write_buffer_size = leveldb::Options().write_buffer_size;
FLAGS_open_files = leveldb::Options().max_open_files;
std::string default_db_path;
for (int i = 1; i < argc; i++) {
double d;
@ -964,6 +965,13 @@ int main(int argc, char** argv) {
}
}
// Choose a location for the test database if none given with --db=<path>
if (FLAGS_db == NULL) {
leveldb::Env::Default()->GetTestDirectory(&default_db_path);
default_db_path += "/dbbench";
FLAGS_db = default_db_path.c_str();
}
leveldb::Benchmark benchmark;
benchmark.Run();
return 0;

+ 19
- 4
db/db_impl.cc View File

@ -608,8 +608,21 @@ void DBImpl::BackgroundCall() {
MutexLock l(&mutex_);
assert(bg_compaction_scheduled_);
if (!shutting_down_.Acquire_Load()) {
BackgroundCompaction();
Status s = BackgroundCompaction();
if (!s.ok()) {
// Wait a little bit before retrying background compaction in
// case this is an environmental problem and we do not want to
// chew up resources for failed compactions for the duration of
// the problem.
bg_cv_.SignalAll(); // In case a waiter can proceed despite the error
Log(options_.info_log, "Waiting after background compaction error: %s",
s.ToString().c_str());
mutex_.Unlock();
env_->SleepForMicroseconds(1000000);
mutex_.Lock();
}
}
bg_compaction_scheduled_ = false;
// Previous compaction may have produced too many files in a level,
@ -618,12 +631,11 @@ void DBImpl::BackgroundCall() {
bg_cv_.SignalAll();
}
void DBImpl::BackgroundCompaction() {
Status DBImpl::BackgroundCompaction() {
mutex_.AssertHeld();
if (imm_ != NULL) {
CompactMemTable();
return;
return CompactMemTable();
}
Compaction* c;
@ -698,6 +710,7 @@ void DBImpl::BackgroundCompaction() {
}
manual_compaction_ = NULL;
}
return status;
}
void DBImpl::CleanupCompaction(CompactionState* compact) {
@ -1263,6 +1276,8 @@ Status DBImpl::MakeRoomForWrite(bool force) {
WritableFile* lfile = NULL;
s = env_->NewWritableFile(LogFileName(dbname_, new_log_number), &lfile);
if (!s.ok()) {
// Avoid chewing through file number space in a tight loop.
versions_->ReuseFileNumber(new_log_number);
break;
}
delete log_;

+ 1
- 1
db/db_impl.h View File

@ -94,7 +94,7 @@ class DBImpl : public DB {
void MaybeScheduleCompaction();
static void BGWork(void* db);
void BackgroundCall();
void BackgroundCompaction();
Status BackgroundCompaction();
void CleanupCompaction(CompactionState* compact);
Status DoCompactionWork(CompactionState* compact);

+ 54
- 9
db/db_test.cc View File

@ -56,12 +56,18 @@ class SpecialEnv : public EnvWrapper {
// Simulate no-space errors while this pointer is non-NULL.
port::AtomicPointer no_space_;
// Simulate non-writable file system while this pointer is non-NULL
port::AtomicPointer non_writable_;
bool count_random_reads_;
AtomicCounter random_read_counter_;
AtomicCounter sleep_counter_;
explicit SpecialEnv(Env* base) : EnvWrapper(base) {
delay_sstable_sync_.Release_Store(NULL);
no_space_.Release_Store(NULL);
non_writable_.Release_Store(NULL);
count_random_reads_ = false;
}
@ -95,6 +101,10 @@ class SpecialEnv : public EnvWrapper {
}
};
if (non_writable_.Acquire_Load() != NULL) {
return Status::IOError("simulated write error");
}
Status s = target()->NewWritableFile(f, r);
if (s.ok()) {
if (strstr(f.c_str(), ".sst") != NULL) {
@ -127,6 +137,11 @@ class SpecialEnv : public EnvWrapper {
}
return s;
}
virtual void SleepForMicroseconds(int micros) {
sleep_counter_.Increment();
target()->SleepForMicroseconds(micros);
}
};
class DBTest {
@ -137,6 +152,7 @@ class DBTest {
enum OptionConfig {
kDefault,
kFilter,
kUncompressed,
kEnd
};
int option_config_;
@ -167,10 +183,10 @@ class DBTest {
// Switch to a fresh database with the next option configuration to
// test. Return false if there are no more configurations to test.
bool ChangeOptions() {
if (option_config_ == kEnd) {
option_config_++;
if (option_config_ >= kEnd) {
return false;
} else {
option_config_++;
DestroyAndReopen();
return true;
}
@ -183,6 +199,9 @@ class DBTest {
case kFilter:
options.filter_policy = filter_policy_;
break;
case kUncompressed:
options.compression = kNoCompression;
break;
default:
break;
}
@ -552,13 +571,15 @@ TEST(DBTest, GetEncountersEmptyLevel) {
ASSERT_EQ(NumTableFilesAtLevel(1), 0);
ASSERT_EQ(NumTableFilesAtLevel(2), 1);
// Step 3: read until level 0 compaction disappears.
int read_count = 0;
while (NumTableFilesAtLevel(0) > 0) {
ASSERT_LE(read_count, 10000) << "did not trigger level 0 compaction";
read_count++;
// Step 3: read a bunch of times
for (int i = 0; i < 1000; i++) {
ASSERT_EQ("NOT_FOUND", Get("missing"));
}
// Step 4: Wait for compaction to finish
env_->SleepForMicroseconds(1000000);
ASSERT_EQ(NumTableFilesAtLevel(0), 0);
} while (ChangeOptions());
}
@ -1432,13 +1453,37 @@ TEST(DBTest, NoSpace) {
Compact("a", "z");
const int num_files = CountFiles();
env_->no_space_.Release_Store(env_); // Force out-of-space errors
for (int i = 0; i < 10; i++) {
env_->sleep_counter_.Reset();
for (int i = 0; i < 5; i++) {
for (int level = 0; level < config::kNumLevels-1; level++) {
dbfull()->TEST_CompactRange(level, NULL, NULL);
}
}
env_->no_space_.Release_Store(NULL);
ASSERT_LT(CountFiles(), num_files + 5);
ASSERT_LT(CountFiles(), num_files + 3);
// Check that compaction attempts slept after errors
ASSERT_GE(env_->sleep_counter_.Read(), 5);
}
TEST(DBTest, NonWritableFileSystem) {
Options options = CurrentOptions();
options.write_buffer_size = 1000;
options.env = env_;
Reopen(&options);
ASSERT_OK(Put("foo", "v1"));
env_->non_writable_.Release_Store(env_); // Force errors for new files
std::string big(100000, 'x');
int errors = 0;
for (int i = 0; i < 20; i++) {
fprintf(stderr, "iter %d; errors %d\n", i, errors);
if (!Put("foo", big).ok()) {
errors++;
env_->SleepForMicroseconds(100000);
}
}
ASSERT_GT(errors, 0);
env_->non_writable_.Release_Store(NULL);
}
TEST(DBTest, FilesDeletedAfterCompaction) {

+ 2
- 2
db/version_set.cc View File

@ -132,7 +132,7 @@ bool SomeFileOverlapsRange(
const Comparator* ucmp = icmp.user_comparator();
if (!disjoint_sorted_files) {
// Need to check against all files
for (int i = 0; i < files.size(); i++) {
for (size_t i = 0; i < files.size(); i++) {
const FileMetaData* f = files[i];
if (AfterFile(ucmp, smallest_user_key, f) ||
BeforeFile(ucmp, largest_user_key, f)) {
@ -1297,7 +1297,7 @@ Compaction* VersionSet::CompactRange(
// Avoid compacting too much in one shot in case the range is large.
const uint64_t limit = MaxFileSizeForLevel(level);
uint64_t total = 0;
for (int i = 0; i < inputs.size(); i++) {
for (size_t i = 0; i < inputs.size(); i++) {
uint64_t s = inputs[i]->file_size;
total += s;
if (total >= limit) {

+ 9
- 0
db/version_set.h View File

@ -173,6 +173,15 @@ class VersionSet {
// Allocate and return a new file number
uint64_t NewFileNumber() { return next_file_number_++; }
// Arrange to reuse "file_number" unless a newer file number has
// already been allocated.
// REQUIRES: "file_number" was returned by a call to NewFileNumber().
void ReuseFileNumber(uint64_t file_number) {
if (next_file_number_ == file_number + 1) {
next_file_number_ = file_number;
}
}
// Return the number of Table files at the specified level.
int NumLevelFiles(int level) const;

+ 25
- 3
doc/bench/db_bench_sqlite3.cc View File

@ -75,6 +75,9 @@ static bool FLAGS_transaction = true;
// If true, we enable Write-Ahead Logging
static bool FLAGS_WAL_enabled = true;
// Use the db with the following name.
static const char* FLAGS_db = NULL;
inline
static void ExecErrorCheck(int status, char *err_msg) {
if (status != SQLITE_OK) {
@ -317,11 +320,16 @@ class Benchmark {
bytes_(0),
rand_(301) {
std::vector<std::string> files;
Env::Default()->GetChildren("/tmp", &files);
std::string test_dir;
Env::Default()->GetTestDirectory(&test_dir);
Env::Default()->GetChildren(test_dir, &files);
if (!FLAGS_use_existing_db) {
for (int i = 0; i < files.size(); i++) {
if (Slice(files[i]).starts_with("dbbench_sqlite3")) {
Env::Default()->DeleteFile("/tmp/" + files[i]);
std::string file_name(test_dir);
file_name += "/";
file_name += files[i];
Env::Default()->DeleteFile(file_name.c_str());
}
}
}
@ -415,7 +423,11 @@ class Benchmark {
db_num_++;
// Open database
snprintf(file_name, sizeof(file_name), "/tmp/dbbench_sqlite3-%d.db",
std::string tmp_dir;
Env::Default()->GetTestDirectory(&tmp_dir);
snprintf(file_name, sizeof(file_name),
"%s/dbbench_sqlite3-%d.db",
tmp_dir.c_str(),
db_num_);
status = sqlite3_open(file_name, &db_);
if (status) {
@ -655,6 +667,7 @@ class Benchmark {
} // namespace leveldb
int main(int argc, char** argv) {
std::string default_db_path;
for (int i = 1; i < argc; i++) {
double d;
int n;
@ -684,12 +697,21 @@ int main(int argc, char** argv) {
} else if (sscanf(argv[i], "--WAL_enabled=%d%c", &n, &junk) == 1 &&
(n == 0 || n == 1)) {
FLAGS_WAL_enabled = n;
} else if (strncmp(argv[i], "--db=", 5) == 0) {
FLAGS_db = argv[i] + 5;
} else {
fprintf(stderr, "Invalid flag '%s'\n", argv[i]);
exit(1);
}
}
// Choose a location for the test database if none given with --db=<path>
if (FLAGS_db == NULL) {
leveldb::Env::Default()->GetTestDirectory(&default_db_path);
default_db_path += "/dbbench";
FLAGS_db = default_db_path.c_str();
}
leveldb::Benchmark benchmark;
benchmark.Run();
return 0;

+ 26
- 4
doc/bench/db_bench_tree_db.cc View File

@ -68,6 +68,9 @@ static bool FLAGS_use_existing_db = false;
// is off.
static bool FLAGS_compression = true;
// Use the db with the following name.
static const char* FLAGS_db = NULL;
inline
static void DBSynchronize(kyotocabinet::TreeDB* db_)
{
@ -292,11 +295,16 @@ class Benchmark {
bytes_(0),
rand_(301) {
std::vector<std::string> files;
Env::Default()->GetChildren("/tmp", &files);
std::string test_dir;
Env::Default()->GetTestDirectory(&test_dir);
Env::Default()->GetChildren(test_dir.c_str(), &files);
if (!FLAGS_use_existing_db) {
for (int i = 0; i < files.size(); i++) {
if (Slice(files[i]).starts_with("dbbench_polyDB")) {
Env::Default()->DeleteFile("/tmp/" + files[i]);
std::string file_name(test_dir);
file_name += "/";
file_name += files[i];
Env::Default()->DeleteFile(file_name.c_str());
}
}
}
@ -385,8 +393,12 @@ class Benchmark {
db_ = new kyotocabinet::TreeDB();
char file_name[100];
db_num_++;
snprintf(file_name, sizeof(file_name), "/tmp/dbbench_polyDB-%d.kct",
db_num_);
std::string test_dir;
Env::Default()->GetTestDirectory(&test_dir);
snprintf(file_name, sizeof(file_name),
"%s/dbbench_polyDB-%d.kct",
test_dir.c_str(),
db_num_);
// Create tuning options and open the database
int open_options = kyotocabinet::PolyDB::OWRITER |
@ -470,6 +482,7 @@ class Benchmark {
} // namespace leveldb
int main(int argc, char** argv) {
std::string default_db_path;
for (int i = 1; i < argc; i++) {
double d;
int n;
@ -494,12 +507,21 @@ int main(int argc, char** argv) {
} else if (sscanf(argv[i], "--compression=%d%c", &n, &junk) == 1 &&
(n == 0 || n == 1)) {
FLAGS_compression = (n == 1) ? true : false;
} else if (strncmp(argv[i], "--db=", 5) == 0) {
FLAGS_db = argv[i] + 5;
} else {
fprintf(stderr, "Invalid flag '%s'\n", argv[i]);
exit(1);
}
}
// Choose a location for the test database if none given with --db=<path>
if (FLAGS_db == NULL) {
leveldb::Env::Default()->GetTestDirectory(&default_db_path);
default_db_path += "/dbbench";
FLAGS_db = default_db_path.c_str();
}
leveldb::Benchmark benchmark;
benchmark.Run();
return 0;

+ 13
- 5
port/atomic_pointer.h View File

@ -73,13 +73,21 @@ inline void MemoryBarrier() {
}
#define LEVELDB_HAVE_MEMORY_BARRIER
// ARM
#elif defined(ARCH_CPU_ARM_FAMILY)
// ARM Linux
#elif defined(ARCH_CPU_ARM_FAMILY) && defined(__linux__)
typedef void (*LinuxKernelMemoryBarrierFunc)(void);
LinuxKernelMemoryBarrierFunc pLinuxKernelMemoryBarrier __attribute__((weak)) =
(LinuxKernelMemoryBarrierFunc) 0xffff0fa0;
// The Linux ARM kernel provides a highly optimized device-specific memory
// barrier function at a fixed memory address that is mapped in every
// user-level process.
//
// This beats using CPU-specific instructions which are, on single-core
// devices, un-necessary and very costly (e.g. ARMv7-A "dmb" takes more
// than 180ns on a Cortex-A8 like the one on a Nexus One). Benchmarking
// shows that the extra function call cost is completely negligible on
// multi-core devices.
//
inline void MemoryBarrier() {
pLinuxKernelMemoryBarrier();
(n>*pan>(LinuxKernelMemoryBarrierFunc)0xffff0fa0)();
}
#define LEVELDB_HAVE_MEMORY_BARRIER

+ 0
- 2
port/port.h View File

@ -14,8 +14,6 @@
# include "port/port_posix.h"
#elif defined(LEVELDB_PLATFORM_CHROMIUM)
# include "port/port_chromium.h"
#elif defined(LEVELDB_PLATFORM_ANDROID)
# include "port/port_android.h"
#endif
#endif // STORAGE_LEVELDB_PORT_PORT_H_

+ 10
- 0
port/port_example.h View File

@ -60,6 +60,16 @@ class CondVar {
void SignallAll();
};
// Thread-safe initialization.
// Used as follows:
// static port::OnceType init_control = LEVELDB_ONCE_INIT;
// static void Initializer() { ... do something ...; }
// ...
// port::InitOnce(&init_control, &Initializer);
typedef intptr_t OnceType;
#define LEVELDB_ONCE_INIT 0
extern void InitOnce(port::OnceType*, void (*initializer)());
// A type that holds a pointer that can be read or written atomically
// (i.e., without word-tearing.)
class AtomicPointer {

+ 4
- 0
port/port_posix.cc View File

@ -46,5 +46,9 @@ void CondVar::SignalAll() {
PthreadCall("broadcast", pthread_cond_broadcast(&cv_));
}
void InitOnce(OnceType* once, void (*initializer)()) {
PthreadCall("once", pthread_once(once, initializer));
}
} // namespace port
} // namespace leveldb

+ 24
- 9
port/port_posix.h View File

@ -7,17 +7,22 @@
#ifndef STORAGE_LEVELDB_PORT_PORT_POSIX_H_
#define STORAGE_LEVELDB_PORT_PORT_POSIX_H_
#undef PLATFORM_IS_LITTLE_ENDIAN
#if defined(OS_MACOSX)
#include <machine/endian.h>
#if defined(__DARWIN_LITTLE_ENDIAN) && defined(__DARWIN_BYTE_ORDER)
#define PLATFORM_IS_LITTLE_ENDIAN \
(__DARWIN_BYTE_ORDER == __DARWIN_LITTLE_ENDIAN)
#endif
#elif defined(OS_SOLARIS)
#include <sys/isa_defs.h>
#ifdef _LITTLE_ENDIAN
#define LITTLE_ENDIAN
#define PLATFORM_IS_LITTLE_ENDIAN true
#else
#define BIG_ENDIAN
#define PLATFORM_IS_LITTLE_ENDIAN false
#endif
#elif defined(OS_FREEBSD) || defined(OS_OPENBSD) || defined(OS_NETBSD) ||\
defined(OS_DRAGONFLYBSD)
defined(OS_DRAGONFLYBSD) || defined(OS_ANDROID)
#include <sys/types.h>
#include <sys/endian.h>
#else
@ -31,14 +36,13 @@
#include <string>
#include "port/atomic_pointer.h"
#ifdef LITTLE_ENDIAN
#define IS_LITTLE_ENDIAN true
#else
#define IS_LITTLE_ENDIAN (__BYTE_ORDER == __LITTLE_ENDIAN)
#ifndef PLATFORM_IS_LITTLE_ENDIAN
#define PLATFORM_IS_LITTLE_ENDIAN (__BYTE_ORDER == __LITTLE_ENDIAN)
#endif
#if defined(OS_MACOSX) || defined(OS_SOLARIS) || defined(OS_FREEBSD) ||\
defined(OS_NETBSD) || defined(OS_OPENBSD) || defined(OS_DRAGONFLYBSD)
defined(OS_NETBSD) || defined(OS_OPENBSD) || defined(OS_DRAGONFLYBSD) ||\
defined(OS_ANDROID)
// Use fread/fwrite/fflush on platforms without _unlocked variants
#define fread_unlocked fread
#define fwrite_unlocked fwrite
@ -51,10 +55,17 @@
#define fdatasync fsync
#endif
#if defined(OS_ANDROID) && __ANDROID_API__ < 9
// fdatasync() was only introduced in API level 9 on Android. Use fsync()
// when targetting older platforms.
#define fdatasync fsync
#endif
namespace leveldb {
namespace port {
static const bool kLittleEndian = IS_LITTLE_ENDIAN;
static const bool kLittleEndian = PLATFORM_IS_LITTLE_ENDIAN;
#undef PLATFORM_IS_LITTLE_ENDIAN
class CondVar;
@ -88,6 +99,10 @@ class CondVar {
Mutex* mu_;
};
typedef pthread_once_t OnceType;
#define LEVELDB_ONCE_INIT PTHREAD_ONCE_INIT
extern void InitOnce(OnceType* once, void (*initializer)());
inline bool Snappy_Compress(const char* input, size_t length,
::std::string* output) {
#ifdef SNAPPY

+ 23
- 0
util/coding_test.cc View File

@ -51,6 +51,29 @@ TEST(Coding, Fixed64) {
}
}
// Test that encoding routines generate little-endian encodings
TEST(Coding, EncodingOutput) {
std::string dst;
PutFixed32(&dst, 0x04030201);
ASSERT_EQ(4, dst.size());
ASSERT_EQ(0x01, static_cast<int>(dst[0]));
ASSERT_EQ(0x02, static_cast<int>(dst[1]));
ASSERT_EQ(0x03, static_cast<int>(dst[2]));
ASSERT_EQ(0x04, static_cast<int>(dst[3]));
dst.clear();
PutFixed64(&dst, 0x0807060504030201ull);
ASSERT_EQ(8, dst.size());
ASSERT_EQ(0x01, static_cast<int>(dst[0]));
ASSERT_EQ(0x02, static_cast<int>(dst[1]));
ASSERT_EQ(0x03, static_cast<int>(dst[2]));
ASSERT_EQ(0x04, static_cast<int>(dst[3]));
ASSERT_EQ(0x05, static_cast<int>(dst[4]));
ASSERT_EQ(0x06, static_cast<int>(dst[5]));
ASSERT_EQ(0x07, static_cast<int>(dst[6]));
ASSERT_EQ(0x08, static_cast<int>(dst[7]));
}
TEST(Coding, Varint32) {
std::string s;
for (uint32_t i = 0; i < (32 * 32); i++) {

+ 8
- 3
util/comparator.cc View File

@ -6,6 +6,7 @@
#include <stdint.h>
#include "leveldb/comparator.h"
#include "leveldb/slice.h"
#include "port/port.h"
#include "util/logging.h"
namespace leveldb {
@ -65,11 +66,15 @@ class BytewiseComparatorImpl : public Comparator {
};
} // namespace
// Intentionally not destroyed to prevent destructor racing
// with background threads.
static const Comparator* bytewise = new BytewiseComparatorImpl;
static port::OnceType once = LEVELDB_ONCE_INIT;
static const Comparator* bytewise;
static void InitModule() {
bytewise = new BytewiseComparatorImpl;
}
const Comparator* BytewiseComparator() {
port::InitOnce(&once, InitModule);
return bytewise;
}

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