summaryrefslogtreecommitdiff
path: root/absl/flags/internal
diff options
context:
space:
mode:
authorGravatar Abseil Team <absl-team@google.com>2019-07-18 15:07:49 -0700
committerGravatar Derek Mauro <dmauro@google.com>2019-07-19 13:04:45 -0400
commitf3840bc5e33ce4932e35986cf3718450c6f02af2 (patch)
tree43dd14bfbd542b155040546c4fab6e592c504988 /absl/flags/internal
parent278b26058c036833a4f7f3047d3f4d9296527f87 (diff)
Export of internal Abseil changes.
-- dcff7cc4eb3837d39d1e083cbf1d4f082054cbf6 by Laramie Leavitt <lar@google.com>: Add default and fallback modes for SaltedSeedSeq::generate(). SeedSeq::generate will often be called with contiguous ranges of uint32_t. Detect this case and use the currently direct code paths to handle it. Otherwise use a fallback mechanism which does an additional copy. PiperOrigin-RevId: 258853656 -- 59ec88845ac2ee6567c493021b54385940d66762 by Gennadiy Rozental <rogeeff@google.com>: Internal change PiperOrigin-RevId: 258822137 -- eb2d1ab21f6f94c24c51c1cd3719846be259e8e7 by Abseil Team <absl-team@google.com>: Add iOS version 11 to the mix of Apple OS versions that have various C++17 header files but do not support them. PiperOrigin-RevId: 258820405 -- 452cea3e13b29797b2c385d7c6da7613d36bdc45 by Gennadiy Rozental <rogeeff@google.com>: Internal change PiperOrigin-RevId: 258802436 GitOrigin-RevId: dcff7cc4eb3837d39d1e083cbf1d4f082054cbf6 Change-Id: I2261cb58e142eb15017ef646a56710dd64f06496
Diffstat (limited to 'absl/flags/internal')
-rw-r--r--absl/flags/internal/registry.cc80
-rw-r--r--absl/flags/internal/registry.h3
2 files changed, 6 insertions, 77 deletions
diff --git a/absl/flags/internal/registry.cc b/absl/flags/internal/registry.cc
index f37871c9..4e5d1106 100644
--- a/absl/flags/internal/registry.cc
+++ b/absl/flags/internal/registry.cc
@@ -54,53 +54,6 @@ void DestroyFlag(CommandLineFlag* flag) NO_THREAD_SAFETY_ANALYSIS {
// the function will acquire it itself if needed.
// --------------------------------------------------------------------
-// A map from flag pointer to CommandLineFlag*. Used when registering
-// validators.
-class FlagPtrMap {
- public:
- void Register(CommandLineFlag* flag) {
- auto& vec = buckets_[BucketForFlag(flag->cur)];
- if (vec.size() == vec.capacity()) {
- // Bypass default 2x growth factor with 1.25 so we have fuller vectors.
- // This saves 4% memory compared to default growth.
- vec.reserve(vec.size() * 1.25 + 0.5);
- }
- vec.push_back(flag);
- }
-
- CommandLineFlag* FindByPtr(const void* flag_ptr) {
- const auto& flag_vector = buckets_[BucketForFlag(flag_ptr)];
- for (CommandLineFlag* entry : flag_vector) {
- if (entry->cur == flag_ptr) {
- return entry;
- }
- }
- return nullptr;
- }
-
- private:
- // Instead of std::map, we use a custom hash table where each bucket stores
- // flags in a vector. This reduces memory usage 40% of the memory that would
- // have been used by std::map.
- //
- // kNumBuckets was picked as a large enough prime. As of writing this code, a
- // typical large binary has ~8k (old-style) flags, and this would gives
- // buckets with roughly 50 elements each.
- //
- // Note that reads to this hash table are rare: exactly as many as we have
- // flags with validators. As of writing, a typical binary only registers 52
- // validated flags.
- static constexpr size_t kNumBuckets = 163;
- std::vector<CommandLineFlag*> buckets_[kNumBuckets];
-
- static int BucketForFlag(const void* ptr) {
- // Modulo a prime is good enough here. On a real program, bucket size stddev
- // after registering 8k flags is ~5 (mean size at 51).
- return reinterpret_cast<uintptr_t>(ptr) % kNumBuckets;
- }
-};
-constexpr size_t FlagPtrMap::kNumBuckets;
-
class FlagRegistry {
public:
FlagRegistry() = default;
@@ -111,9 +64,7 @@ class FlagRegistry {
}
// Store a flag in this registry. Takes ownership of *flag.
- // If ptr is non-null, the flag can later be found by calling
- // FindFlagViaPtrLocked(ptr).
- void RegisterFlag(CommandLineFlag* flag, const void* ptr);
+ void RegisterFlag(CommandLineFlag* flag);
void Lock() EXCLUSIVE_LOCK_FUNCTION(lock_) { lock_.Lock(); }
void Unlock() UNLOCK_FUNCTION(lock_) { lock_.Unlock(); }
@@ -126,9 +77,6 @@ class FlagRegistry {
// found or not retired. Does not emit a warning.
CommandLineFlag* FindRetiredFlagLocked(absl::string_view name);
- // Returns the flag object whose current-value is stored at flag_ptr.
- CommandLineFlag* FindFlagViaPtrLocked(const void* flag_ptr);
-
static FlagRegistry* GlobalRegistry(); // returns a singleton registry
private:
@@ -142,8 +90,6 @@ class FlagRegistry {
using FlagConstIterator = FlagMap::const_iterator;
FlagMap flags_;
- FlagPtrMap flag_ptr_map_;
-
absl::Mutex lock_;
// Disallow
@@ -169,7 +115,7 @@ class FlagRegistryLock {
} // namespace
-void FlagRegistry::RegisterFlag(CommandLineFlag* flag, const void* ptr) {
+void FlagRegistry::RegisterFlag(CommandLineFlag* flag) {
FlagRegistryLock registry_lock(this);
std::pair<FlagIterator, bool> ins =
flags_.insert(FlagMap::value_type(flag->Name(), flag));
@@ -217,11 +163,6 @@ void FlagRegistry::RegisterFlag(CommandLineFlag* flag, const void* ptr) {
// All cases above are fatal, except for the retired flags.
std::exit(1);
}
-
- if (ptr != nullptr) {
- // This must be the first time we're seeing this flag.
- flag_ptr_map_.Register(flag);
- }
}
CommandLineFlag* FlagRegistry::FindFlagLocked(absl::string_view name) {
@@ -247,10 +188,6 @@ CommandLineFlag* FlagRegistry::FindRetiredFlagLocked(absl::string_view name) {
return i->second;
}
-CommandLineFlag* FlagRegistry::FindFlagViaPtrLocked(const void* flag_ptr) {
- return flag_ptr_map_.FindByPtr(flag_ptr);
-}
-
// --------------------------------------------------------------------
// FlagSaver
// FlagSaverImpl
@@ -430,13 +367,6 @@ CommandLineFlag* FindCommandLineFlag(absl::string_view name) {
return registry->FindFlagLocked(name);
}
-CommandLineFlag* FindCommandLineV1Flag(const void* flag_ptr) {
- FlagRegistry* const registry = FlagRegistry::GlobalRegistry();
- FlagRegistryLock frl(registry);
-
- return registry->FindFlagViaPtrLocked(flag_ptr);
-}
-
CommandLineFlag* FindRetiredFlag(absl::string_view name) {
FlagRegistry* const registry = FlagRegistry::GlobalRegistry();
FlagRegistryLock frl(registry);
@@ -477,8 +407,8 @@ void GetAllFlags(std::vector<CommandLineFlagInfo>* OUTPUT) {
// --------------------------------------------------------------------
-bool RegisterCommandLineFlag(CommandLineFlag* flag, const void* ptr) {
- FlagRegistry::GlobalRegistry()->RegisterFlag(flag, ptr);
+bool RegisterCommandLineFlag(CommandLineFlag* flag) {
+ FlagRegistry::GlobalRegistry()->RegisterFlag(flag);
return true;
}
@@ -492,7 +422,7 @@ bool Retire(FlagOpFn ops, FlagMarshallingOpFn marshalling_ops,
/*filename_arg=*/"RETIRED", ops, marshalling_ops,
/*initial_value_gen=*/nullptr,
/*retired_arg=*/true, nullptr, nullptr);
- FlagRegistry::GlobalRegistry()->RegisterFlag(flag, nullptr);
+ FlagRegistry::GlobalRegistry()->RegisterFlag(flag);
return true;
}
diff --git a/absl/flags/internal/registry.h b/absl/flags/internal/registry.h
index bd141e1e..27566fbf 100644
--- a/absl/flags/internal/registry.h
+++ b/absl/flags/internal/registry.h
@@ -57,7 +57,6 @@ void FillCommandLineFlagInfo(CommandLineFlag* flag,
//-----------------------------------------------------------------------------
CommandLineFlag* FindCommandLineFlag(absl::string_view name);
-CommandLineFlag* FindCommandLineV1Flag(const void* flag_ptr);
CommandLineFlag* FindRetiredFlag(absl::string_view name);
// Executes specified visitor for each non-retired flag in the registry.
@@ -74,7 +73,7 @@ void GetAllFlags(std::vector<CommandLineFlagInfo>* OUTPUT);
//-----------------------------------------------------------------------------
-bool RegisterCommandLineFlag(CommandLineFlag*, const void* ptr = nullptr);
+bool RegisterCommandLineFlag(CommandLineFlag*);
//-----------------------------------------------------------------------------
// Retired registrations: