maurice/snix
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Export of internal Abseil changes.

Browse source 
--
ed3a3431eee9e48e6553b0320e0308d2dde6725c by Derek Mauro <dmauro@google.com>:

Project import generated by Copybara.

PiperOrigin-RevId: 258631680
GitOrigin-RevId: ed3a3431eee9e48e6553b0320e0308d2dde6725c
Change-Id: I1d7ae86a79783842092d29504605ba039c369603
This commit is contained in:
Abseil Team 2019-07-17 16:35:47 -04:00 • committed by Derek Mauro
parent 44efe96dfc
commit c6c3c1b498
32 changed files with 1168 additions and 657 deletions
Download patch file Download diff file Expand all files Collapse all files

76
absl/flags/internal/commandlineflag.h
View file

@ -69,11 +69,15 @@ using HelpGenFunc = std::string (*)();
// based on default value supplied in flag's definition)
using InitialValGenFunc = void* (*)();
struct CommandLineFlagInfo;
// Signature for the mutation callback used by watched Flags
// The callback is noexcept.
// TODO(rogeeff): add noexcept after C++17 support is added.
using FlagCallback = void (*)();
using FlagValidator = bool (*)();
extern const char kStrippedFlagHelp[];
// The per-type function
@ -217,6 +221,9 @@ struct CommandLineFlag {
atomic(kAtomicInit),
locks(nullptr) {}
// Revert the init routine.
void Destroy() const;
// Not copyable/assignable.
CommandLineFlag(const CommandLineFlag&) = delete;
CommandLineFlag& operator=(const CommandLineFlag&) = delete;
@ -224,7 +231,9 @@ struct CommandLineFlag {
absl::string_view Name() const { return name; }
std::string Help() const { return help.GetHelpText(); }
bool IsRetired() const { return this->retired; }
bool IsSpecifiedOnCommandLine() const { return on_command_line; }
bool IsModified() const;
void SetModified(bool is_modified);
bool IsSpecifiedOnCommandLine() const;
// Returns true iff this is a handle to an Abseil Flag.
bool IsAbseilFlag() const {
// Set to null for V1 flags
@ -236,6 +245,10 @@ struct CommandLineFlag {
std::string DefaultValue() const;
std::string CurrentValue() const;
bool HasValidatorFn() const;
bool SetValidatorFn(FlagValidator fn);
bool InvokeValidator(const void* value) const;
// Return true iff flag has type T.
template <typename T>
inline bool IsOfType() const {
@ -245,7 +258,7 @@ struct CommandLineFlag {
// Attempts to retrieve the flag value. Returns value on success,
// absl::nullopt otherwise.
template <typename T>
absl::optional<T> Get() {
absl::optional<T> Get() const {
if (IsRetired() || flags_internal::FlagOps<T> != this->op)
return absl::nullopt;
@ -256,6 +269,7 @@ struct CommandLineFlag {
}
void SetCallback(const flags_internal::FlagCallback mutation_callback);
void InvokeCallback();
// Sets the value of the flag based on specified std::string `value`. If the flag
// was successfully set to new value, it returns true. Otherwise, sets `error`
@ -269,27 +283,35 @@ struct CommandLineFlag {
flags_internal::FlagSettingMode set_mode,
flags_internal::ValueSource source, std::string* error);
void StoreAtomic(size_t size);
void CheckDefaultValueParsingRoundtrip() const;
// Invoke the flag validators for old flags.
// TODO(rogeeff): implement proper validators for Abseil Flags
bool ValidateDefaultValue() const;
bool ValidateInputValue(absl::string_view value) const;
// Constant configuration for a particular flag.
private:
const char* const name;
const HelpText help;
const char* const filename;
public:
const FlagOpFn op; // Type-specific handler
protected:
const FlagOpFn op; // Type-specific handler
const FlagMarshallingOpFn marshalling_op; // Marshalling ops handler
const InitialValGenFunc make_init_value; // Makes initial value for the flag
const bool retired; // Is the flag retired?
std::atomic<bool> inited; // fields have been lazily initialized
const bool retired; // Is the flag retired?
std::atomic<bool> inited; // fields have been lazily initialized
// Mutable state (guarded by locks->primary_mu).
bool modified; // Has flag value been modified?
bool on_command_line; // Specified on command line.
bool (*validator)(); // Validator function, or nullptr
FlagCallback callback; // Mutation callback, or nullptr
void* def; // Lazily initialized pointer to default value
void* cur; // Lazily initialized pointer to current value
int64_t counter; // Mutation counter
bool modified; // Has flag value been modified?
bool on_command_line; // Specified on command line.
FlagValidator validator; // Validator function, or nullptr
FlagCallback callback; // Mutation callback, or nullptr
void* def; // Lazily initialized pointer to default value
void* cur; // Lazily initialized pointer to current value
int64_t counter; // Mutation counter
// For some types, a copy of the current value is kept in an atomically
// accessible field.
@ -302,24 +324,26 @@ struct CommandLineFlag {
// TODO(rogeeff): fix it once Mutex has constexpr constructor
struct CommandLineFlagLocks* locks; // locks, laziliy allocated.
// Ensure that the lazily initialized fields of *flag have been initialized,
// and return the lock which should be locked when flag's state is mutated.
absl::Mutex* InitFlagIfNecessary() const;
// copy construct new value of flag's type in a memory referenced by dst
// based on current flag's value
void Read(void* dst, const flags_internal::FlagOpFn dst_op) const;
// updates flag's value to *src (locked)
void Write(const void* src, const flags_internal::FlagOpFn src_op);
ABSL_DEPRECATED(
"temporary until FlagName call sites are migrated and validator API is "
"changed")
const char* NameAsCString() const { return name; }
private:
friend class FlagRegistry;
friend class FlagPtrMap;
friend class FlagSaverImpl;
friend void FillCommandLineFlagInfo(CommandLineFlag* flag,
CommandLineFlagInfo* result);
friend bool TryParseLocked(CommandLineFlag* flag, void* dst,
absl::string_view value, std::string* err);
friend absl::Mutex* InitFlag(CommandLineFlag* flag);
};
// Ensure that the lazily initialized fields of *flag have been initialized,
// and return &flag->locks->primary_mu.
absl::Mutex* InitFlagIfNecessary(CommandLineFlag* flag);
// Update any copy of the flag value that is stored in an atomic word.
// In addition if flag has a mutation callback this function invokes it. While
// callback is being invoked the primary flag's mutex is unlocked and it is
@ -332,15 +356,9 @@ absl::Mutex* InitFlagIfNecessary(CommandLineFlag* flag);
// different by the time the callback invocation is completed.
// Requires that *primary_lock be held in exclusive mode; it may be released
// and reacquired by the implementation.
void UpdateCopy(CommandLineFlag* flag, absl::Mutex* primary_lock);
void UpdateCopy(CommandLineFlag* flag);
// Return true iff flag value was changed via direct-access.
bool ChangedDirectly(CommandLineFlag* flag, const void* a, const void* b);
// Direct-access flags can be modified without going through the
// flag API. Detect such changes and updated the modified bit.
void UpdateModifiedBit(CommandLineFlag* flag);
// Invoke the flag validators for old flags.
// TODO(rogeeff): implement proper validators for Abseil Flags
bool Validate(CommandLineFlag* flag, const void* value);
// This macro is the "source of truth" for the list of supported flag types we
// expect to perform lock free operations on. Specifically it generates code,