diff options
author | 2021-04-15 19:42:51 -0700 | |
---|---|---|
committer | 2021-04-15 19:45:30 -0700 | |
commit | e20fe888fabc1fc995dc61180e8a31b5f809a95f (patch) | |
tree | 5877907889fe35eb3162aa71111e16bd1d59fde4 /absl/strings/cord.h | |
parent | 46dfbfe31ca1dd414e4c33cbcbcd7199bb4efde3 (diff) |
Export of internal Abseil changes
--
341670bce317dd6af8d3c066970230591a47e80c by Martijn Vels <mvels@google.com>:
Change GetStack() and GetParentStack() to return absl::Span
PiperOrigin-RevId: 368765721
--
6aaab9536d6957303c7aba100c3afaa6fb0ea2c8 by Martijn Vels <mvels@google.com>:
Remove locking from parent stack.
This change removes the need to lock all access to `parent_stack' by making the 'copy constructor' logic specify the 'copied from' CordzInfo (where available) to the TrackCord function, after which parent_stack is immutable.
PiperOrigin-RevId: 368760630
--
b19e2059cada35a8ede994833018edac94de6ddc by Martijn Vels <mvels@google.com>:
Add cordz instrumentation to Cord
PiperOrigin-RevId: 368746225
--
67b8bbf980f0f4e1db79aa32968e9a715a09b51a by Martijn Vels <mvels@google.com>:
Create ABSL_INTERNAL_CORDZ_ENABLED define controlling when Cordz code is enabled
There are specific builds and condtions under which we don't support cordz sampling, which is per this change represented by ABSL_INTERNAL_CORDZ_ENABLED being defined.
PiperOrigin-RevId: 368731603
--
8cbfe0e3169637a620f4b66ad2bc2ce340879cb0 by Martijn Vels <mvels@google.com>:
Add a `rep` property to CordzInfo to be managed by Cord logic.
This change adds a `rep` property to CordzInfo, which is intended to be used by collection logic.
Mini design:
Cord invokes TrackCord() providing the active 'root' cordrep of the newly sampled Cord, returning a CordzInfo with a weak (uncounted) reference to this root. Cord invokes `SetCordRep()` each time the root cordrep of the sampled Cord is updated while holding `mutex()`. Cord must also obtain `mutex()` _before_ removing a reference on the old root. i.e.: Cord must guarantee that the (weak) reference held in CordzInfo is at all times valid.
CordzInfo collection code can then safely obtain a (reference counted) rep pointer by adding a reference to `rep_` while holding `mutex()`. This requires only a very brief critical section inside CordzInfo logic, minimizing contention with concurrent Cord updates.
Cord code should typically obtain and hold `mutex()` for the entirety of each mutating Cord operation on a sampled cord. As Cord is thread compatible, it never competes on the lock with any other thread. The only possible concurrent access is from Cordz collection code, which should be a relatively rare event.
PiperOrigin-RevId: 368673758
--
1255120dce2bdd6b4205a34a0e555e0b74b6152f by Martijn Vels <mvels@google.com>:
Remove 'depth' from active recorded metrics.
Going forward we do not 'live' record depth (and size), but will observe these at collection time only.
PiperOrigin-RevId: 368636572
--
83e5146e35f221736b49e9f0a8805f8c159a51db by Martijn Vels <mvels@google.com>:
Make cordz targets visible in OSS
PiperOrigin-RevId: 368615010
--
dcb16a4f1239151f0a8c70a8cfeb29dabbd113b8 by Martijn Vels <mvels@google.com>:
Internal cleanup
PiperOrigin-RevId: 368514666
GitOrigin-RevId: 341670bce317dd6af8d3c066970230591a47e80c
Change-Id: I94cecfbbd441eb386f99fc5186c468a7a5538862
Diffstat (limited to 'absl/strings/cord.h')
-rw-r--r-- | absl/strings/cord.h | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/absl/strings/cord.h b/absl/strings/cord.h index 7ce938ca..de1470b2 100644 --- a/absl/strings/cord.h +++ b/absl/strings/cord.h @@ -70,6 +70,7 @@ #include <string> #include <type_traits> +#include "absl/base/config.h" #include "absl/base/internal/endian.h" #include "absl/base/internal/per_thread_tls.h" #include "absl/base/macros.h" @@ -80,6 +81,9 @@ #include "absl/strings/internal/cord_internal.h" #include "absl/strings/internal/cord_rep_ring.h" #include "absl/strings/internal/cord_rep_ring_reader.h" +#include "absl/strings/internal/cordz_functions.h" +#include "absl/strings/internal/cordz_info.h" +#include "absl/strings/internal/cordz_statistics.h" #include "absl/strings/internal/resize_uninitialized.h" #include "absl/strings/internal/string_constant.h" #include "absl/strings/string_view.h" @@ -772,6 +776,20 @@ class Cord { // Resets the current cordz_info to null / empty. void clear_cordz_info() { data_.clear_cordz_info(); } + // Starts profiling this cord. + void StartProfiling(); + + // Starts profiling this cord which has been copied from `src`. + void StartProfiling(const Cord::InlineRep& src); + + // Returns true if a Cord should be profiled and false otherwise. + static bool should_profile(); + + // Updates the cordz statistics. info may be nullptr if the CordzInfo object + // is unknown. + void UpdateCordzStatistics(); + void UpdateCordzStatisticsSlow(); + private: friend class Cord; @@ -943,6 +961,9 @@ inline Cord::InlineRep::InlineRep(const Cord::InlineRep& src) if (is_tree()) { data_.clear_cordz_info(); absl::cord_internal::CordRep::Ref(as_tree()); + if (ABSL_PREDICT_FALSE(should_profile())) { + StartProfiling(src); + } } } @@ -1004,6 +1025,9 @@ inline size_t Cord::InlineRep::size() const { inline void Cord::InlineRep::set_tree(absl::cord_internal::CordRep* rep) { if (rep == nullptr) { + if (ABSL_PREDICT_FALSE(is_profiled())) { + absl::cord_internal::CordzInfo::UntrackCord(cordz_info()); + } ResetToEmpty(); } else { if (data_.is_tree()) { @@ -1013,7 +1037,11 @@ inline void Cord::InlineRep::set_tree(absl::cord_internal::CordRep* rep) { } else { // `data_` contains inlined data: initialize data_ to tree value `rep`. data_.make_tree(rep); + if (ABSL_PREDICT_FALSE(should_profile())) { + StartProfiling(); + } } + UpdateCordzStatistics(); } } @@ -1024,9 +1052,13 @@ inline void Cord::InlineRep::replace_tree(absl::cord_internal::CordRep* rep) { return; } data_.set_tree(rep); + UpdateCordzStatistics(); } inline absl::cord_internal::CordRep* Cord::InlineRep::clear() { + if (ABSL_PREDICT_FALSE(is_profiled())) { + absl::cord_internal::CordzInfo::UntrackCord(cordz_info()); + } absl::cord_internal::CordRep* result = tree(); ResetToEmpty(); return result; @@ -1039,6 +1071,15 @@ inline void Cord::InlineRep::CopyToArray(char* dst) const { cord_internal::SmallMemmove(dst, data_.as_chars(), n); } +inline ABSL_ATTRIBUTE_ALWAYS_INLINE bool Cord::InlineRep::should_profile() { + return absl::cord_internal::cordz_should_profile(); +} + +inline void Cord::InlineRep::UpdateCordzStatistics() { + if (ABSL_PREDICT_TRUE(!is_profiled())) return; + UpdateCordzStatisticsSlow(); +} + constexpr inline Cord::Cord() noexcept {} template <typename T> |