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authorGravatar Abseil Team <absl-team@google.com>2019-10-02 15:20:57 -0700
committerGravatar CJ Johnson <johnsoncj@google.com>2019-10-03 12:32:02 -0400
commit25597bdfc148e91e27678ec30efa52f4fc8c164f (patch)
treefd31b4d65f454e63d697608e183d97f4c8054bab /absl/container/internal
parentaad33fefaa8f744d71ce747a53717b835bdf8e84 (diff)
Export of internal Abseil changes
-- 3e60f355db5afd7a864591d81a6c383b6c0a0780 by Samuel Benzaquen <sbenza@google.com>: Internal change PiperOrigin-RevId: 272531442 -- 6d189240b8cebe3a390c730de491156d03049229 by Andy Getzendanner <durandal@google.com>: Fix AtomicHook init-order fiasco under MSVC 2019. On this platform, constexpr static init sometimes happens after dynamic init =/. When it does, we should not zero hook_ (overwriting the value written there by dynamic init); instead we should leave it alone. This works even when constexpr static init goes first since all uses of AtomicHook should have static storage duration and be zero-initialized. https://developercommunity.visualstudio.com/content/problem/336946/class-with-constexpr-constructor-not-using-static.html PiperOrigin-RevId: 272525226 -- d01b14fc06bc75b41c51976ed32e7c304ea1aab7 by Abseil Team <absl-team@google.com>: exclude emscripten from running tests involving long doubles PiperOrigin-RevId: 272497628 GitOrigin-RevId: 3e60f355db5afd7a864591d81a6c383b6c0a0780 Change-Id: I3c8a8f5acaf7652a06ef40cf028ef5d2e142f81b
Diffstat (limited to 'absl/container/internal')
-rw-r--r--absl/container/internal/hashtablez_sampler.cc20
-rw-r--r--absl/container/internal/hashtablez_sampler.h2
-rw-r--r--absl/container/internal/hashtablez_sampler_force_weak_definition.cc5
3 files changed, 23 insertions, 4 deletions
diff --git a/absl/container/internal/hashtablez_sampler.cc b/absl/container/internal/hashtablez_sampler.cc
index d03dd82e..054e8981 100644
--- a/absl/container/internal/hashtablez_sampler.cc
+++ b/absl/container/internal/hashtablez_sampler.cc
@@ -228,8 +228,26 @@ int64_t HashtablezSampler::Iterate(
return dropped_samples_.load(std::memory_order_relaxed);
}
+static bool ShouldForceSampling() {
+ enum ForceState {
+ kDontForce,
+ kForce,
+ kUninitialized
+ };
+ ABSL_CONST_INIT static std::atomic<ForceState> global_state{
+ kUninitialized};
+ ForceState state = global_state.load(std::memory_order_relaxed);
+ if (ABSL_PREDICT_TRUE(state == kDontForce)) return false;
+
+ if (state == kUninitialized) {
+ state = AbslContainerInternalSampleEverything() ? kForce : kDontForce;
+ global_state.store(state, std::memory_order_relaxed);
+ }
+ return state == kForce;
+}
+
HashtablezInfo* SampleSlow(int64_t* next_sample) {
- if (kAbslContainerInternalSampleEverything) {
+ if (ABSL_PREDICT_FALSE(ShouldForceSampling())) {
*next_sample = 1;
return HashtablezSampler::Global().Register();
}
diff --git a/absl/container/internal/hashtablez_sampler.h b/absl/container/internal/hashtablez_sampler.h
index 41121754..53996bb9 100644
--- a/absl/container/internal/hashtablez_sampler.h
+++ b/absl/container/internal/hashtablez_sampler.h
@@ -280,7 +280,7 @@ void SetHashtablezMaxSamples(int32_t max);
// initialization of static storage duration objects.
// The definition of this constant is weak, which allows us to inject a
// different value for it at link time.
-extern "C" const bool kAbslContainerInternalSampleEverything;
+extern "C" bool AbslContainerInternalSampleEverything();
} // namespace container_internal
} // namespace absl
diff --git a/absl/container/internal/hashtablez_sampler_force_weak_definition.cc b/absl/container/internal/hashtablez_sampler_force_weak_definition.cc
index 4ca6ffda..984dce5d 100644
--- a/absl/container/internal/hashtablez_sampler_force_weak_definition.cc
+++ b/absl/container/internal/hashtablez_sampler_force_weak_definition.cc
@@ -20,8 +20,9 @@ namespace absl {
namespace container_internal {
// See hashtablez_sampler.h for details.
-extern "C" ABSL_ATTRIBUTE_WEAK const bool
- kAbslContainerInternalSampleEverything = false;
+extern "C" ABSL_ATTRIBUTE_WEAK bool AbslContainerInternalSampleEverything() {
+ return false;
+}
} // namespace container_internal
} // namespace absl