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process wide: fix concurrent callers #21120

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Merged
jmarantz merged 4 commits into from
May 3, 2022
Merged

process wide: fix concurrent callers #21120

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process wide: fix concurrent callers
mattklein123 May 2, 2022
e9adb29
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mattklein123 May 2, 2022
e4ab5cc
Merge remote-tracking branch 'origin/main' into fix-pw
mattklein123 May 3, 2022
ec47f09
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mattklein123 May 3, 2022
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27 changes: 19 additions & 8 deletions source/exe/process_wide.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -9,16 +9,25 @@

namespace Envoy {
namespace {

struct InitData {
uint32_t count_ ABSL_GUARDED_BY(mutex_){};
absl::Mutex mutex_;
};

// Static variable to count initialization pairs. For tests like
// main_common_test, we need to count to avoid double initialization or
// shutdown.
std::atomic<uint32_t>& processWideInitialized() {
MUTABLE_CONSTRUCT_ON_FIRST_USE(std::atomic<uint32_t>);
};
InitData& processWideInitData() { MUTABLE_CONSTRUCT_ON_FIRST_USE(InitData); };
} // namespace

ProcessWide::ProcessWide() {
if (processWideInitialized()++ == 0) {
// Note that the following lock has the dual use of making sure that initialization is complete
// before a second caller can enter and leave this function.
auto& init_data = processWideInitData();
absl::MutexLock lock(&init_data.mutex_);

if (init_data.count_++ == 0) {
ares_library_init(ARES_LIB_INIT_ALL);
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Event::Libevent::Global::initialize();
Envoy::Server::validateProtoDescriptors();
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Expand All @@ -42,10 +51,12 @@ ProcessWide::ProcessWide() {
}

ProcessWide::~ProcessWide() {
auto& process_wide_initialized = processWideInitialized();
ASSERT(process_wide_initialized > 0);
if (--process_wide_initialized == 0) {
process_wide_initialized = false;
auto& init_data = processWideInitData();
absl::MutexLock lock(&init_data.mutex_);

ASSERT(init_data.count_ > 0);
if (--init_data.count_ == 0) {
init_data.count_ = false;
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Outdated
ares_library_cleanup();
}
}
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