firefox-main/js/src/threading
Name Description Size Coverage
ConditionVariable.h 4166 -
CpuCount.h Return the number of cores on the system. If the system provides logical cores (such as hyperthreads) then count each logical core as an actual core. 542 -
ExclusiveData.h [SMDOC] ExclusiveData API A mutual exclusion lock class. `ExclusiveData` provides an RAII guard to automatically lock and unlock when accessing the protected inner value. Unlike the STL's `std::mutex`, the protected value is internal to this class. This is a huge win: one no longer has to rely on documentation to explain the relationship between a lock and its protected data, and the type system can enforce[0] it. For example, suppose we have a counter class: class Counter { int32_t i; public: void inc(int32_t n) { i += n; } }; If we share a counter across threads with `std::mutex`, we rely solely on comments to document the relationship between the lock and its data, like this: class SharedCounter { // Remember to acquire `counter_lock` when accessing `counter`, // pretty please! Counter counter; std::mutex counter_lock; public: void inc(size_t n) { // Whoops, forgot to acquire the lock! Off to the races! counter.inc(n); } }; In contrast, `ExclusiveData` wraps the protected value, enabling the type system to enforce that we acquire the lock before accessing the value: class SharedCounter { ExclusiveData<Counter> counter; public: void inc(size_t n) { auto guard = counter.lock(); guard->inc(n); } }; The API design is based on Rust's `std::sync::Mutex<T>` type. [0]: Of course, we don't have a borrow checker in C++, so the type system cannot guarantee that you don't stash references received from `ExclusiveData<T>::Guard` somewhere such that the reference outlives the guard's lifetime and therefore becomes invalid. To help avoid this last foot-gun, prefer using the guard directly! Do not store raw references to the protected value in other structures! 11713 -
LockGuard.h 1102 -
moz.build 1051 -
Mutex.cpp static 1757 -
Mutex.h 2402 -
noop -
posix -
ProtectedData.cpp static 2659 -
ProtectedData.h 11112 -
Thread.cpp 749 -
Thread.h 8716 -
ThreadId.h 939 -
windows -