diff options
| -rw-r--r-- | indra/llcommon/llthreadsafequeue.h | 229 |
1 files changed, 163 insertions, 66 deletions
diff --git a/indra/llcommon/llthreadsafequeue.h b/indra/llcommon/llthreadsafequeue.h index 26e0d71d31..04f51816d7 100644 --- a/indra/llcommon/llthreadsafequeue.h +++ b/indra/llcommon/llthreadsafequeue.h @@ -1,6 +1,6 @@ /** * @file llthreadsafequeue.h - * @brief Base classes for thread, mutex and condition handling. + * @brief Queue protected with mutexes for cross-thread use * * $LicenseInfo:firstyear=2004&license=viewerlgpl$ * Second Life Viewer Source Code @@ -27,15 +27,15 @@ #ifndef LL_LLTHREADSAFEQUEUE_H #define LL_LLTHREADSAFEQUEUE_H -#include "llexception.h" -#include <deque> -#include <string> -#include <chrono> -#include "mutex.h" #include "llcoros.h" #include LLCOROS_MUTEX_HEADER #include <boost/fiber/timed_mutex.hpp> #include LLCOROS_CONDVAR_HEADER +#include "llexception.h" +#include "mutex.h" +#include <chrono> +#include <queue> +#include <string> // // A general queue exception. @@ -66,61 +66,95 @@ public: } }; -// -// Implements a thread safe FIFO. -// -template<typename ElementT> +/** + * Implements a thread safe FIFO. + */ +// Let the default std::queue default to underlying std::deque. Override if +// desired. +template<typename ElementT, typename QueueT=std::queue<ElementT>> class LLThreadSafeQueue { public: typedef ElementT value_type; - + // If the pool is set to NULL one will be allocated and managed by this // queue. LLThreadSafeQueue(U32 capacity = 1024); - - // Add an element to the front of queue (will block if the queue has + + // Add an element to the queue (will block if the queue has // reached capacity). // // This call will raise an interrupt error if the queue is closed while // the caller is blocked. - void pushFront(ElementT const & element); - - // Try to add an element to the front of queue without blocking. Returns + void push(ElementT const& element); + // legacy name + void pushFront(ElementT const & element) { return push(element); } + + // Try to add an element to the queue without blocking. Returns // true only if the element was actually added. - bool tryPushFront(ElementT const & element); + bool tryPush(ElementT const& element); + // legacy name + bool tryPushFront(ElementT const & element) { return tryPush(element); } - // Try to add an element to the front of queue, blocking if full but with - // timeout. Returns true if the element was added. + // Try to add an element to the queue, blocking if full but with timeout + // after specified duration. Returns true if the element was added. // There are potentially two different timeouts involved: how long to try // to lock the mutex, versus how long to wait for the queue to stop being // full. Careful settings for each timeout might be orders of magnitude // apart. However, this method conflates them. template <typename Rep, typename Period> + bool tryPushFor(const std::chrono::duration<Rep, Period>& timeout, + ElementT const & element); + // legacy name + template <typename Rep, typename Period> bool tryPushFrontFor(const std::chrono::duration<Rep, Period>& timeout, - ElementT const & element); + ElementT const & element) { return tryPushFor(timeout, element); } + + // Try to add an element to the queue, blocking if full but with + // timeout at specified time_point. Returns true if the element was added. + template <typename Clock, typename Duration> + bool tryPushUntil(const std::chrono::time_point<Clock, Duration>& timeout, + ElementT const& element); + // no legacy name because this is a newer method - // Pop the element at the end of the queue (will block if the queue is + // Pop the element at the head of the queue (will block if the queue is // empty). // // This call will raise an interrupt error if the queue is closed while // the caller is blocked. - ElementT popBack(void); - - // Pop an element from the end of the queue if there is one available. + ElementT pop(void); + // legacy name + ElementT popBack(void) { return pop(); } + + // Pop an element from the head of the queue if there is one available. // Returns true only if an element was popped. - bool tryPopBack(ElementT & element); - + bool tryPop(ElementT & element); + // legacy name + bool tryPopBack(ElementT & element) { return tryPop(element); } + + // Pop the element at the head of the queue, blocking if empty, with + // timeout after specified duration. Returns true if an element was popped. + template <typename Rep, typename Period> + bool tryPopFor(const std::chrono::duration<Rep, Period>& timeout, ElementT& element); + // no legacy name because this is a newer method + + // Pop the element at the head of the queue, blocking if empty, with + // timeout at specified time_point. Returns true if an element was popped. + template <typename Clock, typename Duration> + bool tryPopUntil(const std::chrono::time_point<Clock, Duration>& timeout, + ElementT& element); + // no legacy name because this is a newer method + // Returns the size of the queue. size_t size(); // closes the queue: - // - every subsequent pushFront() call will throw LLThreadSafeQueueInterrupt - // - every subsequent tryPushFront() call will return false - // - popBack() calls will return normally until the queue is drained, then - // every subsequent popBack() will throw LLThreadSafeQueueInterrupt - // - tryPopBack() calls will return normally until the queue is drained, - // then every subsequent tryPopBack() call will return false + // - every subsequent push() call will throw LLThreadSafeQueueInterrupt + // - every subsequent tryPush() call will return false + // - pop() calls will return normally until the queue is drained, then + // every subsequent pop() will throw LLThreadSafeQueueInterrupt + // - tryPop() calls will return normally until the queue is drained, + // then every subsequent tryPop() call will return false void close(); // detect closed state @@ -128,8 +162,9 @@ public: // inverse of isClosed() explicit operator bool(); -private: - std::deque< ElementT > mStorage; +protected: + typedef QueueT queue_type; + QueueT mStorage; U32 mCapacity; bool mClosed; @@ -142,16 +177,16 @@ private: // LLThreadSafeQueue //----------------------------------------------------------------------------- -template<typename ElementT> -LLThreadSafeQueue<ElementT>::LLThreadSafeQueue(U32 capacity) : +template<typename ElementT, typename QueueT> +LLThreadSafeQueue<ElementT, QueueT>::LLThreadSafeQueue(U32 capacity) : mCapacity(capacity), mClosed(false) { } -template<typename ElementT> -void LLThreadSafeQueue<ElementT>::pushFront(ElementT const & element) +template<typename ElementT, typename QueueT> +void LLThreadSafeQueue<ElementT, QueueT>::push(ElementT const & element) { lock_t lock1(mLock); while (true) @@ -163,7 +198,7 @@ void LLThreadSafeQueue<ElementT>::pushFront(ElementT const & element) if (mStorage.size() < mCapacity) { - mStorage.push_front(element); + mStorage.push(element); lock1.unlock(); mEmptyCond.notify_one(); return; @@ -175,15 +210,24 @@ void LLThreadSafeQueue<ElementT>::pushFront(ElementT const & element) } -template <typename ElementT> +template <typename ElementT, typename QueueT> template <typename Rep, typename Period> -bool LLThreadSafeQueue<ElementT>::tryPushFrontFor(const std::chrono::duration<Rep, Period>& timeout, - ElementT const & element) +bool LLThreadSafeQueue<ElementT, QueueT>::tryPushFor( + const std::chrono::duration<Rep, Period>& timeout, + ElementT const & element) { // Convert duration to time_point: passing the same timeout duration to // each of multiple calls is wrong. - auto endpoint = std::chrono::steady_clock::now() + timeout; + return tryPushUntil(std::chrono::steady_clock::now() + timeout, element); +} + +template <typename ElementT, typename QueueT> +template <typename Clock, typename Duration> +bool LLThreadSafeQueue<ElementT, QueueT>::tryPushUntil( + const std::chrono::time_point<Clock, Duration>& endpoint, + ElementT const& element) +{ lock_t lock1(mLock, std::defer_lock); if (!lock1.try_lock_until(endpoint)) return false; @@ -197,7 +241,7 @@ bool LLThreadSafeQueue<ElementT>::tryPushFrontFor(const std::chrono::duration<Re if (mStorage.size() < mCapacity) { - mStorage.push_front(element); + mStorage.push(element); lock1.unlock(); mEmptyCond.notify_one(); return true; @@ -215,8 +259,8 @@ bool LLThreadSafeQueue<ElementT>::tryPushFrontFor(const std::chrono::duration<Re } -template<typename ElementT> -bool LLThreadSafeQueue<ElementT>::tryPushFront(ElementT const & element) +template<typename ElementT, typename QueueT> +bool LLThreadSafeQueue<ElementT, QueueT>::tryPush(ElementT const & element) { lock_t lock1(mLock, std::defer_lock); if (!lock1.try_lock()) @@ -228,23 +272,24 @@ bool LLThreadSafeQueue<ElementT>::tryPushFront(ElementT const & element) if (mStorage.size() >= mCapacity) return false; - mStorage.push_front(element); + mStorage.push(element); lock1.unlock(); mEmptyCond.notify_one(); return true; } -template<typename ElementT> -ElementT LLThreadSafeQueue<ElementT>::popBack(void) +template<typename ElementT, typename QueueT> +ElementT LLThreadSafeQueue<ElementT, QueueT>::pop(void) { lock_t lock1(mLock); while (true) { if (!mStorage.empty()) { - ElementT value = mStorage.back(); - mStorage.pop_back(); + // std::queue::front() is the element about to pop() + ElementT value = mStorage.front(); + mStorage.pop(); lock1.unlock(); mCapacityCond.notify_one(); return value; @@ -261,54 +306,106 @@ ElementT LLThreadSafeQueue<ElementT>::popBack(void) } -template<typename ElementT> -bool LLThreadSafeQueue<ElementT>::tryPopBack(ElementT & element) +template<typename ElementT, typename QueueT> +bool LLThreadSafeQueue<ElementT, QueueT>::tryPop(ElementT & element) { lock_t lock1(mLock, std::defer_lock); if (!lock1.try_lock()) return false; - // no need to check mClosed: tryPopBack() behavior when the queue is + // no need to check mClosed: tryPop() behavior when the queue is // closed is implemented by simple inability to push any new elements if (mStorage.empty()) return false; - element = mStorage.back(); - mStorage.pop_back(); + // std::queue::front() is the element about to pop() + element = mStorage.front(); + mStorage.pop(); lock1.unlock(); mCapacityCond.notify_one(); return true; } -template<typename ElementT> -size_t LLThreadSafeQueue<ElementT>::size(void) +template <typename ElementT, typename QueueT> +template <typename Rep, typename Period> +bool LLThreadSafeQueue<ElementT, QueueT>::tryPopFor( + const std::chrono::duration<Rep, Period>& timeout, + ElementT& element) +{ + // Convert duration to time_point: passing the same timeout duration to + // each of multiple calls is wrong. + return tryPopUntil(std::chrono::steady_clock::now() + timeout, element); +} + + +template <typename ElementT, typename QueueT> +template <typename Clock, typename Duration> +bool LLThreadSafeQueue<ElementT, QueueT>::tryPopUntil( + const std::chrono::time_point<Clock, Duration>& endpoint, + ElementT& element) +{ + lock_t lock1(mLock, std::defer_lock); + if (!lock1.try_lock_until(endpoint)) + return false; + + while (true) + { + if (!mStorage.empty()) + { + // std::queue::front() is the element about to pop() + element = mStorage.front(); + mStorage.pop(); + lock1.unlock(); + mCapacityCond.notify_one(); + return true; + } + + if (mClosed) + { + return false; + } + + // Storage empty. Wait for signal. + if (LLCoros::cv_status::timeout == mEmptyCond.wait_until(lock1, endpoint)) + { + // timed out -- formally we might recheck both conditions above + return false; + } + // If we didn't time out, we were notified for some reason. Loop back + // to check. + } +} + + +template<typename ElementT, typename QueueT> +size_t LLThreadSafeQueue<ElementT, QueueT>::size(void) { lock_t lock(mLock); return mStorage.size(); } -template<typename ElementT> -void LLThreadSafeQueue<ElementT>::close() +template<typename ElementT, typename QueueT> +void LLThreadSafeQueue<ElementT, QueueT>::close() { lock_t lock(mLock); mClosed = true; lock.unlock(); - // wake up any blocked popBack() calls + // wake up any blocked pop() calls mEmptyCond.notify_all(); - // wake up any blocked pushFront() calls + // wake up any blocked push() calls mCapacityCond.notify_all(); } -template<typename ElementT> -bool LLThreadSafeQueue<ElementT>::isClosed() +template<typename ElementT, typename QueueT> +bool LLThreadSafeQueue<ElementT, QueueT>::isClosed() { lock_t lock(mLock); return mClosed && mStorage.size() == 0; } -template<typename ElementT> -LLThreadSafeQueue<ElementT>::operator bool() +template<typename ElementT, typename QueueT> +LLThreadSafeQueue<ElementT, QueueT>::operator bool() { return ! isClosed(); } |