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Diffstat (limited to 'external_libs/python/pyzmq-14.7.0/bundled/zeromq/src/ypipe.hpp')
| -rw-r--r-- | external_libs/python/pyzmq-14.7.0/bundled/zeromq/src/ypipe.hpp | 219 |
1 files changed, 0 insertions, 219 deletions
diff --git a/external_libs/python/pyzmq-14.7.0/bundled/zeromq/src/ypipe.hpp b/external_libs/python/pyzmq-14.7.0/bundled/zeromq/src/ypipe.hpp deleted file mode 100644 index c3f2e96d..00000000 --- a/external_libs/python/pyzmq-14.7.0/bundled/zeromq/src/ypipe.hpp +++ /dev/null @@ -1,219 +0,0 @@ -/* - Copyright (c) 2007-2015 Contributors as noted in the AUTHORS file - - This file is part of libzmq, the ZeroMQ core engine in C++. - - libzmq is free software; you can redistribute it and/or modify it under - the terms of the GNU Lesser General Public License (LGPL) as published - by the Free Software Foundation; either version 3 of the License, or - (at your option) any later version. - - As a special exception, the Contributors give you permission to link - this library with independent modules to produce an executable, - regardless of the license terms of these independent modules, and to - copy and distribute the resulting executable under terms of your choice, - provided that you also meet, for each linked independent module, the - terms and conditions of the license of that module. An independent - module is a module which is not derived from or based on this library. - If you modify this library, you must extend this exception to your - version of the library. - - libzmq is distributed in the hope that it will be useful, but WITHOUT - ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public - License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with this program. If not, see <http://www.gnu.org/licenses/>. -*/ - -#ifndef __ZMQ_YPIPE_HPP_INCLUDED__ -#define __ZMQ_YPIPE_HPP_INCLUDED__ - -#include "atomic_ptr.hpp" -#include "yqueue.hpp" -#include "platform.hpp" -#include "ypipe_base.hpp" - -namespace zmq -{ - - // Lock-free queue implementation. - // Only a single thread can read from the pipe at any specific moment. - // Only a single thread can write to the pipe at any specific moment. - // T is the type of the object in the queue. - // N is granularity of the pipe, i.e. how many items are needed to - // perform next memory allocation. - - template <typename T, int N> class ypipe_t : public ypipe_base_t <T> - { - public: - - // Initialises the pipe. - inline ypipe_t () - { - // Insert terminator element into the queue. - queue.push (); - - // Let all the pointers to point to the terminator. - // (unless pipe is dead, in which case c is set to NULL). - r = w = f = &queue.back (); - c.set (&queue.back ()); - } - - // The destructor doesn't have to be virtual. It is mad virtual - // just to keep ICC and code checking tools from complaining. - inline virtual ~ypipe_t () - { - } - - // Following function (write) deliberately copies uninitialised data - // when used with zmq_msg. Initialising the VSM body for - // non-VSM messages won't be good for performance. - -#ifdef ZMQ_HAVE_OPENVMS -#pragma message save -#pragma message disable(UNINIT) -#endif - - // Write an item to the pipe. Don't flush it yet. If incomplete is - // set to true the item is assumed to be continued by items - // subsequently written to the pipe. Incomplete items are never - // flushed down the stream. - inline void write (const T &value_, bool incomplete_) - { - // Place the value to the queue, add new terminator element. - queue.back () = value_; - queue.push (); - - // Move the "flush up to here" poiter. - if (!incomplete_) - f = &queue.back (); - } - -#ifdef ZMQ_HAVE_OPENVMS -#pragma message restore -#endif - - // Pop an incomplete item from the pipe. Returns true is such - // item exists, false otherwise. - inline bool unwrite (T *value_) - { - if (f == &queue.back ()) - return false; - queue.unpush (); - *value_ = queue.back (); - return true; - } - - // Flush all the completed items into the pipe. Returns false if - // the reader thread is sleeping. In that case, caller is obliged to - // wake the reader up before using the pipe again. - inline bool flush () - { - // If there are no un-flushed items, do nothing. - if (w == f) - return true; - - // Try to set 'c' to 'f'. - if (c.cas (w, f) != w) { - - // Compare-and-swap was unseccessful because 'c' is NULL. - // This means that the reader is asleep. Therefore we don't - // care about thread-safeness and update c in non-atomic - // manner. We'll return false to let the caller know - // that reader is sleeping. - c.set (f); - w = f; - return false; - } - - // Reader is alive. Nothing special to do now. Just move - // the 'first un-flushed item' pointer to 'f'. - w = f; - return true; - } - - // Check whether item is available for reading. - inline bool check_read () - { - // Was the value prefetched already? If so, return. - if (&queue.front () != r && r) - return true; - - // There's no prefetched value, so let us prefetch more values. - // Prefetching is to simply retrieve the - // pointer from c in atomic fashion. If there are no - // items to prefetch, set c to NULL (using compare-and-swap). - r = c.cas (&queue.front (), NULL); - - // If there are no elements prefetched, exit. - // During pipe's lifetime r should never be NULL, however, - // it can happen during pipe shutdown when items - // are being deallocated. - if (&queue.front () == r || !r) - return false; - - // There was at least one value prefetched. - return true; - } - - // Reads an item from the pipe. Returns false if there is no value. - // available. - inline bool read (T *value_) - { - // Try to prefetch a value. - if (!check_read ()) - return false; - - // There was at least one value prefetched. - // Return it to the caller. - *value_ = queue.front (); - queue.pop (); - return true; - } - - // Applies the function fn to the first elemenent in the pipe - // and returns the value returned by the fn. - // The pipe mustn't be empty or the function crashes. - inline bool probe (bool (*fn)(const T &)) - { - bool rc = check_read (); - zmq_assert (rc); - - return (*fn) (queue.front ()); - } - - protected: - - // Allocation-efficient queue to store pipe items. - // Front of the queue points to the first prefetched item, back of - // the pipe points to last un-flushed item. Front is used only by - // reader thread, while back is used only by writer thread. - yqueue_t <T, N> queue; - - // Points to the first un-flushed item. This variable is used - // exclusively by writer thread. - T *w; - - // Points to the first un-prefetched item. This variable is used - // exclusively by reader thread. - T *r; - - // Points to the first item to be flushed in the future. - T *f; - - // The single point of contention between writer and reader thread. - // Points past the last flushed item. If it is NULL, - // reader is asleep. This pointer should be always accessed using - // atomic operations. - atomic_ptr_t <T> c; - - // Disable copying of ypipe object. - ypipe_t (const ypipe_t&); - const ypipe_t &operator = (const ypipe_t&); - }; - -} - -#endif |