hphp/util/synchronizable-multi.cpp

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present Facebook, Inc. (http://www.facebook.com)  |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16
  17 #include "hphp/util/synchronizable-multi.h"
  18 #include "hphp/util/compatibility.h"
  19 #include "hphp/util/lock.h"
  20 #include "hphp/util/rank.h"
  21 #include "hphp/util/timer.h"
  22
  23 #ifndef _MSC_VER
  24 #include <sys/errno.h>
  25 #endif
  26
  27 namespace HPHP {
  28 ///////////////////////////////////////////////////////////////////////////////
  29
  30 SynchronizableMulti::SynchronizableMulti(int size) :
  31   m_mutex(RankLeaf), m_group(0), m_conds(size), m_cond_list_vec(1) {
  32   assert(size > 0);
  33 }
  34
  35 inline
  36 bool SynchronizableMulti::waitImpl(int id, int q, Priority pri, timespec *ts) {
  37   assert(id >= 0 && id < m_conds.size());
  38   auto& cond = m_conds[id];
  39
  40   assert(q >= 0);
  41   const uint32_t num_lists = m_cond_list_vec.size();
  42   uint32_t list_index = 0;
  43   if (num_lists == 2) list_index = q & 1;
  44   else if (num_lists > 2) list_index = q % num_lists;
  45   auto& cond_list = m_cond_list_vec[list_index];
  46
  47   cond_list.push(cond, pri);
  48
  49   int ret;
  50   if (ts) {
  51     ret = pthread_cond_timedwait(cond, &m_mutex.getRaw(), ts);
  52   } else {
  53     ret = pthread_cond_wait(cond, &m_mutex.getRaw());
  54   }
  55   assert(ret != EPERM); // did you lock the mutex?
  56
  57   if (ret) {
  58     cond.unlink();
  59   }
  60
  61   return ret != ETIMEDOUT;
  62 }
  63
  64 void SynchronizableMulti::wait(int id, int q, Priority pri) {
  65   waitImpl(id, q, pri, nullptr);
  66 }
  67
  68 bool SynchronizableMulti::wait(int id, int q, Priority pri, long seconds) {
  69   return wait(id, q, pri, seconds, 0);
  70 }
  71
  72 bool SynchronizableMulti::wait(int id, int q, Priority pri, long seconds,
  73                                long long nanosecs) {
  74   struct timespec ts;
  75   Timer::GetRealtimeTime(ts);
  76   ts.tv_sec += seconds;
  77   ts.tv_nsec += nanosecs;
  78   return waitImpl(id, q, pri, &ts);
  79 }
  80
  81 void SynchronizableMulti::setNumGroups(int num_groups) {
  82   Lock l(this);
  83   if (num_groups != m_cond_list_vec.size()) {
  84     assert(num_groups > m_cond_list_vec.size());
  85     m_cond_list_vec.resize(num_groups);
  86   }
  87 }
  88
  89 void SynchronizableMulti::notifySpecific(int id) {
  90   assert(id >= 0 && id < m_conds.size());
  91   auto& cond = m_conds[id];
  92   pthread_cond_signal(cond);
  93   cond.unlink();
  94 }
  95
  96 void SynchronizableMulti::notify() {
  97   for (int i = 0, s = m_cond_list_vec.size(); i < s; i++) {
  98     assert(m_group < s);
  99     auto& cond_list = m_cond_list_vec[m_group++];
 100     if (m_group == s) m_group = 0;
 101     if (!cond_list.empty()) {
 102       auto& cond = cond_list.front();
 103       pthread_cond_signal(cond);
 104       cond_list.pop_front();
 105       break;
 106     }
 107   }
 108 }
 109
 110 void SynchronizableMulti::notifyAll() {
 111   for (auto& cond_list : m_cond_list_vec) {
 112     while (!cond_list.empty()) {
 113       pthread_cond_signal(cond_list.front());
 114       cond_list.pop_front();
 115     }
 116   }
 117 }
 118
 119 ///////////////////////////////////////////////////////////////////////////////
 120 }