hphp/util/rds-local.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/rds-local.h"
  18
  19 #include "hphp/util/alloc.h"
  20
  21 namespace HPHP {
  22 namespace rds {
  23 namespace local {
  24 namespace detail {
  25
  26 RDSLocalNode* head = nullptr;
  27
  28 // Hot rds local storage
  29 //
  30 // TODO(T32634221): Add copying logic.  During request swap.
  31 // This rds local holds the saved hot rds locals.  Hot rds locals
  32 // are stored directly in thread local storage, and are copied in and out of
  33 // this rds local as the request becomes active, or inactive.
  34
  35 static RDS_LOCAL(HotRDSLocals, rl_hotBackingStore);
  36 alignas(64) __thread HotRDSLocals rl_hotSection = {};
  37 uint32_t s_usedbytes = 0;
  38
  39 uint32_t RDSLocalNode::s_RDSLocalsBase = 0;
  40
  41 Configuration g_config;
  42 ///////////////////////////////////////////////////////////////////////////////
  43 }
  44
  45 void RDSInit() {
  46   assertx(detail::g_config.rdsInitFunc);
  47   detail::RDSLocalNode::s_RDSLocalsBase =
  48     detail::g_config.rdsInitFunc(detail::s_usedbytes);
  49 }
  50
  51 void init() {
  52   // We may have already been initialized in the case of a thread creating an
  53   // RDS segment after we already decided to malloc some memory for RDS locals.
  54   // This should not happen on request threads or RDS locals might not be
  55   // accessible from the JIT.
  56   if (detail::rl_hotSection.rdslocal_base != nullptr) return;
  57
  58   assertx(detail::g_config.initFunc);
  59   detail::rl_hotSection.rdslocal_base =
  60     detail::g_config.initFunc(detail::s_usedbytes,
  61                               detail::RDSLocalNode::s_RDSLocalsBase);
  62
  63   always_assert(detail::rl_hotSection.rdslocal_base);
  64   always_assert((uintptr_t)detail::rl_hotSection.rdslocal_base % 16 == 0);
  65   detail::iterate([](detail::RDSLocalNode* p) { p->init(); });
  66 }
  67
  68 void fini(bool inrds) {
  69   // This may be called twice on threads that create a malloced rdslocal area,
  70   // and then initialize a full RDS segment.  As the RDS segment is detroyed
  71   // Fini is called, and it is called again from the context that created the
  72   // malloced area.
  73   if (!detail::rl_hotSection.rdslocal_base) return;
  74
  75   if (detail::g_config.inRdsFunc &&
  76       inrds != detail::g_config.inRdsFunc(detail::rl_hotSection.rdslocal_base,
  77                                   detail::s_usedbytes)) {
  78     // There will be another call to deallocate the rds local section.
  79     return;
  80   }
  81   detail::iterate([](detail::RDSLocalNode* p) { p->fini(); });
  82   if (!inrds) {
  83     assertx(detail::g_config.finiFunc);
  84     detail::g_config.finiFunc(detail::rl_hotSection.rdslocal_base);
  85   }
  86   detail::rl_hotSection.rdslocal_base = nullptr;
  87 }
  88
  89 }}}