hphp/util/thread-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/thread-local.h"
  18
  19 #if defined(__linux__) && defined(__x86_64__)
  20 #define HAVE_ARCH_PRCTL 1
  21 #endif
  22
  23 #ifdef HAVE_ARCH_PRCTL
  24 #include <link.h>
  25 #include <asm/prctl.h>
  26 #include <sys/prctl.h>
  27 extern "C" {
  28 extern int arch_prctl(int, unsigned long*);
  29 }
  30 #endif //HAVE_ARCH_PRCTL
  31
  32 namespace HPHP {
  33
  34 #ifdef USE_GCC_FAST_TLS
  35
  36 void ThreadLocalManager::OnThreadExit(void* p) {
  37   auto list = getList(p);
  38   p = list->head;
  39   list->~ThreadLocalList();
  40   local_free(list);
  41   while (p != nullptr) {
  42     auto* pNode = static_cast<ThreadLocalNode<void>*>(p);
  43     if (pNode->m_on_thread_exit_fn) {
  44       pNode->m_on_thread_exit_fn(p);
  45     }
  46     p = pNode->m_next;
  47   }
  48 }
  49
  50 void ThreadLocalManager::initTypeIndices() {
  51   auto list = getList(pthread_getspecific(m_key));
  52   if (!list) return;
  53   for (auto p = list->head; p != nullptr;) {
  54     auto node = static_cast<ThreadLocalNode<void>*>(p);
  55     node->m_init_tyindex(node);
  56     p = node->m_next;
  57   }
  58 }
  59
  60 void ThreadLocalManager::PushTop(void* nodePtr, uint32_t nodeSize,
  61                                  type_scan::Index tyindex) {
  62   auto& node = *static_cast<ThreadLocalNode<void>*>(nodePtr);
  63   auto key = GetManager().m_key;
  64   auto list = getList(pthread_getspecific(key));
  65   if (UNLIKELY(!list)) {
  66     list = new (local_malloc(sizeof(ThreadLocalList))) ThreadLocalList;
  67     ThreadLocalSetValue(key, list);
  68   }
  69   node.m_next = list->head;
  70   node.m_size = nodeSize;
  71   node.m_tyindex = tyindex;
  72   list->head = &node;
  73 }
  74
  75 ThreadLocalManager& ThreadLocalManager::GetManager() {
  76   static ThreadLocalManager m;
  77   return m;
  78 }
  79
  80 #endif
  81
  82 #ifdef HAVE_ARCH_PRCTL
  83
  84 static int visit_phdr(dl_phdr_info* info, size_t, void*) {
  85   for (size_t i = 0, n = info->dlpi_phnum; i < n; ++i) {
  86     const auto& hdr = info->dlpi_phdr[i];
  87     auto addr = info->dlpi_addr + hdr.p_vaddr;
  88     if (addr < 0x100000000LL && hdr.p_type == PT_TLS) {
  89       // found the main thread-local section
  90       assert(int(hdr.p_memsz) == hdr.p_memsz); // ensure no truncation
  91       return hdr.p_memsz;
  92     }
  93   }
  94   return 0;
  95 }
  96
  97 std::pair<void*,size_t> getCppTdata() {
  98   uintptr_t addr;
  99   if (!arch_prctl(ARCH_GET_FS, &addr)) {
 100     // fs points to the end of the threadlocal area.
 101     size_t size = dl_iterate_phdr(&visit_phdr, nullptr);
 102     return {(void*)(addr - size), size};
 103   }
 104   return {nullptr, 0};
 105 }
 106
 107 #else
 108
 109 // how do you find the thread local section on your system?
 110 std::pair<void*,size_t> getCppTdata() {
 111   return {nullptr, 0};
 112 }
 113
 114 #endif //HAVE_ARCH_PRCTL
 115
 116 }