sync/windows/sync_utils.hpp

0001 //////////////////////////////////////////////////////////////////////////////
0002 //
0003 // (C) Copyright Ion Gaztanaga 2005-2012. Distributed under the Boost
0004 // Software License, Version 1.0. (See accompanying file
0005 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 //
0007 // See http://www.boost.org/libs/interprocess for documentation.
0008 //
0009 //////////////////////////////////////////////////////////////////////////////
0010
0011 #ifndef BOOST_INTERPROCESS_DETAIL_SYNC_UTILS_HPP
0012 #define BOOST_INTERPROCESS_DETAIL_SYNC_UTILS_HPP
0013
0014 #ifndef BOOST_CONFIG_HPP
0015 #  include <boost/config.hpp>
0016 #endif
0017 #
0018 #if defined(BOOST_HAS_PRAGMA_ONCE)
0019 #  pragma once
0020 #endif
0021
0022 #include <boost/interprocess/detail/config_begin.hpp>
0023 #include <boost/interprocess/detail/workaround.hpp>
0024 #include <boost/interprocess/detail/win32_api.hpp>
0025 #include <boost/interprocess/sync/spin/mutex.hpp>
0026 #include <boost/interprocess/exceptions.hpp>
0027 #include <boost/interprocess/sync/scoped_lock.hpp>
0028 #include <boost/interprocess/sync/windows/winapi_semaphore_wrapper.hpp>
0029 #include <boost/interprocess/sync/windows/winapi_mutex_wrapper.hpp>
0030
0031 //Shield against external warnings
0032 #include <boost/interprocess/detail/config_external_begin.hpp>
0033 #include <boost/unordered/unordered_map.hpp>
0034 #include <boost/interprocess/detail/config_external_end.hpp>
0035 #include <boost/container/flat_map.hpp>
0036
0037 #include <cstddef>
0038
0039 namespace boost {
0040 namespace interprocess {
0041 namespace ipcdetail {
0042
0043 inline bool bytes_to_str(const void *mem, const std::size_t mem_length, char *out_str, std::size_t &out_length)
0044 {
0045    const std::size_t need_mem = mem_length*2+1;
0046    if(out_length < need_mem){
0047       out_length = need_mem;
0048       return false;
0049    }
0050
0051    const char Characters [] =
0052       { '0', '1', '2', '3', '4', '5', '6', '7'
0053       , '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
0054
0055    std::size_t char_counter = 0;
0056    const char *buf = (const char *)mem;
0057    for(std::size_t i = 0; i != mem_length; ++i){
0058       out_str[char_counter++] = Characters[(buf[i]&0xF0)>>4];
0059       out_str[char_counter++] = Characters[(buf[i]&0x0F)];
0060    }
0061    out_str[char_counter] = 0;
0062    return true;
0063 }
0064
0065 inline bool bytes_to_str(const void *mem, const std::size_t mem_length, wchar_t *out_str, std::size_t &out_length)
0066 {
0067    const std::size_t need_mem = mem_length*2+1;
0068    if(out_length < need_mem){
0069       out_length = need_mem;
0070       return false;
0071    }
0072
0073    const wchar_t Characters [] =
0074       { L'0', L'1', L'2', L'3', L'4', L'5', L'6', L'7'
0075       , L'8', L'9', L'A', L'B', L'C', L'D', L'E', L'F' };
0076
0077    std::size_t char_counter = 0;
0078    const char *buf = (const char *)mem;
0079    for(std::size_t i = 0; i != mem_length; ++i){
0080       out_str[char_counter++] = Characters[(buf[i]&0xF0)>>4];
0081       out_str[char_counter++] = Characters[(buf[i]&0x0F)];
0082    }
0083    out_str[char_counter] = 0;
0084    return true;
0085 }
0086
0087 class sync_id
0088 {
0089    public:
0090    typedef __int64 internal_type;
0091    sync_id()
0092    {  winapi::query_performance_counter(&rand_);  }
0093
0094    explicit sync_id(internal_type val)
0095    {  rand_ = val;  }
0096
0097    const internal_type &internal_pod() const
0098    {  return rand_;  }
0099
0100    internal_type &internal_pod()
0101    {  return rand_;  }
0102
0103    friend std::size_t hash_value(const sync_id &m)
0104    {  return boost::hash_value(m.rand_);  }
0105
0106    friend bool operator==(const sync_id &l, const sync_id &r)
0107    {  return l.rand_ == r.rand_;  }
0108
0109    private:
0110    internal_type rand_;
0111 };
0112
0113 class sync_handles
0114 {
0115    public:
0116    enum type { MUTEX, SEMAPHORE };
0117
0118    private:
0119
0120    //key: id -> mapped: HANDLE. Hash map to allow efficient sync operations
0121    typedef boost::unordered_map<sync_id, void*> umap_type;
0122    //key: ordered address of the sync type -> iterator from umap_type. Ordered map to allow closing handles when unmapping
0123    typedef boost::container::flat_map<const void*, umap_type::iterator> map_type;
0124    static const std::size_t LengthOfGlobal = sizeof("Global\\boost.ipc")-1;
0125    static const std::size_t StrSize        = LengthOfGlobal + (sizeof(sync_id)*2+1);
0126    typedef char NameBuf[StrSize];
0127
0128    void fill_name(NameBuf &name, const sync_id &id)
0129    {
0130       const char *n = "Global\\boost.ipc";
0131       std::size_t i = 0;
0132       do{
0133          name[i] = n[i];
0134          ++i;
0135       } while(n[i]);
0136       std::size_t len = sizeof(NameBuf) - LengthOfGlobal;
0137       bytes_to_str(&id.internal_pod(), sizeof(id.internal_pod()), &name[LengthOfGlobal], len);
0138    }
0139
0140    void throw_if_error(void *hnd_val)
0141    {
0142       if(!hnd_val){
0143          error_info err(static_cast<int>(winapi::get_last_error()));
0144          throw interprocess_exception(err);
0145       }
0146    }
0147
0148    void* open_or_create_semaphore(const sync_id &id, unsigned int initial_count)
0149    {
0150       NameBuf name;
0151       fill_name(name, id);
0152       permissions unrestricted_security;
0153       unrestricted_security.set_unrestricted();
0154       winapi_semaphore_wrapper sem_wrapper;
0155       bool created;
0156       sem_wrapper.open_or_create
0157          (name, (long)initial_count, winapi_semaphore_wrapper::MaxCount, unrestricted_security, created);
0158       throw_if_error(sem_wrapper.handle());
0159       return sem_wrapper.release();
0160    }
0161
0162    void* open_or_create_mutex(const sync_id &id)
0163    {
0164       NameBuf name;
0165       fill_name(name, id);
0166       permissions unrestricted_security;
0167       unrestricted_security.set_unrestricted();
0168       winapi_mutex_wrapper mtx_wrapper;
0169       mtx_wrapper.open_or_create(name, unrestricted_security);
0170       throw_if_error(mtx_wrapper.handle());
0171       return mtx_wrapper.release();
0172    }
0173
0174    public:
0175    sync_handles()
0176       : num_handles_()
0177    {}
0178
0179    ~sync_handles()
0180    {
0181       BOOST_ASSERT(num_handles_ == 0); //Sanity check that handle we don't leak handles
0182    }
0183
0184    void *obtain_mutex(const sync_id &id, const void *mapping_address, bool *popen_created = 0)
0185    {
0186       umap_type::value_type v(id, (void*)0);
0187       scoped_lock<spin_mutex> lock(mtx_);
0188       umap_type::iterator it = umap_.insert(v).first;
0189       void *&hnd_val = it->second;
0190       if(!hnd_val){
0191          BOOST_ASSERT(map_.find(mapping_address) == map_.end());
0192          map_[mapping_address] = it;
0193          hnd_val = open_or_create_mutex(id);
0194          if(popen_created) *popen_created = true;
0195          ++num_handles_;
0196       }
0197       else if(popen_created){
0198          BOOST_ASSERT(map_.find(mapping_address) != map_.end());
0199          *popen_created = false;
0200       }
0201
0202       return hnd_val;
0203    }
0204
0205    void *obtain_semaphore(const sync_id &id, const void *mapping_address, unsigned int initial_count, bool *popen_created = 0)
0206    {
0207       umap_type::value_type v(id, (void*)0);
0208       scoped_lock<spin_mutex> lock(mtx_);
0209       umap_type::iterator it = umap_.insert(v).first;
0210       void *&hnd_val = it->second;
0211       if(!hnd_val){
0212          BOOST_ASSERT(map_.find(mapping_address) == map_.end());
0213          map_[mapping_address] = it;
0214          hnd_val = open_or_create_semaphore(id, initial_count);
0215          if(popen_created) *popen_created = true;
0216          ++num_handles_;
0217       }
0218       else if(popen_created){
0219          BOOST_ASSERT(map_.find(mapping_address) != map_.end());
0220          *popen_created = false;
0221       }
0222       return hnd_val;
0223    }
0224
0225    void destroy_handle(const sync_id &id, const void *mapping_address)
0226    {
0227       scoped_lock<spin_mutex> lock(mtx_);
0228       umap_type::iterator it = umap_.find(id);
0229       umap_type::iterator itend = umap_.end();
0230
0231       if(it != itend){
0232          winapi::close_handle(it->second);
0233          --num_handles_;
0234          std::size_t i = map_.erase(mapping_address);
0235          (void)i;
0236          BOOST_ASSERT(i == 1);   //The entry should be there
0237          umap_.erase(it);
0238       }
0239    }
0240
0241    void destroy_syncs_in_range(const void *addr, std::size_t size)
0242    {
0243       const void *low_id(addr);
0244       const void *hig_id(static_cast<const char*>(addr)+size);
0245       scoped_lock<spin_mutex> lock(mtx_);
0246       map_type::iterator itlow(map_.lower_bound(low_id)),
0247                          ithig(map_.lower_bound(hig_id)),
0248                          it(itlow);
0249       for (; it != ithig; ++it){
0250          umap_type::iterator uit = it->second;
0251          void * const hnd = uit->second;
0252          umap_.erase(uit);
0253          int ret = winapi::close_handle(hnd);
0254          --num_handles_;
0255          BOOST_ASSERT(ret != 0); (void)ret;  //Sanity check that handle was ok
0256       }
0257
0258       map_.erase(itlow, ithig);
0259    }
0260
0261    private:
0262    spin_mutex mtx_;
0263    umap_type umap_;
0264    map_type map_;
0265    std::size_t num_handles_;
0266 };
0267
0268
0269 }  //namespace ipcdetail {
0270 }  //namespace interprocess {
0271 }  //namespace boost {
0272
0273 #include <boost/interprocess/detail/config_end.hpp>
0274
0275 #endif   //BOOST_INTERPROCESS_DETAIL_SYNC_UTILS_HPP