1 //////////////////////////////////////////////////////////////////////////////
3 // (C) Copyright Ion Gaztanaga 2009-2012. Distributed under the Boost
4 // Software License, Version 1.0. (See accompanying file
5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7 // See http://www.boost.org/libs/interprocess for documentation.
9 //////////////////////////////////////////////////////////////////////////////
11 #ifndef BOOST_INTERPROCESS_WINDOWS_INTERMODULE_SINGLETON_HPP
12 #define BOOST_INTERPROCESS_WINDOWS_INTERMODULE_SINGLETON_HPP
14 #ifndef BOOST_CONFIG_HPP
15 # include <boost/config.hpp>
18 #if defined(BOOST_HAS_PRAGMA_ONCE)
22 #include <boost/interprocess/detail/config_begin.hpp>
23 #include <boost/interprocess/detail/workaround.hpp>
24 #include <boost/container/string.hpp>
26 #if !defined(BOOST_INTERPROCESS_WINDOWS)
27 #error "This header can't be included from non-windows operating systems"
30 #include <boost/assert.hpp>
31 #include <boost/interprocess/detail/intermodule_singleton_common.hpp>
32 #include <boost/interprocess/sync/windows/winapi_semaphore_wrapper.hpp>
33 #include <boost/interprocess/sync/windows/winapi_mutex_wrapper.hpp>
34 #include <boost/interprocess/sync/scoped_lock.hpp>
35 #include <boost/cstdint.hpp>
37 #include <boost/container/map.hpp>
40 namespace interprocess{
43 namespace intermodule_singleton_helpers {
45 //This global map will be implemented using 3 sync primitives:
47 //1) A named mutex that will implement global mutual exclusion between
48 // threads from different modules/dlls
50 //2) A semaphore that will act as a global counter for modules attached to the global map
51 // so that the global map can be destroyed when the last module is detached.
53 //3) A semaphore that will be hacked to hold the address of a heap-allocated map in the
54 // max and current semaphore count.
55 class windows_semaphore_based_map
57 typedef boost::container::map<boost::container::string, ref_count_ptr> map_type;
60 windows_semaphore_based_map()
62 map_type *m = new map_type;
63 boost::uint32_t initial_count = 0;
64 boost::uint32_t max_count = 0;
66 //Windows user address space sizes:
67 //32 bit windows: [32 bit processes] 2GB or 3GB (31/32 bits)
68 //64 bit windows: [32 bit processes] 2GB or 4GB (31/32 bits)
69 // [64 bit processes] 2GB or 8TB (31/43 bits)
71 //Windows semaphores use 'long' parameters (32 bits in LLP64 data model) and
72 //those values can't be negative, so we have 31 bits to store something
73 //in max_count and initial count parameters.
74 //Also, max count must be bigger than 0 and bigger or equal than initial count.
75 if(sizeof(void*) == sizeof(boost::uint32_t)){
76 //This means that for 32 bit processes, a semaphore count (31 usable bits) is
77 //enough to store 4 byte aligned memory (4GB -> 32 bits - 2 bits = 30 bits).
78 //The max count will hold the pointer value and current semaphore count
81 //Relying in UB with a cast through union, but all known windows compilers
82 //accept this (C11 also accepts this).
86 boost::uint32_t addr_uint32;
89 //memory is at least 4 byte aligned in windows
90 BOOST_ASSERT((caster.addr_uint32 & boost::uint32_t(3)) == 0);
91 max_count = caster.addr_uint32 >> 2;
93 else if(sizeof(void*) == sizeof(boost::uint64_t)){
94 //Relying in UB with a cast through union, but all known windows compilers
95 //accept this (C11 accepts this).
99 boost::uint64_t addr_uint64;
102 //We'll encode the address using 30 bits in each 32 bit high and low parts.
103 //High part will be the sem max count, low part will be the sem initial count.
104 //(restrictions: max count > 0, initial count >= 0 and max count >= initial count):
106 // - Low part will be shifted two times (4 byte alignment) so that top
107 // two bits are cleared (the top one for sign, the next one to
108 // assure low part value is always less than the high part value.
109 // - The top bit of the high part will be cleared and the next bit will be 1
110 // (so high part is always bigger than low part due to the quasi-top bit).
112 // This means that the addresses we can store must be 4 byte aligned
113 // and less than 1 ExbiBytes ( 2^60 bytes, ~1 ExaByte). User-level address space in Windows 64
114 // is much less than this (8TB, 2^43 bytes): "1 EByte (or it was 640K?) ought to be enough for anybody" ;-).
116 BOOST_ASSERT((caster.addr_uint64 & boost::uint64_t(3)) == 0);
117 max_count = boost::uint32_t(caster.addr_uint64 >> 32);
118 initial_count = boost::uint32_t(caster.addr_uint64);
119 initial_count = initial_count/4;
120 //Make sure top two bits are zero
121 BOOST_ASSERT((max_count & boost::uint32_t(0xC0000000)) == 0);
123 max_count |= boost::uint32_t(0x40000000);
125 bool created = false;
126 const permissions & perm = permissions();
127 std::string pid_creation_time, name;
128 get_pid_creation_time_str(pid_creation_time);
129 name = "bipc_gmap_sem_lock_";
130 name += pid_creation_time;
131 bool success = m_mtx_lock.open_or_create(name.c_str(), perm);
132 name = "bipc_gmap_sem_count_";
133 name += pid_creation_time;
134 scoped_lock<winapi_mutex_wrapper> lck(m_mtx_lock);
136 success = success && m_sem_count.open_or_create
137 ( name.c_str(), static_cast<long>(0), winapi_semaphore_wrapper::MaxCount, perm, created);
138 name = "bipc_gmap_sem_map_";
139 name += pid_creation_time;
140 success = success && m_sem_map.open_or_create
141 (name.c_str(), initial_count, max_count, perm, created);
144 //winapi_xxx wrappers do the cleanup...
151 BOOST_ASSERT(&get_map_unlocked() == m);
157 map_type &get_map_unlocked()
159 if(sizeof(void*) == sizeof(boost::uint32_t)){
163 boost::uint32_t addr_uint32;
166 caster.addr_uint32 = m_sem_map.limit();
167 caster.addr_uint32 = caster.addr_uint32 << 2;
168 return *static_cast<map_type*>(caster.addr);
174 boost::uint64_t addr_uint64;
176 boost::uint32_t max_count(m_sem_map.limit()), initial_count(m_sem_map.value());
177 //Clear quasi-top bit
178 max_count &= boost::uint32_t(0xBFFFFFFF);
179 caster.addr_uint64 = max_count;
180 caster.addr_uint64 = caster.addr_uint64 << 32;
181 caster.addr_uint64 |= boost::uint64_t(initial_count) << 2;
182 return *static_cast<map_type*>(caster.addr);
186 ref_count_ptr *find(const char *name)
188 scoped_lock<winapi_mutex_wrapper> lck(m_mtx_lock);
189 map_type &map = this->get_map_unlocked();
190 map_type::iterator it = map.find(boost::container::string(name));
199 ref_count_ptr * insert(const char *name, const ref_count_ptr &ref)
201 scoped_lock<winapi_mutex_wrapper> lck(m_mtx_lock);
202 map_type &map = this->get_map_unlocked();
203 map_type::iterator it = map.insert(map_type::value_type(boost::container::string(name), ref)).first;
207 bool erase(const char *name)
209 scoped_lock<winapi_mutex_wrapper> lck(m_mtx_lock);
210 map_type &map = this->get_map_unlocked();
211 return map.erase(boost::container::string(name)) != 0;
215 void atomic_func(F &f)
217 scoped_lock<winapi_mutex_wrapper> lck(m_mtx_lock);
221 ~windows_semaphore_based_map()
223 scoped_lock<winapi_mutex_wrapper> lck(m_mtx_lock);
225 if(0 == m_sem_count.value()){
226 map_type &map = this->get_map_unlocked();
227 BOOST_ASSERT(map.empty());
230 //First close sems to protect this with the external mutex
233 //Once scoped_lock unlocks the mutex, the destructor will close the handle...
237 winapi_mutex_wrapper m_mtx_lock;
238 winapi_semaphore_wrapper m_sem_map;
239 winapi_semaphore_wrapper m_sem_count;
243 struct thread_safe_global_map_dependant<windows_semaphore_based_map>
245 static void apply_gmem_erase_logic(const char *, const char *){}
247 static bool remove_old_gmem()
250 struct lock_file_logic
252 lock_file_logic(windows_semaphore_based_map &)
253 : retry_with_new_map(false)
256 void operator()(void){}
257 bool retry() const { return retry_with_new_map; }
259 const bool retry_with_new_map;
262 static void construct_map(void *addr)
264 ::new (addr)windows_semaphore_based_map;
267 struct unlink_map_logic
269 unlink_map_logic(windows_semaphore_based_map &)
274 static ref_count_ptr *find(windows_semaphore_based_map &map, const char *name)
276 return map.find(name);
279 static ref_count_ptr * insert(windows_semaphore_based_map &map, const char *name, const ref_count_ptr &ref)
281 return map.insert(name, ref);
284 static bool erase(windows_semaphore_based_map &map, const char *name)
286 return map.erase(name);
290 static void atomic_func(windows_semaphore_based_map &map, F &f)
296 } //namespace intermodule_singleton_helpers {
298 template<typename C, bool LazyInit = true, bool Phoenix = false>
299 class windows_intermodule_singleton
300 : public intermodule_singleton_impl
304 , intermodule_singleton_helpers::windows_semaphore_based_map
308 } //namespace ipcdetail{
309 } //namespace interprocess{
312 #include <boost/interprocess/detail/config_end.hpp>
314 #endif //#ifndef BOOST_INTERPROCESS_WINDOWS_INTERMODULE_SINGLETON_HPP