detail/mutex.hpp provides several mutex types that provide a consistent interface for OS-supplied mutex types. These are all thread-level mutexes; interprocess mutexes are not supported.
This header file will try to guess what kind of system it is on. It will auto-configure itself for Win32 or POSIX+pthread systems. To stub out all mutex code, bypassing the auto-configuration, #define BOOST_NO_MT before any inclusion of this header. To prevent ODR violations, this should be defined in every translation unit in your project, including any library files.
namespace details {
namespace pool {
// Only present if on a Win32 system
class Win32_mutex
{
private:
Win32_mutex(const Win32_mutex &);
void operator=(const Win32_mutex &);
public:
Win32_mutex();
~Win32_mutex();
void lock();
void unlock();
};
// Only present if on a POSIX+pthread system
class pthread_mutex
{
private:
pthread_mutex(const pthread_mutex &);
void operator=(const pthread_mutex &);
public:
pthread_mutex();
~pthread_mutex();
void lock();
void unlock();
};
// Present on all systems
class null_mutex
{
private:
null_mutex(const null_mutex &);
void operator=(const null_mutex &);
public:
null_mutex();
~null_mutex();
static void lock();
static void unlock();
};
// This will be one of the types above
typedef ... default_mutex;
} // namespace pool
} // namespace details
| Symbol | Meaning |
|---|---|
| Mutex | Any type defined in this header |
| t | value of type Mutex |
| Expression | Return Type | Assertion/Note/Pre/Post-Condition |
|---|---|---|
| m.lock() | not used | Locks the mutex |
| m.unlock() | not used | Unlocks the mutex |
Each mutex is always either owned or unowned. If owned, then it is owned by a particular thread. To "lock" a mutex means to wait until the mutex is unowned, and then make it owned by the current thread. To "unlock" a mutex means to release ownership from the current thread (note that the current thread must own the mutex to release that ownership!). As a special case, the null_mutex never waits.
May include the system headers <windows.h>, <unistd.h>, and/or <pthread.h>.
This header will eventually be replaced by a Boost multithreading library.
Revised 05 December, 2006
Copyright © 2000, 2001 Stephen Cleary (scleary AT jerviswebb DOT com)
Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)