| // sigslot.h: Signal/Slot classes |
| // |
| // Written by Sarah Thompson (sarah@telergy.com) 2002. |
| // |
| // License: Public domain. You are free to use this code however you like, with |
| // the proviso that the author takes on no responsibility or liability for any |
| // use. |
| // |
| // QUICK DOCUMENTATION |
| // |
| // (see also the full documentation at http://sigslot.sourceforge.net/) |
| // |
| // #define switches |
| // SIGSLOT_PURE_ISO: |
| // Define this to force ISO C++ compliance. This also disables all of |
| // the thread safety support on platforms where it is available. |
| // |
| // SIGSLOT_USE_POSIX_THREADS: |
| // Force use of Posix threads when using a C++ compiler other than gcc |
| // on a platform that supports Posix threads. (When using gcc, this is |
| // the default - use SIGSLOT_PURE_ISO to disable this if necessary) |
| // |
| // SIGSLOT_DEFAULT_MT_POLICY: |
| // Where thread support is enabled, this defaults to |
| // multi_threaded_global. Otherwise, the default is single_threaded. |
| // #define this yourself to override the default. In pure ISO mode, |
| // anything other than single_threaded will cause a compiler error. |
| // |
| // PLATFORM NOTES |
| // |
| // Win32: |
| // On Win32, the WEBRTC_WIN symbol must be #defined. Most mainstream |
| // compilers do this by default, but you may need to define it yourself |
| // if your build environment is less standard. This causes the Win32 |
| // thread support to be compiled in and used automatically. |
| // |
| // Unix/Linux/BSD, etc.: |
| // If you're using gcc, it is assumed that you have Posix threads |
| // available, so they are used automatically. You can override this (as |
| // under Windows) with the SIGSLOT_PURE_ISO switch. If you're using |
| // something other than gcc but still want to use Posix threads, you |
| // need to #define SIGSLOT_USE_POSIX_THREADS. |
| // |
| // ISO C++: |
| // If none of the supported platforms are detected, or if |
| // SIGSLOT_PURE_ISO is defined, all multithreading support is turned |
| // off, along with any code that might cause a pure ISO C++ environment |
| // to complain. Before you ask, gcc -ansi -pedantic won't compile this |
| // library, but gcc -ansi is fine. Pedantic mode seems to throw a lot of |
| // errors that aren't really there. If you feel like investigating this, |
| // please contact the author. |
| // |
| // |
| // THREADING MODES |
| // |
| // single_threaded: |
| // Your program is assumed to be single threaded from the point of view |
| // of signal/slot usage (i.e. all objects using signals and slots are |
| // created and destroyed from a single thread). Behaviour if objects are |
| // destroyed concurrently is undefined (i.e. you'll get the occasional |
| // segmentation fault/memory exception). |
| // |
| // multi_threaded_global: |
| // Your program is assumed to be multi threaded. Objects using signals |
| // and slots can be safely created and destroyed from any thread, even |
| // when connections exist. In multi_threaded_global mode, this is |
| // achieved by a single global mutex (actually a critical section on |
| // Windows because they are faster). This option uses less OS resources, |
| // but results in more opportunities for contention, possibly resulting |
| // in more context switches than are strictly necessary. |
| // |
| // multi_threaded_local: |
| // Behaviour in this mode is essentially the same as |
| // multi_threaded_global, except that each signal, and each object that |
| // inherits has_slots, all have their own mutex/critical section. In |
| // practice, this means that mutex collisions (and hence context |
| // switches) only happen if they are absolutely essential. However, on |
| // some platforms, creating a lot of mutexes can slow down the whole OS, |
| // so use this option with care. |
| // |
| // USING THE LIBRARY |
| // |
| // See the full documentation at http://sigslot.sourceforge.net/ |
| // |
| // Libjingle specific: |
| // |
| // This file has been modified such that has_slots and signalx do not have to be |
| // using the same threading requirements. E.g. it is possible to connect a |
| // has_slots<single_threaded> and signal0<multi_threaded_local> or |
| // has_slots<multi_threaded_local> and signal0<single_threaded>. |
| // If has_slots is single threaded the user must ensure that it is not trying |
| // to connect or disconnect to signalx concurrently or data race may occur. |
| // If signalx is single threaded the user must ensure that disconnect, connect |
| // or signal is not happening concurrently or data race may occur. |
| |
| #ifndef WEBRTC_BASE_SIGSLOT_H_ |
| #define WEBRTC_BASE_SIGSLOT_H_ |
| |
| |
| // This header is deprecated and is just left here temporarily during |
| // refactoring. See https://bugs.webrtc.org/7634 for more details. |
| #include "webrtc/rtc_base/sigslot.h" |
| |
| #endif // WEBRTC_BASE_SIGSLOT_H_ |
