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Diffstat (limited to 'src/boost/libs/context/README.md')
-rw-r--r-- | src/boost/libs/context/README.md | 21 |
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diff --git a/src/boost/libs/context/README.md b/src/boost/libs/context/README.md new file mode 100644 index 000000000..44aeff04f --- /dev/null +++ b/src/boost/libs/context/README.md @@ -0,0 +1,21 @@ +boost.context +============= + +boost.context is a foundational library that provides a sort of cooperative multitasking on a single thread. +By providing an abstraction of the current execution state in the current thread, including the stack (with +local variables) and stack pointer, all registers and CPU flags, and the instruction pointer, a execution_context +instance represents a specific point in the application's execution path. This is useful for building +higher-level abstractions, like coroutines, cooperative threads (userland threads) or an equivalent to +C# keyword yield in C++. + +A fiber provides the means to suspend the current execution path and to transfer execution control, +thereby permitting another fiber to run on the current thread. This state full transfer mechanism +enables a fiber to suspend execution from within nested functions and, later, to resume from where it +was suspended. While the execution path represented by a fiber only runs on a single thread, it can be +migrated to another thread at any given time. + +A context switch between threads requires system calls (involving the OS kernel), which can cost more than +thousand CPU cycles on x86 CPUs. By contrast, transferring control among fibers requires only fewer than +hundred CPU cycles because it does not involve system calls as it is done within a single thread. + +boost.context requires C++11! |