core.thread.fiber

package nothrow @nogc void fiber_switchContext(void** oldp, void* newp);

class Fiber: core.thread.fiber.base.FiberBase;

This class provides a cooperative concurrency mechanism integrated with the threading and garbage collection functionality. Calling a fiber may be considered a blocking operation that returns when the fiber yields (via Fiber.yield()). Execution occurs within the context of the calling thread so synchronization is not necessary to guarantee memory visibility so long as the same thread calls the fiber each time. Please note that there is no requirement that a fiber be bound to one specific thread. Rather, fibers may be freely passed between threads so long as they are not currently executing. Like threads, a new fiber thread may be created using either derivation or composition, as in the following example.

Warning Status registers are not saved by the current implementations. This means floating point exception status bits (overflow, divide by 0), rounding mode and similar stuff is set per-thread, not per Fiber!

Warning On ARM FPU registers are not saved if druntime was compiled as ARM_SoftFloat. If such a build is used on a ARM_SoftFP system which actually has got a FPU and other libraries are using the FPU registers (other code is compiled as ARM_SoftFP) this can cause problems. Druntime must be compiled as ARM_SoftFP in this case.

Authors:

Based on a design by Mikola Lysenko.

enum int defaultStackPages;

nothrow this(void function() fn, size_t sz = pageSize * defaultStackPages, size_t guardPageSize = pageSize);

Initializes a fiber object which is associated with a static D function.

Parameters:

void function() fn	The fiber function.
size_t sz	The stack size for this fiber.
size_t guardPageSize	size of the guard page to trap fiber's stack overflows. Beware that using this will increase the number of mmaped regions on platforms using mmap so an OS-imposed limit may be hit.

In fn must not be null.

nothrow this(void delegate() dg, size_t sz = pageSize * defaultStackPages, size_t guardPageSize = pageSize);

Initializes a fiber object which is associated with a dynamic D function.

Parameters:

void delegate() dg	The fiber function.
size_t sz	The stack size for this fiber.
size_t guardPageSize	size of the guard page to trap fiber's stack overflows. Beware that using this will increase the number of mmaped regions on platforms using mmap so an OS-imposed limit may be hit.

In dg must not be null.

static nothrow @nogc @safe Fiber getThis();

Provides a reference to the calling fiber or null if no fiber is currently active.

Returns:

The fiber object representing the calling fiber or null if no fiber is currently active within this thread. The result of deleting this object is undefined.

protected final nothrow void allocStack(size_t sz, size_t guardPageSize);