| /* fibers.h -- an extremely simple lightweight thread (fiber) implementation |
| Copyright (C) 2015-2019 Free Software Foundation, Inc. |
| Contributed by Pekka Jaaskelainen <pekka.jaaskelainen@parmance.com> |
| for General Processor Tech. |
| |
| Permission is hereby granted, free of charge, to any person obtaining a |
| copy of this software and associated documentation files |
| (the "Software"), to deal in the Software without restriction, including |
| without limitation the rights to use, copy, modify, merge, publish, |
| distribute, sublicense, and/or sell copies of the Software, and to |
| permit persons to whom the Software is furnished to do so, subject to |
| the following conditions: |
| |
| The above copyright notice and this permission notice shall be included |
| in all copies or substantial portions of the Software. |
| |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
| OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, |
| DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR |
| OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE |
| USE OR OTHER DEALINGS IN THE SOFTWARE. |
| */ |
| |
| #ifndef PHSA_RT_FIBERS_H |
| #define PHSA_RT_FIBERS_H |
| |
| #include <ucontext.h> |
| |
| typedef enum |
| { |
| /* Ready to run. */ |
| FIBER_STATUS_READY, |
| /* Exited by calling fiber_thread_exit. */ |
| FIBER_STATUS_EXITED, |
| /* Joined by the main thread. */ |
| FIBER_STATUS_JOINED |
| } fiber_status_t; |
| |
| /* A light weight thread (fiber). */ |
| struct fiber_s |
| { |
| ucontext_t context; |
| volatile fiber_status_t status; |
| struct fiber_s *next; |
| struct fiber_s *prev; |
| }; |
| |
| typedef struct fiber_s fiber_t; |
| |
| typedef void (*fiber_function_t)(int, int); |
| |
| /* Initializes the fiber with the start function given as the first |
| argument, and the argument to pass to the start function, |
| as the second. The allocated stack size is given as the last argument. */ |
| void |
| fiber_init (fiber_t *fiber, fiber_function_t start_function, void *arg, |
| size_t stack_size, size_t stack_align); |
| |
| /* Terminates the fiber execution from within the fiber itself. */ |
| void |
| fiber_exit (); |
| |
| /* Blocks until the given fiber returns. Frees the resources allocated |
| for the fiber. After join returns, the fiber itself can be deleted. */ |
| void |
| fiber_join (fiber_t *fiber); |
| |
| /* Co-operatively transfer execution turn to other fibers. */ |
| void |
| fiber_yield (); |
| |
| /* A multi-entry barrier. After the last fiber has reached the |
| barrier, it is automatically re-initialized to the threshold. */ |
| typedef struct |
| { |
| /* The barrier participant count. */ |
| volatile size_t threshold; |
| /* Number of fibers that have reached the barrier. */ |
| volatile size_t reached; |
| /* Number of fibers that are waiting at the barrier. */ |
| volatile size_t waiting_count; |
| } fiber_barrier_t; |
| |
| /* Reach the given barrier. Blocks (co-operatively switches the execution |
| fibers) until all other parties have reached it. Returns 0 only in case |
| the calling fiber was the first one to return from the barrier. */ |
| size_t |
| fiber_barrier_reach (fiber_barrier_t *barrier); |
| |
| /* Initializes the given barrier. */ |
| void |
| fiber_barrier_init (fiber_barrier_t *barrier, size_t threshold); |
| |
| void * |
| fiber_int_args_to_ptr (int arg0, int arg1); |
| |
| #endif |