06_request_term.c File Reference

#include <stdatomic.h>
#include <stdio.h>
#include <serene/runtime.h>

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Macros
#define	TASK_COUNT   16

Functions
static srn_fiber_result_t	task (srn_context_t *ctx, void *arg)
static srn_fiber_result_t	controller (srn_context_t *ctx, void *arg)
int	main (void)

Variables
static int	ok
static atomic_int	tasks_ran

Macro Definition Documentation

TASK_COUNT

#define TASK_COUNT   16

Definition at line 43 of file 06_request_term.c.

Function Documentation

controller()

static srn_fiber_result_t controller ( srn_context_t * ctx, void * arg )

static

Definition at line 54 of file 06_request_term.c.

                                                                    {
  (void)ctx;
  // The scheduler arrives through the argument, so the controller can act on
  // it.
  srn_scheduler_t *sched = arg;
  printf("controller: stopping the scheduler before the tasks run\n");
  srn_sched_stop(sched);
  // Returning normally is the clean boundary the worker stops on.
  return &ok;
}

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main()

int main

(

void

)

Definition at line 65 of file 06_request_term.c.

               {
  srn_mm_t *mm = srn_mm_init();
  srn_engine_t *engine = srn_engine_make(mm);
  srn_context_t *ctx = srn_context_make(engine);
  srn_scheduler_t *sched = engine->scheduler;
 
  atomic_store(&tasks_ran, 0);
 
  // The controller is created first so it reaches the front of the ready queue
  // first and requests the stop before any task is dequeued.
  (void)srn_fiber_make(ctx, sched, controller, sched, 0);
  for (int i = 0; i < TASK_COUNT; i++) {
    (void)srn_fiber_make(ctx, sched, task, nullptr, 0);
  }
 
  // One worker keeps the order deterministic: the controller runs, stops the
  // scheduler, and the worker exits at the top of its next loop with the tasks
  // still queued.
  srn_sched_run(sched, 1);
 
  int ran = atomic_load(&tasks_ran);
  printf("%d of %d tasks ran before termination\n", ran, TASK_COUNT);
  printf("the rest were left queued and are reclaimed at shutdown\n");
 
  // Teardown order matters once a run stops with work still queued. The unrun
  // tasks are still on the scheduler's registry, yet their fiber structs live
  // in this context's blocks. srn_engine_shutdown reaps the scheduler, walking
  // that registry, so it has to run before the context that owns those structs
  // is released. The examples that drain every fiber leave an empty registry,
  // so the order does not matter for them.
  srn_engine_shutdown(engine);
  srn_context_release(ctx);
  srn_mm_shutdown(mm);
  return 0;
}

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task()

static srn_fiber_result_t task ( srn_context_t * ctx, void * arg )

static

Definition at line 47 of file 06_request_term.c.

                                                              {
  (void)ctx;
  (void)arg;
  atomic_fetch_add(&tasks_ran, 1);
  return &ok;
}

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Variable Documentation

ok

int ok

static

Definition at line 41 of file 06_request_term.c.

tasks_ran

atomic_int tasks_ran

static

Definition at line 45 of file 06_request_term.c.