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sledge/runtime/src/global_request_scheduler_de...

65 lines
2.4 KiB

#include "global_request_scheduler.h"
#include "runtime.h"
static struct deque_sandbox *global_request_scheduler_deque;
static pthread_mutex_t global_request_scheduler_deque_mutex = PTHREAD_MUTEX_INITIALIZER;
/**
* Pushes a sandbox request to the global deque
* @param sandbox_request
* @returns pointer to request if added. NULL otherwise
*/
static struct sandbox_request *
global_request_scheduler_deque_add(void *sandbox_request_raw)
{
struct sandbox_request *sandbox_request = (struct sandbox_request *)sandbox_request_raw;
int return_code = 1;
return_code = deque_push_sandbox(global_request_scheduler_deque, &sandbox_request);
if (return_code != 0) return NULL;
return sandbox_request_raw;
}
/**
* Stealing from the dequeue is a lock-free, cross-core "pop", which removes the element from the end opposite to
* "pop". Because the producer and consumer (the core stealine the sandbox request) modify different ends,
* no locks are required, and coordination is achieved by instead retrying on inconsistent indices.
*
* Relevant Read: https://www.dre.vanderbilt.edu/~schmidt/PDF/work-stealing-dequeue.pdf
*
* @returns 0 if successfully returned a sandbox request, -ENOENT if empty, -EAGAIN if atomic instruction unsuccessful
*/
static int
global_request_scheduler_deque_remove(struct sandbox_request **removed_sandbox_request)
{
return deque_steal_sandbox(global_request_scheduler_deque, removed_sandbox_request);
}
static int
global_request_scheduler_deque_remove_if_earlier(struct sandbox_request **removed_sandbox_request,
uint64_t target_deadline)
{
panic("Deque variant does not support this call\n");
return -1;
}
void
global_request_scheduler_deque_initialize()
{
/* Allocate and Initialize the global deque */
global_request_scheduler_deque = (struct deque_sandbox *)malloc(sizeof(struct deque_sandbox));
assert(global_request_scheduler_deque);
/* Note: Below is a Macro */
deque_init_sandbox(global_request_scheduler_deque, RUNTIME_MAX_SANDBOX_REQUEST_COUNT);
/* Register Function Pointers for Abstract Scheduling API */
struct global_request_scheduler_config config = {
.add_fn = global_request_scheduler_deque_add,
.remove_fn = global_request_scheduler_deque_remove,
.remove_if_earlier_fn = global_request_scheduler_deque_remove_if_earlier
};
global_request_scheduler_initialize(&config);
}