refactor: simplify worker checking logic

runtime/include/listener_thread.h

@@ -1,10 +1,24 @@
 #pragma once
 
+#include <stdbool.h>
+
 #include "generic_thread.h"
 #include "module.h"
 
 #define LISTENER_THREAD_CORE_ID 0
 
+extern pthread_t listener_thread_id;
+
 void                            listener_thread_initialize(void);
 __attribute__((noreturn)) void *listener_thread_main(void *dummy);
 int                             listener_thread_register_module(struct module *mod);
+
+/**
+ * Used to determine if running in the context of a listener thread
+ * @returns true if listener. false if not (probably a worker)
+ */
+static inline bool
+listener_thread_is_running()
+{
+	return pthread_self() == listener_thread_id;
+}

runtime/include/lock.h

@@ -28,7 +28,7 @@ typedef ck_spinlock_mcs_t lock_t;
  * @param unique_variable_name - a unique prefix to hygienically namespace an associated lock/unlock pair
  */
 #define LOCK_LOCK_WITH_BOOKKEEPING(lock, unique_variable_name)                        \
-	assert(!runtime_is_worker() || !software_interrupt_is_enabled());             \
+	assert(listener_thread_is_running() || !software_interrupt_is_enabled());     \
 	struct ck_spinlock_mcs _hygiene_##unique_variable_name##_node;                \
 	uint64_t               _hygiene_##unique_variable_name##_pre = __getcycles(); \
 	ck_spinlock_mcs_lock((lock), &(_hygiene_##unique_variable_name##_node));      \
@@ -40,7 +40,7 @@ typedef ck_spinlock_mcs_t lock_t;
  * @param unique_variable_name - a unique prefix to hygienically namespace an associated lock/unlock pair
  */
 #define LOCK_UNLOCK_WITH_BOOKKEEPING(lock, unique_variable_name)                  \
-	assert(!runtime_is_worker() || !software_interrupt_is_enabled()); \
+	assert(listener_thread_is_running() || !software_interrupt_is_enabled()); \
 	ck_spinlock_mcs_unlock(lock, &(_hygiene_##unique_variable_name##_node));
 
 /**

runtime/include/runtime.h

@@ -71,21 +71,6 @@ extern void  runtime_initialize(void);
 extern void  runtime_set_resource_limits_to_max();
 extern void  stub_init(int32_t offset);
 
-/**
- * Used to determine if running in the context of a worker thread
- * @returns true if worker. false if listener core
- */
-static inline bool
-runtime_is_worker()
-{
-	pthread_t self = pthread_self();
-	for (int i = 0; i < runtime_worker_threads_count; i++) {
-		if (runtime_worker_threads[i] == self) return true;
-	}
-
-	return false;
-}
-
 static inline char *
 runtime_print_scheduler(enum RUNTIME_SCHEDULER variant)
 {

runtime/src/global_request_scheduler_minheap.c

@@ -1,6 +1,7 @@
 #include <assert.h>
 
 #include "global_request_scheduler.h"
+#include "listener_thread.h"
 #include "panic.h"
 #include "priority_queue.h"
 #include "runtime.h"
@@ -17,7 +18,7 @@ global_request_scheduler_minheap_add(void *sandbox_request)
 {
 	assert(sandbox_request);
 	assert(global_request_scheduler_minheap);
-	if (unlikely(runtime_is_worker())) panic("%s is only callable by the listener thread\n", __func__);
+	if (unlikely(!listener_thread_is_running())) panic("%s is only callable by the listener thread\n", __func__);
 
 	int return_code = priority_queue_enqueue(global_request_scheduler_minheap, sandbox_request);
 	/* TODO: Propagate -1 to caller. Issue #91 */

runtime/src/listener_thread.c

@@ -17,6 +17,8 @@ int listener_thread_epoll_file_descriptor;
 /* Timestamp when listener thread began executing */
 static __thread uint64_t listener_thread_start_timestamp;
 
+pthread_t listener_thread_id;
+
 /**
  * Initializes the listener thread, pinned to core 0, and starts to listen for requests
  */
@@ -33,15 +35,14 @@ listener_thread_initialize(void)
 	listener_thread_epoll_file_descriptor = epoll_create1(0);
 	assert(listener_thread_epoll_file_descriptor >= 0);
 
-	pthread_t listener_thread;
+	int ret = pthread_create(&listener_thread_id, NULL, listener_thread_main, NULL);
-	int       ret = pthread_create(&listener_thread, NULL, listener_thread_main, NULL);
 	assert(ret == 0);
-	ret = pthread_setaffinity_np(listener_thread, sizeof(cpu_set_t), &cs);
+	ret = pthread_setaffinity_np(listener_thread_id, sizeof(cpu_set_t), &cs);
 	assert(ret == 0);
 	ret = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), &cs);
 	assert(ret == 0);
 
-	printf("\tListener core thread: %lx\n", listener_thread);
+	printf("\tListener core thread: %lx\n", listener_thread_id);
 }
 
 /**

runtime/src/priority_queue.c

@@ -5,6 +5,7 @@
 #include <string.h>
 #include <stdlib.h>
 
+#include "listener_thread.h"
 #include "panic.h"
 #include "priority_queue.h"
 
@@ -55,7 +56,7 @@ priority_queue_is_empty(struct priority_queue *self)
 {
 	assert(self != NULL);
 	assert(!self->use_lock || LOCK_IS_LOCKED(&self->lock));
-	assert(!runtime_is_worker() || !software_interrupt_is_enabled());
+	assert(listener_thread_is_running() || !software_interrupt_is_enabled());
 
 	return self->size == 0;
 }
@@ -133,7 +134,7 @@ priority_queue_percolate_down(struct priority_queue *self, int parent_index)
 	assert(self != NULL);
 	assert(self->get_priority_fn != NULL);
 	assert(!self->use_lock || LOCK_IS_LOCKED(&self->lock));
-	assert(runtime_is_worker());
+	assert(!listener_thread_is_running());
 	assert(!software_interrupt_is_enabled());
 
 	bool update_highest_value = parent_index == 1;
@@ -179,7 +180,7 @@ struct priority_queue *
 priority_queue_initialize(size_t capacity, bool use_lock, priority_queue_get_priority_fn_t get_priority_fn)
 {
 	assert(get_priority_fn != NULL);
-	assert(!runtime_is_worker() || !software_interrupt_is_enabled());
+	assert(!software_interrupt_is_enabled());
 
 	/* Add one to capacity because this data structure ignores the element at 0 */
 	size_t one_based_capacity = capacity + 1;
@@ -207,7 +208,7 @@ void
 priority_queue_free(struct priority_queue *self)
 {
 	assert(self != NULL);
-	assert(!runtime_is_worker() || !software_interrupt_is_enabled());
+	assert(listener_thread_is_running() || !software_interrupt_is_enabled());
 
 	free(self);
 }
@@ -220,7 +221,7 @@ int
 priority_queue_length_nolock(struct priority_queue *self)
 {
 	assert(self != NULL);
-	assert(runtime_is_worker());
+	assert(!listener_thread_is_running());
 	assert(!software_interrupt_is_enabled());
 	assert(!self->use_lock || LOCK_IS_LOCKED(&self->lock));
 
@@ -250,7 +251,7 @@ priority_queue_enqueue_nolock(struct priority_queue *self, void *value)
 {
 	assert(self != NULL);
 	assert(value != NULL);
-	assert(!runtime_is_worker() || !software_interrupt_is_enabled());
+	assert(listener_thread_is_running() || !software_interrupt_is_enabled());
 	assert(!self->use_lock || LOCK_IS_LOCKED(&self->lock));
 
 	int rc;
@@ -294,7 +295,7 @@ priority_queue_delete_nolock(struct priority_queue *self, void *value)
 {
 	assert(self != NULL);
 	assert(value != NULL);
-	assert(runtime_is_worker());
+	assert(!listener_thread_is_running());
 	assert(!software_interrupt_is_enabled());
 	assert(!self->use_lock || LOCK_IS_LOCKED(&self->lock));
 
@@ -361,7 +362,7 @@ priority_queue_dequeue_if_earlier_nolock(struct priority_queue *self, void **deq
 	assert(self != NULL);
 	assert(dequeued_element != NULL);
 	assert(self->get_priority_fn != NULL);
-	assert(runtime_is_worker());
+	assert(!listener_thread_is_running());
 	assert(!software_interrupt_is_enabled());
 	assert(!self->use_lock || LOCK_IS_LOCKED(&self->lock));
 
@@ -414,7 +415,7 @@ priority_queue_top_nolock(struct priority_queue *self, void **dequeued_element)
 	assert(self != NULL);
 	assert(dequeued_element != NULL);
 	assert(self->get_priority_fn != NULL);
-	assert(runtime_is_worker());
+	assert(!listener_thread_is_running());
 	assert(!software_interrupt_is_enabled());
 	assert(!self->use_lock || LOCK_IS_LOCKED(&self->lock));
 

runtime/src/software_interrupt.c

@@ -11,6 +11,7 @@
 #include "current_sandbox.h"
 #include "debuglog.h"
 #include "global_request_scheduler.h"
+#include "listener_thread.h"
 #include "local_runqueue.h"
 #include "module.h"
 #include "panic.h"
@@ -169,7 +170,7 @@ static inline void
 software_interrupt_validate_worker()
 {
 #ifndef NDEBUG
-	if (!runtime_is_worker()) panic("A non-worker thread has unexpectedly received a signal!");
+	if (listener_thread_is_running()) panic("The listener thread unexpectedly received a signal!");
 #endif
 }