remove epoll from workers (#365)

.vscode/settings.json

@@ -126,7 +126,8 @@
 		"local_cleanup_queue.h": "c",
 		"sandbox_state_transition.h": "c",
 		"http_session_perf_log.h": "c",
-		"perf_window.h": "c"
+		"perf_window.h": "c",
+		"global_request_scheduler_deque.h": "c"
 	},
 	"files.exclude": {
 		"**/.git": true,

runtime/include/scheduler.h

@@ -22,7 +22,6 @@
 #include "sandbox_set_as_running_sys.h"
 #include "sandbox_set_as_interrupted.h"
 #include "sandbox_set_as_running_user.h"
-#include "scheduler_execute_epoll_loop.h"
 #include "scheduler_options.h"
 
 
@@ -313,7 +312,6 @@ scheduler_preemptive_sched(ucontext_t *interrupted_context)
 	assert(interrupted_context != NULL);
 
 	/* Process epoll to make sure that all runnable jobs are considered for execution */
-	scheduler_execute_epoll_loop();
 
 	struct sandbox *interrupted_sandbox = current_sandbox_get();
 	assert(interrupted_sandbox != NULL);
@@ -401,9 +399,6 @@ scheduler_idle_loop()
 		/* Deferred signals should have been cleared by this point */
 		assert(deferred_sigalrm == 0);
 
-		/* Try to wakeup sleeping sandboxes */
-		scheduler_execute_epoll_loop();
-
 		/* Switch to a sandbox if one is ready to run */
 		struct sandbox *next_sandbox = scheduler_get_next();
 		if (next_sandbox != NULL) {
@@ -441,9 +436,6 @@ scheduler_cooperative_sched(bool add_to_cleanup_queue)
 	/* Deferred signals should have been cleared by this point */
 	assert(deferred_sigalrm == 0);
 
-	/* Try to wakeup sleeping sandboxes */
-	scheduler_execute_epoll_loop();
-
 	/* We have not added ourself to the cleanup queue, so we can free */
 	local_cleanup_queue_free();
 

runtime/include/scheduler_execute_epoll_loop.h

@@ -1,70 +0,0 @@
-#pragma once
-
-#include <assert.h>
-#include <errno.h>
-
-#include "http_session.h"
-#include "panic.h"
-#include "runtime.h"
-#include "sandbox_functions.h"
-#include "sandbox_set_as_error.h"
-#include "sandbox_state.h"
-#include "sandbox_types.h"
-#include "worker_thread.h"
-
-
-/**
- * Run all outstanding events in the local thread's epoll loop
- */
-static inline void
-scheduler_execute_epoll_loop(void)
-{
-	while (true) {
-		struct epoll_event epoll_events[RUNTIME_MAX_EPOLL_EVENTS];
-		int                descriptor_count = epoll_wait(worker_thread_epoll_file_descriptor, epoll_events,
-		                                                 RUNTIME_MAX_EPOLL_EVENTS, 0);
-
-		if (descriptor_count < 0) {
-			if (errno == EINTR) continue;
-
-			panic_err();
-		}
-
-		if (descriptor_count == 0) break;
-
-		for (int i = 0; i < descriptor_count; i++) {
-			if (epoll_events[i].events & (EPOLLIN | EPOLLOUT)) {
-				/* Re-add to runqueue if asleep */
-				struct sandbox *sandbox = (struct sandbox *)epoll_events[i].data.ptr;
-				assert(sandbox);
-
-				if (sandbox->state == SANDBOX_ASLEEP) { sandbox_wakeup(sandbox); }
-			} else if (epoll_events[i].events & (EPOLLERR | EPOLLHUP)) {
-				/* Close socket and set as error on socket error or unexpected client hangup */
-				struct sandbox *sandbox = (struct sandbox *)epoll_events[i].data.ptr;
-				int             error   = 0;
-				socklen_t       errlen  = sizeof(error);
-				getsockopt(epoll_events[i].data.fd, SOL_SOCKET, SO_ERROR, (void *)&error, &errlen);
-
-				if (error > 0) {
-					debuglog("Socket error: %s", strerror(error));
-				} else if (epoll_events[i].events & EPOLLHUP) {
-					debuglog("Client Hungup");
-				} else {
-					debuglog("Unknown Socket error");
-				}
-
-				switch (sandbox->state) {
-				case SANDBOX_RETURNED:
-				case SANDBOX_COMPLETE:
-				case SANDBOX_ERROR:
-					panic("Expected to have closed socket");
-				default:
-					sandbox_set_as_error(sandbox, sandbox->state);
-				}
-			} else {
-				panic("Mystery epoll event!\n");
-			};
-		}
-	}
-}

runtime/include/worker_thread.h

@@ -5,7 +5,6 @@
 #include "runtime.h"
 
 extern thread_local struct arch_context worker_thread_base_context;
-extern thread_local int                 worker_thread_epoll_file_descriptor;
 extern thread_local int                 worker_thread_idx;
 
 void *worker_thread_main(void *return_code);

runtime/include/worker_thread_epoll.h

@@ -1,23 +0,0 @@
-#pragma once
-
-#include "worker_thread.h"
-
-static inline void
-worker_thread_epoll_add_sandbox(struct sandbox *sandbox)
-{
-	assert(sandbox != NULL);
-	/* Freshly allocated sandbox going runnable for first time, so register client socket with epoll */
-	struct epoll_event accept_evt;
-	accept_evt.data.ptr = (void *)sandbox;
-	accept_evt.events   = EPOLLIN | EPOLLOUT | EPOLLET;
-	int rc = epoll_ctl(worker_thread_epoll_file_descriptor, EPOLL_CTL_ADD, sandbox->http->socket, &accept_evt);
-	if (unlikely(rc < 0)) panic_err();
-}
-
-static inline void
-worker_thread_epoll_remove_sandbox(struct sandbox *sandbox)
-{
-	assert(sandbox != NULL);
-	int rc = epoll_ctl(worker_thread_epoll_file_descriptor, EPOLL_CTL_DEL, sandbox->http->socket, NULL);
-	if (unlikely(rc < 0)) panic_err();
-}

runtime/src/current_sandbox.c

@@ -13,7 +13,6 @@
 #include "scheduler.h"
 #include "software_interrupt.h"
 #include "wasi.h"
-#include "worker_thread_epoll.h"
 
 thread_local struct sandbox *worker_thread_current_sandbox = NULL;
 
@@ -102,7 +101,6 @@ current_sandbox_wasm_trap_handler(int trapno)
 	}
 
 	debuglog("%s", error_message);
-	worker_thread_epoll_remove_sandbox(sandbox);
 	current_sandbox_exit();
 	assert(0);
 }
@@ -118,8 +116,6 @@ current_sandbox_init()
 	int   rc            = 0;
 	char *error_message = NULL;
 
-	worker_thread_epoll_add_sandbox(sandbox);
-
 	/* Initialize sandbox memory */
 	struct module *current_module = sandbox_get_module(sandbox);
 	module_initialize_memory(current_module);
@@ -149,7 +145,6 @@ current_sandbox_init()
 
 err:
 	debuglog("%s", error_message);
-	worker_thread_epoll_remove_sandbox(sandbox);
 	current_sandbox_exit();
 	return NULL;
 }
@@ -167,7 +162,6 @@ current_sandbox_fini()
 	sandbox->total_time              = sandbox->timestamp_of.completion - sandbox->timestamp_of.allocation;
 
 	assert(sandbox->state == SANDBOX_RUNNING_SYS);
-	worker_thread_epoll_remove_sandbox(sandbox);
 
 done:
 	sandbox_set_as_returned(sandbox, SANDBOX_RUNNING_SYS);

runtime/src/main.c

@@ -22,6 +22,7 @@
 #include "listener_thread.h"
 #include "panic.h"
 #include "runtime.h"
+#include "sandbox_perf_log.h"
 #include "sandbox_types.h"
 #include "scheduler.h"
 #include "software_interrupt.h"

runtime/src/runtime.c

@@ -22,6 +22,7 @@
 #include "sandbox_total.h"
 #include "scheduler.h"
 #include "software_interrupt.h"
+#include "sandbox_perf_log.h"
 
 /***************************
  * Shared Process State    *

runtime/src/worker_thread.c

@@ -25,8 +25,6 @@
 /* context of the runtime thread before running sandboxes or to resume its "main". */
 thread_local struct arch_context worker_thread_base_context;
 
-thread_local int worker_thread_epoll_file_descriptor;
-
 /* Used to index into global arguments and deadlines arrays */
 thread_local int worker_thread_idx;
 
@@ -64,10 +62,6 @@ worker_thread_main(void *argument)
 		                                                        tenant_timeout_get_priority);
 	}
 
-	/* Initialize epoll */
-	worker_thread_epoll_file_descriptor = epoll_create1(0);
-	if (unlikely(worker_thread_epoll_file_descriptor < 0)) panic_err();
-
 	software_interrupt_unmask_signal(SIGFPE);
 	software_interrupt_unmask_signal(SIGSEGV);