diff --git a/cont.c b/cont.c
index 853787567f..b4f9fce241 100644
--- a/cont.c
+++ b/cont.c
@@ -1414,7 +1414,7 @@ rb_fiber_start(void)
 	th->ec->root_lep = rb_vm_proc_local_ep(fib->first_proc);
 	th->ec->root_svar = Qfalse;
 
-	EXEC_EVENT_HOOK(th, RUBY_EVENT_FIBER_SWITCH, th->self, 0, 0, 0, Qnil);
+	EXEC_EVENT_HOOK(th->ec, RUBY_EVENT_FIBER_SWITCH, th->self, 0, 0, 0, Qnil);
 	cont->value = rb_vm_invoke_proc(th->ec, proc, argc, argv, VM_BLOCK_HANDLER_NONE);
     }
     EC_POP_TAG();
@@ -1671,7 +1671,7 @@ fiber_switch(rb_fiber_t *fib, int argc, const VALUE *argv, int is_resume)
     value = fiber_store(fib, th);
     RUBY_VM_CHECK_INTS(th);
 
-    EXEC_EVENT_HOOK(th, RUBY_EVENT_FIBER_SWITCH, th->self, 0, 0, 0, Qnil);
+    EXEC_EVENT_HOOK(th->ec, RUBY_EVENT_FIBER_SWITCH, th->self, 0, 0, 0, Qnil);
 
     return value;
 }
diff --git a/error.c b/error.c
index 176659b8ee..420539e4a4 100644
--- a/error.c
+++ b/error.c
@@ -1015,12 +1015,12 @@ rb_get_backtrace(VALUE exc)
     ID mid = id_backtrace;
     if (rb_method_basic_definition_p(CLASS_OF(exc), id_backtrace)) {
 	VALUE info, klass = rb_eException;
-	rb_thread_t *th = GET_THREAD();
+	rb_execution_context_t *ec = GET_EC();
 	if (NIL_P(exc))
 	    return Qnil;
-	EXEC_EVENT_HOOK(th, RUBY_EVENT_C_CALL, exc, mid, mid, klass, Qundef);
+	EXEC_EVENT_HOOK(ec, RUBY_EVENT_C_CALL, exc, mid, mid, klass, Qundef);
 	info = exc_backtrace(exc);
-	EXEC_EVENT_HOOK(th, RUBY_EVENT_C_RETURN, exc, mid, mid, klass, info);
+	EXEC_EVENT_HOOK(ec, RUBY_EVENT_C_RETURN, exc, mid, mid, klass, info);
 	if (NIL_P(info))
 	    return Qnil;
 	return rb_check_backtrace(info);
diff --git a/eval.c b/eval.c
index 419e1d31a6..fa97b9d973 100644
--- a/eval.c
+++ b/eval.c
@@ -577,7 +577,7 @@ setup_exception(rb_execution_context_t *ec, int tag, volatile VALUE mesg, VALUE
 
     if (tag != TAG_FATAL) {
 	RUBY_DTRACE_HOOK(RAISE, rb_obj_classname(ec->errinfo));
-	EXEC_EVENT_HOOK(rb_ec_thread_ptr(ec), RUBY_EVENT_RAISE, ec->cfp->self, 0, 0, 0, mesg);
+	EXEC_EVENT_HOOK(ec, RUBY_EVENT_RAISE, ec->cfp->self, 0, 0, 0, mesg);
     }
 }
 
@@ -796,17 +796,17 @@ rb_make_exception(int argc, const VALUE *argv)
 void
 rb_raise_jump(VALUE mesg, VALUE cause)
 {
-    rb_thread_t *th = GET_THREAD();
-    const rb_control_frame_t *cfp = th->ec->cfp;
+    rb_execution_context_t *ec = GET_EC();
+    const rb_control_frame_t *cfp = ec->cfp;
     const rb_callable_method_entry_t *me = rb_vm_frame_method_entry(cfp);
     VALUE klass = me->owner;
     VALUE self = cfp->self;
     ID mid = me->called_id;
 
-    rb_vm_pop_frame(th->ec);
-    EXEC_EVENT_HOOK(th, RUBY_EVENT_C_RETURN, self, me->def->original_id, mid, klass, Qnil);
+    rb_vm_pop_frame(ec);
+    EXEC_EVENT_HOOK(ec, RUBY_EVENT_C_RETURN, self, me->def->original_id, mid, klass, Qnil);
 
-    rb_longjmp(th->ec, TAG_RAISE, mesg, cause);
+    rb_longjmp(ec, TAG_RAISE, mesg, cause);
 }
 
 /*!
diff --git a/gc.c b/gc.c
index 48053b66c5..17d2a09769 100644
--- a/gc.c
+++ b/gc.c
@@ -1811,9 +1811,9 @@ rb_objspace_set_event_hook(const rb_event_flag_t event)
 }
 
 static void
-gc_event_hook_body(rb_thread_t *th, rb_objspace_t *objspace, const rb_event_flag_t event, VALUE data)
+gc_event_hook_body(rb_execution_context_t *ec, rb_objspace_t *objspace, const rb_event_flag_t event, VALUE data)
 {
-    EXEC_EVENT_HOOK(th, event, th->ec->cfp->self, 0, 0, 0, data);
+    EXEC_EVENT_HOOK(ec, event, ec->cfp->self, 0, 0, 0, data);
 }
 
 #define gc_event_hook_available_p(objspace) ((objspace)->flags.has_hook)
@@ -1821,7 +1821,7 @@ gc_event_hook_body(rb_thread_t *th, rb_objspace_t *objspace, const rb_event_flag
 
 #define gc_event_hook(objspace, event, data) do { \
     if (UNLIKELY(gc_event_hook_needed_p(objspace, event))) { \
-	gc_event_hook_body(GET_THREAD(), (objspace), (event), (data)); \
+	gc_event_hook_body(GET_EC(), (objspace), (event), (data)); \
     } \
 } while (0)
 
diff --git a/insns.def b/insns.def
index 61b61f6187..b254193a4c 100644
--- a/insns.def
+++ b/insns.def
@@ -790,7 +790,7 @@ trace
     rb_event_flag_t flag = (rb_event_flag_t)nf;
 
     vm_dtrace(flag, rb_ec_thread_ptr(ec));
-    EXEC_EVENT_HOOK(rb_ec_thread_ptr(ec), flag, GET_SELF(), 0, 0, 0 /* id and klass are resolved at callee */,
+    EXEC_EVENT_HOOK(ec, flag, GET_SELF(), 0, 0, 0 /* id and klass are resolved at callee */,
 		    (flag & (RUBY_EVENT_RETURN | RUBY_EVENT_B_RETURN)) ? TOPN(0) : Qundef);
 }
 
@@ -808,7 +808,7 @@ trace2
     rb_event_flag_t flag = (rb_event_flag_t)nf;
 
     vm_dtrace(flag, rb_ec_thread_ptr(ec));
-    EXEC_EVENT_HOOK(rb_ec_thread_ptr(ec), flag, GET_SELF(), 0, 0, 0 /* id and klass are resolved at callee */, data);
+    EXEC_EVENT_HOOK(ec, flag, GET_SELF(), 0, 0, 0 /* id and klass are resolved at callee */, data);
 }
 
 /**********************************************************/
diff --git a/thread.c b/thread.c
index e3330cab4a..5a98a19cf3 100644
--- a/thread.c
+++ b/thread.c
@@ -584,11 +584,11 @@ thread_do_start(rb_thread_t *th, VALUE args)
 	th->ec->errinfo = Qnil;
 	th->ec->root_lep = rb_vm_proc_local_ep(th->first_proc);
 	th->ec->root_svar = Qfalse;
-	EXEC_EVENT_HOOK(th, RUBY_EVENT_THREAD_BEGIN, th->self, 0, 0, 0, Qundef);
+	EXEC_EVENT_HOOK(th->ec, RUBY_EVENT_THREAD_BEGIN, th->self, 0, 0, 0, Qundef);
 	th->value = rb_vm_invoke_proc(th->ec, proc,
 				      (int)RARRAY_LEN(args), RARRAY_CONST_PTR(args),
 				      VM_BLOCK_HANDLER_NONE);
-	EXEC_EVENT_HOOK(th, RUBY_EVENT_THREAD_END, th->self, 0, 0, 0, Qundef);
+	EXEC_EVENT_HOOK(th->ec, RUBY_EVENT_THREAD_END, th->self, 0, 0, 0, Qundef);
     }
     else {
 	th->value = (*th->first_func)((void *)args);
@@ -2094,7 +2094,7 @@ rb_threadptr_execute_interrupts(rb_thread_t *th, int blocking_timing)
 	    if (th->status == THREAD_RUNNABLE)
 		th->running_time_us += TIME_QUANTUM_USEC;
 
-	    EXEC_EVENT_HOOK(th, RUBY_INTERNAL_EVENT_SWITCH, th->ec->cfp->self,
+	    EXEC_EVENT_HOOK(th->ec, RUBY_INTERNAL_EVENT_SWITCH, th->ec->cfp->self,
 			    0, 0, 0, Qundef);
 
 	    rb_thread_schedule_limits(limits_us);
diff --git a/vm.c b/vm.c
index 95949765b2..146a255e99 100644
--- a/vm.c
+++ b/vm.c
@@ -532,13 +532,13 @@ vm_get_ruby_level_caller_cfp(const rb_execution_context_t *ec, const rb_control_
 void
 rb_vm_pop_cfunc_frame(void)
 {
-    rb_thread_t *th = GET_THREAD();
-    rb_control_frame_t *cfp = th->ec->cfp;
+    rb_execution_context_t *ec = GET_EC();
+    rb_control_frame_t *cfp = ec->cfp;
     const rb_callable_method_entry_t *me = rb_vm_frame_method_entry(cfp);
 
-    EXEC_EVENT_HOOK(th, RUBY_EVENT_C_RETURN, cfp->self, me->def->original_id, me->called_id, me->owner, Qnil);
-    RUBY_DTRACE_CMETHOD_RETURN_HOOK(th, me->owner, me->def->original_id);
-    vm_pop_frame(th->ec, cfp, cfp->ep);
+    EXEC_EVENT_HOOK(ec, RUBY_EVENT_C_RETURN, cfp->self, me->def->original_id, me->called_id, me->owner, Qnil);
+    RUBY_DTRACE_CMETHOD_RETURN_HOOK(rb_ec_thread_ptr(ec), me->owner, me->def->original_id);
+    vm_pop_frame(ec, cfp, cfp->ep);
 }
 
 void
@@ -1000,10 +1000,10 @@ invoke_bmethod(rb_execution_context_t *ec, const rb_iseq_t *iseq, VALUE self, co
 		  iseq->body->stack_max);
 
     RUBY_DTRACE_METHOD_ENTRY_HOOK(rb_ec_thread_ptr(ec), me->owner, me->def->original_id);
-    EXEC_EVENT_HOOK(rb_ec_thread_ptr(ec), RUBY_EVENT_CALL, self, me->def->original_id, me->called_id, me->owner, Qnil);
+    EXEC_EVENT_HOOK(ec, RUBY_EVENT_CALL, self, me->def->original_id, me->called_id, me->owner, Qnil);
     VM_ENV_FLAGS_SET(ec->cfp->ep, VM_FRAME_FLAG_FINISH);
     ret = vm_exec(ec);
-    EXEC_EVENT_HOOK(rb_ec_thread_ptr(ec), RUBY_EVENT_RETURN, self, me->def->original_id, me->called_id, me->owner, ret);
+    EXEC_EVENT_HOOK(ec, RUBY_EVENT_RETURN, self, me->def->original_id, me->called_id, me->owner, ret);
     RUBY_DTRACE_METHOD_RETURN_HOOK(rb_ec_thread_ptr(ec), me->owner, me->def->original_id);
     return ret;
 }
@@ -1665,38 +1665,38 @@ frame_name(const rb_control_frame_t *cfp)
 #endif
 
 static void
-hook_before_rewind(rb_thread_t *th, const rb_control_frame_t *cfp, int will_finish_vm_exec, int state, struct vm_throw_data *err)
+hook_before_rewind(rb_execution_context_t *ec, const rb_control_frame_t *cfp, int will_finish_vm_exec, int state, struct vm_throw_data *err)
 {
     if (state == TAG_RAISE && RBASIC_CLASS(err) == rb_eSysStackError) {
 	return;
     }
-    switch (VM_FRAME_TYPE(th->ec->cfp)) {
+    switch (VM_FRAME_TYPE(ec->cfp)) {
       case VM_FRAME_MAGIC_METHOD:
-	RUBY_DTRACE_METHOD_RETURN_HOOK(th, 0, 0);
-	EXEC_EVENT_HOOK_AND_POP_FRAME(th, RUBY_EVENT_RETURN, th->ec->cfp->self, 0, 0, 0, frame_return_value(err));
+	RUBY_DTRACE_METHOD_RETURN_HOOK(rb_ec_thread_ptr(ec), 0, 0);
+	EXEC_EVENT_HOOK_AND_POP_FRAME(ec, RUBY_EVENT_RETURN, ec->cfp->self, 0, 0, 0, frame_return_value(err));
 	THROW_DATA_CONSUMED_SET(err);
 	break;
       case VM_FRAME_MAGIC_BLOCK:
-	if (VM_FRAME_BMETHOD_P(th->ec->cfp)) {
-	    EXEC_EVENT_HOOK(th, RUBY_EVENT_B_RETURN, th->ec->cfp->self, 0, 0, 0, frame_return_value(err));
+	if (VM_FRAME_BMETHOD_P(ec->cfp)) {
+	    EXEC_EVENT_HOOK(ec, RUBY_EVENT_B_RETURN, ec->cfp->self, 0, 0, 0, frame_return_value(err));
 
 	    if (!will_finish_vm_exec) {
 		/* kick RUBY_EVENT_RETURN at invoke_block_from_c() for bmethod */
-		EXEC_EVENT_HOOK_AND_POP_FRAME(th, RUBY_EVENT_RETURN, th->ec->cfp->self,
-					      rb_vm_frame_method_entry(th->ec->cfp)->def->original_id,
-					      rb_vm_frame_method_entry(th->ec->cfp)->called_id,
-					      rb_vm_frame_method_entry(th->ec->cfp)->owner,
+		EXEC_EVENT_HOOK_AND_POP_FRAME(ec, RUBY_EVENT_RETURN, ec->cfp->self,
+					      rb_vm_frame_method_entry(ec->cfp)->def->original_id,
+					      rb_vm_frame_method_entry(ec->cfp)->called_id,
+					      rb_vm_frame_method_entry(ec->cfp)->owner,
 					      frame_return_value(err));
 	    }
 	    THROW_DATA_CONSUMED_SET(err);
 	}
 	else {
-	    EXEC_EVENT_HOOK_AND_POP_FRAME(th, RUBY_EVENT_B_RETURN, th->ec->cfp->self, 0, 0, 0, frame_return_value(err));
+	    EXEC_EVENT_HOOK_AND_POP_FRAME(ec, RUBY_EVENT_B_RETURN, ec->cfp->self, 0, 0, 0, frame_return_value(err));
 	    THROW_DATA_CONSUMED_SET(err);
 	}
 	break;
       case VM_FRAME_MAGIC_CLASS:
-	EXEC_EVENT_HOOK_AND_POP_FRAME(th, RUBY_EVENT_END, th->ec->cfp->self, 0, 0, 0, Qnil);
+	EXEC_EVENT_HOOK_AND_POP_FRAME(ec, RUBY_EVENT_END, ec->cfp->self, 0, 0, 0, Qnil);
 	break;
     }
 }
@@ -1821,7 +1821,7 @@ vm_exec(rb_execution_context_t *ec)
 
 	while (ec->cfp->pc == 0 || ec->cfp->iseq == 0) {
 	    if (UNLIKELY(VM_FRAME_TYPE(ec->cfp) == VM_FRAME_MAGIC_CFUNC)) {
-		EXEC_EVENT_HOOK(rb_ec_thread_ptr(ec), RUBY_EVENT_C_RETURN, ec->cfp->self,
+		EXEC_EVENT_HOOK(ec, RUBY_EVENT_C_RETURN, ec->cfp->self,
 				rb_vm_frame_method_entry(ec->cfp)->def->original_id,
 				rb_vm_frame_method_entry(ec->cfp)->called_id,
 				rb_vm_frame_method_entry(ec->cfp)->owner, Qnil);
@@ -1862,7 +1862,7 @@ vm_exec(rb_execution_context_t *ec)
 			    ec->errinfo = Qnil;
 			    result = THROW_DATA_VAL(err);
 			    THROW_DATA_CATCH_FRAME_SET(err, cfp + 1);
-			    hook_before_rewind(rb_ec_thread_ptr(ec), ec->cfp, TRUE, state, err);
+			    hook_before_rewind(ec, ec->cfp, TRUE, state, err);
 			    rb_vm_pop_frame(ec);
 			    goto finish_vme;
 			}
@@ -2004,7 +2004,7 @@ vm_exec(rb_execution_context_t *ec)
 	    goto vm_loop_start;
 	}
 	else {
-	    hook_before_rewind(rb_ec_thread_ptr(ec), ec->cfp, FALSE, state, err);
+	    hook_before_rewind(ec, ec->cfp, FALSE, state, err);
 
 	    if (VM_FRAME_FINISHED_P(ec->cfp)) {
 		rb_vm_pop_frame(ec);
diff --git a/vm_core.h b/vm_core.h
index e54cf5c6f8..11ee962fc7 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -1712,18 +1712,19 @@ struct rb_trace_arg_struct {
 void rb_threadptr_exec_event_hooks(struct rb_trace_arg_struct *trace_arg);
 void rb_threadptr_exec_event_hooks_and_pop_frame(struct rb_trace_arg_struct *trace_arg);
 
-#define EXEC_EVENT_HOOK_ORIG(th_, flag_, self_, id_, called_id_, klass_, data_, pop_p_) do { \
+#define EXEC_EVENT_HOOK_ORIG(ec_, flag_, self_, id_, called_id_, klass_, data_, pop_p_) do { \
     const rb_event_flag_t flag_arg_ = (flag_); \
     if (UNLIKELY(ruby_vm_event_flags & (flag_arg_))) { \
 	/* defer evaluating the other arguments */ \
-	ruby_exec_event_hook_orig(th_, flag_arg_, self_, id_, called_id_, klass_, data_, pop_p_); \
+	ruby_exec_event_hook_orig(ec_, flag_arg_, self_, id_, called_id_, klass_, data_, pop_p_); \
     } \
 } while (0)
 
 static inline void
-ruby_exec_event_hook_orig(rb_thread_t *const th, const rb_event_flag_t flag,
+ruby_exec_event_hook_orig(rb_execution_context_t *ec, const rb_event_flag_t flag,
 			  VALUE self, ID id, ID called_id, VALUE klass, VALUE data, int pop_p)
 {
+    const rb_thread_t *th = rb_ec_thread_ptr(ec);
     if ((th->event_hooks.events | th->vm->event_hooks.events) & flag) {
 	struct rb_trace_arg_struct trace_arg;
 	trace_arg.event = flag;
@@ -1741,11 +1742,11 @@ ruby_exec_event_hook_orig(rb_thread_t *const th, const rb_event_flag_t flag,
     }
 }
 
-#define EXEC_EVENT_HOOK(th_, flag_, self_, id_, called_id_, klass_, data_) \
-  EXEC_EVENT_HOOK_ORIG(th_, flag_, self_, id_, called_id_, klass_, data_, 0)
+#define EXEC_EVENT_HOOK(ec_, flag_, self_, id_, called_id_, klass_, data_) \
+  EXEC_EVENT_HOOK_ORIG(ec_, flag_, self_, id_, called_id_, klass_, data_, 0)
 
-#define EXEC_EVENT_HOOK_AND_POP_FRAME(th_, flag_, self_, id_, called_id_, klass_, data_) \
-  EXEC_EVENT_HOOK_ORIG(th_, flag_, self_, id_, called_id_, klass_, data_, 1)
+#define EXEC_EVENT_HOOK_AND_POP_FRAME(ec_, flag_, self_, id_, called_id_, klass_, data_) \
+  EXEC_EVENT_HOOK_ORIG(ec_, flag_, self_, id_, called_id_, klass_, data_, 1)
 
 RUBY_SYMBOL_EXPORT_BEGIN
 
diff --git a/vm_eval.c b/vm_eval.c
index 15cdce77cc..4d4ac4dc02 100644
--- a/vm_eval.c
+++ b/vm_eval.c
@@ -71,7 +71,7 @@ vm_call0_cfunc_with_frame(rb_execution_context_t* ec, struct rb_calling_info *ca
     VALUE block_handler = calling->block_handler;
 
     RUBY_DTRACE_CMETHOD_ENTRY_HOOK(rb_ec_thread_ptr(ec), me->owner, me->def->original_id);
-    EXEC_EVENT_HOOK(rb_ec_thread_ptr(ec), RUBY_EVENT_C_CALL, recv, me->def->original_id, mid, me->owner, Qnil);
+    EXEC_EVENT_HOOK(ec, RUBY_EVENT_C_CALL, recv, me->def->original_id, mid, me->owner, Qnil);
     {
 	rb_control_frame_t *reg_cfp = ec->cfp;
 
@@ -88,7 +88,7 @@ vm_call0_cfunc_with_frame(rb_execution_context_t* ec, struct rb_calling_info *ca
 	VM_PROFILE_UP(C2C_POPF);
 	rb_vm_pop_frame(ec);
     }
-    EXEC_EVENT_HOOK(rb_ec_thread_ptr(ec), RUBY_EVENT_C_RETURN, recv, me->def->original_id, mid, me->owner, val);
+    EXEC_EVENT_HOOK(ec, RUBY_EVENT_C_RETURN, recv, me->def->original_id, mid, me->owner, val);
     RUBY_DTRACE_CMETHOD_RETURN_HOOK(rb_ec_thread_ptr(ec), me->owner, me->def->original_id);
 
     return val;
diff --git a/vm_insnhelper.c b/vm_insnhelper.c
index 92d7490e86..6d82b1cc01 100644
--- a/vm_insnhelper.c
+++ b/vm_insnhelper.c
@@ -1911,7 +1911,7 @@ vm_call_cfunc_with_frame(rb_execution_context_t *ec, rb_control_frame_t *reg_cfp
     int argc = calling->argc;
 
     RUBY_DTRACE_CMETHOD_ENTRY_HOOK(rb_ec_thread_ptr(ec), me->owner, me->def->original_id);
-    EXEC_EVENT_HOOK(rb_ec_thread_ptr(ec), RUBY_EVENT_C_CALL, recv, me->def->original_id, ci->mid, me->owner, Qundef);
+    EXEC_EVENT_HOOK(ec, RUBY_EVENT_C_CALL, recv, me->def->original_id, ci->mid, me->owner, Qundef);
 
     vm_push_frame(ec, NULL, VM_FRAME_MAGIC_CFUNC | VM_FRAME_FLAG_CFRAME | VM_ENV_FLAG_LOCAL, recv,
 		  block_handler, (VALUE)me,
@@ -1927,7 +1927,7 @@ vm_call_cfunc_with_frame(rb_execution_context_t *ec, rb_control_frame_t *reg_cfp
 
     rb_vm_pop_frame(ec);
 
-    EXEC_EVENT_HOOK(rb_ec_thread_ptr(ec), RUBY_EVENT_C_RETURN, recv, me->def->original_id, ci->mid, me->owner, val);
+    EXEC_EVENT_HOOK(ec, RUBY_EVENT_C_RETURN, recv, me->def->original_id, ci->mid, me->owner, val);
     RUBY_DTRACE_CMETHOD_RETURN_HOOK(rb_ec_thread_ptr(ec), me->owner, me->def->original_id);
 
     return val;