From d3ee0d5c76626849756e1bff9ffb23de30706c7e Mon Sep 17 00:00:00 2001
From: Craig Tiller <ctiller@google.com>
Date: Mon, 10 Oct 2016 14:09:18 -0700
Subject: [PATCH] Better readability
---
src/core/lib/iomgr/combiner.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/src/core/lib/iomgr/combiner.c b/src/core/lib/iomgr/combiner.c
index 24ffe41d99..60ee14eb23 100644
--- a/src/core/lib/iomgr/combiner.c
+++ b/src/core/lib/iomgr/combiner.c
@@ -266,28 +266,34 @@ bool grpc_combiner_continue_exec_ctx(grpc_exec_ctx *exec_ctx) {
gpr_atm_full_fetch_add(&lock->state, -STATE_ELEM_COUNT_LOW_BIT);
GRPC_COMBINER_TRACE(
gpr_log(GPR_DEBUG, "C:%p finish old_state=%" PRIdPTR, lock, old_state));
+// Define a macro to ease readability of the following switch statement.
+#define OLD_STATE_WAS(orphaned, elem_count) \
+ (((orphaned) ? 0 : STATE_UNORPHANED) | \
+ ((elem_count)*STATE_ELEM_COUNT_LOW_BIT))
+ // Depending on what the previous state was, we need to perform different
+ // actions.
switch (old_state) {
default:
// we have multiple queued work items: just continue executing them
break;
- case STATE_UNORPHANED | (2 * STATE_ELEM_COUNT_LOW_BIT):
- case 0 | (2 * STATE_ELEM_COUNT_LOW_BIT):
+ case OLD_STATE_WAS(false, 2):
+ case OLD_STATE_WAS(true, 2):
// we're down to one queued item: if it's the final list we should do that
if (!grpc_closure_list_empty(lock->final_list)) {
lock->time_to_execute_final_list = true;
}
break;
- case STATE_UNORPHANED | STATE_ELEM_COUNT_LOW_BIT:
+ case OLD_STATE_WAS(false, 1):
// had one count, one unorphaned --> unlocked unorphaned
GPR_TIMER_END("combiner.continue_exec_ctx", 0);
return true;
- case 0 | STATE_ELEM_COUNT_LOW_BIT:
+ case OLD_STATE_WAS(true, 1):
// and one count, one orphaned --> unlocked and orphaned
really_destroy(exec_ctx, lock);
GPR_TIMER_END("combiner.continue_exec_ctx", 0);
return true;
- case STATE_UNORPHANED:
- case 0:
+ case OLD_STATE_WAS(false, 0):
+ case OLD_STATE_WAS(true, 0):
// these values are illegal - representing an already unlocked or
// deleted lock
GPR_TIMER_END("combiner.continue_exec_ctx", 0);
--
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