From 1867a6c1ce015462db5038739e3d15b6b47e6a74 Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Thu, 8 Oct 2015 16:24:10 +0200
Subject: [PATCH] src: replace QUEUE_SPLIT with QUEUE_MOVE
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All uses of QUEUE_SPLIT in libuv split the list at the head so introduce
a QUEUE_MOVE macro that automates that.

PR-URL: https://github.com/libuv/libuv/pull/565
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>
---
 src/queue.h         | 11 +++++++++++
 src/threadpool.c    |  7 +------
 src/unix/core.c     |  4 +---
 src/unix/fsevents.c | 14 +++-----------
 4 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/src/queue.h b/src/queue.h
index 60c80000..f942e13f 100644
--- a/src/queue.h
+++ b/src/queue.h
@@ -66,6 +66,17 @@ typedef void *QUEUE[2];
   }                                                                           \
   while (0)
 
+#define QUEUE_MOVE(h, n)                                                      \
+  do {                                                                        \
+    if (QUEUE_EMPTY(h))                                                       \
+      QUEUE_INIT(n);                                                          \
+    else {                                                                    \
+      QUEUE* q = QUEUE_HEAD(h);                                               \
+      QUEUE_SPLIT(h, q, n);                                                   \
+    }                                                                         \
+  }                                                                           \
+  while (0)
+
 #define QUEUE_INSERT_HEAD(h, q)                                               \
   do {                                                                        \
     QUEUE_NEXT(q) = QUEUE_NEXT(h);                                            \
diff --git a/src/threadpool.c b/src/threadpool.c
index 15d71994..2c5152b4 100644
--- a/src/threadpool.c
+++ b/src/threadpool.c
@@ -223,13 +223,8 @@ void uv__work_done(uv_async_t* handle) {
   int err;
 
   loop = container_of(handle, uv_loop_t, wq_async);
-  QUEUE_INIT(&wq);
-
   uv_mutex_lock(&loop->wq_mutex);
-  if (!QUEUE_EMPTY(&loop->wq)) {
-    q = QUEUE_HEAD(&loop->wq);
-    QUEUE_SPLIT(&loop->wq, q, &wq);
-  }
+  QUEUE_MOVE(&loop->wq, &wq);
   uv_mutex_unlock(&loop->wq_mutex);
 
   while (!QUEUE_EMPTY(&wq)) {
diff --git a/src/unix/core.c b/src/unix/core.c
index e149357e..48dbfd0a 100644
--- a/src/unix/core.c
+++ b/src/unix/core.c
@@ -721,9 +721,7 @@ static int uv__run_pending(uv_loop_t* loop) {
   if (QUEUE_EMPTY(&loop->pending_queue))
     return 0;
 
-  QUEUE_INIT(&pq);
-  q = QUEUE_HEAD(&loop->pending_queue);
-  QUEUE_SPLIT(&loop->pending_queue, q, &pq);
+  QUEUE_MOVE(&loop->pending_queue, &pq);
 
   while (!QUEUE_EMPTY(&pq)) {
     q = QUEUE_HEAD(&pq);
diff --git a/src/unix/fsevents.c b/src/unix/fsevents.c
index 8143f7c1..8f582c41 100644
--- a/src/unix/fsevents.c
+++ b/src/unix/fsevents.c
@@ -149,11 +149,7 @@ static void (*pFSEventStreamStop)(FSEventStreamRef);
       int err;                                                                \
       uv_mutex_lock(&(handle)->cf_mutex);                                     \
       /* Split-off all events and empty original queue */                     \
-      QUEUE_INIT(&events);                                                    \
-      if (!QUEUE_EMPTY(&(handle)->cf_events)) {                               \
-        q = QUEUE_HEAD(&(handle)->cf_events);                                 \
-        QUEUE_SPLIT(&(handle)->cf_events, q, &events);                        \
-      }                                                                       \
+      QUEUE_MOVE(&(handle)->cf_events, &events);                              \
       /* Get error (if any) and zero original one */                          \
       err = (handle)->cf_error;                                               \
       (handle)->cf_error = 0;                                                 \
@@ -735,17 +731,14 @@ static void uv__cf_loop_cb(void* arg) {
 
   loop = arg;
   state = loop->cf_state;
-  QUEUE_INIT(&split_head);
 
   uv_mutex_lock(&loop->cf_mutex);
-  if (!QUEUE_EMPTY(&loop->cf_signals)) {
-    QUEUE* split_pos = QUEUE_HEAD(&loop->cf_signals);
-    QUEUE_SPLIT(&loop->cf_signals, split_pos, &split_head);
-  }
+  QUEUE_MOVE(&loop->cf_signals, &split_head);
   uv_mutex_unlock(&loop->cf_mutex);
 
   while (!QUEUE_EMPTY(&split_head)) {
     item = QUEUE_HEAD(&split_head);
+    QUEUE_REMOVE(item);
 
     s = QUEUE_DATA(item, uv__cf_loop_signal_t, member);
 
@@ -755,7 +748,6 @@ static void uv__cf_loop_cb(void* arg) {
     else
       uv__fsevents_reschedule(s->handle);
 
-    QUEUE_REMOVE(item);
     uv__free(s);
   }
 }