commit a1dd243adb0b9ebf78263a5f2ec5729e903abe32
author Emeric Brun <ebrun@haproxy.com> Wed Jun 21 15:42:52 2017 +0200
committer Willy Tarreau <w@1wt.eu> Tue Oct 31 13:58:31 2017 +0100
tree 3daadb66298b3d180dd142d279e0aee33debc1a7
parent 80527f5bb605ab7a50533175c611686e62fe23b6

MAJOR: threads/buffer: Make buffer wait queue thread safe

Adds a global lock to protect the buffer wait queue.

src/buffer.c

diff --git a/src/buffer.c b/src/buffer.c
index 83e4e9e..e892d1e 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -33,6 +33,9 @@
 
 /* list of objects waiting for at least one buffer */
 struct list buffer_wq = LIST_HEAD_INIT(buffer_wq);
+#ifdef USE_THREAD
+HA_SPINLOCK_T buffer_wq_lock;
+#endif
 
 /* this buffer is always the same size as standard buffers and is used for
  * swapping data inside a buffer.
@@ -72,6 +75,8 @@
 	if (global.tune.buf_limit)
 		pool2_buffer->limit = global.tune.buf_limit;
 
+	SPIN_INIT(&buffer_wq_lock);
+
 	buffer = pool_refill_alloc(pool2_buffer, pool2_buffer->minavail - 1);
 	if (!buffer)
 		return 0;

src/flt_spoe.c

diff --git a/src/flt_spoe.c b/src/flt_spoe.c
index aa3f37a..7fc4ed8 100644
--- a/src/flt_spoe.c
+++ b/src/flt_spoe.c
@@ -18,6 +18,7 @@
 #include <common/debug.h>
 #include <common/memory.h>
 #include <common/time.h>
+#include <common/hathreads.h>
 
 #include <types/arg.h>
 #include <types/global.h>
@@ -2685,14 +2686,18 @@
 		return 1;
 
 	if (!LIST_ISEMPTY(&buffer_wait->list)) {
+		SPIN_LOCK(BUF_WQ_LOCK, &buffer_wq_lock);
 		LIST_DEL(&buffer_wait->list);
 		LIST_INIT(&buffer_wait->list);
+		SPIN_UNLOCK(BUF_WQ_LOCK, &buffer_wq_lock);
 	}
 
 	if (b_alloc_margin(buf, global.tune.reserved_bufs))
 		return 1;
 
+	SPIN_LOCK(BUF_WQ_LOCK, &buffer_wq_lock);
 	LIST_ADDQ(&buffer_wq, &buffer_wait->list);
+	SPIN_UNLOCK(BUF_WQ_LOCK, &buffer_wq_lock);
 	return 0;
 }
 
@@ -2700,8 +2705,10 @@
 spoe_release_buffer(struct buffer **buf, struct buffer_wait *buffer_wait)
 {
 	if (!LIST_ISEMPTY(&buffer_wait->list)) {
+		SPIN_LOCK(BUF_WQ_LOCK, &buffer_wq_lock);
 		LIST_DEL(&buffer_wait->list);
 		LIST_INIT(&buffer_wait->list);
+		SPIN_UNLOCK(BUF_WQ_LOCK, &buffer_wq_lock);
 	}
 
 	/* Release the buffer if needed */

src/stream.c

diff --git a/src/stream.c b/src/stream.c
index 8975638..51d2354 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -320,8 +320,10 @@
 
 	/* We may still be present in the buffer wait queue */
 	if (!LIST_ISEMPTY(&s->buffer_wait.list)) {
+		SPIN_LOCK(BUF_WQ_LOCK, &buffer_wq_lock);
 		LIST_DEL(&s->buffer_wait.list);
 		LIST_INIT(&s->buffer_wait.list);
+		SPIN_UNLOCK(BUF_WQ_LOCK, &buffer_wq_lock);
 	}
 	if (s->req.buf->size || s->res.buf->size) {
 		b_drop(&s->req.buf);
@@ -415,14 +417,18 @@
 static int stream_alloc_work_buffer(struct stream *s)
 {
 	if (!LIST_ISEMPTY(&s->buffer_wait.list)) {
+		SPIN_LOCK(BUF_WQ_LOCK, &buffer_wq_lock);
 		LIST_DEL(&s->buffer_wait.list);
 		LIST_INIT(&s->buffer_wait.list);
+		SPIN_UNLOCK(BUF_WQ_LOCK, &buffer_wq_lock);
 	}
 
 	if (b_alloc_margin(&s->res.buf, 0))
 		return 1;
 
+	SPIN_LOCK(BUF_WQ_LOCK, &buffer_wq_lock);
 	LIST_ADDQ(&buffer_wq, &s->buffer_wait.list);
+	SPIN_UNLOCK(BUF_WQ_LOCK, &buffer_wq_lock);
 	return 0;
 }