hcq/MaxScale
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

MXS-1338: Fix memory leak of after buffer cloning

Browse Source 
When a buffer is cloned and then the original buffer parsed and freed, the
freeing of the cloned buffer will not release the memory that was
allocated when the original buffer is parsed.

This is a side-effect of how the buffer objects are stored in the buffer
and not in the shared memory buffer. The creation of a buffer object after
cloning will cause the buffer object to be lost as the cloned buffer
didn't have a pointer to the buffer object that was created later.

By moving the buffer objects into the shared memory buffer, the memory
leak is fixed.
This commit is contained in:
Markus Mäkelä
2017-08-01 22:41:11 +03:00
parent 0dbf64b1ab
commit 63b16243e7
2 changed files with 21 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
server/core/buffer.c
View File

@ -78,18 +78,19 @@ gwbuf_alloc(unsigned int size)
rval = NULL;
goto retblock;
}
sbuf->refcount = 1;
sbuf->info = GWBUF_INFO_NONE;
sbuf->bufobj = NULL;
spinlock_init(&rval->gwbuf_lock);
rval->start = sbuf->data;
rval->end = (void *)((char *)rval->start + size);
sbuf->refcount = 1;
rval->sbuf = sbuf;
rval->next = NULL;
rval->tail = rval;
rval->hint = NULL;
rval->properties = NULL;
rval->gwbuf_type = GWBUF_TYPE_UNDEFINED;
rval->gwbuf_info = GWBUF_INFO_NONE;
rval->gwbuf_bufobj = NULL;
CHK_GWBUF(rval);
retblock:
if (rval == NULL)
@ -258,7 +259,7 @@ gwbuf_free_one(GWBUF *buf)
{
MXS_FREE(buf->sbuf->data);
MXS_FREE(buf->sbuf);
bo = buf->gwbuf_bufobj;
bo = buf->sbuf->bufobj;
while (bo != NULL)
{
@ -312,8 +313,6 @@ gwbuf_clone_one(GWBUF *buf)
rval->start = buf->start;
rval->end = buf->end;
rval->gwbuf_type = buf->gwbuf_type;
rval->gwbuf_info = buf->gwbuf_info;
rval->gwbuf_bufobj = buf->gwbuf_bufobj;
rval->tail = rval;
rval->next = NULL;
CHK_GWBUF(rval);
@ -376,8 +375,6 @@ static GWBUF *gwbuf_clone_portion(GWBUF *buf,
clonebuf->gwbuf_type = buf->gwbuf_type; /*< clone the type for now */
clonebuf->properties = NULL;
clonebuf->hint = NULL;
clonebuf->gwbuf_info = buf->gwbuf_info;
clonebuf->gwbuf_bufobj = buf->gwbuf_bufobj;
clonebuf->next = NULL;
clonebuf->tail = clonebuf;
CHK_GWBUF(clonebuf);
@ -674,7 +671,7 @@ void gwbuf_add_buffer_object(GWBUF* buf,
newb->bo_next = NULL;
/** Lock */
spinlock_acquire(&buf->gwbuf_lock);
p_b = &buf->gwbuf_bufobj;
p_b = &buf->sbuf->bufobj;
/** Search the end of the list and add there */
while (*p_b != NULL)
{
@ -682,7 +679,7 @@ void gwbuf_add_buffer_object(GWBUF* buf,
}
*p_b = newb;
/** Set flag */
buf->gwbuf_info |= GWBUF_INFO_PARSED;
buf->sbuf->info |= GWBUF_INFO_PARSED;
/** Unlock */
spinlock_release(&buf->gwbuf_lock);
}
@ -694,7 +691,7 @@ void* gwbuf_get_buffer_object_data(GWBUF* buf, bufobj_id_t id)
CHK_GWBUF(buf);
/** Lock */
spinlock_acquire(&buf->gwbuf_lock);
bo = buf->gwbuf_bufobj;
bo = buf->sbuf->bufobj;
while (bo != NULL && bo->bo_id != id)
{