Redirecting buffer completion handler to specific engine.

There is a case in router where we use port in router connection thread.
Buffers are allocated within connection memory pool which can be used only in
this router thread. sendmsg() can be postponed into main router thread and
completion handler will compare current engine and post itself to correct
engine.

src/nxt_port_memory.c

@@ -35,6 +35,10 @@ nxt_port_mmap_buf_completion(nxt_task_t *task, void *obj, void *data)
     nxt_chunk_id_t          c;
     nxt_port_mmap_header_t  *hdr;
 
+    if (nxt_buf_ts_handle(task, obj, data)) {
+        return;
+    }
+
     b = obj;
 
     nxt_debug(task, "mmap buf completion: %p %p", b, b->mem.start);
@@ -71,7 +75,7 @@ nxt_port_mmap_buf_completion(nxt_task_t *task, void *obj, void *data)
         c++;
     }
 
-    nxt_buf_free(mp, b);
+    nxt_mp_release(mp, b);
 }
 
 
@@ -150,6 +154,10 @@ nxt_port_mmap_send_fd_buf_completion(nxt_task_t *task, void *obj, void *data)
     nxt_buf_t  *b;
     nxt_mp_t   *mp;
 
+    if (nxt_buf_ts_handle(task, obj, data)) {
+        return;
+    }
+
     b = obj;
     mp = b->data;
     fd = (nxt_fd_t) (intptr_t) data;
@@ -166,7 +174,7 @@ nxt_port_mmap_send_fd_buf_completion(nxt_task_t *task, void *obj, void *data)
 
     nxt_fd_close(fd);
 
-    nxt_buf_free(mp, b);
+    nxt_mp_release(mp, b);
 }
 
 
@@ -252,13 +260,12 @@ nxt_port_new_port_mmap(nxt_task_t *task, nxt_process_t *process,
 
     port_mmap->hdr = mem;
 
-    b = nxt_buf_mem_alloc(port->mem_pool, 0, 0);
+    b = nxt_buf_mem_ts_alloc(task, port->mem_pool, 0);
     if (nxt_slow_path(b == NULL)) {
         goto remove_fail;
     }
 
     b->completion_handler = nxt_port_mmap_send_fd_buf_completion;
-    b->data = port->mem_pool;
     b->parent = (void *) (intptr_t) fd;
 
     /* Init segment header. */
@@ -396,24 +403,22 @@ nxt_port_mmap_get_buf(nxt_task_t *task, nxt_port_t *port, size_t size)
         return NULL;
     }
 
-    b = nxt_mp_zalloc(port->mem_pool, NXT_BUF_PORT_MMAP_SIZE);
+    b = nxt_buf_mem_ts_alloc(task, port->mem_pool, 0);
     if (nxt_slow_path(b == NULL)) {
         return NULL;
     }
 
-    b->data = port->mem_pool;
     b->completion_handler = nxt_port_mmap_buf_completion;
-    b->size = NXT_BUF_PORT_MMAP_SIZE;
-
     nxt_buf_set_port_mmap(b);
 
     hdr = nxt_port_mmap_get(task, port, &c, size);
     if (nxt_slow_path(hdr == NULL)) {
-        nxt_buf_free(port->mem_pool, b);
+        nxt_mp_release(port->mem_pool, b);
         return NULL;
     }
 
     b->parent = hdr;
+
     b->mem.start = nxt_port_mmap_chunk_start(hdr, c);
     b->mem.pos = b->mem.start;
     b->mem.free = b->mem.start;
@@ -517,14 +522,12 @@ nxt_port_mmap_get_incoming_buf(nxt_task_t *task, nxt_port_t *port,
         return NULL;
     }
 
-    b = nxt_mp_zalloc(port->mem_pool, NXT_BUF_PORT_MMAP_SIZE);
+    b = nxt_buf_mem_ts_alloc(task, port->mem_pool, 0);
     if (nxt_slow_path(b == NULL)) {
         return NULL;
     }
 
-    b->data = port->mem_pool;
     b->completion_handler = nxt_port_mmap_buf_completion;
-    b->size = NXT_BUF_PORT_MMAP_SIZE;
 
     nxt_buf_set_port_mmap(b);
 
@@ -559,7 +562,7 @@ nxt_port_mmap_write(nxt_task_t *task, nxt_port_t *port,
 
     bsize = sb->niov * sizeof(nxt_port_mmap_msg_t);
 
-    b = nxt_buf_mem_alloc(port->mem_pool, bsize, 0);
+    b = nxt_buf_mem_ts_alloc(task, port->mem_pool, bsize);
     if (nxt_slow_path(b == NULL)) {
         return;
     }