diff options
Diffstat (limited to 'dirmngr/workqueue.c')
| -rw-r--r-- | dirmngr/workqueue.c | 214 |
1 files changed, 214 insertions, 0 deletions
diff --git a/dirmngr/workqueue.c b/dirmngr/workqueue.c new file mode 100644 index 0000000..2cb8573 --- /dev/null +++ b/dirmngr/workqueue.c @@ -0,0 +1,214 @@ +/* workqueue.c - Maintain a queue of background tasks + * Copyright (C) 2017 Werner Koch + * + * This file is part of GnuPG. + * + * GnuPG is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * GnuPG is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <https://www.gnu.org/licenses/>. + * + * SPDX-License-Identifier: GPL-3.0+ + */ + +#include <config.h> +#include <stdlib.h> +#include <string.h> + +#include "dirmngr.h" + + +/* An object for one item in the workqueue. */ +struct wqitem_s +{ + struct wqitem_s *next; + + /* This flag is set if the task requires network access. */ + unsigned int need_network:1; + + /* The id of the session which created this task. If this is 0 the + * task is not associated with a specific session. */ + unsigned int session_id; + + /* The function to perform the backgrount task. */ + wqtask_t func; + + /* A string with the string argument for that task. */ + char args[1]; +}; +typedef struct wqitem_s *wqitem_t; + + +/* The workque is a simple linked list. */ +static wqitem_t workqueue; + + +/* Dump the queue using Assuan status comments. */ +void +workqueue_dump_queue (ctrl_t ctrl) +{ + wqitem_t saved_workqueue; + wqitem_t item; + unsigned int count; + + /* Temporay detach the entiere workqueue so that other threads don't + * get into our way. */ + saved_workqueue = workqueue; + workqueue = NULL; + + for (count=0, item = saved_workqueue; item; item = item->next) + count++; + + dirmngr_status_helpf (ctrl, "wq: number of entries: %u", count); + for (item = saved_workqueue; item; item = item->next) + dirmngr_status_helpf (ctrl, "wq: sess=%u net=%d %s(\"%.100s%s\")", + item->session_id, item->need_network, + item->func? item->func (NULL, NULL): "nop", + item->args, strlen (item->args) > 100? "[...]":""); + + /* Restore then workqueue. Actually we append the saved queue do a + * possibly updated workqueue. */ + if (!(item=workqueue)) + workqueue = saved_workqueue; + else + { + while (item->next) + item = item->next; + item->next = saved_workqueue; + } +} + + +/* Append the task (FUNC,ARGS) to the work queue. FUNC shall return + * its name when called with (NULL, NULL). */ +gpg_error_t +workqueue_add_task (wqtask_t func, const char *args, unsigned int session_id, + int need_network) +{ + wqitem_t item, wi; + + item = xtrycalloc (1, sizeof *item + strlen (args)); + if (!item) + return gpg_error_from_syserror (); + strcpy (item->args, args); + item->func = func; + item->session_id = session_id; + item->need_network = !!need_network; + + if (!(wi=workqueue)) + workqueue = item; + else + { + while (wi->next) + wi = wi->next; + wi->next = item; + } + return 0; +} + + +/* Run the task described by ITEM. ITEM must have been detached from + * the workqueue; its ownership is transferred to this fucntion. */ +static void +run_a_task (ctrl_t ctrl, wqitem_t item) +{ + log_assert (!item->next); + + if (opt.verbose) + log_info ("session %u: running %s(\"%s%s\")\n", + item->session_id, + item->func? item->func (NULL, NULL): "nop", + item->args, strlen (item->args) > 100? "[...]":""); + if (item->func) + item->func (ctrl, item->args); + + xfree (item); +} + + +/* Run tasks not associated with a session. This is called from the + * ticker every few minutes. If WITH_NETWORK is not set tasks which + * require the network are not run. */ +void +workqueue_run_global_tasks (ctrl_t ctrl, int with_network) +{ + wqitem_t item, prev; + + with_network = !!with_network; + + if (opt.verbose) + log_info ("running scheduled tasks%s\n", with_network?" (with network)":""); + + for (;;) + { + prev = NULL; + for (item = workqueue; item; prev = item, item = item->next) + if (!item->session_id + && (!item->need_network || (item->need_network && with_network))) + break; + if (!item) + break; /* No more tasks to run. */ + + /* Detach that item from the workqueue. */ + if (!prev) + workqueue = item->next; + else + prev->next = item->next; + item->next = NULL; + + /* Run the task. */ + run_a_task (ctrl, item); + } +} + + +/* Run tasks scheduled for running after a session. Those tasks are + * identified by the SESSION_ID. */ +void +workqueue_run_post_session_tasks (unsigned int session_id) +{ + struct server_control_s ctrlbuf; + ctrl_t ctrl = NULL; + wqitem_t item, prev; + + if (!session_id) + return; + + for (;;) + { + prev = NULL; + for (item = workqueue; item; prev = item, item = item->next) + if (item->session_id == session_id) + break; + if (!item) + break; /* No more tasks for this session. */ + + /* Detach that item from the workqueue. */ + if (!prev) + workqueue = item->next; + else + prev->next = item->next; + item->next = NULL; + + /* Create a CTRL object the first time we need it. */ + if (!ctrl) + { + memset (&ctrlbuf, 0, sizeof ctrlbuf); + ctrl = &ctrlbuf; + dirmngr_init_default_ctrl (ctrl); + } + + /* Run the task. */ + run_a_task (ctrl, item); + } + + dirmngr_deinit_default_ctrl (ctrl); +} |