From f5db3711b28db4e364ac01be8b124dd24d573782 Mon Sep 17 00:00:00 2001 From: Ole Troan Date: Wed, 20 May 2020 15:47:06 +0200 Subject: api: add new stream message convention Instead of having to wrap dump/detail calls in control ping, send details messages in between a normal reply / request pair. As expressed in the below service statement. Example: service { rpc map_domains_gets returns map_domains_get_reply stream map_domain_details; }; define map_domains_get { u32 client_index; u32 context; u32 cursor; }; define map_domains_get_reply { u32 context; i32 retval; u32 cursor; }; To avoid blocking the main thread for too long, the replies are now sent in client message queue size chunks. The reply message returns VNET_API_ERROR_EAGAIN when there is more to read. The API handler must also include a "cursor" that is used to the next call to the get function. API handler example: REPLY_AND_DETAILS_MACRO (VL_API_MAP_DOMAINS_GET_REPLY, mm->domains, ({ send_domain_details (cursor, rp, mp->context); })); The macro starts from cursor and iterates through the pool until vl_api_process_may_suspend() returns true or the iteration reaches the end of the list. Client Example: cursor = 0 d = [] while True: rv, details = map_domains_get(cursor=cursor) d += details if rv.retval == 0 or rv.retval != -165: break cursor = rv.cursor or the convenience iterator: for x in vpp.details_iter(vpp.api.map_domains_get): pass or list(details_iter(map_domains_get)) Change-Id: Iad9f6b41b0ef886adb584c97708dd91cf552749e Type: feature Signed-off-by: Ole Troan --- src/vlibmemory/api.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'src/vlibmemory/api.h') diff --git a/src/vlibmemory/api.h b/src/vlibmemory/api.h index 6cd645bb1d5..662805373ba 100644 --- a/src/vlibmemory/api.h +++ b/src/vlibmemory/api.h @@ -53,6 +53,28 @@ vl_api_can_send_msg (vl_api_registration_t * rp) return vl_mem_api_can_send (rp->vl_input_queue); } +/* + * Suggests to an API handler to relinguish control. Currently limits + * an handler to a maximum of 1ms or it earlier if the client queue is + * full. + * + * May be enhanced in the future based on other performance + * characteristics of the main thread. + */ +#define VL_API_MAX_TIME_IN_HANDLER 0.001 /* 1 ms */ +always_inline int +vl_api_process_may_suspend (vlib_main_t * vm, vl_api_registration_t * rp, + f64 start) +{ + /* Is client queue full (leave space for reply message) */ + if (rp->registration_type <= REGISTRATION_TYPE_SHMEM && + rp->vl_input_queue->cursize + 1 >= rp->vl_input_queue->maxsize) + return true; + if (vlib_time_now (vm) > start + VL_API_MAX_TIME_IN_HANDLER) + return true; + return false; +} + always_inline vl_api_registration_t * vl_api_client_index_to_registration (u32 index) { -- cgit 1.2.3-korg