From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id 2EE7174A0A; Wed, 2 Jun 2021 16:38:49 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id E9C6ED163; Wed, 2 Jun 2021 16:38:48 +0200 (CEST) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [94.136.29.106]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS id DA149C976; Wed, 2 Jun 2021 16:38:44 +0200 (CEST) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id B4169466F2; Wed, 2 Jun 2021 16:38:44 +0200 (CEST) From: Stefan Reiter To: pve-devel@lists.proxmox.com, pbs-devel@lists.proxmox.com Date: Wed, 2 Jun 2021 16:38:32 +0200 Message-Id: <20210602143833.4423-9-s.reiter@proxmox.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210602143833.4423-1-s.reiter@proxmox.com> References: <20210602143833.4423-1-s.reiter@proxmox.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SPAM-LEVEL: Spam detection results: 0 AWL 0.028 Adjusted score from AWL reputation of From: address KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [lib.rs] Subject: [pve-devel] [PATCH proxmox-backup-qemu 8/9] add shared_cache module X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Jun 2021 14:38:49 -0000 Provides a shared AsyncLruCache of 256MB (w/ 4MB chunks) that can be used by multiple readers at the same time. It is dropped once no more readers exist, so the memory gets freed if all QEMU block/pbs instances disappear. Signed-off-by: Stefan Reiter --- src/lib.rs | 7 ++++++- src/shared_cache.rs | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 42 insertions(+), 1 deletion(-) create mode 100644 src/shared_cache.rs diff --git a/src/lib.rs b/src/lib.rs index 05d7b58..aa167f7 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -25,6 +25,7 @@ mod restore; use restore::*; mod tools; +mod shared_cache; pub const PROXMOX_BACKUP_DEFAULT_CHUNK_SIZE: u64 = 1024*1024*4; @@ -804,7 +805,11 @@ pub extern "C" fn proxmox_restore_connect_async( pub extern "C" fn proxmox_restore_disconnect(handle: *mut ProxmoxRestoreHandle) { let restore_task = handle as * mut Arc; - unsafe { Box::from_raw(restore_task) }; //drop(restore_task) + let restore_task = unsafe { Box::from_raw(restore_task) }; + drop(restore_task); + + // after dropping, cache may be unused (if no other handles open) + shared_cache::shared_chunk_cache_cleanup(); } /// Restore an image (sync) diff --git a/src/shared_cache.rs b/src/shared_cache.rs new file mode 100644 index 0000000..bebae5b --- /dev/null +++ b/src/shared_cache.rs @@ -0,0 +1,36 @@ +use once_cell::sync::OnceCell; +use proxmox_backup::backup::ChunkCache; +use proxmox_backup::tools::async_lru_cache::AsyncLruCache; +use std::sync::{Arc, Mutex}; + +const SHARED_CACHE_CAPACITY: usize = 64; // 256 MB +static SHARED_CACHE: OnceCell>> = OnceCell::new(); + +pub fn get_shared_chunk_cache() -> ChunkCache { + let mut guard = SHARED_CACHE + .get_or_init(|| Mutex::new(None)) + .lock() + .unwrap(); + match &*guard { + Some(cache) => Arc::clone(cache), + None => { + let cache = Arc::new(AsyncLruCache::new(SHARED_CACHE_CAPACITY)); + *guard = Some(Arc::clone(&cache)); + cache + } + } +} + +pub fn shared_chunk_cache_cleanup() { + let mut guard = SHARED_CACHE + .get_or_init(|| Mutex::new(None)) + .lock() + .unwrap(); + if let Some(arc) = guard.as_ref() { + let refcount = Arc::strong_count(arc); + if refcount == 1 { + // no one else is using the cache anymore, drop it + let _drop = guard.take(); + } + } +} -- 2.30.2