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{
    "id": 23995,
    "url": "https://patchwork.libcamera.org/api/patches/23995/?format=api",
    "web_url": "https://patchwork.libcamera.org/patch/23995/",
    "project": {
        "id": 1,
        "url": "https://patchwork.libcamera.org/api/projects/1/?format=api",
        "name": "libcamera",
        "link_name": "libcamera",
        "list_id": "libcamera_core",
        "list_email": "libcamera-devel@lists.libcamera.org",
        "web_url": "",
        "scm_url": "",
        "webscm_url": ""
    },
    "msgid": "<20250728113641.238256-6-barnabas.pocze@ideasonboard.com>",
    "date": "2025-07-28T11:36:40",
    "name": "[v6,5/6] libcamera: process: Use `close_range()` when available",
    "commit_ref": null,
    "pull_url": null,
    "state": "accepted",
    "archived": false,
    "hash": "bf73690ebeca93ae5e204b867694bd8ba03ecba2",
    "submitter": {
        "id": 216,
        "url": "https://patchwork.libcamera.org/api/people/216/?format=api",
        "name": "Barnabás Pőcze",
        "email": "barnabas.pocze@ideasonboard.com"
    },
    "delegate": null,
    "mbox": "https://patchwork.libcamera.org/patch/23995/mbox/",
    "series": [
        {
            "id": 5342,
            "url": "https://patchwork.libcamera.org/api/series/5342/?format=api",
            "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=5342",
            "date": "2025-07-28T11:36:35",
            "name": "libcamera: process: Remove `ProcessManager` singleton",
            "version": 6,
            "mbox": "https://patchwork.libcamera.org/series/5342/mbox/"
        }
    ],
    "comments": "https://patchwork.libcamera.org/api/patches/23995/comments/",
    "check": "pending",
    "checks": "https://patchwork.libcamera.org/api/patches/23995/checks/",
    "tags": {},
    "headers": {
        "Return-Path": "<libcamera-devel-bounces@lists.libcamera.org>",
        "X-Original-To": "parsemail@patchwork.libcamera.org",
        "Delivered-To": "parsemail@patchwork.libcamera.org",
        "Received": [
            "from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id A8BC4C332C\n\tfor <parsemail@patchwork.libcamera.org>;\n\tMon, 28 Jul 2025 11:37:02 +0000 (UTC)",
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        ],
        "Authentication-Results": "lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"P4d0S07j\"; dkim-atps=neutral",
        "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1753702565;\n\tbh=zU468YZgi0yylox2Et+YlkCakIhOIDFwylOmeVyQzb4=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=P4d0S07jzrLVhBsrQq6e1i0+/CkCVwjH7XtH4MxOgex7aEEprjL57BwQGKY00EmW+\n\t89ZOkEC0aKRclc1KQ+T041Qc/Bgv00vrxPQu28LUgq57n5DyhD5gz8lpfUuHVRNinX\n\t3tS0s/W2E9l5wAnj4D/9LeHf0Q1Hcqp2JRR1+xlI=",
        "From": "=?utf-8?q?Barnab=C3=A1s_P=C5=91cze?= <barnabas.pocze@ideasonboard.com>",
        "To": "libcamera-devel@lists.libcamera.org",
        "Cc": "Laurent Pinchart <laurent.pinchart@ideasonboard.com>,\n\tKieran Bingham <kieran.bingham@ideasonboard.com>",
        "Subject": "[PATCH v6 5/6] libcamera: process: Use `close_range()` when\n\tavailable",
        "Date": "Mon, 28 Jul 2025 13:36:40 +0200",
        "Message-ID": "<20250728113641.238256-6-barnabas.pocze@ideasonboard.com>",
        "X-Mailer": "git-send-email 2.50.1",
        "In-Reply-To": "<20250728113641.238256-1-barnabas.pocze@ideasonboard.com>",
        "References": "<20250728113641.238256-1-barnabas.pocze@ideasonboard.com>",
        "MIME-Version": "1.0",
        "Content-Type": "text/plain; charset=UTF-8",
        "Content-Transfer-Encoding": "8bit",
        "X-BeenThere": "libcamera-devel@lists.libcamera.org",
        "X-Mailman-Version": "2.1.29",
        "Precedence": "list",
        "List-Id": "<libcamera-devel.lists.libcamera.org>",
        "List-Unsubscribe": "<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>",
        "List-Archive": "<https://lists.libcamera.org/pipermail/libcamera-devel/>",
        "List-Post": "<mailto:libcamera-devel@lists.libcamera.org>",
        "List-Help": "<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>",
        "List-Subscribe": "<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>",
        "Errors-To": "libcamera-devel-bounces@lists.libcamera.org",
        "Sender": "\"libcamera-devel\" <libcamera-devel-bounces@lists.libcamera.org>"
    },
    "content": "Use the `close_range()` system call when available as it is simpler\nand faster than iterating `/proc/self/fd/`.\n\nSigned-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>\nReviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>\nReviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>\n---\n meson.build               |  4 ++++\n src/libcamera/process.cpp | 25 +++++++++++++++++++++++++\n 2 files changed, 29 insertions(+)",
    "diff": "diff --git a/meson.build b/meson.build\nindex 4ed8017eb..6fc4504ab 100644\n--- a/meson.build\n+++ b/meson.build\n@@ -74,6 +74,10 @@ cc = meson.get_compiler('c')\n cxx = meson.get_compiler('cpp')\n config_h = configuration_data()\n \n+if cc.has_header_symbol('unistd.h', 'close_range', prefix : '#define _GNU_SOURCE')\n+    config_h.set('HAVE_CLOSE_RANGE', 1)\n+endif\n+\n if cc.has_header_symbol('fcntl.h', 'F_ADD_SEALS', prefix : '#define _GNU_SOURCE')\n     config_h.set('HAVE_FILE_SEALS', 1)\n endif\ndiff --git a/src/libcamera/process.cpp b/src/libcamera/process.cpp\nindex 4b87c5591..ce6e4c380 100644\n--- a/src/libcamera/process.cpp\n+++ b/src/libcamera/process.cpp\n@@ -69,6 +69,31 @@ void closeAllFdsExcept(std::vector<int> v)\n \n \tASSERT(v.empty() || v.front() >= 0);\n \n+#if HAVE_CLOSE_RANGE\n+\t/*\n+\t * At the moment libcamera does not require at least Linux 5.9,\n+\t * which introduced the `close_range()` system call, so a runtime\n+\t * check is also needed to make sure that it is supported.\n+\t */\n+\tstatic const bool hasCloseRange = [] {\n+\t\treturn close_range(~0u, 0, 0) < 0 && errno == EINVAL;\n+\t}();\n+\n+\tif (hasCloseRange) {\n+\t\tunsigned int prev = 0;\n+\n+\t\tfor (unsigned int curr : v) {\n+\t\t\tASSERT(prev <= curr + 1);\n+\t\t\tif (prev < curr)\n+\t\t\t\tclose_range(prev, curr - 1, 0);\n+\t\t\tprev = curr + 1;\n+\t\t}\n+\n+\t\tclose_range(prev, ~0u, 0);\n+\t\treturn;\n+\t}\n+#endif\n+\n \tDIR *dir = opendir(\"/proc/self/fd\");\n \tif (!dir)\n \t\treturn;\n",
    "prefixes": [
        "v6",
        "5/6"
    ]
}