doc: add maintaining-libuv guide

This commit adds a document to describe the steps needed for updating
the libuv dependency.

deps/uv/src/unix/hurd.c

@@ -0,0 +1,167 @@
+/* Copyright libuv project contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#define _GNU_SOURCE 1
+
+#include "uv.h"
+#include "internal.h"
+
+#include <hurd.h>
+#include <hurd/process.h>
+#include <mach/task_info.h>
+#include <mach/vm_statistics.h>
+#include <mach/vm_param.h>
+
+#include <inttypes.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <string.h>
+#include <limits.h>
+
+int uv_exepath(char* buffer, size_t* size) {
+  kern_return_t err;
+  /* XXX in current Hurd, strings are char arrays of 1024 elements */
+  string_t exepath;
+  ssize_t copied;
+
+  if (buffer == NULL || size == NULL || *size == 0)
+    return UV_EINVAL;
+
+  if (*size - 1 > 0) {
+    /* XXX limited length of buffer in current Hurd, this API will probably
+     * evolve in the future */
+    err = proc_get_exe(getproc(), getpid(), exepath);
+
+    if (err)
+      return UV__ERR(err);
+  }
+
+  copied = uv__strscpy(buffer, exepath, *size);
+
+  /* do not return error on UV_E2BIG failure */
+  *size = copied < 0 ? strlen(buffer) : (size_t) copied;
+
+  return 0;
+}
+
+int uv_resident_set_memory(size_t* rss) {
+  kern_return_t err;
+  struct task_basic_info bi;
+  mach_msg_type_number_t count;
+
+  count = TASK_BASIC_INFO_COUNT;
+  err = task_info(mach_task_self(), TASK_BASIC_INFO,
+		  (task_info_t) &bi, &count);
+
+  if (err)
+    return UV__ERR(err);
+
+  *rss = bi.resident_size;
+
+  return 0;
+}
+
+uint64_t uv_get_free_memory(void) {
+  kern_return_t err;
+  struct vm_statistics vmstats;
+
+  err = vm_statistics(mach_task_self(), &vmstats);
+
+  if (err)
+    return 0;
+
+  return vmstats.free_count * vm_page_size;
+}
+
+
+uint64_t uv_get_total_memory(void) {
+  kern_return_t err;
+  host_basic_info_data_t hbi;
+  mach_msg_type_number_t cnt;
+
+  cnt = HOST_BASIC_INFO_COUNT;
+  err = host_info(mach_host_self(), HOST_BASIC_INFO, (host_info_t) &hbi, &cnt); 
+
+  if (err)
+    return 0;
+
+  return hbi.memory_size;
+}
+
+
+int uv_uptime(double* uptime) {
+  char buf[128];
+
+  /* Try /proc/uptime first */
+  if (0 == uv__slurp("/proc/uptime", buf, sizeof(buf)))
+    if (1 == sscanf(buf, "%lf", uptime))
+      return 0;
+
+  /* Reimplement here code from procfs to calculate uptime if not mounted? */
+
+  return UV__ERR(EIO);
+}
+
+void uv_loadavg(double avg[3]) {
+  char buf[128];  /* Large enough to hold all of /proc/loadavg. */
+
+  if (0 == uv__slurp("/proc/loadavg", buf, sizeof(buf)))
+    if (3 == sscanf(buf, "%lf %lf %lf", &avg[0], &avg[1], &avg[2]))
+      return;
+
+  /* Reimplement here code from procfs to calculate loadavg if not mounted? */
+}
+
+
+int uv_cpu_info(uv_cpu_info_t** cpu_infos, int* count) {
+  kern_return_t err;
+  host_basic_info_data_t hbi;
+  mach_msg_type_number_t cnt;
+
+  /* Get count of cpus  */
+  cnt = HOST_BASIC_INFO_COUNT;
+  err = host_info(mach_host_self(), HOST_BASIC_INFO, (host_info_t) &hbi, &cnt); 
+
+  if (err) {
+    err = UV__ERR(err);
+    goto abort;
+  }
+
+  /* XXX not implemented on the Hurd */
+  *cpu_infos = uv__calloc(hbi.avail_cpus, sizeof(**cpu_infos));
+  if (*cpu_infos == NULL) {
+    err = UV_ENOMEM;
+    goto abort;
+  }
+
+  *count = hbi.avail_cpus;
+
+  return 0;
+
+ abort:
+  *cpu_infos = NULL;
+  *count = 0;
+  return err;
+}
+
+uint64_t uv_get_constrained_memory(void) {
+  return 0;  /* Memory constraints are unknown. */
+}

doc/contributing/maintaining-libuv.md

@@ -0,0 +1,64 @@
+# Maintaining libuv
+
+This documents contains instructions about how to update libuv.
+
+## Updating libuv
+
+[Download](https://github.com/libuv/libuv/releases) the distribution and
+signature file of the version to update to.
+
+### Verify the download
+
+Import the public key of the person who signed the distribution:
+
+```console
+git tag -l | grep pubkey
+pubkey-bnoordhuis
+pubkey-cjihrig
+pubkey-cjihrig-kb
+pubkey-indutny
+pubkey-iwuzhere
+pubkey-richardlau
+pubkey-saghul
+pubkey-santigimeno
+pubkey-vtjnash
+pubkey2022-vtjnash
+
+git show <pubkey-signer> | gpg --import
+gpg --verify /path/to/download/libuv-v1.44.1-dist.tar.gz.sign libuv-v1.44.1-dist.tar.gz
+gpg: Signature made Wed 09 Mar 2022 06:58:08 PM CET
+gpg:                using RSA key CFBB9CA9A5BEAFD70E2B3C5A79A67C55A3679C8B
+gpg: Good signature from "Jameson Nash <vtjnash@gmail.com>" [unknown]
+gpg: WARNING: This key is not certified with a trusted signature!
+gpg:          There is no indication that the signature belongs to the owner.
+Primary key fingerprint: CFBB 9CA9 A5BE AFD7 0E2B  3C5A 79A6 7C55 A367 9C8B
+```
+
+### Extract the distribution into deps/uv
+
+```bash
+cd /path/to/nodejs/node
+tar xvzf /path/to/download/libuv-v1.44.1-dist.tar.gz -C deps/uv --strip 1
+```
+
+### Check that Node.js still builds and tests
+
+```console
+./configure && make -j8 test
+./node -p process.versions.uv
+1.44.1
+```
+
+### Committing zlib
+
+```console
+git add --all deps/uv
+```
+
+Commit the changes with a message like:
+
+```text
+deps: update libuv to upstream version
+
+Updated as described in doc/contributing/maintaining-libuv.md.
+```