nsh:support wait command to wait task exit.

usage like: nsh> sleep 10 & [5:100] nsh>set pid1=$! nsh>sleep 15 & [6:100] nsh>set pid2=$! nsh>wait $pid1 $pid2 'wait' command will block nsh from running until pid1 and pid2 finish. This is useful for parallel requirements to perform certain tasks Signed-off-by: anjiahao <anjiahao@xiaomi.com>
2025-10-18 08:52:01 +08:00 · 2023-12-27 14:57:30 +08:00
parent 8d1966e9fc
commit c916f163f2
7 changed files with 179 additions and 6 deletions
--- a/nshlib/nsh_wait.c
+++ b/nshlib/nsh_wait.c
@@ -0,0 +1,150 @@
+/****************************************************************************
+ * apps/nshlib/nsh_wait.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <nuttx/sched.h>
+#include <sys/wait.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <pthread.h>
+
+#include "nsh.h"
+#include "nsh_console.h"
+
+#if !defined(CONFIG_NSH_DISABLE_WAIT) && defined(CONFIG_SCHED_WAITPID) && \
+    !defined(CONFIG_DISABLE_PTHREAD)
+
+static const char g_groupid[] = "Group:";
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: cmd_wait
+ *
+ * Description:
+ *   Handle 'cmd_wait' command from terminal.
+ *   wait pid1 [pid2 [pid3] ..] - wait for a pid to exit.
+ *
+ * Input Parameters:
+ *   vtbl - The NSH console.
+ *   argc - Amount of argument strings in command.
+ *   argv - The argument strings.
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ****************************************************************************/
+
+int cmd_wait(FAR struct nsh_vtbl_s *vtbl, int argc, FAR char **argv)
+{
+  FAR char *nextline;
+  FAR char *line;
+  char buf[128];
+  char path[32];
+  int status = 0;
+  int ret = OK;
+  pid_t self;
+  pid_t tid;
+  int fd;
+  int i;
+
+  if (argc == 1)
+    {
+      return OK;
+    }
+
+  self = getpid();
+  for (i = 1; i < argc; i++)
+    {
+      tid = atoi(argv[i]);
+      if (tid == 0)
+        {
+          continue;
+        }
+
+      snprintf(path, sizeof(path), "/proc/%d/status", tid);
+      fd = open(path, O_RDONLY);
+      if (fd < 0)
+        {
+          nsh_error(vtbl, g_fmtcmdfailed, argv[0], "wait", NSH_ERRNO);
+          continue;
+        }
+
+      ret = read(fd, buf, sizeof(buf) - 1);
+      if (ret < 0)
+        {
+          nsh_error(vtbl, g_fmtcmdfailed, argv[0], "wait", NSH_ERRNO);
+          close(fd);
+          continue;
+        }
+
+      close(fd);
+      nextline = buf;
+      do
+        {
+          line = nextline;
+          for (nextline++;
+               *nextline != '\0' && *nextline != '\n';
+               nextline++);
+
+          if (*nextline == '\n')
+            {
+              *nextline++ = '\0';
+            }
+          else
+            {
+              nextline = NULL;
+            }
+
+          if (strncmp(line, g_groupid, sizeof(g_groupid) - 1) == 0)
+            {
+              if (atoi(line + sizeof(g_groupid)) == self)
+                {
+                  ret = pthread_join(tid, (FAR pthread_addr_t *)&status);
+                }
+              else
+                {
+                  ret = waitpid(tid, &status, 0);
+                }
+
+              if (ret < 0)
+                {
+                  nsh_error(vtbl, g_fmtcmdfailed,
+                            argv[0], "wait", NSH_ERRNO);
+                }
+
+              break;
+            }
+        }
+      while (nextline != NULL);
+    }
+
+  return ret < 0 ? ret : status;
+}
+
+#endif /* CONFIG_NSH_DISABLE_WAIT */