From 86a8509b26238479b5b240a6c1edcd5727de1eca Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Tue, 20 Oct 2020 17:06:36 -0700
Subject: [PATCH] ircd::m::exec: Add options structure; add logging/detach
 related options.

---
 include/ircd/exec.h | 26 ++++++++++++++++++++++++++
 ircd/exec.cc        | 19 +++++++++++++++----
 2 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/include/ircd/exec.h b/include/ircd/exec.h
index b07482287..893cce90a 100644
--- a/include/ircd/exec.h
+++ b/include/ircd/exec.h
@@ -34,6 +34,7 @@ namespace boost::process
 struct ircd::exec
 :instance_list<ircd::exec>
 {
+	struct opts;
 	using args = vector_view<const string_view>;
 	using const_buffers = vector_view<const const_buffer>;
 	using mutable_buffers = vector_view<const mutable_buffer>;
@@ -42,6 +43,7 @@ struct ircd::exec
 	static uint64_t id_ctr;
 
 	uint64_t id {0};
+	std::unique_ptr<opts> opt;
 	std::string path;
 	std::vector<std::string> argv;
 	std::unique_ptr<pair<boost::process::async_pipe>> pipe;
@@ -55,6 +57,7 @@ struct ircd::exec
 	bool signal(const int &sig);
 	long join(const int &sig = 0);
 
+	exec(const args &, const opts &);
 	exec(const args &);
 	exec(exec &&) = delete;
 	exec(const exec &) = delete;
@@ -63,6 +66,29 @@ struct ircd::exec
 	~exec() noexcept;
 };
 
+/// Exec options
+///
+struct ircd::exec::opts
+{
+	/// When false (default) the child is terminated by the dtor of
+	/// ircd::exec. Note setting this to true does not detach the boost
+	/// handles until destruction time; it also does not affect calling
+	/// the interface join() manually.
+	bool detach {false};
+
+	/// Child executions will be logged at this level (use DEBUG to quiet)
+	ircd::log::level exec_log_level = ircd::log::level::NOTICE;
+
+	/// Child exits will be logged at this level (use DEBUG to quiet); note
+	/// non-zero exits are still logged with level::ERROR.
+	ircd::log::level exit_log_level = ircd::log::level::INFO;
+};
+
+inline
+ircd::exec::exec(const args &args)
+:exec{args, opts{}}
+{}
+
 inline ircd::const_buffer
 ircd::write(exec &p,
             const const_buffer &buf)
diff --git a/ircd/exec.cc b/ircd/exec.cc
index 92b90e926..ef2a6cec0 100644
--- a/ircd/exec.cc
+++ b/ircd/exec.cc
@@ -30,11 +30,16 @@ ircd::util::instance_list<ircd::exec>::list
 	allocator
 };
 
-ircd::exec::exec(const args &args)
+ircd::exec::exec(const args &args,
+                 const opts &opt)
 :id
 {
 	++id_ctr
 }
+,opt
+{
+	std::make_unique<opts>(opt)
+}
 ,path
 (
 	args.at(0)
@@ -66,9 +71,10 @@ ircd::exec::exec(const args &args)
 	child->id()
 }
 {
-	log::notice
+	log::logf
 	{
-		log, "id:%lu pid:%ld `%s' exec argc:%zu",
+		log, this->opt->exec_log_level,
+		"id:%lu pid:%ld `%s' exec argc:%zu",
 		id,
 		pid,
 		path,
@@ -79,6 +85,10 @@ ircd::exec::exec(const args &args)
 ircd::exec::~exec()
 noexcept try
 {
+	assert(opt);
+	if(opt->detach)
+		return;
+
 	join(SIGKILL);
 }
 catch(const std::exception &e)
@@ -126,10 +136,11 @@ try
 	assert(!child->running());
 	code = child->exit_code();
 
+	assert(opt);
 	const auto &level
 	{
 		code == 0?
-			log::level::INFO:
+			opt->exit_log_level:
 			log::level::ERROR
 	};