From 4db52804cba220261ce1bc7c5c83667fd1f1d2c0 Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Fri, 19 Apr 2019 20:50:22 -0700
Subject: [PATCH] ircd::ctx: Use iteration closure rather than exposing
 ctx::list.

---
 include/ircd/ctx/ctx.h |  3 ++-
 ircd/ctx.cc            | 17 ++++++++------
 modules/console.cc     | 50 ++++++++++++++++++++++++++----------------
 3 files changed, 43 insertions(+), 27 deletions(-)

diff --git a/include/ircd/ctx/ctx.h b/include/ircd/ctx/ctx.h
index 11a150200..7a7101f8a 100644
--- a/include/ircd/ctx/ctx.h
+++ b/include/ircd/ctx/ctx.h
@@ -44,7 +44,6 @@ namespace ircd::ctx
 	IRCD_OVERLOAD(threadsafe)
 
 	extern log::log log;
-	extern const std::list<ctx *> &ctxs;         // List of all ctx instances
 
 	const uint64_t &id(const ctx &);             // Unique ID for context
 	string_view name(const ctx &);               // User's optional label for context
@@ -68,6 +67,8 @@ namespace ircd::ctx
 	void notify(ctx &, threadsafe_t);            // Notify context with threadsafety.
 	bool notify(ctx &);                          // Queue a context switch to arg
 	void yield(ctx &);                           // Direct context switch to arg
+
+	bool for_each(const std::function<bool (ctx &)> &);
 }
 
 #include "prof.h"
diff --git a/ircd/ctx.cc b/ircd/ctx.cc
index 199184318..eb1e427f0 100644
--- a/ircd/ctx.cc
+++ b/ircd/ctx.cc
@@ -40,13 +40,6 @@ ircd::util::instance_list<ircd::ctx::ctx>::list
 	allocator
 };
 
-/// Public interface linkage for the list of all ctx instances
-decltype(ircd::ctx::ctxs)
-ircd::ctx::ctxs
-{
-	reinterpret_cast<const decltype(ircd::ctx::ctxs) &>(ctx::ctx::list)
-};
-
 decltype(ircd::ctx::log)
 ircd::ctx::log
 {
@@ -350,6 +343,16 @@ const
 // ctx/ctx.h
 //
 
+bool
+ircd::ctx::for_each(const std::function<bool (ctx &)> &closure)
+{
+	for(auto &ctx : ctx::list)
+		if(!closure(*ctx))
+			return false;
+
+	return true;
+}
+
 /// Yield to context `ctx`.
 ///
 ///
diff --git a/modules/console.cc b/modules/console.cc
index 2e1b8c6af..68d77855f 100644
--- a/modules/console.cc
+++ b/modules/console.cc
@@ -1575,13 +1575,17 @@ console_cmd__ctx__interrupt(opt &out, const string_view &line)
 		"id", "[id]..."
 	}};
 
-	for(size_t i(0); i < param.count(); ++i)
-		for(auto *const &ctx : ctx::ctxs)
-			if(id(*ctx) == param.at<uint64_t>(i))
+	bool cont{true};
+	for(size_t i(0); i < param.count() && cont; ++i)
+		cont = ctx::for_each([&](auto &ctx)
+		{
+			if(id(ctx) == param.at<uint64_t>(i))
 			{
-				interrupt(*ctx);
-				break;
+				interrupt(ctx);
+				return false;
 			}
+			else return true;
+		});
 
 	return true;
 }
@@ -1615,16 +1619,20 @@ console_cmd__ctx__prof(opt &out, const string_view &line)
 		return true;
 	}
 
-	for(size_t i(0); i < param.count(); ++i)
-		for(auto *const &ctx : ctx::ctxs)
-			if(id(*ctx) == param.at<uint64_t>(i))
+	bool cont{true};
+	for(size_t i(0); i < param.count() && cont; ++i)
+		cont = ctx::for_each([&](auto &ctx)
+		{
+			if(id(ctx) == param.at<uint64_t>(i))
 			{
-				out << "Profile for ctx:" << id(*ctx) << " '" << name(*ctx) << "':\n"
+				out << "Profile for ctx:" << id(ctx) << " '" << name(ctx) << "':\n"
 				    << std::endl;
 
-				display(ctx::prof::get(*ctx));
-				break;
+				display(ctx::prof::get(ctx));
+				return false;
 			}
+			else return true;
+		});
 
 	return true;
 }
@@ -1637,13 +1645,17 @@ console_cmd__ctx__term(opt &out, const string_view &line)
 		"id", "[id]..."
 	}};
 
-	for(size_t i(0); i < param.count(); ++i)
-		for(auto *const &ctx : ctx::ctxs)
-			if(id(*ctx) == param.at<uint64_t>(i))
+	bool cont {true};
+	for(size_t i(0); i < param.count() && cont; ++i)
+		cont = ctx::for_each([&](auto &ctx)
+		{
+			if(id(ctx) == param.at<uint64_t>(i))
 			{
-				ctx::terminate(*ctx);
-				break;
+				ctx::terminate(ctx);
+				return false;
 			}
+			else return true;
+		});
 
 	return true;
 }
@@ -1682,9 +1694,8 @@ console_cmd__ctx__list(opt &out, const string_view &line)
 	    << ":NAME"
 	    << std::endl;
 
-	for(const auto *const &ctxp : ctx::ctxs)
+	ctx::for_each([&out](auto &ctx)
 	{
-		const auto &ctx{*ctxp};
 		out << std::setw(5) << std::right << id(ctx);
 		out << " "
 		    << (started(ctx)? 'A' : '-')
@@ -1736,7 +1747,8 @@ console_cmd__ctx__list(opt &out, const string_view &line)
 		    << name(ctx);
 
 		out << std::endl;
-	}
+		return true;
+	});
 
 	return true;
 }