From: Stefan Sperling <stsp@stsp.name>
Subject: tog yield commit reverted
To: mpi@openbsd.org
Cc: gameoftrees@openbsd.org
Date: Mon, 3 Feb 2020 19:13:57 +0100

FYI,

I had to revert commit 6b8a2b8fcd99 because it broke tog search.
It's quite likely that this could be fixed differently?

-----------------------------------------------
commit 82954512f323c8a2d4f89d51be1e6b0f707b6c3a (master, noel/master, origin/master)
from: Stefan Sperling <stsp@stsp.name>
date: Mon Feb  3 18:10:18 2020 UTC
 
 revert 6b8a2b8fcd99c4365b1aa9513c0f0149beac2491; it broke 'n' (search next)
 
 In the log view, 'n' sometimes failed to search for the next matching commit
 and tog dead-locked. So a yield or mutex unlock/lock is required for search
 to work. Perhaps we need a different fix?
 
diff 044a69d55c4202e3cfefd2d420edfdf6de1e881a 4a3424f61f444454c2c44245fd95ffdea17c2dac
blob - ca9591498c8d4a77dd452d5394cd10141c63e07f
blob + 99c464bbb1c0922bc325ee00100e39b70f857f7f
--- tog/tog.c
+++ tog/tog.c
@@ -755,6 +755,15 @@ view_input(struct tog_view **new, struct tog_view **de
 	*focus = NULL;
 
 	if (view->searching && !view->search_next_done) {
+		errcode = pthread_mutex_unlock(&tog_mutex);
+		if (errcode)
+			return got_error_set_errno(errcode,
+			    "pthread_mutex_unlock");
+		pthread_yield();
+		errcode = pthread_mutex_lock(&tog_mutex);
+		if (errcode)
+			return got_error_set_errno(errcode,
+			    "pthread_mutex_lock");
 		view->search_next(view);
 		return NULL;
 	}
@@ -1633,6 +1642,16 @@ trigger_log_thread(int load_all, int *commits_needed, 
 		if (errcode)
 			return got_error_set_errno(errcode,
 			    "pthread_cond_signal");
+		errcode = pthread_mutex_unlock(&tog_mutex);
+		if (errcode)
+			return got_error_set_errno(errcode,
+			    "pthread_mutex_unlock");
+		pthread_yield();
+		errcode = pthread_mutex_lock(&tog_mutex);
+		if (errcode)
+			return got_error_set_errno(errcode,
+			    "pthread_mutex_lock");
+
 		if (*commits_needed > 0 && (!load_all || --max_wait <= 0)) {
 			/*
 			 * Thread is not done yet; lose a key press