[refactor] Replace global int nScriptCheckThreads with bool

The global nScriptCheckThreads int is confusing and is only needed for
its int-ness in AppInitMain. Move all `-par` parsing logic there and
replace the int nScriptCheckThreads with a bool
g_parallel_script_checks.

Also tidy up logic and improve comments.

1 files changed, 6 insertions, 3 deletions

diff --git a/src/validation.h b/src/validation.h
index 7f9582adfd..fd846e9090 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -76,8 +76,8 @@ static const unsigned int BLOCKFILE_CHUNK_SIZE = 0x1000000; // 16 MiB
 /** The pre-allocation chunk size for rev?????.dat files (since 0.8) */
 static const unsigned int UNDOFILE_CHUNK_SIZE = 0x100000; // 1 MiB
 
-/** Maximum number of script-checking threads allowed */
-static const int MAX_SCRIPTCHECK_THREADS = 16;
+/** Maximum number of dedicated script-checking threads allowed */
+static const int MAX_SCRIPTCHECK_THREADS = 15;
 /** -par default (number of script-checking threads, 0 = auto) */
 static const int DEFAULT_SCRIPTCHECK_THREADS = 0;
 /** Number of blocks that can be requested at any given time from a single peer. */
@@ -146,7 +146,10 @@ extern std::condition_variable g_best_block_cv;
 extern uint256 g_best_block;
 extern std::atomic_bool fImporting;
 extern std::atomic_bool fReindex;
-extern int nScriptCheckThreads;
+/** Whether there are dedicated script-checking threads running.
+ * False indicates all script checking is done on the main threadMessageHandler thread.
+ */
+extern bool g_parallel_script_checks;
 extern bool fRequireStandard;
 extern bool fCheckBlockIndex;
 extern bool fCheckpointsEnabled;