From 1e853072dce9c1f9cf121489ab24f07d6c371020 Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Fri, 22 May 2020 02:22:56 +0200
Subject: [PATCH] parser: parallel parser, part 1

---
 vlib/v/parser/parser.v      | 72 ++++++++++++++++++++++---------------
 vlib/v/pref/pref.v          |  6 +++-
 vlib/v/tests/generic_test.v |  4 +++
 3 files changed, 52 insertions(+), 30 deletions(-)

diff --git a/vlib/v/parser/parser.v b/vlib/v/parser/parser.v
index e749ccc4b3..81633cdd3c 100644
--- a/vlib/v/parser/parser.v
+++ b/vlib/v/parser/parser.v
@@ -11,6 +11,9 @@ import v.pref
 import v.util
 import v.errors
 import os
+import runtime
+import sync
+import time
 
 pub struct Parser {
 	scanner           &scanner.Scanner
@@ -134,48 +137,59 @@ pub fn parse_file(path string, b_table &table.Table, comments_mode scanner.Comme
 	}
 }
 
-/*
 struct Queue {
 mut:
 	idx              int
-	mu               sync.Mutex
+	mu               &sync.Mutex
+	mu2              &sync.Mutex
 	paths            []string
 	table            &table.Table
 	parsed_ast_files []ast.File
+	pref             &pref.Preferences
+	global_scope     &ast.Scope
 }
 
-fn (q mut Queue) run() {
-	q.mu.lock()
-	idx := q.idx
-	if idx >= q.paths.len {
+fn (mut q Queue) run() {
+	for {
+		q.mu.lock()
+		idx := q.idx
+		if idx >= q.paths.len {
+			q.mu.unlock()
+			return
+		}
+		q.idx++
 		q.mu.unlock()
-		return
+		println('run(idx=$idx)')
+		path := q.paths[idx]
+		file := parse_file(path, q.table, .skip_comments, q.pref, q.global_scope)
+		q.mu2.lock()
+		q.parsed_ast_files << file
+		q.mu2.unlock()
+		println('run done(idx=$idx)')
 	}
-	q.idx++
-	q.mu.unlock()
-	path := q.paths[idx]
-	file := parse_file(path, q.table, .skip_comments)
-	q.mu.lock()
-	q.parsed_ast_files << file
-	q.mu.unlock()
 }
-*/
+
 pub fn parse_files(paths []string, table &table.Table, pref &pref.Preferences, global_scope &ast.Scope) []ast.File {
-	/*
-	println('\n\n\nparse_files()')
-	println(paths)
-	nr_cpus := runtime.nr_cpus()
-	println('nr_cpus= $nr_cpus')
-	mut q := &Queue{
-		paths: paths
-		table: table
+	// println('nr_cpus= $nr_cpus')
+	if pref.is_parallel && paths[0].contains('/array.v') {
+		println('\n\n\nparse_files() nr_files=$paths.len')
+		println(paths)
+		nr_cpus := runtime.nr_cpus()
+		mut q := &Queue{
+			paths: paths
+			table: table
+			pref: pref
+			global_scope: global_scope
+			mu: sync.new_mutex()
+			mu2: sync.new_mutex()
+		}
+		for _ in 0 .. nr_cpus - 1 {
+			go q.run()
+		}
+		time.sleep_ms(1000)
+		println('all done')
+		return q.parsed_ast_files
 	}
-	for i in 0 .. nr_cpus {
-		go q.run()
-	}
-	time.sleep_ms(100)
-	return q.parsed_ast_files
-	*/
 	// ///////////////
 	mut files := []ast.File{}
 	for path in paths {
diff --git a/vlib/v/pref/pref.v b/vlib/v/pref/pref.v
index 07bade1053..db427e9390 100644
--- a/vlib/v/pref/pref.v
+++ b/vlib/v/pref/pref.v
@@ -24,7 +24,7 @@ pub enum ColorOutput {
 	auto
 	always
 	never
-}    
+}
 
 pub enum Backend {
 	c            // The (default) C backend
@@ -108,6 +108,7 @@ pub mut:
 	skip_running        bool     // when true, do no try to run the produced file (set by b.cc(), when -o x.c or -o x.js)
 	skip_warnings       bool     // like C's "-w"
 	use_color           ColorOutput // whether the warnings/errors should use ANSI color escapes.
+	is_parallel bool
 }
 
 pub fn parse_args(args []string) (&Preferences, string) {
@@ -188,6 +189,9 @@ pub fn parse_args(args []string) (&Preferences, string) {
 			'-keepc' {
 				res.keep_c = true
 			}
+			'-parallel' {
+				res.is_parallel = true
+			}
 			'-x64' {
 				res.backend = .x64
 			}
diff --git a/vlib/v/tests/generic_test.v b/vlib/v/tests/generic_test.v
index b7e26cbd8d..290f76aac8 100644
--- a/vlib/v/tests/generic_test.v
+++ b/vlib/v/tests/generic_test.v
@@ -6,6 +6,8 @@ fn simple<T>(p T) T {
 }
 
 fn plus<T>(a, b T) T {
+	// x := a
+	// y := b
 	// ww := ww
 	// q := xx + 1
 	return a + b
@@ -17,6 +19,8 @@ fn test_generic_fn() {
 	assert simple<string>('g') == 'g'
 	assert simple<string>('g') + 'h' == 'gh'
 	a := plus<int>(2, 3)
+	assert a == 5
+	assert plus<int>(10, 1) == 11
 	// plus<string>('a', 'b')
 	println(a)
 }