Fix race conditions

Signed-off-by: Nicolas Paul <n@nc0.fr>

5 files changed, 28 insertions, 13 deletions

diff --git a/cmd/svgu/svgu.go b/cmd/svgu/svgu.go
index a9d81f6..cd765e8 100644
--- a/cmd/svgu/svgu.go
+++ b/cmd/svgu/svgu.go
@@ -15,7 +15,7 @@ var (
 	cfg     = flag.String("c", "DOMAINS.star", "the configuration file to use.")
 	out     = flag.String("o", "dst", "output directory")
 	verbose = flag.Bool("v", false, "prints additional information logs")
-) // todo(nc0): verbose
+)
 
 func main() {
 	log.SetFlags(0)
@@ -86,14 +86,18 @@ func main() {
 	}
 
 	var wg sync.WaitGroup
+	var mu sync.Mutex
 	for _, mod := range idx.Modules {
 		wg.Add(1)
 		go func(m *types.Module) {
 			defer wg.Done()
+			defer mu.Unlock()
+
+			mu.Lock()
 			if err := m.GenerateFile(*out, idx.Domain); err != nil {
 				log.Fatalf("could not generate module %q: %v", m.Path, err)
 			}
-		}(&mod)
+		}(mod)
 	}
 
 	wg.Wait()
diff --git a/pkg/config/lib/prelude/prelude.go b/pkg/config/lib/prelude/prelude.go
index c1e42f4..c703625 100644
--- a/pkg/config/lib/prelude/prelude.go
+++ b/pkg/config/lib/prelude/prelude.go
@@ -81,7 +81,7 @@ func InternModule(_ *starlark.Thread, _ *starlark.Builtin, args starlark.Tuple,
 		return nil, fmt.Errorf("unknown vcs %q", vcs)
 	}
 
-	Registered.AddModule(name, types.Module{
+	Registered.AddModule(name, &types.Module{
 		Path: name,
 		Vcs:  v,
 		Repo: repo,
diff --git a/pkg/config/starlark.go b/pkg/config/starlark.go
index d739a4a..c8a2998 100644
--- a/pkg/config/starlark.go
+++ b/pkg/config/starlark.go
@@ -30,7 +30,7 @@ func ExecConfig(fl string) (*types.Index, error) {
 
 	prelude.Registered = types.Index{
 		Domain:  "",
-		Modules: make(map[string]types.Module),
+		Modules: make(map[string]*types.Module),
 	}
 	if _, err := starlark.ExecFile(th, fl, nil, env); err != nil {
 		return &types.Index{}, err
diff --git a/pkg/types/index.go b/pkg/types/index.go
index 623555c..ebb6f52 100644
--- a/pkg/types/index.go
+++ b/pkg/types/index.go
@@ -10,7 +10,7 @@ import (
 // Index is the global object representing the Starlark configuration.
 type Index struct {
 	Domain  string
-	Modules map[string]Module
+	Modules map[string]*Module
 	// internal
 	lock sync.Mutex
 }
@@ -23,14 +23,14 @@ func (i *Index) SetDomain(d string) {
 }
 
 // AddModule adds a module to the index.
-func (i *Index) AddModule(n string, m Module) {
+func (i *Index) AddModule(n string, m *Module) {
 	i.lock.Lock()
 	defer i.lock.Unlock()
 	i.Modules[n] = m
 }
 
 // GetModule returns a module from the index.
-func (i *Index) GetModule(n string) Module {
+func (i *Index) GetModule(n string) *Module {
 	i.lock.Lock()
 	defer i.lock.Unlock()
 	return i.Modules[n]
diff --git a/pkg/types/module.go b/pkg/types/module.go
index e0ec5ea..ad3208f 100644
--- a/pkg/types/module.go
+++ b/pkg/types/module.go
@@ -6,6 +6,7 @@ import (
 	"os"
 	"path"
 	"strings"
+	"sync"
 )
 
 // Vcs is an enum for version control systems supported by the standard Go
@@ -30,21 +31,31 @@ type Module struct {
 	Repo string // repository's home
 	Dir  string // url template
 	File string // url template
+
+	// internal
+	mu sync.Mutex
 }
 
 // GenerateFile generates the index file.
 func (m *Module) GenerateFile(out string, domain string) error {
+	m.mu.Lock()
+	p := m.Path
+	v := m.Vcs
+	r := m.Repo
+	d := m.Dir
+	f := m.File
+	m.mu.Unlock()
 
-	f := path.Join(out, m.Path+".html")
+	outf := path.Join(out, p+".html")
 
 	// Create the file.
-	if strings.Contains(m.Path, "/") {
-		if err := os.MkdirAll(path.Dir(f), 0755); err != nil {
+	if strings.Contains(p, "/") {
+		if err := os.MkdirAll(path.Dir(outf), 0755); err != nil {
 			return err
 		}
 	}
 
-	fd, err := os.Create(f)
+	fd, err := os.Create(outf)
 	if err != nil {
 		return err
 	}
@@ -57,8 +68,8 @@ func (m *Module) GenerateFile(out string, domain string) error {
 
 	// Execute the template and write the output to the file.
 	if err := templates.ExecModule(fd,
-		fmt.Sprintf("%s/%s", domain, m.Path), string(m.Vcs),
-		m.Repo, m.Dir, m.File); err != nil {
+		fmt.Sprintf("%s/%s", domain, p), string(v), r,
+		d, f); err != nil {
 		return err
 	}