1 files changed, 54 insertions, 62 deletions
diff --git a/vendor/codeberg.org/gruf/go-runners/process.go b/vendor/codeberg.org/gruf/go-runners/process.go
index ca39ac0d0..3feeff258 100644
--- a/vendor/codeberg.org/gruf/go-runners/process.go
+++ b/vendor/codeberg.org/gruf/go-runners/process.go
@@ -2,80 +2,72 @@ package runners
 
 import (
 	"fmt"
+	"unsafe"
+
 	"sync"
 )
 
-// Processable defines a runnable process with error return
-// that can be passed to a Processor instance for managed running.
-type Processable func() error
-
 // Processor acts similarly to a sync.Once object, except that it is reusable. After
 // the first call to Process(), any further calls before this first has returned will
 // block until the first call has returned, and return the same error. This ensures
 // that only a single instance of it is ever running at any one time.
-type Processor struct {
-	mutex sync.Mutex
-	wait  *sync.WaitGroup
-	err   *error
-}
+type Processor struct{ p atomic_pointer }
 
 // Process will process the given function if first-call, else blocking until
 // the first function has returned, returning the same error result.
-func (p *Processor) Process(proc Processable) (err error) {
-	// Acquire state lock.
-	p.mutex.Lock()
-
-	if p.wait != nil {
-		// Already running.
-		//
-		// Get current ptrs.
-		waitPtr := p.wait
-		errPtr := p.err
-
-		// Free state lock.
-		p.mutex.Unlock()
-
-		// Wait for finish.
-		waitPtr.Wait()
-		return *errPtr
-	}
-
-	// Alloc waiter for new process.
-	var wait sync.WaitGroup
-
-	// No need to alloc new error as
-	// we use the alloc'd named error
-	// return required for panic handling.
-
-	// Reset ptrs.
-	p.wait = &wait
-	p.err = &err
-
-	// Set started.
-	wait.Add(1)
-	p.mutex.Unlock()
-
-	defer func() {
-		if r := recover(); r != nil {
-			if err != nil {
-				rOld := r // wrap the panic so we don't lose existing returned error
-				r = fmt.Errorf("panic occured after error %q: %v", err.Error(), rOld)
-			}
-
-			// Catch any panics and wrap as error.
-			err = fmt.Errorf("caught panic: %v", r)
+func (p *Processor) Process(proc func() error) (err error) {
+	var i *proc_instance
+
+	for {
+		// Attempt to load existing instance.
+		ptr := (*proc_instance)(p.p.Load())
+		if ptr != nil {
+
+			// Wait on existing.
+			ptr.wait.Wait()
+			err = ptr.err
+			return
 		}
 
-		// Mark done.
-		wait.Done()
+		if i == nil {
+			// Allocate instance.
+			i = new(proc_instance)
+			i.wait.Add(1)
+		}
 
-		// Set stopped.
-		p.mutex.Lock()
-		p.wait = nil
-		p.mutex.Unlock()
-	}()
+		// Try to acquire start slot by
+		// setting ptr to *our* instance.
+		if p.p.CAS(nil, unsafe.Pointer(i)) {
+			defer func() {
+				if r := recover(); r != nil {
+					if i.err != nil {
+						rOld := r // wrap the panic so we don't lose existing returned error
+						r = fmt.Errorf("panic occured after error %q: %v", i.err.Error(), rOld)
+					}
+
+					// Catch panics and wrap as error return.
+					i.err = fmt.Errorf("caught panic: %v", r)
+				}
+
+				// Set return.
+				err = i.err
+
+				// Release the
+				// goroutines.
+				i.wait.Done()
+
+				// Free processor.
+				p.p.Store(nil)
+			}()
+
+			// Run func.
+			i.err = proc()
+			return
+		}
+	}
+}
 
-	// Run process.
-	err = proc()
-	return
+type proc_instance struct {
+	wait sync.WaitGroup
+	err  error
 }