Make the lock recursive, this is because processEventsWhileBlocked may cause us to lock multiple times

src/fastlock.cpp

@@ -1,25 +1,41 @@
 #include "fastlock.h"
 #include <unistd.h>
 
+thread_local int tls_pid = -1; 
+
 extern "C" void fastlock_init(struct fastlock *lock)
 {
     lock->m_lock = 0;
+    lock->m_depth = 0;
 }
 
 extern "C" void fastlock_lock(struct fastlock *lock)
 {
     while (!__sync_bool_compare_and_swap(&lock->m_lock, 0, 1))
     {
+        if (lock->m_pidOwner == getpid())
+        {
+            ++lock->m_depth;
+            return;
+        }
     }
+    lock->m_depth = 1;
+    lock->m_pidOwner = getpid();
 }
 
 extern "C" void fastlock_unlock(struct fastlock *lock)
 {
-    __sync_bool_compare_and_swap(&lock->m_lock, 1, 0);
+    --lock->m_depth;
+    if (lock->m_depth == 0)
+    {
+        lock->m_pidOwner = -1;
+        asm volatile ("": : :"memory");
+        __sync_bool_compare_and_swap(&lock->m_lock, 1, 0);
+    }
 }
 
 extern "C" void fastlock_free(struct fastlock *lock)
 {
     // NOP
     (void)lock;
-}
+}

src/fastlock.h

@@ -18,7 +18,9 @@ void fastlock_free(struct fastlock *lock);
 
 struct fastlock
 {
-    int m_lock;
+    volatile int m_lock;
+    int m_pidOwner;
+    int m_depth;
 
 #ifdef __cplusplus
     fastlock()