Review changes

src/core/lib/gprpp/fork.cc

@@ -56,7 +56,7 @@ class ExecCtxState {
   }
 
   void IncExecCtxCount() {
-    intptr_t count = static_cast<intptr_t>(gpr_atm_no_barrier_load(&count_));
+    gpr_atm count = gpr_atm_no_barrier_load(&count_);
     while (true) {
       if (count <= BLOCKED(1)) {
         // This only occurs if we are trying to fork.  Wait until the fork()
@@ -80,7 +80,9 @@ class ExecCtxState {
   bool BlockExecCtx() {
     // Assumes there is an active ExecCtx when this function is called
     if (gpr_atm_no_barrier_cas(&count_, UNBLOCKED(1), BLOCKED(1))) {
+      gpr_mu_lock(&mu_);
       fork_complete_ = false;
+      gpr_mu_unlock(&mu_);
       return true;
     }
     return false;
@@ -155,6 +157,7 @@ class ThreadState {
 }  // namespace
 
 void Fork::GlobalInit() {
+  if (!overrideEnabled_) {
 #ifdef GRPC_ENABLE_FORK_SUPPORT
     supportEnabled_ = true;
 #else
@@ -185,8 +188,6 @@ void Fork::GlobalInit() {
       }
       gpr_free(env);
     }
-  if (overrideEnabled_ != -1) {
-    supportEnabled_ = (overrideEnabled_ == 1);
   }
   if (supportEnabled_) {
     execCtxState_ = grpc_core::New<internal::ExecCtxState>();
@@ -204,7 +205,10 @@ void Fork::GlobalShutdown() {
 bool Fork::Enabled() { return supportEnabled_; }
 
 // Testing Only
-void Fork::Enable(bool enable) { overrideEnabled_ = enable ? 1 : 0; }
+void Fork::Enable(bool enable) {
+  overrideEnabled_ = true;
+  supportEnabled_ = enable;
+}
 
 void Fork::IncExecCtxCount() {
   if (supportEnabled_) {
@@ -251,6 +255,6 @@ void Fork::AwaitThreads() {
 internal::ExecCtxState* Fork::execCtxState_ = nullptr;
 internal::ThreadState* Fork::threadState_ = nullptr;
 bool Fork::supportEnabled_ = false;
-int Fork::overrideEnabled_ = -1;
+bool Fork::overrideEnabled_ = false;
 
 }  // namespace grpc_core

src/core/lib/gprpp/fork.h

@@ -71,7 +71,7 @@ class Fork {
   static internal::ExecCtxState* execCtxState_;
   static internal::ThreadState* threadState_;
   static bool supportEnabled_;
-  static int overrideEnabled_;
+  static bool overrideEnabled_;
 };
 
 }  // namespace grpc_core