Merge pull request #13025 from kpayson64/fork_bug_fixes

Bug fixes for fork support

include/grpc/impl/codegen/fork.h

@@ -24,10 +24,9 @@
  * active gRPC function calls between calling grpc_prefork() and
  * grpc_postfork_parent()/grpc_postfork_child().
  *
- * Returns 1 on success, 0 otherwise.
  *
  * Typical use:
- * assert(grpc_prefork() == 1);
+ * grpc_prefork();
  * int pid = fork();
  * if (pid) {
  *  grpc_postfork_parent();
@@ -38,7 +37,7 @@
  * }
  */
 
-int grpc_prefork();
+void grpc_prefork();
 
 void grpc_postfork_parent();
 

src/core/lib/iomgr/fork_posix.c

@@ -34,44 +34,49 @@
 #include "src/core/lib/support/env.h"
 #include "src/core/lib/support/fork.h"
 #include "src/core/lib/support/thd_internal.h"
+#include "src/core/lib/surface/init.h"
 
 /*
  * NOTE: FORKING IS NOT GENERALLY SUPPORTED, THIS IS ONLY INTENDED TO WORK
  *       AROUND VERY SPECIFIC USE CASES.
  */
 
-int grpc_prefork() {
+void grpc_prefork() {
   if (!grpc_fork_support_enabled()) {
     gpr_log(GPR_ERROR,
             "Fork support not enabled; try running with the "
             "environment variable GRPC_ENABLE_FORK_SUPPORT=1");
-    return 0;
+    return;
   }
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  grpc_timer_manager_set_threading(false);
-  grpc_executor_set_threading(&exec_ctx, false);
-  grpc_exec_ctx_finish(&exec_ctx);
-  if (!gpr_await_threads(
-          gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
-                       gpr_time_from_seconds(3, GPR_TIMESPAN)))) {
-    gpr_log(GPR_ERROR, "gRPC thread still active! Cannot fork!");
-    return 0;
+  if (grpc_is_initialized()) {
+    grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+    grpc_timer_manager_set_threading(false);
+    grpc_executor_set_threading(&exec_ctx, false);
+    grpc_exec_ctx_finish(&exec_ctx);
+    if (!gpr_await_threads(
+            gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
+                         gpr_time_from_seconds(3, GPR_TIMESPAN)))) {
+      gpr_log(GPR_ERROR, "gRPC thread still active! Cannot fork!");
+    }
   }
-  return 1;
 }
 
 void grpc_postfork_parent() {
-  grpc_timer_manager_set_threading(true);
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  grpc_executor_set_threading(&exec_ctx, true);
-  grpc_exec_ctx_finish(&exec_ctx);
+  if (grpc_is_initialized()) {
+    grpc_timer_manager_set_threading(true);
+    grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+    grpc_executor_set_threading(&exec_ctx, true);
+    grpc_exec_ctx_finish(&exec_ctx);
+  }
 }
 
 void grpc_postfork_child() {
-  grpc_timer_manager_set_threading(true);
-  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
-  grpc_executor_set_threading(&exec_ctx, true);
-  grpc_exec_ctx_finish(&exec_ctx);
+  if (grpc_is_initialized()) {
+    grpc_timer_manager_set_threading(true);
+    grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+    grpc_executor_set_threading(&exec_ctx, true);
+    grpc_exec_ctx_finish(&exec_ctx);
+  }
 }
 
 void grpc_fork_handlers_auto_register() {

src/core/lib/iomgr/fork_windows.c

@@ -28,10 +28,7 @@
  *       AROUND VERY SPECIFIC USE CASES.
  */
 
-int grpc_prefork() {
-  gpr_log(GPR_ERROR, "Forking not supported on Windows");
-  return 0;
-}
+void grpc_prefork() { gpr_log(GPR_ERROR, "Forking not supported on Windows"); }
 
 void grpc_postfork_parent() {}
 

src/core/lib/iomgr/port.h

@@ -30,6 +30,7 @@
 #define GRPC_HAVE_IP_PKTINFO 1
 #define GRPC_HAVE_MSG_NOSIGNAL 1
 #define GRPC_HAVE_UNIX_SOCKET 1
+#define GRPC_POSIX_FORK 1
 #define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
 #define GRPC_POSIX_SOCKET 1
 #define GRPC_POSIX_SOCKETADDR 1
@@ -59,6 +60,7 @@
 #define GRPC_HAVE_MSG_NOSIGNAL 1
 #define GRPC_HAVE_UNIX_SOCKET 1
 #define GRPC_LINUX_MULTIPOLL_WITH_EPOLL 1
+#define GRPC_POSIX_FORK 1
 #define GRPC_POSIX_HOST_NAME_MAX 1
 #define GRPC_POSIX_SOCKET 1
 #define GRPC_POSIX_SOCKETADDR 1
@@ -90,6 +92,7 @@
 #define GRPC_HAVE_SO_NOSIGPIPE 1
 #define GRPC_HAVE_UNIX_SOCKET 1
 #define GRPC_MSG_IOVLEN_TYPE int
+#define GRPC_POSIX_FORK 1
 #define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
 #define GRPC_POSIX_SOCKET 1
 #define GRPC_POSIX_SOCKETADDR 1
@@ -103,6 +106,7 @@
 #define GRPC_HAVE_IPV6_RECVPKTINFO 1
 #define GRPC_HAVE_SO_NOSIGPIPE 1
 #define GRPC_HAVE_UNIX_SOCKET 1
+#define GRPC_POSIX_FORK 1
 #define GRPC_POSIX_NO_SPECIAL_WAKEUP_FD 1
 #define GRPC_POSIX_SOCKET 1
 #define GRPC_POSIX_SOCKETADDR 1