Revert "runtime/cgo: store M for C-created thread in pthread key"

[gostls13.git] / src / runtime / cgo / gcc_libinit.c

diff --git a/src/runtime/cgo/gcc_libinit.c b/src/runtime/cgo/gcc_libinit.c
index 96765932117ee6a49c6d431ecb09260720629879..57620fe4de81eda8f075af0d939b9013c7197cf0 100644 (file)
--- a/src/runtime/cgo/gcc_libinit.c
+++ b/src/runtime/cgo/gcc_libinit.c
@@ -17,14 +17,6 @@ static pthread_cond_t runtime_init_cond = PTHREAD_COND_INITIALIZER;
 static pthread_mutex_t runtime_init_mu = PTHREAD_MUTEX_INITIALIZER;
 static int runtime_init_done;
 
-// pthread_g is a pthread specific key, for storing the g that binded to the C thread.
-// The registered pthread_key_destructor will dropm, when the pthread-specified value g is not NULL,
-// while a C thread is exiting.
-static pthread_key_t pthread_g;
-static void pthread_key_destructor(void* g);
-uintptr_t x_cgo_pthread_key_created;
-void (*x_crosscall2_ptr)(void (*fn)(void *), void *, int, size_t);
-
 // The context function, used when tracing back C calls into Go.
 static void (*cgo_context_function)(struct context_arg*);
 
@@ -47,12 +39,6 @@ _cgo_wait_runtime_init_done(void) {
                pthread_cond_wait(&runtime_init_cond, &runtime_init_mu);
        }
 
-       // The key and x_cgo_pthread_key_created are for the whole program,
-       // whereas the specific and destructor is per thread.
-       if (x_cgo_pthread_key_created == 0 && pthread_key_create(&pthread_g, pthread_key_destructor) == 0) {
-               x_cgo_pthread_key_created = 1;
-       }
-
        // TODO(iant): For the case of a new C thread calling into Go, such
        // as when using -buildmode=c-archive, we know that Go runtime
        // initialization is complete but we do not know that all Go init
@@ -75,16 +61,6 @@ _cgo_wait_runtime_init_done(void) {
        return 0;
 }
 
-// Store the g into a thread-specific value associated with the pthread key pthread_g.
-// And pthread_key_destructor will dropm when the thread is exiting.
-void x_cgo_bindm(void* g) {
-       // We assume this will always succeed, otherwise, there might be extra M leaking,
-       // when a C thread exits after a cgo call.
-       // We only invoke this function once per thread in runtime.needAndBindM,
-       // and the next calls just reuse the bound m.
-       pthread_setspecific(pthread_g, g);
-}
-
 void
 x_cgo_notify_runtime_init_done(void* dummy __attribute__ ((unused))) {
        pthread_mutex_lock(&runtime_init_mu);
@@ -134,14 +110,3 @@ _cgo_try_pthread_create(pthread_t* thread, const pthread_attr_t* attr, void* (*p
        }
        return EAGAIN;
 }
-
-static void
-pthread_key_destructor(void* g) {
-       if (x_crosscall2_ptr != NULL) {
-               // fn == NULL means dropm.
-               // We restore g by using the stored g, before dropm in runtime.cgocallback,
-               // since the g stored in the TLS by Go might be cleared in some platforms,
-               // before this destructor invoked.
-               x_crosscall2_ptr(NULL, g, 0, 0);
-       }
-}