runtime/cgo: create C pthreads in detached state

Rather than explicitly calling pthread_detach.

Fixes #68850

Change-Id: I7b4042283f9feb5383bffd40fae6db6d23217f97
Reviewed-on: https://go-review.googlesource.com/c/go/+/605257
Commit-Queue: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>

src/runtime/cgo/gcc_darwin_amd64.c

@@ -34,6 +34,7 @@ _cgo_sys_thread_start(ThreadStart *ts)
 	size = pthread_get_stacksize_np(pthread_self());
 	pthread_attr_init(&attr);
 	pthread_attr_setstacksize(&attr, size);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
 	ts->g->stackhi = size;
 	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

src/runtime/cgo/gcc_darwin_arm64.c

@@ -39,6 +39,7 @@ _cgo_sys_thread_start(ThreadStart *ts)
 	size = pthread_get_stacksize_np(pthread_self());
 	pthread_attr_init(&attr);
 	pthread_attr_setstacksize(&attr, size);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
 	ts->g->stackhi = size;
 	err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);

src/runtime/cgo/gcc_dragonfly_amd64.c

@@ -33,6 +33,7 @@ _cgo_sys_thread_start(ThreadStart *ts)
 	pthread_sigmask(SIG_SETMASK, &ign, &oset);
 
 	pthread_attr_init(&attr);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 	pthread_attr_getstacksize(&attr, &size);
 
 	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.

src/runtime/cgo/gcc_freebsd.c

@@ -45,6 +45,7 @@ _cgo_sys_thread_start(ThreadStart *ts)
 	pthread_sigmask(SIG_SETMASK, &ign, &oset);
 
 	pthread_attr_init(&attr);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 	pthread_attr_getstacksize(&attr, &size);
 	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
 	ts->g->stackhi = size;

src/runtime/cgo/gcc_freebsd_amd64.c

@@ -43,6 +43,7 @@ _cgo_sys_thread_start(ThreadStart *ts)
 	pthread_sigmask(SIG_SETMASK, &ign, &oset);
 
 	pthread_attr_init(&attr);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 	pthread_attr_getstacksize(&attr, &size);
 	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
 	ts->g->stackhi = size;

src/runtime/cgo/gcc_libinit.c

@@ -37,8 +37,12 @@ static void (*cgo_context_function)(struct context_arg*);
 
 void
 x_cgo_sys_thread_create(void* (*func)(void*), void* arg) {
+	pthread_attr_t attr;
 	pthread_t p;
-	int err = _cgo_try_pthread_create(&p, NULL, func, arg);
+
+	pthread_attr_init(&attr);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+	int err = _cgo_try_pthread_create(&p, &attr, func, arg);
 	if (err != 0) {
 		fprintf(stderr, "pthread_create failed: %s", strerror(err));
 		abort();
@@ -153,7 +157,6 @@ _cgo_try_pthread_create(pthread_t* thread, const pthread_attr_t* attr, void* (*p
 	for (tries = 0; tries < 20; tries++) {
 		err = pthread_create(thread, attr, pfn, arg);
 		if (err == 0) {
-			pthread_detach(*thread);
 			return 0;
 		}
 		if (err != EAGAIN) {

src/runtime/cgo/gcc_linux.c

@@ -40,6 +40,7 @@ _cgo_sys_thread_start(ThreadStart *ts)
 	pthread_sigmask(SIG_SETMASK, &ign, &oset);
 
 	pthread_attr_init(&attr);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 	pthread_attr_getstacksize(&attr, &size);
 	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
 	ts->g->stackhi = size;

src/runtime/cgo/gcc_linux_amd64.c

@@ -63,6 +63,7 @@ _cgo_sys_thread_start(ThreadStart *ts)
 	pthread_sigmask(SIG_SETMASK, &ign, &oset);
 
 	pthread_attr_init(&attr);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 	pthread_attr_getstacksize(&attr, &size);
 	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
 	ts->g->stackhi = size;

src/runtime/cgo/gcc_linux_arm64.c

@@ -28,6 +28,7 @@ _cgo_sys_thread_start(ThreadStart *ts)
 	pthread_sigmask(SIG_SETMASK, &ign, &oset);
 
 	pthread_attr_init(&attr);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 	pthread_attr_getstacksize(&attr, &size);
 	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
 	ts->g->stackhi = size;

src/runtime/cgo/gcc_linux_s390x.c

@@ -33,6 +33,7 @@ _cgo_sys_thread_start(ThreadStart *ts)
 	pthread_sigmask(SIG_SETMASK, &ign, &oset);
 
 	pthread_attr_init(&attr);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 	pthread_attr_getstacksize(&attr, &size);
 	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
 	ts->g->stackhi = size;

src/runtime/cgo/gcc_netbsd.c

@@ -35,6 +35,7 @@ _cgo_sys_thread_start(ThreadStart *ts)
 	pthread_sigmask(SIG_SETMASK, &ign, &oset);
 
 	pthread_attr_init(&attr);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 	pthread_attr_getstacksize(&attr, &size);
 	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
 	ts->g->stackhi = size;

src/runtime/cgo/gcc_openbsd.c

@@ -34,6 +34,7 @@ _cgo_sys_thread_start(ThreadStart *ts)
 	pthread_sigmask(SIG_SETMASK, &ign, &oset);
 
 	pthread_attr_init(&attr);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 	pthread_attr_getstacksize(&attr, &size);
 
 	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.

src/runtime/cgo/gcc_ppc64x.c

@@ -35,6 +35,7 @@ _cgo_sys_thread_start(ThreadStart *ts)
 	pthread_sigmask(SIG_SETMASK, &ign, &oset);
 
 	pthread_attr_init(&attr);
+	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 	pthread_attr_getstacksize(&attr, &size);
 	// Leave stacklo=0 and set stackhi=size; mstart will do the rest.
 	ts->g->stackhi = size;