1 files changed, 43 insertions, 0 deletions
diff --git a/src/runtime/cgo/gcc_android_arm.c b/src/runtime/cgo/gcc_android_arm.c
new file mode 100644
index 000000000..07f7e72e3
--- /dev/null
+++ b/src/runtime/cgo/gcc_android_arm.c
@@ -0,0 +1,43 @@
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include <pthread.h>
+#include <signal.h>
+#include <stdio.h>
+#include <sys/limits.h>
+#include "libcgo.h"
+
+#define magic1 (0x23581321U)
+
+// PTHREAD_KEYS_MAX has been added to sys/limits.h at head in bionic:
+// https://android.googlesource.com/platform/bionic/+/master/libc/include/sys/limits.h
+// TODO(crawshaw): remove this definition when a new NDK is released.
+#define PTHREAD_KEYS_MAX 128
+
+// inittls allocates a thread-local storage slot for g.
+//
+// It finds the first available slot using pthread_key_create and uses
+// it as the offset value for runtime.tlsg.
+static void
+inittls(void **tlsg, void **tlsbase)
+{
+	pthread_key_t k;
+	int i, err;
+
+	err = pthread_key_create(&k, nil);
+	if(err != 0) {
+		fatalf("pthread_key_create failed: %d", err);
+	}
+	pthread_setspecific(k, (void*)magic1);
+	for (i=0; i<PTHREAD_KEYS_MAX; i++) {
+		if (*(tlsbase+i) == (void*)magic1) {
+			*tlsg = (void*)(i*sizeof(void *));
+			pthread_setspecific(k, 0);
+			return;
+		}
+	}
+	fatalf("could not find pthread key");
+}
+
+void (*x_cgo_inittls)(void **tlsg, void **tlsbase) = inittls;