Make ThreadLocalBuffer a class rather than a macro.
Bug: 19995392
Change-Id: I497c512648fbe66257da3fb3bcd5c9911f983705
diff --git a/libc/private/ThreadLocalBuffer.h b/libc/private/ThreadLocalBuffer.h
index cc47317..5e43665 100644
--- a/libc/private/ThreadLocalBuffer.h
+++ b/libc/private/ThreadLocalBuffer.h
@@ -32,32 +32,30 @@
#include <malloc.h>
#include <pthread.h>
-// libstdc++ currently contains __cxa_guard_acquire and __cxa_guard_release,
-// so we make do with macros instead of a C++ class.
-// TODO: move __cxa_guard_acquire and __cxa_guard_release into libc.
+// TODO: use __thread instead?
-// We used to use pthread_once to initialize the keys, but life is more predictable
-// if we allocate them all up front when the C library starts up, via __constructor__.
-#define BIONIC_PTHREAD_KEY_WITH_CONSTRUCTOR(key_name, key_destructor) \
- static pthread_key_t key_name; \
- __attribute__((constructor)) static void __bionic_tls_ ## key_name ## _key_init() { \
- pthread_key_create(&key_name, key_destructor); \
+template <typename T, size_t Size = sizeof(T)>
+class ThreadLocalBuffer {
+ public:
+ ThreadLocalBuffer() {
+ // We used to use pthread_once to initialize the keys, but life is more predictable
+ // if we allocate them all up front when the C library starts up, via __constructor__.
+ pthread_key_create(&key_, free);
}
-#define GLOBAL_INIT_THREAD_LOCAL_BUFFER(name) \
- static void __bionic_tls_ ## name ## _key_destroy(void* buffer) { \
- free(buffer); \
- } \
- BIONIC_PTHREAD_KEY_WITH_CONSTRUCTOR(__bionic_tls_ ## name ## _key, __bionic_tls_ ## name ## _key_destroy)
+ T* get() {
+ T* result = reinterpret_cast<T*>(pthread_getspecific(key_));
+ if (result == nullptr) {
+ result = reinterpret_cast<T*>(calloc(1, Size));
+ pthread_setspecific(key_, result);
+ }
+ return result;
+ }
-// Leaves "name_tls_buffer" and "name_tls_buffer_size" defined and initialized.
-#define LOCAL_INIT_THREAD_LOCAL_BUFFER(type, name, byte_count) \
- type name ## _tls_buffer = \
- reinterpret_cast<type>(pthread_getspecific(__bionic_tls_ ## name ## _key)); \
- if (name ## _tls_buffer == NULL) { \
- name ## _tls_buffer = reinterpret_cast<type>(calloc(1, byte_count)); \
- pthread_setspecific(__bionic_tls_ ## name ## _key, name ## _tls_buffer); \
- } \
- const size_t name ## _tls_buffer_size __attribute__((unused)) = byte_count
+ size_t size() { return Size; }
+
+ private:
+ pthread_key_t key_;
+};
#endif // _BIONIC_THREAD_LOCAL_BUFFER_H_included
diff --git a/libc/private/bionic_tls.h b/libc/private/bionic_tls.h
index 1ab8d4a..414d171 100644
--- a/libc/private/bionic_tls.h
+++ b/libc/private/bionic_tls.h
@@ -72,22 +72,26 @@
/*
* Bionic uses some pthread keys internally. All pthread keys used internally
- * should be created in constructors, except for keys that may be used in or before constructors.
+ * should be created in constructors, except for keys that may be used in or
+ * before constructors.
+ *
* We need to manually maintain the count of pthread keys used internally, but
* pthread_test should fail if we forget.
- * Following are current pthread keys used internally by libc:
- * basename libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
- * dirname libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
+ *
+ * These are the pthread keys currently used internally by libc:
+ *
+ * basename libc (ThreadLocalBuffer)
+ * dirname libc (ThreadLocalBuffer)
* uselocale libc (can be used in constructors)
- * getmntent_mntent libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
- * getmntent_strings libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
- * ptsname libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
- * ttyname libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
- * strerror libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
- * strsignal libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
- * passwd libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
- * group libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
- * _res_key libc (BIONIC_PTHREAD_KEY_WITH_CONSTRUCTOR)
+ * getmntent_mntent libc (ThreadLocalBuffer)
+ * getmntent_strings libc (ThreadLocalBuffer)
+ * ptsname libc (ThreadLocalBuffer)
+ * ttyname libc (ThreadLocalBuffer)
+ * strerror libc (ThreadLocalBuffer)
+ * strsignal libc (ThreadLocalBuffer)
+ * passwd libc (ThreadLocalBuffer)
+ * group libc (ThreadLocalBuffer)
+ * _res_key libc (constructor in BSD code)
*/
#define LIBC_PTHREAD_KEY_RESERVED_COUNT 12