From 4a2891d8c8f09a64ea9e1479518b0cc969bd5969 Mon Sep 17 00:00:00 2001
From: Yabin Cui <yabinc@google.com>
Date: Wed, 4 Mar 2015 16:53:23 -0800
Subject: [PATCH] Better control of pthread keys used in bionic.

Change-Id: I1e1bc77c0e7879baead6c3417282ce549a1153b5
---
 libc/bionic/locale.cpp           |  6 ++----
 libc/dns/resolv/res_state.c      | 11 +++--------
 libc/private/ThreadLocalBuffer.h | 10 ++++++----
 libc/private/bionic_tls.h        |  4 ++--
 4 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/libc/bionic/locale.cpp b/libc/bionic/locale.cpp
index 90aa7b8aa..e5a170ff7 100644
--- a/libc/bionic/locale.cpp
+++ b/libc/bionic/locale.cpp
@@ -36,6 +36,7 @@
 #include <wchar.h>
 
 #include "private/bionic_macros.h"
+#include "private/ThreadLocalBuffer.h"
 
 // We currently support a single locale, the "C" locale (also known as "POSIX").
 
@@ -62,10 +63,7 @@ static pthread_once_t g_locale_once = PTHREAD_ONCE_INIT;
 static lconv g_locale;
 
 // We don't use pthread_once for this so that we know when the resource (a TLS slot) will be taken.
-static pthread_key_t g_uselocale_key;
-__attribute__((constructor)) static void __bionic_tls_uselocale_key_init() {
-  pthread_key_create(&g_uselocale_key, NULL);
-}
+BIONIC_PTHREAD_KEY_WITH_CONSTRUCTOR(g_uselocale_key, NULL);
 
 static void __locale_init() {
   g_locale.decimal_point = const_cast<char*>(".");
diff --git a/libc/dns/resolv/res_state.c b/libc/dns/resolv/res_state.c
index 7533d1957..459f07394 100644
--- a/libc/dns/resolv/res_state.c
+++ b/libc/dns/resolv/res_state.c
@@ -39,6 +39,8 @@
 #define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
 #include <sys/_system_properties.h>
 
+#include "private/ThreadLocalBuffer.h"
+
 /* Set to 1 to enable debug traces */
 #define DEBUG 0
 
@@ -50,8 +52,6 @@
 #  define D(...)  do{}while(0)
 #endif
 
-static pthread_key_t   _res_key;
-
 typedef struct {
     int                  _h_errno;
     // TODO: Have one __res_state per network so we don't have to repopulate frequently.
@@ -105,12 +105,7 @@ _res_thread_free( void*  _rt )
     free(rt);
 }
 
-__attribute__((constructor))
-static void
-_res_init_key( void )
-{
-    pthread_key_create( &_res_key, _res_thread_free );
-}
+BIONIC_PTHREAD_KEY_WITH_CONSTRUCTOR(_res_key, _res_thread_free);
 
 static _res_thread*
 _res_thread_get(void)
diff --git a/libc/private/ThreadLocalBuffer.h b/libc/private/ThreadLocalBuffer.h
index e5bd28c37..cc4731703 100644
--- a/libc/private/ThreadLocalBuffer.h
+++ b/libc/private/ThreadLocalBuffer.h
@@ -38,15 +38,17 @@
 
 // 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); \
+  }
 
 #define GLOBAL_INIT_THREAD_LOCAL_BUFFER(name) \
-  static pthread_key_t __bionic_tls_ ## name ## _key; \
   static void __bionic_tls_ ## name ## _key_destroy(void* buffer) { \
     free(buffer); \
   } \
-  __attribute__((constructor)) static void __bionic_tls_ ## name ## _key_init() { \
-    pthread_key_create(&__bionic_tls_ ## name ## _key, __bionic_tls_ ## name ## _key_destroy); \
-  }
+  BIONIC_PTHREAD_KEY_WITH_CONSTRUCTOR(__bionic_tls_ ## name ## _key, __bionic_tls_ ## name ## _key_destroy)
 
 // Leaves "name_tls_buffer" and "name_tls_buffer_size" defined and initialized.
 #define LOCAL_INIT_THREAD_LOCAL_BUFFER(type, name, byte_count) \
diff --git a/libc/private/bionic_tls.h b/libc/private/bionic_tls.h
index 04f5fd256..724f8965d 100644
--- a/libc/private/bionic_tls.h
+++ b/libc/private/bionic_tls.h
@@ -78,7 +78,7 @@ enum {
  * Following are current pthread keys used internally by libc:
  *  basename               libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
  *  dirname                libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
- *  uselocale              libc
+ *  uselocale              libc (BIONIC_PTHREAD_KEY_WITH_CONSTRUCTOR)
  *  getmntent_mntent       libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
  *  getmntent_strings      libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
  *  ptsname                libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
@@ -87,7 +87,7 @@ enum {
  *  strsignal              libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
  *  passwd                 libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
  *  group                  libc (GLOBAL_INIT_THREAD_LOCAL_BUFFER)
- *  _res_key               libc
+ *  _res_key               libc (BIONIC_PTHREAD_KEY_WITH_CONSTRUCTOR)
  */
 
 #define LIBC_PTHREAD_KEY_RESERVED_COUNT 12