bpo-25658: Implement PEP 539 for Thread Specific Storage (TSS) API (GH-1362)

See PEP 539 for details.

Highlights of changes:

- Add Thread Specific Storage (TSS) API
- Document the Thread Local Storage (TLS) API as deprecated
- Update code that used TLS API to use TSS API

1 files changed, 8 insertions, 17 deletions

diff --git a/Modules/_tracemalloc.c b/Modules/_tracemalloc.c
index 386f2f1..af2a2fa 100644
--- a/Modules/_tracemalloc.c
+++ b/Modules/_tracemalloc.c
@@ -167,14 +167,7 @@ tracemalloc_error(const char *format, ...)
 #if defined(TRACE_RAW_MALLOC)
 #define REENTRANT_THREADLOCAL
 
-/* If your OS does not provide native thread local storage, you can implement
-   it manually using a lock. Functions of thread.c cannot be used because
-   they use PyMem_RawMalloc() which leads to a reentrant call. */
-#if !(defined(_POSIX_THREADS) || defined(NT_THREADS))
-#  error "need native thread local storage (TLS)"
-#endif
-
-static int tracemalloc_reentrant_key = -1;
+static Py_tss_t tracemalloc_reentrant_key = Py_tss_NEEDS_INIT;
 
 /* Any non-NULL pointer can be used */
 #define REENTRANT Py_True
@@ -184,8 +177,8 @@ get_reentrant(void)
 {
     void *ptr;
 
-    assert(tracemalloc_reentrant_key != -1);
-    ptr = PyThread_get_key_value(tracemalloc_reentrant_key);
+    assert(PyThread_tss_is_created(&tracemalloc_reentrant_key));
+    ptr = PyThread_tss_get(&tracemalloc_reentrant_key);
     if (ptr != NULL) {
         assert(ptr == REENTRANT);
         return 1;
@@ -198,15 +191,15 @@ static void
 set_reentrant(int reentrant)
 {
     assert(reentrant == 0 || reentrant == 1);
-    assert(tracemalloc_reentrant_key != -1);
+    assert(PyThread_tss_is_created(&tracemalloc_reentrant_key));
 
     if (reentrant) {
         assert(!get_reentrant());
-        PyThread_set_key_value(tracemalloc_reentrant_key, REENTRANT);
+        PyThread_tss_set(&tracemalloc_reentrant_key, REENTRANT);
     }
     else {
         assert(get_reentrant());
-        PyThread_set_key_value(tracemalloc_reentrant_key, NULL);
+        PyThread_tss_set(&tracemalloc_reentrant_key, NULL);
     }
 }
 
@@ -975,8 +968,7 @@ tracemalloc_init(void)
     PyMem_GetAllocator(PYMEM_DOMAIN_RAW, &allocators.raw);
 
 #ifdef REENTRANT_THREADLOCAL
-    tracemalloc_reentrant_key = PyThread_create_key();
-    if (tracemalloc_reentrant_key == -1) {
+    if (PyThread_tss_create(&tracemalloc_reentrant_key) != 0) {
 #ifdef MS_WINDOWS
         PyErr_SetFromWindowsErr(0);
 #else
@@ -1061,8 +1053,7 @@ tracemalloc_deinit(void)
 #endif
 
 #ifdef REENTRANT_THREADLOCAL
-    PyThread_delete_key(tracemalloc_reentrant_key);
-    tracemalloc_reentrant_key = -1;
+    PyThread_tss_delete(&tracemalloc_reentrant_key);
 #endif
 
     Py_XDECREF(unknown_filename);