From 66d769e1b2c4e15174e82b292f2595842f081fdb Mon Sep 17 00:00:00 2001
From: Ivan Zhakov <ivan@apache.org>
Date: Sun, 26 May 2024 19:40:59 +0000
Subject: [PATCH] win32: Use SRW Lock instead of CRITICAL_SECTION: - The are
 the same in terms of performance. - The SRW Lock can be statically
 initialized and does not need to be freed.

* include/arch/win32/apr_arch_threadproc.h
  (apr_threadproc_init): Remove declaration.

* misc/win32/start.c
  (): Do not include apr_arch_threadproc.h.
  (apr_initialize): Do not call apr_threadproc_init() because it's not longer
   exists.

* threadproc/win32/proc.c
  (proc_lock): Change type to SRW_LOCK and initialize it to SRWLOCK_INIT.
  (threadproc_global_cleanup, apr_threadproc_init): Remove.
  (apr_proc_create): Use AcquireSRWLockExclusive()/ReleaseSRWLockExclusive()
   instead of EnterCriticalSection()/LeaveCriticalSection().

git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@1917990 13f79535-47bb-0310-9956-ffa450edef68
---
 include/arch/win32/apr_arch_threadproc.h |  2 --
 misc/win32/start.c                       |  3 --
 threadproc/win32/proc.c                  | 38 +++++-------------------
 3 files changed, 8 insertions(+), 35 deletions(-)

diff --git a/include/arch/win32/apr_arch_threadproc.h b/include/arch/win32/apr_arch_threadproc.h
index 23b0172ec69..6bcd90e7fa3 100644
--- a/include/arch/win32/apr_arch_threadproc.h
+++ b/include/arch/win32/apr_arch_threadproc.h
@@ -68,7 +68,5 @@ struct apr_thread_once_t {
     INIT_ONCE once;
 };
 
-extern apr_status_t apr_threadproc_init(apr_pool_t *pool);
-
 #endif  /* ! THREAD_PROC_H */
 
diff --git a/misc/win32/start.c b/misc/win32/start.c
index 2524707c25b..bcb1ab631b2 100644
--- a/misc/win32/start.c
+++ b/misc/win32/start.c
@@ -23,7 +23,6 @@
 #include "apr_arch_misc.h"       /* for WSAHighByte / WSALowByte */
 #include "wchar.h"
 #include "apr_arch_file_io.h"    /* bring in unicode-ness */
-#include "apr_arch_threadproc.h" /* bring in apr_threadproc_init */
 #include "assert.h"
 
 /* This symbol is _private_, although it must be exported.
@@ -197,8 +196,6 @@ APR_DECLARE(apr_status_t) apr_initialize(void)
 
     apr_signal_init(pool);
 
-    apr_threadproc_init(pool);
-
     return APR_SUCCESS;
 }
 
diff --git a/threadproc/win32/proc.c b/threadproc/win32/proc.c
index 84fe77ed587..3d12f6e3258 100644
--- a/threadproc/win32/proc.c
+++ b/threadproc/win32/proc.c
@@ -465,32 +465,10 @@ APR_DECLARE(apr_status_t) apr_procattr_addrspace_set(apr_procattr_t *attr,
     return APR_SUCCESS;
 }
 
-/* Used only for the NT code path, a critical section is the fastest
- * implementation available.
+/* Used only for the NT code path.  Use Slim RW lock because it does not
+ * require free.
  */
-static CRITICAL_SECTION proc_lock;
-
-static apr_status_t threadproc_global_cleanup(void *ignored)
-{
-    DeleteCriticalSection(&proc_lock);
-    return APR_SUCCESS;
-}
-
-/* Called from apr_initialize, we need a critical section to handle
- * the pipe inheritance on win32.  This will mutex any process create
- * so as we change our inherited pipes, we prevent another process from
- * also inheriting those alternate handles, and prevent the other process
- * from failing to inherit our standard handles.
- */
-apr_status_t apr_threadproc_init(apr_pool_t *pool)
-{
-    InitializeCriticalSection(&proc_lock);
-    /* register the cleanup */
-    apr_pool_cleanup_register(pool, &proc_lock,
-                                threadproc_global_cleanup,
-                                apr_pool_cleanup_null);
-    return APR_SUCCESS;
-}
+static SRWLOCK proc_lock = SRWLOCK_INIT;
 
 APR_DECLARE(apr_status_t) apr_proc_create(apr_proc_t *new,
                                           const char *progname,
@@ -794,10 +772,10 @@ APR_DECLARE(apr_status_t) apr_proc_create(apr_proc_t *new,
             si.wShowWindow = SW_HIDE;
         }
 
-        /* LOCK CRITICAL SECTION
+        /* LOCK SRW Lock
          * before we begin to manipulate the inherited handles
          */
-        EnterCriticalSection(&proc_lock);
+        AcquireSRWLockExclusive(&proc_lock);
 
         if ((attr->child_in && attr->child_in->filehand)
             || (attr->child_out && attr->child_out->filehand)
@@ -862,7 +840,7 @@ APR_DECLARE(apr_status_t) apr_proc_create(apr_proc_t *new,
                 rv = apr_get_os_error();
                 CloseHandle(attr->user_token);
                 attr->user_token = NULL;
-                LeaveCriticalSection(&proc_lock);
+                ReleaseSRWLockExclusive(&proc_lock);
                 return rv;
             }
             if (!CreateProcessAsUserW(attr->user_token,
@@ -932,10 +910,10 @@ APR_DECLARE(apr_status_t) apr_proc_create(apr_proc_t *new,
             }
         }
 
-        /* RELEASE CRITICAL SECTION
+        /* RELEASE SRW Lock
          * The state of the inherited handles has been restored.
          */
-        LeaveCriticalSection(&proc_lock);
+        ReleaseSRWLockExclusive(&proc_lock);
 
     }