[PATCH] Support APR_APPEND (O_APPEND) with apr_file_write on Windows

[Bill Stoddard]

The only problem with this patch is that it occasionally causes the
WriteFile to block indefinitely and all the other worker threads block on
apr_file_lock waiting for the file lock.   I can send several thousand
requests through the server before it hangs.  I don't see anything obviously
wrong here or in apr_file_lock|unlock. Obviously I will not commit this
until we figure out and fix what is causing the WriteFile block.

I generally see the hang writing to the access log. I did see a hang writing
to the error log at startup once.

Bill

--- readwrite.c 19 Sep 2002 12:20:20 -0000      1.1.1.1
+++ readwrite.c 25 Oct 2002 13:44:53 -0000
@@ -303,15 +303,28 @@
         apr_thread_mutex_unlock(thefile->mutex);
         return rv;
     } else {
-        if (thefile->pOverlapped && !thefile->pipe) {
-            thefile->pOverlapped->Offset     = (DWORD)thefile->filePtr;
-            thefile->pOverlapped->OffsetHigh = (DWORD)(thefile->filePtr >>
32);
-        }
-        else if (!thefile->pipe && thefile->append) {
+        if (thefile->append && !thefile->pipe) {
+            int rc;
+            rc = apr_file_lock(thefile, APR_FLOCK_EXCLUSIVE);
+            if (rc != APR_SUCCESS) {
+                rc = APR_SUCCESS;
+            }
             SetFilePointer(thefile->filehand, 0, NULL, FILE_END);
+            rv = WriteFile(thefile->filehand, buf, *nbytes, &bwrote, NULL);
+            rc = apr_file_unlock(thefile);
+            if (rc != APR_SUCCESS) {
+                rc = APR_SUCCESS;
+            }
+        }
+        else {
+            if (thefile->pOverlapped && !thefile->pipe) {
+                thefile->pOverlapped->Offset     = (DWORD)thefile->filePtr;
+                thefile->pOverlapped->OffsetHigh = (DWORD)(thefile->filePtr
>> 32);
+            }
+            rv = WriteFile(thefile->filehand, buf, *nbytes, &bwrote,
+                           thefile->pOverlapped);
         }
-        if (WriteFile(thefile->filehand, buf, *nbytes, &bwrote,
-                      thefile->pOverlapped)) {
+        if (rv) {
             *nbytes = bwrote;
             rv = APR_SUCCESS;
         }
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