wal.diff

diff --git a/src/wal.c b/src/wal.c
index fdc4ac39b..a554c86b8 100644
--- a/src/wal.c
+++ b/src/wal.c
@@ -3597,6 +3597,13 @@ static int walRewriteChecksums(Wal *pWal, u32 iLast){
   return rc;
 }
 
+typedef struct magic_async_job {
+  int pgno;
+  sqlite3_int64 offset;
+} magic_async_job;
+
+static magic_async_job magic_job = {0, 0};
+
 /* 
 ** Write a set of frames to the log. The caller must hold the write-lock
 ** on the log file (obtained using sqlite3WalBeginWriteTransaction()).
@@ -3700,6 +3707,8 @@ int sqlite3WalFrames(
   iOffset = walFrameOffset(iFrame+1, szPage);
   szFrame = szPage + WAL_FRAME_HDRSIZE;
 
+  int return_busy = 0;
+ if (magic_job.pgno == 0 && magic_job.offset == 0) {
   /* Write all frames into the log file exactly once */
   for(p=pList; p; p=p->pDirty){
     int nDbSize;   /* 0 normally.  Positive == commit flag */
@@ -3729,12 +3738,31 @@ int sqlite3WalFrames(
     iFrame++;
     assert( iOffset==walFrameOffset(iFrame, szPage) );
     nDbSize = (isCommit && p->pDirty==0) ? nTruncate : 0;
+    if (magic_job.pgno == 0 && magic_job.offset == 0) {
+      // sarna: this is where we would enqueue all write operations into io_uring,
+      // and then wait until all of them finished successfully
+      fprintf(stderr, "\trecorded that {%d, %u} is in progress\n", p->pgno, iOffset);
+      magic_job.pgno = p->pgno;
+      magic_job.offset = iOffset;
+      return_busy = 1;
+    }
+    fprintf(stderr, "\t (actually writing <%d, %d>\n", p->pgno, iOffset);
     rc = walWriteOneFrame(&w, p, nDbSize, iOffset);
     if( rc ) return rc;
     pLast = p;
     iOffset += szFrame;
     p->flags |= PGHDR_WAL_APPEND;
   }
+ } else {
+    // sarna: this branch would be called once polling returns that the async i/o operation succeeded
+    fprintf(stderr, "\treturning that {%d, %u} job succeeded asynchronously\n", magic_job.pgno, magic_job.offset);
+    magic_job.pgno = 0;
+    magic_job.offset = 0;
+    rc = SQLITE_OK;
+ }
+  if (return_busy) {
+    return SQLITE_BUSY;
+  }