Changeset f3ed2af

Timestamp:

Jul 27, 2020, 1:43:16 PM (4 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

3a1cf0d

Parents:

a86b1b85

Message:

Fixed example with O_DIRECT to use proper alignment

File:

• examples/io_uring.c (modified) (6 diffs)

examples/io_uring.c

@@ +1 @@
+#ifndef _GNU_SOURCE
 #define _GNU_SOURCE
+#endif
 
 #include <fcntl.h>
@@ -8 +10 @@
 
 struct io_uring ring;
+
+__attribute__((aligned(1024))) char data[1024];
 
 int main(int argc,  char * argv[]) {
@@ -22 +26 @@
 
       /* prep the array */
-      char data[512];
-      struct iovec iov = { data, 512 };
+      struct iovec iov = { data, 1024 };
 
       /* init liburing */
@@ -35 +38 @@
       sqe = io_uring_get_sqe(&ring);
       io_uring_prep_readv(sqe, fd, &iov, 1, 0);
+      // io_uring_prep_read(sqe, fd, data, 1024, 0);
 
-      sqe->user_data = data;
+      sqe->user_data = (uint64_t)(uintptr_t)data;
 
       /* tell the kernel we have an sqe ready for consumption */
@@ -46 +50 @@
       /* read and process cqe event */
       if(ret == 0) {
-            char * out = cqe->user_data;
+            char * out = (char *)(uintptr_t)cqe->user_data;
             signed int len = cqe->res;
             io_uring_cqe_seen(&ring, cqe);
@@ -54 +58 @@
             }
             else if( len < 0 ) {
-                  fprintf(stderr, "readv returned error : %s\n", strerror(-len));
+                  fprintf(stderr, "readv/read returned error : %s\n", strerror(-len));
             }
       }