man: update explanation for sigmask passing

Signed-off-by: Jens Axboe <[email protected]>
axboe · Jan 12, 2024 · 0de6020 · 0de6020
1 parent cc7dac4
commit 0de6020
Show file tree

Hide file tree

Showing 2 changed files with 30 additions and 6 deletions.
diff --git a/man/io_uring_submit_and_wait_timeout.3 b/man/io_uring_submit_and_wait_timeout.3
@@ -28,11 +28,23 @@ completion events, or until the timeout
 .I ts
 expires. The completion events are stored in the
 .I cqe_ptr
-array. The
+array.
+.PP
+The
 .I sigmask
-specifies the set of signals to block. The prevailing signal mask is restored
-before returning.
+specifies the set of signals to block. If set, it is equivalent to atomically
+executing the following calls:
+.PP
+.in +4n
+.EX
+sigset_t origmask;
 
+pthread_sigmask(SIG_SETMASK, &sigmask, &origmask);
+ret = io_uring_submit_and_wait_timeout(ring, cqe, wait_nr, ts, NULL);
+pthread_sigmask(SIG_SETMASK, &origmask, NULL);
+.EE
+.in
+.PP
 After the caller retrieves a submission queue entry (SQE) with
 .BR io_uring_get_sqe (3)
 and prepares the SQE, it can be submitted with

diff --git a/man/io_uring_wait_cqes.3 b/man/io_uring_wait_cqes.3
@@ -25,11 +25,23 @@ IO completions from the queue belonging to the
 .I ring
 param, waiting for them if necessary or until the timeout
 .I ts
-expires. The
+expires.
+.PP
+The
 .I sigmask
-specifies the set of signals to block. The prevailing signal mask is restored
-before returning.
+specifies the set of signals to block. If set, it is equivalent to atomically
+executing the following calls:
+.PP
+.in +4n
+.EX
+sigset_t origmask;
 
+pthread_sigmask(SIG_SETMASK, &sigmask, &origmask);
+ret = io_uring_wait_cqes(ring, cqe, wait_nr, ts, NULL);
+pthread_sigmask(SIG_SETMASK, &origmask, NULL);
+.EE
+.in
+.PP
 The
 .I cqe_ptr
 param is filled in on success with the first CQE. Callers of this function