Changeset a1026da in mainline

Timestamp:

2017-12-22T22:43:25Z (6 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

1569a9b

Parents:

f04b5b3

git-author:

Jakub Jermar <jakub@…> (2017-12-22 21:47:09)

git-committer:

Jakub Jermar <jakub@…> (2017-12-22 22:43:25)

Message:

Introduce IPC_CALL_AUTO_REPLY call flag

Calls that never make it to userspace due to error are answered by the
kernel and decorated with the newly introduced IPC_CALL_AUTO_REPLY. This
gives the sender a way to reliably figure out that the recipient is
still waiting for the call.

Files:

• abi/include/abi/ipc/ipc.h (modified) (1 diff)
• kernel/generic/src/ipc/sysipc.c (modified) (5 diffs)
• uspace/lib/c/generic/async.c (modified) (1 diff)

abi/include/abi/ipc/ipc.h

@@ -60 +60 @@
 #define IPC_CALL_NOTIF           (1 << 3)
 
+/** The call was automatically answered by the kernel due to error */
+#define IPC_CALL_AUTO_REPLY      (1 << 4)
+
 /**
  * Maximum buffer size allowed for IPC_M_DATA_WRITE and

kernel/generic/src/ipc/sysipc.c

@@ -761 +761 @@
 
         if (!call) {
-                ipc_data_t data = {0};
+                ipc_data_t data = {};
                 data.cap_handle = CAP_NIL;
                 STRUCT_TO_USPACE(calldata, &data);
@@ -767 +767 @@
         }
         
+        call->data.flags = call->flags;
         if (call->flags & IPC_CALL_NOTIF) {
                 /* Set in_phone_hash to the interrupt counter */
                 call->data.phone = (void *) call->priv;
                 
-                call->data.flags = IPC_CALL_NOTIF;
                 call->data.cap_handle = CAP_NIL;
 
@@ -788 +788 @@
                 }
 
-                call->data.flags = IPC_CALL_ANSWERED;
                 call->data.cap_handle = CAP_NIL;
                 
@@ -826 +825 @@
         /*
          * The callee will not receive this call and no one else has a chance to
-         * answer it. Reply with the EPARTY error code.
+         * answer it. Set the IPC_CALL_AUTO_REPLY flag and return the EPARTY
+         * error code.
          */
         ipc_data_t saved_data;
@@ -839 +839 @@
         IPC_SET_RETVAL(call->data, EPARTY);
         (void) answer_preprocess(call, saved ? &saved_data : NULL);
+        call->flags |= IPC_CALL_AUTO_REPLY;
         ipc_answer(&TASK->answerbox, call);
 

uspace/lib/c/generic/async.c

@@ -1496 +1496 @@
 
                 if (call.cap_handle == CAP_NIL) {
-                        if (call.flags == 0) {
-                                /* This neither a notification nor an answer. */
+                        if ((call.flags &
+                            (IPC_CALL_NOTIF | IPC_CALL_ANSWERED)) == 0) {
+                                /* Neither a notification nor an answer. */
                                 handle_expired_timeouts();
                                 continue;