commit 6e9a327504e6aa2488b736fd5592525278a0916f
author Jerry Zhang <zhangjerry@google.com> Mon Mar 19 17:54:39 2018 -0700
committer Jerry Zhang <zhangjerry@google.com> Fri Mar 23 00:11:05 2018 +0000
tree ee25ad86f69268ca0fb52057405c838c0cee4e19
parent 1f70d1cac570550daa67796241f3885dd09f7e2e

adb: Retry io in case of interrupt

io_submit sleeps waiting for the gadget
to be enabled. Currently if that sleep
is interrupted it will shut down adb,
causing it to have to start back up again.

Rather than return EINTR if interrupted,
io_submit actually completes and the EINTR
is found later when looking through events.
Since an io that is interrupted will be
small anyway, add a loop to retry small ios.

Also upgrade aio logs in accordance with
their importance.

Fixes: 75981904
Test: adb works, logs show successful interrupt handling
Change-Id: I35973fce130ee849ce59fef80d15b65afb816ba4

adb/daemon/usb.cpp

diff --git a/adb/daemon/usb.cpp b/adb/daemon/usb.cpp
index c2e9337..7869324 100644
--- a/adb/daemon/usb.cpp
+++ b/adb/daemon/usb.cpp
@@ -437,23 +437,29 @@
         num_bufs += 1;
     }
 
-    if (io_submit(aiob->ctx, num_bufs, aiob->iocbs.data()) < num_bufs) {
-        D("[ aio: got error submitting %s (%d) ]", read ? "read" : "write", errno);
-        return -1;
-    }
-    if (TEMP_FAILURE_RETRY(
-            io_getevents(aiob->ctx, num_bufs, num_bufs, aiob->events.data(), nullptr)) < num_bufs) {
-        D("[ aio: got error waiting %s (%d) ]", read ? "read" : "write", errno);
-        return -1;
-    }
-    for (int i = 0; i < num_bufs; i++) {
-        if (aiob->events[i].res < 0) {
-            errno = aiob->events[i].res;
-            D("[ aio: got error event on %s (%d) ]", read ? "read" : "write", errno);
+    while (true) {
+        if (TEMP_FAILURE_RETRY(io_submit(aiob->ctx, num_bufs, aiob->iocbs.data())) < num_bufs) {
+            PLOG(ERROR) << "aio: got error submitting " << (read ? "read" : "write");
             return -1;
         }
+        if (TEMP_FAILURE_RETRY(io_getevents(aiob->ctx, num_bufs, num_bufs, aiob->events.data(),
+                                            nullptr)) < num_bufs) {
+            PLOG(ERROR) << "aio: got error waiting " << (read ? "read" : "write");
+            return -1;
+        }
+        if (num_bufs == 1 && aiob->events[0].res == -EINTR) {
+            continue;
+        }
+        for (int i = 0; i < num_bufs; i++) {
+            if (aiob->events[i].res < 0) {
+                errno = -aiob->events[i].res;
+                PLOG(ERROR) << "aio: got error event on " << (read ? "read" : "write")
+                            << " total bufs " << num_bufs;
+                return -1;
+            }
+        }
+        return 0;
     }
-    return 0;
 }
 
 static int usb_ffs_aio_read(usb_handle* h, void* data, int len) {