session: fix race condition in fifo allocation
Under some timing conditions,VCL may receive CONNECTED/ACCEPTED
event before ADD_SEGMENT event.
Timing example:
2 threads call segment_manager_alloc_session_fifos() parallelly
Thread 1 Thread 2
sm read lock |
| |
try to alloc fifo =>failed |
| |
sm read unlock |
| |
sm write lock |
| |
add segment |
| |
sm write unlock |
| sm read lock
| |
| try to alloc fifo=>successful
sm read lock |
| sm read unlock
| |
| emit CONNECTED/ACCEPTED
emit ADD_SEGMENT event
|
sm read unlock
This commit move ADD_SEGMENT notification under the protection
of the write lock in some scenarios.
Type: fix
Signed-off-by: liuyacan <liuyacan@corp.netease.com>
Change-Id: I25d5475c5e6d37cfccefa9506f6030c26ce8ee9b