From 1dacdd482894bee9fbc1993cbb525fb800750222 Mon Sep 17 00:00:00 2001 From: Christopher Tate Date: Sun, 8 Nov 2009 14:29:02 -0800 Subject: [PATCH] Reset binder service threads' cgroup/priority after command completion To prevent buggy command implementations from poisoning binder threads' scheduling class & priority for future command execution, we now reset the cgroup and thread priority to foreground/normal when a binder service thread finishes executing the designated command. Change-Id: Ibc0ab2485751453f6dc96fdb4eb877fd02796e3f --- libs/binder/IPCThreadState.cpp | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/libs/binder/IPCThreadState.cpp b/libs/binder/IPCThreadState.cpp index e04b2bfab8584..b2a7db8301b36 100644 --- a/libs/binder/IPCThreadState.cpp +++ b/libs/binder/IPCThreadState.cpp @@ -426,6 +426,21 @@ void IPCThreadState::joinThreadPool(bool isMain) result = executeCommand(cmd); } + // After executing the command, ensure that the thread is returned to the + // default cgroup and priority before rejoining the pool. This is a failsafe + // in case the command implementation failed to properly restore the thread's + // scheduling parameters upon completion. + int my_id; +#ifdef HAVE_GETTID + my_id = gettid(); +#else + my_id = getpid(); +#endif + if (!set_sched_policy(my_id, SP_FOREGROUND)) { + // success; reset the priority as well + setpriority(PRIO_PROCESS, my_id, ANDROID_PRIORITY_NORMAL); + } + // Let this thread exit the thread pool if it is no longer // needed and it is not the main process thread. if(result == TIMED_OUT && !isMain) {