Disallow shrinking threadpool size once started.
If a larger threadpool is started, and concurrent binder transactions
are cause these threads to actually be started, and then we shrink
the threadpool, these extra threads won't be shut down. So, when we
detect that this race may happen, we abort with an error.
It's best practice to setup a threadpool at process startup time.
Bug: 147699567
Test: TH
Change-Id: I12d2e6e6b1ebf92c2b2abbfccffb011c4248d8ec
diff --git a/libs/binder/ProcessState.cpp b/libs/binder/ProcessState.cpp
index c0f5e31..6627618 100644
--- a/libs/binder/ProcessState.cpp
+++ b/libs/binder/ProcessState.cpp
@@ -324,6 +324,8 @@
}
status_t ProcessState::setThreadPoolMaxThreadCount(size_t maxThreads) {
+ LOG_ALWAYS_FATAL_IF(mThreadPoolStarted && maxThreads < mMaxThreads,
+ "Binder threadpool cannot be shrunk after starting");
status_t result = NO_ERROR;
if (ioctl(mDriverFD, BINDER_SET_MAX_THREADS, &maxThreads) != -1) {
mMaxThreads = maxThreads;
