libbinder: add build option for single-threaded RPC
Trusty does not support threading. This adds a build option
to disable mutexes and other threading code from RpcState,
RpcSession, and RpcServer.
Bug: 224644083
Test: build Trusty
Change-Id: Iaa78caca1ddee45be7c2def2755598decc0d4d15
diff --git a/libs/binder/FdTrigger.cpp b/libs/binder/FdTrigger.cpp
index 5e22593..d123fd1 100644
--- a/libs/binder/FdTrigger.cpp
+++ b/libs/binder/FdTrigger.cpp
@@ -28,25 +28,45 @@
std::unique_ptr<FdTrigger> FdTrigger::make() {
auto ret = std::make_unique<FdTrigger>();
+#ifndef BINDER_RPC_SINGLE_THREADED
if (!android::base::Pipe(&ret->mRead, &ret->mWrite)) {
ALOGE("Could not create pipe %s", strerror(errno));
return nullptr;
}
+#endif
return ret;
}
void FdTrigger::trigger() {
+#ifdef BINDER_RPC_SINGLE_THREADED
+ mTriggered = true;
+#else
mWrite.reset();
+#endif
}
bool FdTrigger::isTriggered() {
+#ifdef BINDER_RPC_SINGLE_THREADED
+ return mTriggered;
+#else
return mWrite == -1;
+#endif
}
status_t FdTrigger::triggerablePoll(base::borrowed_fd fd, int16_t event) {
+#ifdef BINDER_RPC_SINGLE_THREADED
+ if (mTriggered) {
+ return DEAD_OBJECT;
+ }
+#endif
+
LOG_ALWAYS_FATAL_IF(event == 0, "triggerablePoll %d with event 0 is not allowed", fd.get());
- pollfd pfd[]{{.fd = fd.get(), .events = static_cast<int16_t>(event), .revents = 0},
- {.fd = mRead.get(), .events = 0, .revents = 0}};
+ pollfd pfd[]{
+ {.fd = fd.get(), .events = static_cast<int16_t>(event), .revents = 0},
+#ifndef BINDER_RPC_SINGLE_THREADED
+ {.fd = mRead.get(), .events = 0, .revents = 0},
+#endif
+ };
int ret = TEMP_FAILURE_RETRY(poll(pfd, arraysize(pfd), -1));
if (ret < 0) {
return -errno;
@@ -55,6 +75,7 @@
// At least one FD has events. Check them.
+#ifndef BINDER_RPC_SINGLE_THREADED
// Detect explicit trigger(): DEAD_OBJECT
if (pfd[1].revents & POLLHUP) {
return DEAD_OBJECT;
@@ -68,6 +89,7 @@
// pfd[1].revents is 0, hence pfd[0].revents must be set, and only possible values are
// a subset of event | POLLHUP | POLLERR | POLLNVAL.
+#endif
// POLLNVAL: invalid FD number, e.g. not opened.
if (pfd[0].revents & POLLNVAL) {