Merge changes from topic "lshal_stuck"
* changes:
lshal: Allow read to timeout in debug()
Revert "lshal: close fd before joining thread"
diff --git a/cmds/lshal/PipeRelay.cpp b/cmds/lshal/PipeRelay.cpp
index 3a17e03..820679f 100644
--- a/cmds/lshal/PipeRelay.cpp
+++ b/cmds/lshal/PipeRelay.cpp
@@ -16,33 +16,75 @@
#include "PipeRelay.h"
+#include <sys/select.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <atomic>
+
+#include <android-base/logging.h>
#include <utils/Thread.h>
namespace android {
namespace lshal {
+static constexpr struct timeval READ_TIMEOUT { .tv_sec = 1, .tv_usec = 0 };
+
struct PipeRelay::RelayThread : public Thread {
explicit RelayThread(int fd, std::ostream &os);
bool threadLoop() override;
+ void setFinished();
private:
int mFd;
std::ostream &mOutStream;
+ // If we were to use requestExit() and exitPending() instead, threadLoop()
+ // may not run at all by the time ~PipeRelay is called (i.e. debug() has
+ // returned from HAL). By using our own flag, we ensure that select() and
+ // read() are executed until data are drained.
+ std::atomic_bool mFinished;
+
DISALLOW_COPY_AND_ASSIGN(RelayThread);
};
////////////////////////////////////////////////////////////////////////////////
PipeRelay::RelayThread::RelayThread(int fd, std::ostream &os)
- : mFd(fd),
- mOutStream(os) {
-}
+ : mFd(fd), mOutStream(os), mFinished(false) {}
bool PipeRelay::RelayThread::threadLoop() {
char buffer[1024];
- ssize_t n = read(mFd, buffer, sizeof(buffer));
+
+ fd_set set;
+ FD_ZERO(&set);
+ FD_SET(mFd, &set);
+
+ struct timeval timeout = READ_TIMEOUT;
+
+ int res = TEMP_FAILURE_RETRY(select(mFd + 1, &set, nullptr, nullptr, &timeout));
+ if (res < 0) {
+ PLOG(INFO) << "select() failed";
+ return false;
+ }
+
+ if (res == 0 || !FD_ISSET(mFd, &set)) {
+ if (mFinished) {
+ LOG(WARNING) << "debug: timeout reading from pipe, output may be truncated.";
+ return false;
+ }
+ // timeout, but debug() has not returned, so wait for HAL to finish.
+ return true;
+ }
+
+ // FD_ISSET(mFd, &set) == true. Data available, start reading
+ ssize_t n = TEMP_FAILURE_RETRY(read(mFd, buffer, sizeof(buffer)));
+
+ if (n < 0) {
+ PLOG(ERROR) << "read() failed";
+ }
if (n <= 0) {
return false;
@@ -53,6 +95,10 @@
return true;
}
+void PipeRelay::RelayThread::setFinished() {
+ mFinished = true;
+}
+
////////////////////////////////////////////////////////////////////////////////
PipeRelay::PipeRelay(std::ostream &os)
@@ -77,12 +123,14 @@
PipeRelay::~PipeRelay() {
CloseFd(&mFds[1]);
- CloseFd(&mFds[0]);
if (mThread != nullptr) {
+ mThread->setFinished();
mThread->join();
mThread.clear();
}
+
+ CloseFd(&mFds[0]);
}
status_t PipeRelay::initCheck() const {