lshal: Add fqname to debug error messages

If any error comes up when invoking debug, write fqname and the error
message to the error output stream.

Test: manual. Add addPostCommandTask to a HAL that keeps writing to the
fd after debug() finishes. lshal debug terminates with fqname and
the error message `timeout reading from pipe, output may be truncated.`

Fixes: 169247570

Change-Id: Idf8944e3cde08dc86766b144c4a3037cbcf6b3dc

3 files changed, 31 insertions, 13 deletions

diff --git a/cmds/lshal/Lshal.cpp b/cmds/lshal/Lshal.cpp
index 2c3efe524e..99cb93afe2 100644
--- a/cmds/lshal/Lshal.cpp
+++ b/cmds/lshal/Lshal.cpp
@@ -141,7 +141,7 @@ Status Lshal::emitDebugInfo(
         }
     }
 
-    PipeRelay relay(out);
+    PipeRelay relay(out, err, interfaceName, instanceName);
 
     if (relay.initCheck() != OK) {
         std::string msg = "PipeRelay::initCheck() FAILED w/ " + std::to_string(relay.initCheck());
diff --git a/cmds/lshal/PipeRelay.cpp b/cmds/lshal/PipeRelay.cpp
index 820679fbe2..4e9763635b 100644
--- a/cmds/lshal/PipeRelay.cpp
+++ b/cmds/lshal/PipeRelay.cpp
@@ -23,7 +23,6 @@
 
 #include <atomic>
 
-#include <android-base/logging.h>
 #include <utils/Thread.h>
 
 namespace android {
@@ -31,8 +30,15 @@ namespace lshal {
 
 static constexpr struct timeval READ_TIMEOUT { .tv_sec = 1, .tv_usec = 0 };
 
+static std::string getThreadName(std::string interfaceName, const std::string &instanceName) {
+    auto dot = interfaceName.rfind(".");
+    if (dot != std::string::npos) interfaceName = interfaceName.substr(dot + 1);
+    return "RelayThread_" + interfaceName + "_" + instanceName;
+}
+
 struct PipeRelay::RelayThread : public Thread {
-    explicit RelayThread(int fd, std::ostream &os);
+    explicit RelayThread(int fd, std::ostream &os, const NullableOStream<std::ostream> &err,
+                         const std::string &fqName);
 
     bool threadLoop() override;
     void setFinished();
@@ -40,6 +46,7 @@ struct PipeRelay::RelayThread : public Thread {
 private:
     int mFd;
     std::ostream &mOutStream;
+    NullableOStream<std::ostream> mErrStream;
 
     // 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
@@ -47,13 +54,17 @@ private:
     // read() are executed until data are drained.
     std::atomic_bool mFinished;
 
+    std::string mFqName;
+
     DISALLOW_COPY_AND_ASSIGN(RelayThread);
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 
-PipeRelay::RelayThread::RelayThread(int fd, std::ostream &os)
-      : mFd(fd), mOutStream(os), mFinished(false) {}
+PipeRelay::RelayThread::RelayThread(int fd, std::ostream &os,
+                                    const NullableOStream<std::ostream> &err,
+                                    const std::string &fqName)
+      : mFd(fd), mOutStream(os), mErrStream(err), mFinished(false), mFqName(fqName) {}
 
 bool PipeRelay::RelayThread::threadLoop() {
     char buffer[1024];
@@ -66,13 +77,14 @@ bool PipeRelay::RelayThread::threadLoop() {
 
     int res = TEMP_FAILURE_RETRY(select(mFd + 1, &set, nullptr, nullptr, &timeout));
     if (res < 0) {
-        PLOG(INFO) << "select() failed";
+        mErrStream << "debug " << mFqName << ": select() failed";
         return false;
     }
 
     if (res == 0 || !FD_ISSET(mFd, &set)) {
         if (mFinished) {
-            LOG(WARNING) << "debug: timeout reading from pipe, output may be truncated.";
+            mErrStream << "debug " << mFqName
+                       << ": timeout reading from pipe, output may be truncated.";
             return false;
         }
         // timeout, but debug() has not returned, so wait for HAL to finish.
@@ -83,7 +95,7 @@ bool PipeRelay::RelayThread::threadLoop() {
     ssize_t n = TEMP_FAILURE_RETRY(read(mFd, buffer, sizeof(buffer)));
 
     if (n < 0) {
-        PLOG(ERROR) << "read() failed";
+        mErrStream << "debug " << mFqName << ": read() failed";
     }
 
     if (n <= 0) {
@@ -101,8 +113,9 @@ void PipeRelay::RelayThread::setFinished() {
 
 ////////////////////////////////////////////////////////////////////////////////
 
-PipeRelay::PipeRelay(std::ostream &os)
-    : mInitCheck(NO_INIT) {
+PipeRelay::PipeRelay(std::ostream &os, const NullableOStream<std::ostream> &err,
+                     const std::string &interfaceName, const std::string &instanceName)
+      : mInitCheck(NO_INIT) {
     int res = pipe(mFds);
 
     if (res < 0) {
@@ -110,8 +123,8 @@ PipeRelay::PipeRelay(std::ostream &os)
         return;
     }
 
-    mThread = new RelayThread(mFds[0], os);
-    mInitCheck = mThread->run("RelayThread");
+    mThread = new RelayThread(mFds[0], os, err, interfaceName + "/" + instanceName);
+    mInitCheck = mThread->run(getThreadName(interfaceName, instanceName).c_str());
 }
 
 void PipeRelay::CloseFd(int *fd) {
diff --git a/cmds/lshal/PipeRelay.h b/cmds/lshal/PipeRelay.h
index 8350160419..bd994b48b8 100644
--- a/cmds/lshal/PipeRelay.h
+++ b/cmds/lshal/PipeRelay.h
@@ -21,6 +21,8 @@
 #include <utils/Errors.h>
 #include <utils/RefBase.h>
 
+#include "NullableOStream.h"
+
 namespace android {
 namespace lshal {
 
@@ -28,7 +30,10 @@ namespace lshal {
  * written to the "write"-end of the pair to the specified output stream "os".
  */
 struct PipeRelay {
-    explicit PipeRelay(std::ostream &os);
+    explicit PipeRelay(std::ostream& os,
+                       const NullableOStream<std::ostream>& err,
+                       const std::string& interfaceName,
+                       const std::string& instanceName);
     ~PipeRelay();
 
     status_t initCheck() const;