Added histograms on process singleton create when remote process exists and we cannot notify it

chrome/browser/process_singleton_posix.cc

Index: chrome/browser/process_singleton_posix.cc
diff --git a/chrome/browser/process_singleton_posix.cc b/chrome/browser/process_singleton_posix.cc
index f8786c67e6404c2678b65f8c0b16da815ce02d74..72282f631fdc4d0bfe8e5e8a26f566fb0f321c73 100644
--- a/chrome/browser/process_singleton_posix.cc
+++ b/chrome/browser/process_singleton_posix.cc
@@ -776,6 +776,9 @@ ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcessWithTimeout(
     if (hostname.empty()) {
       // Invalid lockfile.
       UnlinkPath(lock_path_);
+      UMA_HISTOGRAM_ENUMERATION(
+          "Chrome.ProcessSingleton.RemoteProcessInteractionResult",
+          INVALID_LOCK_FILE, MAX_HUNG_REMOTE_PROCESS_ACTION);

[gab, 2017/05/10 15:16:50]

Each UMA macro expands to a fair amount of code. Extract this to a helper method
that takes the enum instead of inlining the macro multiple times for the same
enum.

[Alexey Seren, 2017/05/11 13:42:05]

Acknowledged.

       return PROCESS_NONE;
     }
 
@@ -784,6 +787,9 @@ ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcessWithTimeout(
       // the profile, try to continue; otherwise quit.
       if (DisplayProfileInUseError(lock_path_, hostname, pid)) {
         UnlinkPath(lock_path_);
+        UMA_HISTOGRAM_ENUMERATION(
+            "Chrome.ProcessSingleton.RemoteProcessInteractionResult",
+            PROFILE_UNLOCKED, MAX_HUNG_REMOTE_PROCESS_ACTION);
         return PROCESS_NONE;
       }
       return PROFILE_IN_USE;
@@ -791,6 +797,9 @@ ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcessWithTimeout(
 
     if (!IsChromeProcess(pid)) {
       // Orphaned lockfile (no process with pid, or non-chrome process.)
+      UMA_HISTOGRAM_ENUMERATION(
+          "Chrome.ProcessSingleton.RemoteProcessInteractionResult",
+          ORPHANED_LOCK_FILE, MAX_HUNG_REMOTE_PROCESS_ACTION);

[gab, 2017/05/10 15:16:50]

To be consistent I'd say have the UMA logging always on the line just before
"return PROCESS_NONE;"

[Alexey Seren, 2017/05/11 13:42:05]

Acknowledged.

       UnlinkPath(lock_path_);
       return PROCESS_NONE;
     }
@@ -799,10 +808,18 @@ ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcessWithTimeout(
       // Orphaned lockfile (pid is part of same chrome instance we are, even
       // though we haven't tried to create a lockfile yet).
       UnlinkPath(lock_path_);
+      UMA_HISTOGRAM_ENUMERATION(
+          "Chrome.ProcessSingleton.RemoteProcessInteractionResult",
+          SAME_BROWSER_INSTANCE, MAX_HUNG_REMOTE_PROCESS_ACTION);
       return PROCESS_NONE;
     }
 
     if (retries == retry_attempts) {
+      if (kill_unresponsive) {
+        UMA_HISTOGRAM_ENUMERATION(
+            "Chrome.ProcessSingleton.RemoteHungProcessTerminateReason",
+            NOTIFY_ATTEMPTS_EXCEEDED, MAX_REMOTE_HUNG_PROCESS_TERMINATE_REASON);

[gab, 2017/05/10 15:16:50]

Same here, instead of if (kill_unresponsive) {}, move this to right before
PROCESS_NONE (below as well)

[Alexey Seren, 2017/05/11 13:42:05]

Acknowledged.

+      }
       // Retries failed.  Kill the unresponsive chrome process and continue.
       if (!kill_unresponsive || !KillProcessByLockPath())
         return PROFILE_IN_USE;
@@ -838,6 +855,11 @@ ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcessWithTimeout(
 
   // Send the message
   if (!WriteToSocket(socket.fd(), to_send.data(), to_send.length())) {
+    if (kill_unresponsive) {
+      UMA_HISTOGRAM_ENUMERATION(
+          "Chrome.ProcessSingleton.RemoteHungProcessTerminateReason",
+          SOCKET_WRITE_FAILED, MAX_REMOTE_HUNG_PROCESS_TERMINATE_REASON);
+    }
     // Try to kill the other process, because it might have been dead.
     if (!kill_unresponsive || !KillProcessByLockPath())
       return PROFILE_IN_USE;
@@ -854,6 +876,11 @@ ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcessWithTimeout(
 
   // Failed to read ACK, the other process might have been frozen.
   if (len <= 0) {
+    if (kill_unresponsive) {
+      UMA_HISTOGRAM_ENUMERATION(
+          "Chrome.ProcessSingleton.RemoteHungProcessTerminateReason",
+          SOCKET_READ_FAILED, MAX_REMOTE_HUNG_PROCESS_TERMINATE_REASON);
+    }
     if (!kill_unresponsive || !KillProcessByLockPath())
       return PROFILE_IN_USE;
     return PROCESS_NONE;
@@ -862,6 +889,9 @@ ProcessSingleton::NotifyResult ProcessSingleton::NotifyOtherProcessWithTimeout(
   buf[len] = '\0';
   if (strncmp(buf, kShutdownToken, arraysize(kShutdownToken) - 1) == 0) {
     // The other process is shutting down, it's safe to start a new process.
+    UMA_HISTOGRAM_ENUMERATION(
+        "Chrome.ProcessSingleton.RemoteProcessInteractionResult",
+        REMOTE_PROCESS_SHUTTING_DOWN, MAX_HUNG_REMOTE_PROCESS_ACTION);
     return PROCESS_NONE;
   } else if (strncmp(buf, kACKToken, arraysize(kACKToken) - 1) == 0) {
 #if defined(TOOLKIT_VIEWS) && defined(OS_LINUX) && !defined(OS_CHROMEOS)
@@ -1057,18 +1087,33 @@ bool ProcessSingleton::KillProcessByLockPath() {
   ParseLockPath(lock_path_, &hostname, &pid);
 
   if (!hostname.empty() && hostname != net::GetHostName()) {
-    return DisplayProfileInUseError(lock_path_, hostname, pid);
+    bool res = DisplayProfileInUseError(lock_path_, hostname, pid);
+    if (res) {
+      UnlinkPath(lock_path_);

[Alexey Seren, 2017/05/10 04:27:07]

We need to unlink lock file if user selects to unlock profile.

[gab, 2017/05/10 15:16:50]

Is this a bug fix? If so, should go in a separate CL.

[Alexey Seren, 2017/05/11 13:42:05]

Yes it is a bug fix. I will move it to separate CL

+      UMA_HISTOGRAM_ENUMERATION(
+          "Chrome.ProcessSingleton.RemoteProcessInteractionResult",
+          PROFILE_UNLOCKED, MAX_HUNG_REMOTE_PROCESS_ACTION);
+    }
+    return res;
   }
   UnlinkPath(lock_path_);
 
-  if (IsSameChromeInstance(pid))
+  if (IsSameChromeInstance(pid)) {
+    UMA_HISTOGRAM_ENUMERATION(
+        "Chrome.ProcessSingleton.RemoteProcessInteractionResult",
+        SAME_BROWSER_INSTANCE, MAX_HUNG_REMOTE_PROCESS_ACTION);
     return true;
+  }
 
   if (pid > 0) {
     kill_callback_.Run(pid);
     return true;
   }
 
+  UMA_HISTOGRAM_ENUMERATION(
+      "Chrome.ProcessSingleton.RemoteProcessInteractionResult",
+      FAILED_TO_EXTRACT_PID, MAX_HUNG_REMOTE_PROCESS_ACTION);
+
   LOG(ERROR) << "Failed to extract pid from path: " << lock_path_.value();
   return true;
 }
@@ -1080,4 +1125,24 @@ void ProcessSingleton::KillProcess(int pid) {
   // progress of shutting down and finishes before we try to kill it).
   DCHECK(rv == 0 || errno == ESRCH) << "Error killing process: "
                                     << base::safe_strerror(errno);
+
+  int error_code = (rv == 0) ? 0 : errno;
+  UMA_HISTOGRAM_SPARSE_SLOWLY(
+      "Chrome.ProcessSingleton.TerminateProcessErrorCode.Posix", error_code);
+
+  RemoteProcessInteractionResult action = TERMINATE_SUCCEEDED;
+  if (rv != 0) {
+    switch (error_code) {
+      case ESRCH:
+        action = REMOTE_PROCESS_NOT_FOUND;
+        break;
+      case EPERM:
+        action = TERMINATE_NOT_ENOUGH_PERMISSIONS;
+        break;
+      default: { action = TERMINATE_FAILED; }

[gab, 2017/05/10 15:16:50]

use same syntax as other cases for default, i.e. 
  action = TERMINATE_FAILED;
  break;

[Alexey Seren, 2017/05/11 13:42:05]

Acknowledged.

+    }
+  }
+  UMA_HISTOGRAM_ENUMERATION(
+      "Chrome.ProcessSingleton.RemoteProcessInteractionResult", action,
+      MAX_HUNG_REMOTE_PROCESS_ACTION);
 }