Print 'waiting for other blaze command' on its own line.

It now prints a newline char immediately, rather than waiting until
the lock is released, and printing 'done!' at the end of the line.

This allows per-line parsers (like IntelliJ) to display this progress
notification without special-case hacks.

PiperOrigin-RevId: 177180918

2 files changed, 9 insertions, 20 deletions

diff --git a/src/main/cpp/blaze_util_posix.cc b/src/main/cpp/blaze_util_posix.cc
index 947faba021..139fc21ade 100644
--- a/src/main/cpp/blaze_util_posix.cc
+++ b/src/main/cpp/blaze_util_posix.cc
@@ -622,7 +622,7 @@ uint64_t AcquireLock(const string& output_base, bool batch_mode, bool block,
   // ones) mention that the Blaze invocation hangs on a non-existent PID.  This
   // should help troubleshoot those scenarios in case there really is a bug
   // somewhere.
-  size_t attempts = 0;
+  bool multiple_attempts = false;
   string owner;
   const uint64_t start_time = GetMillisecondsMonotonic();
   while (setlk(lockfd, &lock) == -1) {
@@ -636,13 +636,10 @@ uint64_t AcquireLock(const string& output_base, bool batch_mode, bool block,
     if (owner != buffer) {
       // Each time we learn a new lock owner, print it out.
       owner = buffer;
-      if (attempts > 0) {
-        fprintf(stderr, " client lock owner changed\n");
-      }
       fprintf(stderr, "Another command holds the client lock: \n%s\n",
               owner.c_str());
       if (block) {
-        fprintf(stderr, "Waiting for it to complete...");
+        fprintf(stderr, "Waiting for it to complete...\n");
         fflush(stderr);
       }
     }
@@ -653,10 +650,7 @@ uint64_t AcquireLock(const string& output_base, bool batch_mode, bool block,
     }
 
     TrySleep(500);
-    attempts += 1;
-  }
-  if (attempts > 0) {
-    fprintf(stderr, " done!\n");
+    multiple_attempts = true;
   }
   const uint64_t end_time = GetMillisecondsMonotonic();
 
@@ -664,7 +658,7 @@ uint64_t AcquireLock(const string& output_base, bool batch_mode, bool block,
   // avoid unnecessary noise in the logs.  In this metric, we are only
   // interested in knowing how long it took for other commands to complete, not
   // how fast acquiring a lock is.
-  const uint64_t wait_time = attempts == 0 ? 0 : end_time - start_time;
+  const uint64_t wait_time = !multiple_attempts ? 0 : end_time - start_time;
 
   // Identify ourselves in the lockfile.
   // The contents are printed for human consumption when another client
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java b/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java
index 7653fd892f..0cab34771d 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BlazeCommandDispatcher.java
@@ -175,7 +175,7 @@ public class BlazeCommandDispatcher {
     // holding the lock has changed under the hood.  There have been multiple bug reports where
     // users (especially macOS ones) mention that the Blaze invocation hangs on a non-existent PID.
     // This should help troubleshoot those scenarios in case there really is a bug somewhere.
-    int attempts = 0;
+    boolean multipleAttempts = false;
     long clockBefore = BlazeClock.nanoTime();
     String otherClientDescription = "";
     synchronized (commandLock) {
@@ -183,10 +183,7 @@ public class BlazeCommandDispatcher {
         switch (lockingMode) {
           case WAIT:
             if (!otherClientDescription.equals(currentClientDescription)) {
-              if (attempts > 0) {
-                outErr.printErrLn(" lock taken by another command");
-              }
-              outErr.printErr("Another command (" + currentClientDescription + ") is running. "
+              outErr.printErrLn("Another command (" + currentClientDescription + ") is running. "
                   + " Waiting for it to complete on the server...");
               otherClientDescription = currentClientDescription;
             }
@@ -202,18 +199,16 @@ public class BlazeCommandDispatcher {
             throw new IllegalStateException();
         }
 
-        attempts += 1;
+        multipleAttempts = true;
       }
       Verify.verify(currentClientDescription == null);
       currentClientDescription = clientDescription;
     }
-    if (attempts > 0) {
-      outErr.printErrLn(" done!");
-    }
     // If we took the lock on the first try, force the reported wait time to 0 to avoid unnecessary
     // noise in the logs.  In this metric, we are only interested in knowing how long it took for
     // other commands to complete, not how fast acquiring a lock is.
-    long waitTimeInMs = attempts == 0 ? 0 : (BlazeClock.nanoTime() - clockBefore) / (1000L * 1000L);
+    long waitTimeInMs =
+        !multipleAttempts ? 0 : (BlazeClock.nanoTime() - clockBefore) / (1000L * 1000L);
 
     try {
       if (shutdownReason != null) {