From: Oliver Kurth <okurth@vmware.com>
Date: Fri, 15 Sep 2017 18:23:48 +0000 (-0700)
Subject: lib/file: Add a comment on why sleeps for file locks are randomized
X-Git-Tag: stable-10.2.0~129
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=564668d513a4fdb595fd4440f4e640c752c24e12;p=thirdparty%2Fopen-vm-tools.git

lib/file: Add a comment on why sleeps for file locks are randomized

The randomization prevents lock cadence issues (thundering herds).
---

diff --git a/open-vm-tools/lib/file/fileLockPrimitive.c b/open-vm-tools/lib/file/fileLockPrimitive.c
index f1a3b5212..2a64cc5b1 100644
--- a/open-vm-tools/lib/file/fileLockPrimitive.c
+++ b/open-vm-tools/lib/file/fileLockPrimitive.c
@@ -148,6 +148,11 @@ FileLockSleeper(LockValues *myValues)  // IN/OUT:
       maxSleepTimeMsec = MIN(ageMsec / 10, 2000);
    }
 
+   /*
+    * Randomize the time slept. This will prevent any potential cadence issues
+    * (thundering herds).
+    */
+
    (void) FileSleeper(maxSleepTimeMsec / 10, maxSleepTimeMsec);
 
    return 0;