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authorCarl Shapiro <cshapiro@google.com>2011-02-01 11:32:44 -0800
committerCarl Shapiro <cshapiro@google.com>2011-02-01 11:32:44 -0800
commit01605d2b668e8e1701cfdfa302dde847b9171fc9 (patch)
tree0e4191085609463310771764c2e877c9499b5080 /docs
parent83d17b3741cfa07176f8559b6585fe9a61a27091 (diff)
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Remove the unused monitor tracking and deadlock prediction code.
This feature has been in the code base for several releases but has never been enabled. Change-Id: Ia770b03ebc90a3dc7851c0cd8ef301f9762f50db
Diffstat (limited to 'docs')
-rw-r--r--docs/embedded-vm-control.html35
1 files changed, 0 insertions, 35 deletions
diff --git a/docs/embedded-vm-control.html b/docs/embedded-vm-control.html
index 11751e075..a0bdd292b 100644
--- a/docs/embedded-vm-control.html
+++ b/docs/embedded-vm-control.html
@@ -13,7 +13,6 @@
<li><a href="#assertions">Assertions</a>
<li><a href="#verifier">Bytecode Verification and Optimization</a>
<li><a href="#execmode">Execution Mode</a>
- <li><a href="#dp">Deadlock Prediction</a>
<li><a href="#stackdump">Stack Dumps</a>
<li><a href="#dexcheck">DEX File Checksums</a>
<li><a href="#general">General Flags</a>
@@ -207,40 +206,6 @@ suspect that JIT compilation is causing your application to behave
incorrectly.
-<h2><a name="dp">Deadlock Prediction</a></h2>
-
-<p>If the VM is built with <code>WITH_DEADLOCK_PREDICTION</code>, the deadlock
-predictor can be enabled with the <code>-Xdeadlockpredict</code> argument.
-(The output from <code>dalvikvm -help</code> will tell you if the VM was
-built appropriately -- look for <code>deadlock_prediction</code> on the
-<code>Configured with:</code> line.)
-This feature tells the VM to keep track of the order in which object
-monitor locks are acquired. If the program attempts to acquire a set
-of locks in a different order from what was seen earlier, the VM logs
-a warning and optionally throws an exception.
-
-<p>Valid values for the command-line argument are
-<code>off</code> to disable it (default), <code>warn</code> to log the
-problem but continue executing, <code>err</code> to cause a
-<code>dalvik.system.PotentialDeadlockError</code> to be thrown from the
-<code>monitor-enter</code> instruction, and <code>abort</code> to have
-the entire VM abort.
-
-<p>You will usually want to use:
-<pre>adb shell setprop dalvik.vm.extra-opts -Xdeadlockpredict:err</pre>
-unless you are keeping an eye on the logs as they scroll by.
-
-<p>Please note that this feature is deadlock prediction, not deadlock
-detection -- in the current implementation, the computations are performed
-after the lock is acquired (this simplifies the code, reducing the
-overhead added to every mutex operation). You can spot a deadlock in a
-hung process by sending a <code>kill -3</code> and examining the stack
-trace written to the log.
-
-<p>This only takes monitors into account. Native mutexes and other resources
-can also be the cause of deadlocks, but will not be detected by this.
-
-
<h2><a name="stackdump">Stack Dumps</a></h2>
<p>Like other desktop VMs, when the Dalvik VM receives a SIGQUIT