2 * lock-tracer.c: Runtime simple lock tracer
5 * Rodrigo Kumpera (rkumpera@novell.com)
13 #include <sys/types.h>
19 #ifdef HAVE_EXECINFO_H
23 #include <mono/io-layer/io-layer.h>
25 #include "lock-tracer.h"
28 * This is a very simple lock trace implementation. It can be used to verify that the runtime is
29 * correctly following all locking rules.
31 * To log more kind of locks just do the following:
32 * - add an entry into the RuntimeLocks enum
33 * - change EnterCriticalSection(mutex) to mono_locks_acquire (mutex, LockName)
34 * - change LeaveCriticalSection to mono_locks_release (mutex, LockName)
35 * - change the decoder to understand the new lock kind.
38 * - Use unbuffered IO without fsync
39 * - Switch to a binary log format
40 * - Enable tracing of more runtime locks
41 * - Add lock check assertions (must_not_hold_any_lock_but, must_hold_lock, etc)
42 * This should be used to verify methods that expect that a given lock is held at entrypoint, for example.
44 * To use the trace, define LOCK_TRACER in lock-trace.h and when running mono define MONO_ENABLE_LOCK_TRACER.
45 * This will produce a locks.ZZZ where ZZZ is the pid of the mono process.
46 * Use the decoder to verify the result.
51 static FILE *trace_file;
52 static CRITICAL_SECTION tracer_lock;
55 RECORD_MUST_NOT_HOLD_ANY,
56 RECORD_MUST_NOT_HOLD_ONE,
63 mono_locks_tracer_init (void)
66 InitializeCriticalSection (&tracer_lock);
67 if (!getenv ("MONO_ENABLE_LOCK_TRACER"))
69 name = g_strdup_printf ("locks.%d", getpid ());
70 trace_file = fopen (name, "w+");
75 #ifdef HAVE_EXECINFO_H
78 mono_backtrace (gpointer array[], int traces)
80 return backtrace (array, traces);
86 mono_backtrace (gpointer array[], int traces)
94 add_record (RecordType record_kind, RuntimeLocks kind, gpointer lock)
101 memset (frames, 0, sizeof (gpointer));
102 mono_backtrace (frames, 6);
104 /*We only dump 5 frames, which should be more than enough to most analysis.*/
105 msg = g_strdup_printf ("%x,%d,%d,%p,%p,%p,%p,%p,%p\n", (guint32)GetCurrentThreadId (), record_kind, kind, lock, frames [1], frames [2], frames [3], frames [4], frames [5]);
106 fwrite (msg, strlen (msg), 1, trace_file);
112 mono_locks_lock_acquired (RuntimeLocks kind, gpointer lock)
114 add_record (RECORD_LOCK_ACQUIRED, kind, lock);
118 mono_locks_lock_released (RuntimeLocks kind, gpointer lock)
120 add_record (RECORD_LOCK_RELEASED, kind, lock);