This patch adds support for PTHREAD_MUTEX_NORMAL (fast and deadlocking) mutexes and slightly modifies the lock counter logic. The counter now start at 0.
Attached are also additional testcases for the MUTEX_NORMAL type.
2002-03-27 Thomas Pfaff <[EMAIL PROTECTED]>
* include/pthread.h (PTHREAD_MUTEX_NORMAL): New define.
* thread.cc: Remove errno.h include.
(pthread::precreate): Change internal mutex type to normal.
(pthread_mutex::canBeUnlocked): Implement.
(pthread_mutex::pthread_mutex): Initialize lock_counter with 0.
(pthread_mutex::Lock): Rename to _Lock. Add self parameter.
Change lock_counter logic. Update SetOwner call.
(pthread_mutex::TryLock): Rename to _TryLock. Add self parameter.
Change lock_counter logic. Update SetOwner call.
(pthread_mutex::UnLock): Rename to _UnLock. Add self parameter.
Change lock_counter logic.
(pthread_mutex::Destroy): Rename to _Destroy. Update TryLock call.
(pthread_mutex::SetOwner): Move to thread.h as inline.
(pthread_mutex::LockRecursive): Ditto.
(pthread_mutex::fixup_after_fork): Change lock_counter logic.
(__pthread_mutexattr_settype): Add PTHREAD_MUTEX_NORMAL to valid
types check.
* thread.h: Include errno.h and limits.h
(MUTEX_LOCK_COUNTER_INITIAL): Remove
(MUTEX_OWNER_ANONYMOUS): New define.
(pthread_mutex::canBeUnlocked): New static method.
(pthread_mutex::lock_counter): Change type to unsigned long.
(pthread_mutex::_Lock): New method.
(pthread_mutex::_TryLock): New method.
(pthread_mutex::_UnLock): New method.
(pthread_mutex::_Destroy): New method.
(pthread_mutex::GetPthreadSelf): New method.
(pthread_mutex::Lock): Call _Lock with pthread_self pointer.
(pthread_mutex::TryLock): Call _TryLock with pthread_self pointer.
(pthread_mutex::UnLock): Call _UnLock with pthread_self pointer.
(pthread_mutex::Destroy): Call _Destroy with pthread_self pointer.
(pthread_mutex::SetOwner): Moved from thread.cc as inline.
(pthread_mutex::LockRecursive): Ditto.
mutexn.tar.gz
Description: GNU Zip compressed data
diff -urp src.old/winsup/cygwin/include/pthread.h src/winsup/cygwin/include/pthread.h
--- src.old/winsup/cygwin/include/pthread.h 2003-02-27 09:14:21.000000000 +0100
+++ src/winsup/cygwin/include/pthread.h 2003-02-27 09:20:24.000000000 +0100
@@ -52,6 +52,7 @@ extern "C"
#define PTHREAD_INHERIT_SCHED 0
#define PTHREAD_MUTEX_RECURSIVE 0
#define PTHREAD_MUTEX_ERRORCHECK 1
+#define PTHREAD_MUTEX_NORMAL 2
#define PTHREAD_MUTEX_DEFAULT PTHREAD_MUTEX_ERRORCHECK
/* this should be too low to ever be a valid address */
#define PTHREAD_MUTEX_INITIALIZER (pthread_mutex_t)20
diff -urp src.old/winsup/cygwin/thread.cc src/winsup/cygwin/thread.cc
--- src.old/winsup/cygwin/thread.cc 2003-02-27 09:14:21.000000000 +0100
+++ src/winsup/cygwin/thread.cc 2003-02-27 09:23:10.000000000 +0100
@@ -32,7 +32,6 @@ details. */
#ifdef _MT_SAFE
#include "winsup.h"
#include <limits.h>
-#include <errno.h>
#include "cygerrno.h"
#include <assert.h>
#include <stdlib.h>
@@ -328,6 +327,8 @@ pthread::precreate (pthread_attr *newatt
magic = 0;
return;
}
+ /* Change the mutex type to NORMAL to speed up mutex operations */
+ mutex.type = PTHREAD_MUTEX_NORMAL;
cancel_event = ::CreateEvent (&sec_none_nih, TRUE, FALSE, NULL);
if (!cancel_event)
@@ -1157,6 +1158,19 @@ pthread_mutex::isGoodInitializerOrBadObj
return true;
}
+bool
+pthread_mutex::canBeUnlocked (pthread_mutex_t const *mutex)
+{
+ pthread_t self = pthread::self ();
+
+ if (!isGoodObject (mutex))
+ return false;
+ /*
+ * Check if the mutex is owned by the current thread and can be unlocked
+ */
+ return (__pthread_equal (&(*mutex)->owner, &self)) && 1 ==
(*mutex)->recursion_counter;
+}
+
/* This is used for mutex creation protection within a single process only */
nativeMutex NO_COPY pthread_mutex::mutexInitializationLock;
@@ -1172,7 +1186,7 @@ pthread_mutex::initMutex ()
pthread_mutex::pthread_mutex (pthread_mutexattr *attr) :
verifyable_object (PTHREAD_MUTEX_MAGIC),
- lock_counter (MUTEX_LOCK_COUNTER_INITIAL),
+ lock_counter (0),
win32_obj_id (NULL), recursion_counter (0),
condwaits (0), owner (NULL), type (PTHREAD_MUTEX_DEFAULT),
pshared (PTHREAD_PROCESS_PRIVATE)
@@ -1221,16 +1235,15 @@ pthread_mutex::~pthread_mutex ()
}
int
-pthread_mutex::Lock ()
+pthread_mutex::_Lock (pthread_t self)
{
int result = 0;
- pthread_t self = pthread::self ();
- if (0 == InterlockedIncrement (&lock_counter))
- SetOwner ();
- else if (__pthread_equal (&owner, &self))
+ if (1 == InterlockedIncrement ((long *)&lock_counter))
+ SetOwner (self);
+ else if (PTHREAD_MUTEX_NORMAL != type && __pthread_equal (&owner, &self))
{
- InterlockedDecrement (&lock_counter);
+ InterlockedDecrement ((long *) &lock_counter);
if (PTHREAD_MUTEX_RECURSIVE == type)
result = LockRecursive ();
else
@@ -1239,23 +1252,20 @@ pthread_mutex::Lock ()
else
{
WaitForSingleObject (win32_obj_id, INFINITE);
- SetOwner ();
+ SetOwner (self);
}
return result;
}
-/* returns non-zero on failure */
int
-pthread_mutex::TryLock ()
+pthread_mutex::_TryLock (pthread_t self)
{
int result = 0;
- pthread_t self = pthread::self ();
- if (MUTEX_LOCK_COUNTER_INITIAL ==
- InterlockedCompareExchange (&lock_counter, 0, MUTEX_LOCK_COUNTER_INITIAL ))
- SetOwner ();
- else if (__pthread_equal (&owner, &self) && PTHREAD_MUTEX_RECURSIVE == type)
+ if (0 == InterlockedCompareExchange ((long *)&lock_counter, 1, 0 ))
+ SetOwner (self);
+ else if (PTHREAD_MUTEX_RECURSIVE == type && __pthread_equal (&owner, &self))
result = LockRecursive ();
else
result = EBUSY;
@@ -1264,17 +1274,15 @@ pthread_mutex::TryLock ()
}
int
-pthread_mutex::UnLock ()
+pthread_mutex::_UnLock (pthread_t self)
{
- pthread_t self = pthread::self ();
-
if (!__pthread_equal (&owner, &self))
return EPERM;
if (0 == --recursion_counter)
{
owner = NULL;
- if (MUTEX_LOCK_COUNTER_INITIAL != InterlockedDecrement (&lock_counter))
+ if (InterlockedDecrement ((long *)&lock_counter))
// Another thread is waiting
::ReleaseSemaphore (win32_obj_id, 1, NULL);
}
@@ -1283,9 +1291,9 @@ pthread_mutex::UnLock ()
}
int
-pthread_mutex::Destroy ()
+pthread_mutex::_Destroy (pthread_t self)
{
- if (condwaits || TryLock ())
+ if (condwaits || _TryLock (self))
// Do not destroy a condwaited or locked mutex
return EBUSY;
else if (recursion_counter != 1)
@@ -1300,22 +1308,6 @@ pthread_mutex::Destroy ()
}
void
-pthread_mutex::SetOwner ()
-{
- recursion_counter = 1;
- owner = pthread::self ();
-}
-
-int
-pthread_mutex::LockRecursive ()
-{
- if (UINT_MAX == recursion_counter)
- return EAGAIN;
- ++recursion_counter;
- return 0;
-}
-
-void
pthread_mutex::fixup_after_fork ()
{
debug_printf ("mutex %x in fixup_after_fork", this);
@@ -1324,10 +1316,10 @@ pthread_mutex::fixup_after_fork ()
if (NULL == owner)
/* mutex has no owner, reset to initial */
- lock_counter = MUTEX_LOCK_COUNTER_INITIAL;
- else if (lock_counter != MUTEX_LOCK_COUNTER_INITIAL)
- /* All waiting threads are gone after a fork */
lock_counter = 0;
+ else if (lock_counter != 0)
+ /* All waiting threads are gone after a fork */
+ lock_counter = 1;
win32_obj_id = ::CreateSemaphore (&sec_none_nih, 0, LONG_MAX, NULL);
if (!win32_obj_id)
@@ -2615,6 +2607,7 @@ __pthread_mutexattr_settype (pthread_mut
{
case PTHREAD_MUTEX_ERRORCHECK:
case PTHREAD_MUTEX_RECURSIVE:
+ case PTHREAD_MUTEX_NORMAL:
(*attr)->mutextype = type;
break;
default:
diff -urp src.old/winsup/cygwin/thread.h src/winsup/cygwin/thread.h
--- src.old/winsup/cygwin/thread.h 2003-02-27 09:14:21.000000000 +0100
+++ src/winsup/cygwin/thread.h 2003-02-27 09:20:24.000000000 +0100
@@ -39,6 +39,8 @@ extern "C"
#else
#include <pthread.h>
+#include <limits.h>
+#include <errno.h>
#include <signal.h>
#include <pwd.h>
#include <grp.h>
@@ -160,9 +162,9 @@ private:
#define PTHREAD_COND_MAGIC PTHREAD_MAGIC+5
#define PTHREAD_CONDATTR_MAGIC PTHREAD_MAGIC+6
#define SEM_MAGIC PTHREAD_MAGIC+7
-#define PTHREAD_ONCE_MAGIC PTHREAD_MAGIC+8;
+#define PTHREAD_ONCE_MAGIC PTHREAD_MAGIC+8
-#define MUTEX_LOCK_COUNTER_INITIAL (-1)
+#define MUTEX_OWNER_ANONYMOUS ((pthread_t) -1)
/* verifyable_object should not be defined here - it's a general purpose class */
@@ -304,10 +306,11 @@ public:
static bool isGoodInitializer (pthread_mutex_t const *);
static bool isGoodInitializerOrObject (pthread_mutex_t const *);
static bool isGoodInitializerOrBadObject (pthread_mutex_t const *mutex);
+ static bool canBeUnlocked (pthread_mutex_t const *mutex);
static void initMutex ();
static int init (pthread_mutex_t *, const pthread_mutexattr_t *);
- LONG lock_counter;
+ unsigned long lock_counter;
HANDLE win32_obj_id;
unsigned int recursion_counter;
LONG condwaits;
@@ -316,12 +319,48 @@ public:
int pshared;
class pthread_mutex * next;
- int Lock ();
- int TryLock ();
- int UnLock ();
- int Destroy ();
- void SetOwner ();
- int LockRecursive ();
+ int _Lock (pthread_t self);
+ int _TryLock (pthread_t self);
+ int _UnLock (pthread_t self);
+ int _Destroy (pthread_t self);
+
+ pthread_t GetPthreadSelf ()
+ {
+ return PTHREAD_MUTEX_NORMAL == type ? MUTEX_OWNER_ANONYMOUS :
+ ::pthread_self ();
+ }
+
+ int Lock ()
+ {
+ return _Lock (GetPthreadSelf ());
+ }
+ int TryLock ()
+ {
+ return _TryLock (GetPthreadSelf ());
+ }
+ int UnLock ()
+ {
+ return _UnLock (GetPthreadSelf ());
+ }
+ int Destroy ()
+ {
+ return _Destroy (GetPthreadSelf ());
+ }
+
+ void SetOwner (pthread_t self)
+ {
+ recursion_counter = 1;
+ owner = self;
+ }
+
+ int LockRecursive ()
+ {
+ if (UINT_MAX == recursion_counter)
+ return EAGAIN;
+ ++recursion_counter;
+ return 0;
+ }
+
void fixup_after_fork ();
pthread_mutex (pthread_mutexattr * = NULL);
