add rtt mutex support

components/external/SQLite-3.8.1/src/mutex.h

@@ -33,6 +33,8 @@
 **                             implementation can be overridden at
 **                             start-time.
 **
+**   SQLITE_MUTEX_RTT          For multi_threaded  applications on rt-thread.
+**
 **   SQLITE_MUTEX_PTHREADS     For multi-threaded applications on Unix.
 **
 **   SQLITE_MUTEX_W32          For multi-threaded applications on Win32.
@@ -45,6 +47,8 @@
 #    define SQLITE_MUTEX_PTHREADS
 #  elif SQLITE_OS_WIN
 #    define SQLITE_MUTEX_W32
+#  elif SQLITE_OS_RTT
+#    define SQLITE_MUTEX_RTT
 #  else
 #    define SQLITE_MUTEX_NOOP
 #  endif
@@ -56,9 +60,9 @@
 */
 #define sqlite3_mutex_alloc(X)    ((sqlite3_mutex*)8)
 #define sqlite3_mutex_free(X)
-#define sqlite3_mutex_enter(X)    
+#define sqlite3_mutex_enter(X)
 #define sqlite3_mutex_try(X)      SQLITE_OK
-#define sqlite3_mutex_leave(X)    
+#define sqlite3_mutex_leave(X)
 #define sqlite3_mutex_held(X)     ((void)(X),1)
 #define sqlite3_mutex_notheld(X)  ((void)(X),1)
 #define sqlite3MutexAlloc(X)      ((sqlite3_mutex*)8)

components/external/SQLite-3.8.1/src/mutex_rtt.c

+/*
+** 2007 August 28
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains the C functions that implement mutexes for rtthread
+*/
+#include "sqliteInt.h"
+
+/*
+** The code in this file is only used if we are compiling threadsafe
+** under rt-thread with rt_mutex.
+**
+** Note that this implementation requires a version of rt-thread that
+** supports recursive mutexes.
+*/
+#ifdef SQLITE_MUTEX_RTT
+
+#include <rtthread.h>
+
+/*
+** The sqlite3_mutex.id, sqlite3_mutex.nRef, and sqlite3_mutex.owner fields
+** are necessary under two condidtions:  (1) Debug builds and (2) using
+** home-grown mutexes.  Encapsulate these conditions into a single #define.
+*/
+#if defined(SQLITE_DEBUG) || defined(SQLITE_HOMEGROWN_RECURSIVE_MUTEX)
+# define SQLITE_MUTEX_NREF 1
+#else
+# define SQLITE_MUTEX_NREF 0
+#endif
+
+/*
+** Each recursive mutex is an instance of the following structure.
+*/
+struct sqlite3_mutex {
+  struct rt_mutex mutex;     /* Mutex controlling the lock */
+#if SQLITE_MUTEX_NREF
+  int id;                    /* Mutex type */
+  volatile int nRef;         /* Number of entrances */
+  volatile rt_thread_t owner;  /* Thread that is within this mutex */
+  int trace;                 /* True to trace changes */
+#endif
+};
+#define RTT_MUTEX_INITIALIZER   { 0 }
+#if SQLITE_MUTEX_NREF
+#define SQLITE3_MUTEX_INITIALIZER { RTT_MUTEX_INITIALIZER, 0, 0, (rt_thread_t)0, 0 }
+#else
+#define SQLITE3_MUTEX_INITIALIZER { RTT_MUTEX_INITIALIZER }
+#endif
+
+/*
+** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are
+** intended for use only inside assert() statements.  On some platforms,
+** there might be race conditions that can cause these routines to
+** deliver incorrect results.  In particular, if rtt_equal() is
+** not an atomic operation, then these routines might delivery
+** incorrect results.  On most platforms, rtt_equal() is a
+** comparison of two integers and is therefore atomic.  But we are
+** told that HPUX is not such a platform.  If so, then these routines
+** will not always work correctly on HPUX.
+**
+** On those platforms where rtt_equal() is not atomic, SQLite
+** should be compiled without -DSQLITE_DEBUG and with -DNDEBUG to
+** make sure no assert() statements are evaluated and hence these
+** routines are never called.
+*/
+#if !defined(NDEBUG) || defined(SQLITE_DEBUG)
+static int rttMutexHeld(sqlite3_mutex *p){
+  return (p->nRef != 0 && p->owner == rt_thread_self());
+}
+static int rttMutexNotheld(sqlite3_mutex *p){
+  return (p->nRef == 0 || p->owner != rt_thread_self());
+}
+#endif
+
+/*
+** Initialize and deinitialize the mutex subsystem.
+*/
+static int rttMutexInit(void){ return SQLITE_OK; }
+static int rttMutexEnd(void){ return SQLITE_OK; }
+
+/*
+** The sqlite3_mutex_alloc() routine allocates a new
+** mutex and returns a pointer to it.  If it returns NULL
+** that means that a mutex could not be allocated.  SQLite
+** will unwind its stack and return an error.  The argument
+** to sqlite3_mutex_alloc() is one of these integer constants:
+**
+** <ul>
+** <li>  SQLITE_MUTEX_FAST
+** <li>  SQLITE_MUTEX_RECURSIVE
+** <li>  SQLITE_MUTEX_STATIC_MASTER
+** <li>  SQLITE_MUTEX_STATIC_MEM
+** <li>  SQLITE_MUTEX_STATIC_MEM2
+** <li>  SQLITE_MUTEX_STATIC_PRNG
+** <li>  SQLITE_MUTEX_STATIC_LRU
+** <li>  SQLITE_MUTEX_STATIC_PMEM
+** </ul>
+**
+** The first two constants cause sqlite3_mutex_alloc() to create
+** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
+** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
+** The mutex implementation does not need to make a distinction
+** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
+** not want to.  But SQLite will only request a recursive mutex in
+** cases where it really needs one.  If a faster non-recursive mutex
+** implementation is available on the host platform, the mutex subsystem
+** might return such a mutex in response to SQLITE_MUTEX_FAST.
+**
+** The other allowed parameters to sqlite3_mutex_alloc() each return
+** a pointer to a static preexisting mutex.  Six static mutexes are
+** used by the current version of SQLite.  Future versions of SQLite
+** may add additional static mutexes.  Static mutexes are for internal
+** use by SQLite only.  Applications that use SQLite mutexes should
+** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
+** SQLITE_MUTEX_RECURSIVE.
+**
+** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
+** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
+** returns a different mutex on every call.  But for the static
+** mutex types, the same mutex is returned on every call that has
+** the same type number.
+*/
+static sqlite3_mutex *rttMutexAlloc(int iType){
+  static sqlite3_mutex staticMutexes[] = {
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER,
+    SQLITE3_MUTEX_INITIALIZER
+  };
+  sqlite3_mutex *p;
+  switch( iType ){
+    case SQLITE_MUTEX_RECURSIVE: {
+      p = sqlite3MallocZero( sizeof(*p) );
+      if( p ){
+        /* Use a recursive mutex if it is available */
+       rt_mutex_init(&p->mutex, "sqlmtx", RT_IPC_FLAG_PRIO);
+#if SQLITE_MUTEX_NREF
+        p->id = iType;
+#endif
+      }
+      break;
+    }
+    case SQLITE_MUTEX_FAST: {
+      p = sqlite3MallocZero( sizeof(*p) );
+      if( p ){
+#if SQLITE_MUTEX_NREF
+        p->id = iType;
+#endif
+        rt_mutex_init(&p->mutex, "sqlmtx", RT_IPC_FLAG_PRIO);
+      }
+      break;
+    }
+    default: {
+      assert( iType-2 >= 0 );
+      assert( iType-2 < ArraySize(staticMutexes) );
+      p = &staticMutexes[iType-2];
+#if SQLITE_MUTEX_NREF
+      p->id = iType;
+#endif
+      break;
+    }
+  }
+  return p;
+}
+
+
+/*
+** This routine deallocates a previously
+** allocated mutex.  SQLite is careful to deallocate every
+** mutex that it allocates.
+*/
+static void rttMutexFree(sqlite3_mutex *p){
+  assert( p->nRef==0 );
+  assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE );
+  rt_mutex_delete(&p->mutex);
+  sqlite3_free(p);
+}
+
+/*
+** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
+** to enter a mutex.  If another thread is already within the mutex,
+** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
+** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK
+** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can
+** be entered multiple times by the same thread.  In such cases the,
+** mutex must be exited an equal number of times before another thread
+** can enter.  If the same thread tries to enter any other kind of mutex
+** more than once, the behavior is undefined.
+*/
+static void rttMutexEnter(sqlite3_mutex *p){
+  assert( p->id==SQLITE_MUTEX_RECURSIVE || rttMutexNotheld(p) );
+
+#ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX
+  /* If recursive mutexes are not available, then we have to grow
+  ** our own.  This implementation assumes that rtt_equal()
+  ** is atomic - that it cannot be deceived into thinking self
+  ** and p->owner are equal if p->owner changes between two values
+  ** that are not equal to self while the comparison is taking place.
+  ** This implementation also assumes a coherent cache - that
+  ** separate processes cannot read different values from the same
+  ** address at the same time.  If either of these two conditions
+  ** are not met, then the mutexes will fail and problems will result.
+  */
+  {
+    rt_thread_t self = rt_thread_self();
+    if( p->nRef>0 && (p->owner == self) ){
+      p->nRef++;
+    }else{
+      rt_mutex_take(&p->mutex, RT_WAITING_FOREVER);
+      assert( p->nRef==0 );
+      p->owner = self;
+      p->nRef = 1;
+    }
+  }
+#else
+  /* Use the built-in recursive mutexes if they are available.
+  */
+  rt_mutex_take(&p->mutex, RT_WAITING_FOREVER);
+#if SQLITE_MUTEX_NREF
+  assert( p->nRef>0 || p->owner==0 );
+  p->owner = rt_thread_self();
+  p->nRef++;
+#endif
+#endif
+
+#ifdef SQLITE_DEBUG
+  if( p->trace ){
+    rt_kprintf("enter mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);
+  }
+#endif
+}
+static int rttMutexTry(sqlite3_mutex *p){
+  int rc;
+  assert( p->id==SQLITE_MUTEX_RECURSIVE || rttMutexNotheld(p) );
+
+#ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX
+  /* If recursive mutexes are not available, then we have to grow
+  ** our own.  This implementation assumes that rtt_equal()
+  ** is atomic - that it cannot be deceived into thinking self
+  ** and p->owner are equal if p->owner changes between two values
+  ** that are not equal to self while the comparison is taking place.
+  ** This implementation also assumes a coherent cache - that
+  ** separate processes cannot read different values from the same
+  ** address at the same time.  If either of these two conditions
+  ** are not met, then the mutexes will fail and problems will result.
+  */
+  {
+    rt_thread_t self = rt_thread_self();
+    if( p->nRef>0 && (p->owner == self) ){
+      p->nRef++;
+      rc = SQLITE_OK;
+    }else if( rt_mutex_take(&p->mutex, RT_WAITING_NO)==RT_EOK ){
+      assert( p->nRef==0 );
+      p->owner = self;
+      p->nRef = 1;
+      rc = SQLITE_OK;
+    }else{
+      rc = SQLITE_BUSY;
+    }
+  }
+#else
+  /* Use the built-in recursive mutexes if they are available.
+  */
+  if( rt_mutex_take(&p->mutex, RT_WAITING_NO)==RT_EOK ){
+#if SQLITE_MUTEX_NREF
+    p->owner = rt_thread_self();
+    p->nRef++;
+#endif
+    rc = SQLITE_OK;
+  }else{
+    rc = SQLITE_BUSY;
+  }
+#endif
+
+#ifdef SQLITE_DEBUG
+  if( rc==SQLITE_OK && p->trace ){
+    rt_kprintf("enter mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);
+  }
+#endif
+  return rc;
+}
+
+/*
+** The sqlite3_mutex_leave() routine exits a mutex that was
+** previously entered by the same thread.  The behavior
+** is undefined if the mutex is not currently entered or
+** is not currently allocated.  SQLite will never do either.
+*/
+static void rttMutexLeave(sqlite3_mutex *p){
+  assert( rttMutexHeld(p) );
+#if SQLITE_MUTEX_NREF
+  p->nRef--;
+  if( p->nRef==0 ) p->owner = 0;
+#endif
+  assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE );
+
+#ifdef SQLITE_HOMEGROWN_RECURSIVE_MUTEX
+  if( p->nRef==0 ){
+    rt_mutex_release(&p->mutex);
+  }
+#else
+  rt_mutex_release(&p->mutex);
+#endif
+
+#ifdef SQLITE_DEBUG
+  if( p->trace ){
+    rt_kprintf("leave mutex %p (%d) with nRef=%d\n", p, p->trace, p->nRef);
+  }
+#endif
+}
+
+sqlite3_mutex_methods const *sqlite3DefaultMutex(void){
+  static const sqlite3_mutex_methods sMutex = {
+    rttMutexInit,
+    rttMutexEnd,
+    rttMutexAlloc,
+    rttMutexFree,
+    rttMutexEnter,
+    rttMutexTry,
+    rttMutexLeave,
+#ifdef SQLITE_DEBUG
+    rttMutexHeld,
+    rttMutexNotheld
+#else
+    0,
+    0
+#endif
+  };
+
+  return &sMutex;
+}
+
+#endif /* SQLITE_MUTEX_RTT */
+