Get `gn gen` to succeed on Windows

third_party/sqlite/src/src/test_thread.c

+/*
+** 2007 September 9
+**
+** 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 implementation of some Tcl commands used to
+** test that sqlite3 database handles may be concurrently accessed by 
+** multiple threads. Right now this only works on unix.
+*/
+
+#include "sqliteInt.h"
+#include <tcl.h>
+
+#if SQLITE_THREADSAFE
+
+#include <errno.h>
+
+#if !defined(_MSC_VER)
+#include <unistd.h>
+#endif
+
+/*
+** One of these is allocated for each thread created by [sqlthread spawn].
+*/
+typedef struct SqlThread SqlThread;
+struct SqlThread {
+  Tcl_ThreadId parent;     /* Thread id of parent thread */
+  Tcl_Interp *interp;      /* Parent interpreter */
+  char *zScript;           /* The script to execute. */
+  char *zVarname;          /* Varname in parent script */
+};
+
+/*
+** A custom Tcl_Event type used by this module. When the event is
+** handled, script zScript is evaluated in interpreter interp. If
+** the evaluation throws an exception (returns TCL_ERROR), then the
+** error is handled by Tcl_BackgroundError(). If no error occurs,
+** the result is simply discarded.
+*/
+typedef struct EvalEvent EvalEvent;
+struct EvalEvent {
+  Tcl_Event base;          /* Base class of type Tcl_Event */
+  char *zScript;           /* The script to execute. */
+  Tcl_Interp *interp;      /* The interpreter to execute it in. */
+};
+
+static Tcl_ObjCmdProc sqlthread_proc;
+static Tcl_ObjCmdProc clock_seconds_proc;
+#if SQLITE_OS_UNIX && defined(SQLITE_ENABLE_UNLOCK_NOTIFY)
+static Tcl_ObjCmdProc blocking_step_proc;
+static Tcl_ObjCmdProc blocking_prepare_v2_proc;
+#endif
+int Sqlitetest1_Init(Tcl_Interp *);
+int Sqlite3_Init(Tcl_Interp *);
+
+/* Functions from test1.c */
+void *sqlite3TestTextToPtr(const char *);
+const char *sqlite3TestErrorName(int);
+int getDbPointer(Tcl_Interp *, const char *, sqlite3 **);
+int sqlite3TestMakePointerStr(Tcl_Interp *, char *, void *);
+int sqlite3TestErrCode(Tcl_Interp *, sqlite3 *, int);
+
+/*
+** Handler for events of type EvalEvent.
+*/
+static int tclScriptEvent(Tcl_Event *evPtr, int flags){
+  int rc;
+  EvalEvent *p = (EvalEvent *)evPtr;
+  rc = Tcl_Eval(p->interp, p->zScript);
+  if( rc!=TCL_OK ){
+    Tcl_BackgroundError(p->interp);
+  }
+  UNUSED_PARAMETER(flags);
+  return 1;
+}
+
+/*
+** Register an EvalEvent to evaluate the script pScript in the
+** parent interpreter/thread of SqlThread p.
+*/
+static void postToParent(SqlThread *p, Tcl_Obj *pScript){
+  EvalEvent *pEvent;
+  char *zMsg;
+  int nMsg;
+
+  zMsg = Tcl_GetStringFromObj(pScript, &nMsg); 
+  pEvent = (EvalEvent *)ckalloc(sizeof(EvalEvent)+nMsg+1);
+  pEvent->base.nextPtr = 0;
+  pEvent->base.proc = tclScriptEvent;
+  pEvent->zScript = (char *)&pEvent[1];
+  memcpy(pEvent->zScript, zMsg, nMsg+1);
+  pEvent->interp = p->interp;
+
+  Tcl_ThreadQueueEvent(p->parent, (Tcl_Event *)pEvent, TCL_QUEUE_TAIL);
+  Tcl_ThreadAlert(p->parent);
+}
+
+/*
+** The main function for threads created with [sqlthread spawn].
+*/
+static Tcl_ThreadCreateType tclScriptThread(ClientData pSqlThread){
+  Tcl_Interp *interp;
+  Tcl_Obj *pRes;
+  Tcl_Obj *pList;
+  int rc;
+  SqlThread *p = (SqlThread *)pSqlThread;
+  extern int Sqlitetest_mutex_Init(Tcl_Interp*);
+
+  interp = Tcl_CreateInterp();
+  Tcl_CreateObjCommand(interp, "clock_seconds", clock_seconds_proc, 0, 0);
+  Tcl_CreateObjCommand(interp, "sqlthread", sqlthread_proc, pSqlThread, 0);
+#if SQLITE_OS_UNIX && defined(SQLITE_ENABLE_UNLOCK_NOTIFY)
+  Tcl_CreateObjCommand(interp, "sqlite3_blocking_step", blocking_step_proc,0,0);
+  Tcl_CreateObjCommand(interp, 
+      "sqlite3_blocking_prepare_v2", blocking_prepare_v2_proc, (void *)1, 0);
+  Tcl_CreateObjCommand(interp, 
+      "sqlite3_nonblocking_prepare_v2", blocking_prepare_v2_proc, 0, 0);
+#endif
+  Sqlitetest1_Init(interp);
+  Sqlitetest_mutex_Init(interp);
+  Sqlite3_Init(interp);
+
+  rc = Tcl_Eval(interp, p->zScript);
+  pRes = Tcl_GetObjResult(interp);
+  pList = Tcl_NewObj();
+  Tcl_IncrRefCount(pList);
+  Tcl_IncrRefCount(pRes);
+
+  if( rc!=TCL_OK ){
+    Tcl_ListObjAppendElement(interp, pList, Tcl_NewStringObj("error", -1));
+    Tcl_ListObjAppendElement(interp, pList, pRes);
+    postToParent(p, pList);
+    Tcl_DecrRefCount(pList);
+    pList = Tcl_NewObj();
+  }
+
+  Tcl_ListObjAppendElement(interp, pList, Tcl_NewStringObj("set", -1));
+  Tcl_ListObjAppendElement(interp, pList, Tcl_NewStringObj(p->zVarname, -1));
+  Tcl_ListObjAppendElement(interp, pList, pRes);
+  postToParent(p, pList);
+
+  ckfree((void *)p);
+  Tcl_DecrRefCount(pList);
+  Tcl_DecrRefCount(pRes);
+  Tcl_DeleteInterp(interp);
+  while( Tcl_DoOneEvent(TCL_ALL_EVENTS|TCL_DONT_WAIT) );
+  Tcl_ExitThread(0);
+  TCL_THREAD_CREATE_RETURN;
+}
+
+/*
+** sqlthread spawn VARNAME SCRIPT
+**
+**     Spawn a new thread with its own Tcl interpreter and run the
+**     specified SCRIPT(s) in it. The thread terminates after running
+**     the script. The result of the script is stored in the variable
+**     VARNAME.
+**
+**     The caller can wait for the script to terminate using [vwait VARNAME].
+*/
+static int sqlthread_spawn(
+  ClientData clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  Tcl_ThreadId x;
+  SqlThread *pNew;
+  int rc;
+
+  int nVarname; char *zVarname;
+  int nScript; char *zScript;
+
+  /* Parameters for thread creation */
+  const int nStack = TCL_THREAD_STACK_DEFAULT;
+  const int flags = TCL_THREAD_NOFLAGS;
+
+  assert(objc==4);
+  UNUSED_PARAMETER(clientData);
+  UNUSED_PARAMETER(objc);
+
+  zVarname = Tcl_GetStringFromObj(objv[2], &nVarname);
+  zScript = Tcl_GetStringFromObj(objv[3], &nScript);
+
+  pNew = (SqlThread *)ckalloc(sizeof(SqlThread)+nVarname+nScript+2);
+  pNew->zVarname = (char *)&pNew[1];
+  pNew->zScript = (char *)&pNew->zVarname[nVarname+1];
+  memcpy(pNew->zVarname, zVarname, nVarname+1);
+  memcpy(pNew->zScript, zScript, nScript+1);
+  pNew->parent = Tcl_GetCurrentThread();
+  pNew->interp = interp;
+
+  rc = Tcl_CreateThread(&x, tclScriptThread, (void *)pNew, nStack, flags);
+  if( rc!=TCL_OK ){
+    Tcl_AppendResult(interp, "Error in Tcl_CreateThread()", 0);
+    ckfree((char *)pNew);
+    return TCL_ERROR;
+  }
+
+  return TCL_OK;
+}
+
+/*
+** sqlthread parent SCRIPT
+**
+**     This can be called by spawned threads only. It sends the specified
+**     script back to the parent thread for execution. The result of
+**     evaluating the SCRIPT is returned. The parent thread must enter
+**     the event loop for this to work - otherwise the caller will
+**     block indefinitely.
+**
+**     NOTE: At the moment, this doesn't work. FIXME.
+*/
+static int sqlthread_parent(
+  ClientData clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  EvalEvent *pEvent;
+  char *zMsg;
+  int nMsg;
+  SqlThread *p = (SqlThread *)clientData;
+
+  assert(objc==3);
+  UNUSED_PARAMETER(objc);
+
+  if( p==0 ){
+    Tcl_AppendResult(interp, "no parent thread", 0);
+    return TCL_ERROR;
+  }
+
+  zMsg = Tcl_GetStringFromObj(objv[2], &nMsg);
+  pEvent = (EvalEvent *)ckalloc(sizeof(EvalEvent)+nMsg+1);
+  pEvent->base.nextPtr = 0;
+  pEvent->base.proc = tclScriptEvent;
+  pEvent->zScript = (char *)&pEvent[1];
+  memcpy(pEvent->zScript, zMsg, nMsg+1);
+  pEvent->interp = p->interp;
+  Tcl_ThreadQueueEvent(p->parent, (Tcl_Event *)pEvent, TCL_QUEUE_TAIL);
+  Tcl_ThreadAlert(p->parent);
+
+  return TCL_OK;
+}
+
+static int xBusy(void *pArg, int nBusy){
+  UNUSED_PARAMETER(pArg);
+  UNUSED_PARAMETER(nBusy);
+  sqlite3_sleep(50);
+  return 1;             /* Try again... */
+}
+
+/*
+** sqlthread open
+**
+**     Open a database handle and return the string representation of
+**     the pointer value.
+*/
+static int sqlthread_open(
+  ClientData clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int sqlite3TestMakePointerStr(Tcl_Interp *interp, char *zPtr, void *p);
+
+  const char *zFilename;
+  sqlite3 *db;
+  int rc;
+  char zBuf[100];
+  extern void Md5_Register(sqlite3*);
+
+  UNUSED_PARAMETER(clientData);
+  UNUSED_PARAMETER(objc);
+
+  zFilename = Tcl_GetString(objv[2]);
+  rc = sqlite3_open(zFilename, &db);
+  Md5_Register(db);
+  sqlite3_busy_handler(db, xBusy, 0);
+  
+  if( sqlite3TestMakePointerStr(interp, zBuf, db) ) return TCL_ERROR;
+  Tcl_AppendResult(interp, zBuf, 0);
+
+  return TCL_OK;
+}
+
+
+/*
+** sqlthread open
+**
+**     Return the current thread-id (Tcl_GetCurrentThread()) cast to
+**     an integer.
+*/
+static int sqlthread_id(
+  ClientData clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  Tcl_ThreadId id = Tcl_GetCurrentThread();
+  Tcl_SetObjResult(interp, Tcl_NewIntObj((int)id));
+  UNUSED_PARAMETER(clientData);
+  UNUSED_PARAMETER(objc);
+  UNUSED_PARAMETER(objv);
+  return TCL_OK;
+}
+
+
+/*
+** Dispatch routine for the sub-commands of [sqlthread].
+*/
+static int sqlthread_proc(
+  ClientData clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  struct SubCommand {
+    char *zName;
+    Tcl_ObjCmdProc *xProc;
+    int nArg;
+    char *zUsage;
+  } aSub[] = {
+    {"parent", sqlthread_parent, 1, "SCRIPT"},
+    {"spawn",  sqlthread_spawn,  2, "VARNAME SCRIPT"},
+    {"open",   sqlthread_open,   1, "DBNAME"},
+    {"id",     sqlthread_id,     0, ""},
+    {0, 0, 0}
+  };
+  struct SubCommand *pSub;
+  int rc;
+  int iIndex;
+
+  if( objc<2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "SUB-COMMAND");
+    return TCL_ERROR;
+  }
+
+  rc = Tcl_GetIndexFromObjStruct(
+      interp, objv[1], aSub, sizeof(aSub[0]), "sub-command", 0, &iIndex
+  );
+  if( rc!=TCL_OK ) return rc;
+  pSub = &aSub[iIndex];
+
+  if( objc!=(pSub->nArg+2) ){
+    Tcl_WrongNumArgs(interp, 2, objv, pSub->zUsage);
+    return TCL_ERROR;
+  }
+
+  return pSub->xProc(clientData, interp, objc, objv);
+}
+
+/*
+** The [clock_seconds] command. This is more or less the same as the
+** regular tcl [clock seconds], except that it is available in testfixture
+** when linked against both Tcl 8.4 and 8.5. Because [clock seconds] is
+** implemented as a script in Tcl 8.5, it is not usually available to
+** testfixture.
+*/ 
+static int clock_seconds_proc(
+  ClientData clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  Tcl_Time now;
+  Tcl_GetTime(&now);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(now.sec));
+  UNUSED_PARAMETER(clientData);
+  UNUSED_PARAMETER(objc);
+  UNUSED_PARAMETER(objv);
+  return TCL_OK;
+}
+
+/*************************************************************************
+** This block contains the implementation of the [sqlite3_blocking_step]
+** command available to threads created by [sqlthread spawn] commands. It
+** is only available on UNIX for now. This is because pthread condition
+** variables are used.
+**
+** The source code for the C functions sqlite3_blocking_step(),
+** blocking_step_notify() and the structure UnlockNotification is
+** automatically extracted from this file and used as part of the
+** documentation for the sqlite3_unlock_notify() API function. This
+** should be considered if these functions are to be extended (i.e. to 
+** support windows) in the future.
+*/ 
+#if SQLITE_OS_UNIX && defined(SQLITE_ENABLE_UNLOCK_NOTIFY)
+
+/* BEGIN_SQLITE_BLOCKING_STEP */
+/* This example uses the pthreads API */
+#include <pthread.h>
+
+/*
+** A pointer to an instance of this structure is passed as the user-context
+** pointer when registering for an unlock-notify callback.
+*/
+typedef struct UnlockNotification UnlockNotification;
+struct UnlockNotification {
+  int fired;                           /* True after unlock event has occured */
+  pthread_cond_t cond;                 /* Condition variable to wait on */
+  pthread_mutex_t mutex;               /* Mutex to protect structure */
+};
+
+/*
+** This function is an unlock-notify callback registered with SQLite.
+*/
+static void unlock_notify_cb(void **apArg, int nArg){
+  int i;
+  for(i=0; i<nArg; i++){
+    UnlockNotification *p = (UnlockNotification *)apArg[i];
+    pthread_mutex_lock(&p->mutex);
+    p->fired = 1;
+    pthread_cond_signal(&p->cond);
+    pthread_mutex_unlock(&p->mutex);
+  }
+}
+
+/*
+** This function assumes that an SQLite API call (either sqlite3_prepare_v2() 
+** or sqlite3_step()) has just returned SQLITE_LOCKED. The argument is the
+** associated database connection.
+**
+** This function calls sqlite3_unlock_notify() to register for an 
+** unlock-notify callback, then blocks until that callback is delivered 
+** and returns SQLITE_OK. The caller should then retry the failed operation.
+**
+** Or, if sqlite3_unlock_notify() indicates that to block would deadlock 
+** the system, then this function returns SQLITE_LOCKED immediately. In 
+** this case the caller should not retry the operation and should roll 
+** back the current transaction (if any).
+*/
+static int wait_for_unlock_notify(sqlite3 *db){
+  int rc;
+  UnlockNotification un;
+
+  /* Initialize the UnlockNotification structure. */
+  un.fired = 0;
+  pthread_mutex_init(&un.mutex, 0);
+  pthread_cond_init(&un.cond, 0);
+
+  /* Register for an unlock-notify callback. */
+  rc = sqlite3_unlock_notify(db, unlock_notify_cb, (void *)&un);
+  assert( rc==SQLITE_LOCKED || rc==SQLITE_OK );
+
+  /* The call to sqlite3_unlock_notify() always returns either SQLITE_LOCKED 
+  ** or SQLITE_OK. 
+  **
+  ** If SQLITE_LOCKED was returned, then the system is deadlocked. In this
+  ** case this function needs to return SQLITE_LOCKED to the caller so 
+  ** that the current transaction can be rolled back. Otherwise, block
+  ** until the unlock-notify callback is invoked, then return SQLITE_OK.
+  */
+  if( rc==SQLITE_OK ){
+    pthread_mutex_lock(&un.mutex);
+    if( !un.fired ){
+      pthread_cond_wait(&un.cond, &un.mutex);
+    }
+    pthread_mutex_unlock(&un.mutex);
+  }
+
+  /* Destroy the mutex and condition variables. */
+  pthread_cond_destroy(&un.cond);
+  pthread_mutex_destroy(&un.mutex);
+
+  return rc;
+}
+
+/*
+** This function is a wrapper around the SQLite function sqlite3_step().
+** It functions in the same way as step(), except that if a required
+** shared-cache lock cannot be obtained, this function may block waiting for
+** the lock to become available. In this scenario the normal API step()
+** function always returns SQLITE_LOCKED.
+**
+** If this function returns SQLITE_LOCKED, the caller should rollback
+** the current transaction (if any) and try again later. Otherwise, the
+** system may become deadlocked.
+*/
+int sqlite3_blocking_step(sqlite3_stmt *pStmt){
+  int rc;
+  while( SQLITE_LOCKED==(rc = sqlite3_step(pStmt)) ){
+    rc = wait_for_unlock_notify(sqlite3_db_handle(pStmt));
+    if( rc!=SQLITE_OK ) break;
+    sqlite3_reset(pStmt);
+  }
+  return rc;
+}
+
+/*
+** This function is a wrapper around the SQLite function sqlite3_prepare_v2().
+** It functions in the same way as prepare_v2(), except that if a required
+** shared-cache lock cannot be obtained, this function may block waiting for
+** the lock to become available. In this scenario the normal API prepare_v2()
+** function always returns SQLITE_LOCKED.
+**
+** If this function returns SQLITE_LOCKED, the caller should rollback
+** the current transaction (if any) and try again later. Otherwise, the
+** system may become deadlocked.
+*/
+int sqlite3_blocking_prepare_v2(
+  sqlite3 *db,              /* Database handle. */
+  const char *zSql,         /* UTF-8 encoded SQL statement. */
+  int nSql,                 /* Length of zSql in bytes. */
+  sqlite3_stmt **ppStmt,    /* OUT: A pointer to the prepared statement */
+  const char **pz           /* OUT: End of parsed string */
+){
+  int rc;
+  while( SQLITE_LOCKED==(rc = sqlite3_prepare_v2(db, zSql, nSql, ppStmt, pz)) ){
+    rc = wait_for_unlock_notify(db);
+    if( rc!=SQLITE_OK ) break;
+  }
+  return rc;
+}
+/* END_SQLITE_BLOCKING_STEP */
+
+/*
+** Usage: sqlite3_blocking_step STMT
+**
+** Advance the statement to the next row.
+*/
+static int blocking_step_proc(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+
+  sqlite3_stmt *pStmt;
+  int rc;
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "STMT");
+    return TCL_ERROR;
+  }
+
+  pStmt = (sqlite3_stmt*)sqlite3TestTextToPtr(Tcl_GetString(objv[1]));
+  rc = sqlite3_blocking_step(pStmt);
+
+  Tcl_SetResult(interp, (char *)sqlite3TestErrorName(rc), 0);
+  return TCL_OK;
+}
+
+/*
+** Usage: sqlite3_blocking_prepare_v2 DB sql bytes ?tailvar?
+** Usage: sqlite3_nonblocking_prepare_v2 DB sql bytes ?tailvar?
+*/
+static int blocking_prepare_v2_proc(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  const char *zSql;
+  int bytes;
+  const char *zTail = 0;
+  sqlite3_stmt *pStmt = 0;
+  char zBuf[50];
+  int rc;
+  int isBlocking = !(clientData==0);
+
+  if( objc!=5 && objc!=4 ){
+    Tcl_AppendResult(interp, "wrong # args: should be \"", 
+       Tcl_GetString(objv[0]), " DB sql bytes tailvar", 0);
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  zSql = Tcl_GetString(objv[2]);
+  if( Tcl_GetIntFromObj(interp, objv[3], &bytes) ) return TCL_ERROR;
+
+  if( isBlocking ){
+    rc = sqlite3_blocking_prepare_v2(db, zSql, bytes, &pStmt, &zTail);
+  }else{
+    rc = sqlite3_prepare_v2(db, zSql, bytes, &pStmt, &zTail);
+  }
+
+  assert(rc==SQLITE_OK || pStmt==0);
+  if( zTail && objc>=5 ){
+    if( bytes>=0 ){
+      bytes = bytes - (zTail-zSql);
+    }
+    Tcl_ObjSetVar2(interp, objv[4], 0, Tcl_NewStringObj(zTail, bytes), 0);
+  }
+  if( rc!=SQLITE_OK ){
+    assert( pStmt==0 );
+    sprintf(zBuf, "%s ", (char *)sqlite3TestErrorName(rc));
+    Tcl_AppendResult(interp, zBuf, sqlite3_errmsg(db), 0);
+    return TCL_ERROR;
+  }
+
+  if( pStmt ){
+    if( sqlite3TestMakePointerStr(interp, zBuf, pStmt) ) return TCL_ERROR;
+    Tcl_AppendResult(interp, zBuf, 0);
+  }
+  return TCL_OK;
+}
+
+#endif /* SQLITE_OS_UNIX && SQLITE_ENABLE_UNLOCK_NOTIFY */
+/*
+** End of implementation of [sqlite3_blocking_step].
+************************************************************************/
+
+/*
+** Register commands with the TCL interpreter.
+*/
+int SqlitetestThread_Init(Tcl_Interp *interp){
+  Tcl_CreateObjCommand(interp, "sqlthread", sqlthread_proc, 0, 0);
+  Tcl_CreateObjCommand(interp, "clock_seconds", clock_seconds_proc, 0, 0);
+#if SQLITE_OS_UNIX && defined(SQLITE_ENABLE_UNLOCK_NOTIFY)
+  Tcl_CreateObjCommand(interp, "sqlite3_blocking_step", blocking_step_proc,0,0);
+  Tcl_CreateObjCommand(interp, 
+      "sqlite3_blocking_prepare_v2", blocking_prepare_v2_proc, (void *)1, 0);
+  Tcl_CreateObjCommand(interp, 
+      "sqlite3_nonblocking_prepare_v2", blocking_prepare_v2_proc, 0, 0);
+#endif
+  return TCL_OK;
+}
+#else
+int SqlitetestThread_Init(Tcl_Interp *interp){
+  return TCL_OK;
+}
+#endif