Add a test to ensure os_unix.c works with 64KiB OS pages.

FossilOrigin-Name: e3d2be3ba47cdaafd26347620ae3bc2813203f16

src/os_unix.c

@@ -323,6 +323,7 @@ static int posixFchown(int fd, uid_t uid, gid_t gid){
 
 /* Forward reference */
 static int openDirectory(const char*, int*);
+static int unixGetpagesize(void);
 
 /*
 ** Many system calls are accessed through pointer-to-functions so that
@@ -446,6 +447,9 @@ static struct unix_syscall {
 #define osMremap ((void*(*)(void*,size_t,size_t,int,...))aSyscall[23].pCurrent)
 #endif
 
+  { "getpagesize",  (sqlite3_syscall_ptr)unixGetpagesize, 0 },
+#define osGetpagesize ((int(*)(void))aSyscall[24].pCurrent)
+
 }; /* End of the overrideable system calls */
 
 /*
@@ -4107,8 +4111,11 @@ static int unixShmSystemLock(
 
 /*
 ** Return the system page size.
+**
+** This function should not be called directly by other code in this file. 
+** Instead, it should be called via macro osGetpagesize().
 */
-static int unixGetPagesize(void){
+static int unixGetpagesize(void){
 #if defined(_BSD_SOURCE)
   return getpagesize();
 #else
@@ -4127,7 +4134,7 @@ static int unixGetPagesize(void){
 */
 static int unixShmRegionPerMap(void){
   int shmsz = 32*1024;            /* SHM region size */
-  int pgsz = unixGetPagesize();   /* System page size */
+  int pgsz = osGetpagesize();   /* System page size */
   assert( ((pgsz-1)&pgsz)==0 );   /* Page size must be a power of 2 */
   if( pgsz<shmsz ) return 1;
   return pgsz/shmsz;
@@ -4710,7 +4717,7 @@ static void unixRemapfile(
 #if HAVE_MREMAP
     i64 nReuse = pFd->mmapSize;
 #else
-    const int szSyspage = unixGetPagesize();
+    const int szSyspage = osGetpagesize();
     i64 nReuse = (pFd->mmapSize & ~(szSyspage-1));
 #endif
     u8 *pReq = &pOrig[nReuse];
@@ -7458,7 +7465,7 @@ int sqlite3_os_init(void){
 
   /* Double-check that the aSyscall[] array has been constructed
   ** correctly.  See ticket [bb3a86e890c8e96ab] */
-  assert( ArraySize(aSyscall)==24 );
+  assert( ArraySize(aSyscall)==25 );
 
   /* Register all VFSes defined in the aVfs[] array */
   for(i=0; i<(sizeof(aVfs)/sizeof(sqlite3_vfs)); i++){

src/test_syscall.c

@@ -67,6 +67,11 @@
 **   test_syscall list
 **     Return a list of all system calls. The list is constructed using
 **     the xNextSystemCall() VFS method.
+**
+**   test_syscall pagesize PGSZ
+**     If PGSZ is a power of two greater than 256, install a wrapper around
+**     OS function getpagesize() that reports the system page size as PGSZ.
+**     Or, if PGSZ is less than zero, remove any wrapper already installed.
 */
 
 #include "sqliteInt.h"
@@ -89,7 +94,9 @@ static struct TestSyscallGlobal {
   int bPersist;                   /* 1 for persistent errors, 0 for transient */
   int nCount;                     /* Fail after this many more calls */
   int nFail;                      /* Number of failures that have occurred */
-} gSyscall = { 0, 0 };
+  int pgsz;
+  sqlite3_syscall_ptr orig_getpagesize;
+} gSyscall = { 0, 0, 0, 0, 0 };
 
 static int ts_open(const char *, int, int);
 static int ts_close(int fd);
@@ -650,6 +657,45 @@ static int test_syscall_defaultvfs(
   return TCL_OK;
 }
 
+static int ts_getpagesize(void){
+  return gSyscall.pgsz;
+}
+
+static int test_syscall_pagesize(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_vfs *pVfs = sqlite3_vfs_find(0);
+  int pgsz;
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 2, objv, "PGSZ");
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[2], &pgsz) ){
+    return TCL_ERROR;
+  }
+
+  if( pgsz<0 ){
+    if( gSyscall.orig_getpagesize ){
+      pVfs->xSetSystemCall(pVfs, "getpagesize", gSyscall.orig_getpagesize);
+    }
+  }else{
+    if( pgsz<512 || (pgsz & (pgsz-1)) ){
+      Tcl_AppendResult(interp, "pgsz out of range", 0);
+      return TCL_ERROR;
+    }
+    gSyscall.orig_getpagesize = pVfs->xGetSystemCall(pVfs, "getpagesize");
+    gSyscall.pgsz = pgsz;
+    pVfs->xSetSystemCall(
+        pVfs, "getpagesize", (sqlite3_syscall_ptr)ts_getpagesize
+    );
+  }
+
+  return TCL_OK;
+}
+
 static int test_syscall(
   void * clientData,
   Tcl_Interp *interp,
@@ -668,6 +714,7 @@ static int test_syscall(
     { "exists",     test_syscall_exists },
     { "list",       test_syscall_list },
     { "defaultvfs", test_syscall_defaultvfs },
+    { "pagesize",   test_syscall_pagesize },
     { 0, 0 }
   };
   int iCmd;