merge 5.5

7 files changed, 780 insertions, 32 deletions

diff --git a/mysys/CMakeLists.txt b/mysys/CMakeLists.txt
index c565f7f12d5..7397990eddb 100644
--- a/mysys/CMakeLists.txt
+++ b/mysys/CMakeLists.txt
@@ -37,7 +37,7 @@ SET(MYSYS_SOURCES  array.c charset-def.c charset.c checksum.c default.c
                 safemalloc.c my_new.cc
 				my_atomic.c my_getncpus.c my_safehash.c my_chmod.c my_rnd.c
                                 my_uuid.c wqueue.c waiting_threads.c ma_dyncol.c
-				my_rdtsc.c)
+				my_rdtsc.c my_context.c)
 
 IF (WIN32)
  SET (MYSYS_SOURCES ${MYSYS_SOURCES} my_winthread.c my_wincond.c my_winerr.c my_winfile.c my_windac.c my_conio.c)
diff --git a/mysys/my_access.c b/mysys/my_access.c
index 210946d50a8..d7d06f814d6 100644
--- a/mysys/my_access.c
+++ b/mysys/my_access.c
@@ -26,11 +26,6 @@
     path 	Path to file
     amode	Access method
  
-  DESCRIPTION
-    This function wraps the normal access method because the access 
-    available in MSVCRT> +reports that filenames such as LPT1 and 
-    COM1 are valid (they are but should not be so for us).
- 
   RETURN VALUES
   0    ok
   -1   error  (We use -1 as my_access is mapped to access on other platforms)
@@ -38,12 +33,11 @@
 
 int my_access(const char *path, int amode) 
 { 
-  WIN32_FILE_ATTRIBUTE_DATA fileinfo;
-  BOOL result;
-	
-  result= GetFileAttributesEx(path, GetFileExInfoStandard, &fileinfo);
-  if (! result ||
-      (fileinfo.dwFileAttributes & FILE_ATTRIBUTE_READONLY) && (amode & W_OK))
+  DWORD attributes;
+
+  attributes = GetFileAttributes(path);
+  if (attributes == INVALID_FILE_ATTRIBUTES ||
+      (attributes & FILE_ATTRIBUTE_READONLY) && (amode & W_OK))
   {
     my_errno= errno= EACCES;
     return -1;
diff --git a/mysys/my_context.c b/mysys/my_context.c
new file mode 100644
index 00000000000..d2374391a39
--- /dev/null
+++ b/mysys/my_context.c
@@ -0,0 +1,717 @@
+/*
+  Copyright 2011 Kristian Nielsen and Monty Program Ab
+
+  This file is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+  Implementation of async context spawning using Posix ucontext and
+  swapcontext().
+*/
+
+#include "mysys_priv.h"
+#include "m_string.h"
+#include "my_context.h"
+
+#ifdef HAVE_VALGRIND
+#include <valgrind/valgrind.h>
+#endif
+
+#ifdef MY_CONTEXT_USE_UCONTEXT
+/*
+  The makecontext() only allows to pass integers into the created context :-(
+  We want to pass pointers, so we do it this kinda hackish way.
+  Anyway, it should work everywhere, and at least it does not break strict
+  aliasing.
+*/
+union pass_void_ptr_as_2_int {
+  int a[2];
+  void *p;
+};
+
+
+/*
+  We use old-style function definition here, as this is passed to
+  makecontext(). And the type of the makecontext() argument does not match
+  the actual type (as the actual type can differ from call to call).
+*/
+static void
+my_context_spawn_internal(i0, i1)
+int i0, i1;
+{
+  int err;
+  struct my_context *c;
+  union pass_void_ptr_as_2_int u;
+
+  u.a[0]= i0;
+  u.a[1]= i1;
+  c= (struct my_context *)u.p;
+
+  (*c->user_func)(c->user_data);
+  c->active= 0;
+  err= setcontext(&c->base_context);
+  fprintf(stderr, "Aieie, setcontext() failed: %d (errno=%d)\n", err, errno);
+}
+
+
+int
+my_context_continue(struct my_context *c)
+{
+  int err;
+
+  if (!c->active)
+    return 0;
+
+  DBUG_SWAP_CODE_STATE(&c->dbug_state);
+  err= swapcontext(&c->base_context, &c->spawned_context);
+  DBUG_SWAP_CODE_STATE(&c->dbug_state);
+  if (err)
+  {
+    fprintf(stderr, "Aieie, swapcontext() failed: %d (errno=%d)\n",
+            err, errno);
+    return -1;
+  }
+
+  return c->active;
+}
+
+
+int
+my_context_spawn(struct my_context *c, void (*f)(void *), void *d)
+{
+  int err;
+  union pass_void_ptr_as_2_int u;
+
+  err= getcontext(&c->spawned_context);
+  if (err)
+    return -1;
+  c->spawned_context.uc_stack.ss_sp= c->stack;
+  c->spawned_context.uc_stack.ss_size= c->stack_size;
+  c->spawned_context.uc_link= NULL;
+  c->user_func= f;
+  c->user_data= d;
+  c->active= 1;
+  u.p= c;
+  makecontext(&c->spawned_context, my_context_spawn_internal, 2,
+              u.a[0], u.a[1]);
+
+  return my_context_continue(c);
+}
+
+
+int
+my_context_yield(struct my_context *c)
+{
+  int err;
+
+  if (!c->active)
+    return -1;
+
+  err= swapcontext(&c->spawned_context, &c->base_context);
+  if (err)
+    return -1;
+  return 0;
+}
+
+int
+my_context_init(struct my_context *c, size_t stack_size)
+{
+#if SIZEOF_CHARP > SIZEOF_INT*2
+#error Error: Unable to store pointer in 2 ints on this architecture
+#endif
+  bzero(c, sizeof(*c));
+  if (!(c->stack= malloc(stack_size)))
+    return -1;                                  /* Out of memory */
+  c->stack_size= stack_size;
+#ifdef HAVE_VALGRIND
+  c->valgrind_stack_id=
+    VALGRIND_STACK_REGISTER(c->stack, ((unsigned char *)(c->stack))+stack_size);
+#endif
+  return 0;
+}
+
+void
+my_context_destroy(struct my_context *c)
+{
+  if (c->stack)
+  {
+#ifdef HAVE_VALGRIND
+    VALGRIND_STACK_DEREGISTER(c->valgrind_stack_id);
+#endif
+    free(c->stack);
+  }
+  DBUG_FREE_CODE_STATE(&c->dbug_state);
+}
+
+#endif  /* MY_CONTEXT_USE_UCONTEXT */
+
+
+#ifdef MY_CONTEXT_USE_X86_64_GCC_ASM
+/*
+  GCC-amd64 implementation of my_context.
+
+  This is slightly optimized in the common case where we never yield
+  (eg. fetch next row and it is already fully received in buffer). In this
+  case we do not need to restore registers at return (though we still need to
+  save them as we cannot know if we will yield or not in advance).
+*/
+
+#include <stdint.h>
+#include <stdlib.h>
+
+/*
+  Layout of saved registers etc.
+  Since this is accessed through gcc inline assembler, it is simpler to just
+  use numbers than to try to define nice constants or structs.
+
+   0    0   %rsp
+   1    8   %rbp
+   2   16   %rbx
+   3   24   %r12
+   4   32   %r13
+   5   40   %r14
+   6   48   %r15
+   7   56   %rip for done
+   8   64   %rip for yield/continue
+*/
+
+int
+my_context_spawn(struct my_context *c, void (*f)(void *), void *d)
+{
+  int ret;
+
+  DBUG_SWAP_CODE_STATE(&c->dbug_state);
+
+  /*
+    There are 6 callee-save registers we need to save and restore when
+    suspending and continuing, plus stack pointer %rsp and instruction pointer
+    %rip.
+
+    However, if we never suspend, the user-supplied function will in any case
+    restore the 6 callee-save registers, so we can avoid restoring them in
+    this case.
+  */
+  __asm__ __volatile__
+    (
+     "movq %%rsp, (%[save])\n\t"
+     "movq %[stack], %%rsp\n\t"
+#if __GNUC__ >= 4 && __GNUC_MINOR__ >= 4
+     /*
+       This emits a DWARF DW_CFA_undefined directive to make the return address
+       undefined. This indicates that this is the top of the stack frame, and
+       helps tools that use DWARF stack unwinding to obtain stack traces.
+       (I use numeric constant to avoid a dependency on libdwarf includes).
+     */
+     ".cfi_escape 0x07, 16\n\t"
+#endif
+     "movq %%rbp, 8(%[save])\n\t"
+     "movq %%rbx, 16(%[save])\n\t"
+     "movq %%r12, 24(%[save])\n\t"
+     "movq %%r13, 32(%[save])\n\t"
+     "movq %%r14, 40(%[save])\n\t"
+     "movq %%r15, 48(%[save])\n\t"
+     "leaq 1f(%%rip), %%rax\n\t"
+     "leaq 2f(%%rip), %%rcx\n\t"
+     "movq %%rax, 56(%[save])\n\t"
+     "movq %%rcx, 64(%[save])\n\t"
+     /*
+       Constraint below puts the argument to the user function into %rdi, as
+       needed for the calling convention.
+     */
+     "callq *%[f]\n\t"
+     "jmpq *56(%[save])\n"
+     /*
+       Come here when operation is done.
+       We do not need to restore callee-save registers, as the called function
+       will do this for us if needed.
+     */
+     "1:\n\t"
+     "movq (%[save]), %%rsp\n\t"
+     "xorl %[ret], %[ret]\n\t"
+     "jmp 3f\n"
+     /* Come here when operation was suspended. */
+     "2:\n\t"
+     "movl $1, %[ret]\n"
+     "3:\n"
+     : [ret] "=a" (ret),
+       [f] "+S" (f),
+       /* Need this in %rdi to follow calling convention. */
+       [d] "+D" (d)
+     : [stack] "a" (c->stack_top),
+       /* Need this in callee-save register to preserve in function call. */
+       [save] "b" (&c->save[0])
+     : "rcx", "rdx", "r8", "r9", "r10", "r11", "memory", "cc"
+  );
+
+  DBUG_SWAP_CODE_STATE(&c->dbug_state);
+
+  return ret;
+}
+
+int
+my_context_continue(struct my_context *c)
+{
+  int ret;
+
+  DBUG_SWAP_CODE_STATE(&c->dbug_state);
+
+  __asm__ __volatile__
+    (
+     "movq (%[save]), %%rax\n\t"
+     "movq %%rsp, (%[save])\n\t"
+     "movq %%rax, %%rsp\n\t"
+     "movq 8(%[save]), %%rax\n\t"
+     "movq %%rbp, 8(%[save])\n\t"
+     "movq %%rax, %%rbp\n\t"
+     "movq 24(%[save]), %%rax\n\t"
+     "movq %%r12, 24(%[save])\n\t"
+     "movq %%rax, %%r12\n\t"
+     "movq 32(%[save]), %%rax\n\t"
+     "movq %%r13, 32(%[save])\n\t"
+     "movq %%rax, %%r13\n\t"
+     "movq 40(%[save]), %%rax\n\t"
+     "movq %%r14, 40(%[save])\n\t"
+     "movq %%rax, %%r14\n\t"
+     "movq 48(%[save]), %%rax\n\t"
+     "movq %%r15, 48(%[save])\n\t"
+     "movq %%rax, %%r15\n\t"
+
+     "leaq 1f(%%rip), %%rax\n\t"
+     "leaq 2f(%%rip), %%rcx\n\t"
+     "movq %%rax, 56(%[save])\n\t"
+     "movq 64(%[save]), %%rax\n\t"
+     "movq %%rcx, 64(%[save])\n\t"
+
+     "movq 16(%[save]), %%rcx\n\t"
+     "movq %%rbx, 16(%[save])\n\t"
+     "movq %%rcx, %%rbx\n\t"
+
+     "jmpq *%%rax\n"
+     /*
+       Come here when operation is done.
+       Be sure to use the same callee-save register for %[save] here and in
+       my_context_spawn(), so we preserve the value correctly at this point.
+     */
+     "1:\n\t"
+     "movq (%[save]), %%rsp\n\t"
+     "movq 8(%[save]), %%rbp\n\t"
+     /* %rbx is preserved from my_context_spawn() in this case. */
+     "movq 24(%[save]), %%r12\n\t"
+     "movq 32(%[save]), %%r13\n\t"
+     "movq 40(%[save]), %%r14\n\t"
+     "movq 48(%[save]), %%r15\n\t"
+     "xorl %[ret], %[ret]\n\t"
+     "jmp 3f\n"
+     /* Come here when operation is suspended. */
+     "2:\n\t"
+     "movl $1, %[ret]\n"
+     "3:\n"
+     : [ret] "=a" (ret)
+     : /* Need this in callee-save register to preserve in function call. */
+       [save] "b" (&c->save[0])
+     : "rcx", "rdx", "rsi", "rdi", "r8", "r9", "r10", "r11", "memory", "cc"
+        );
+
+  DBUG_SWAP_CODE_STATE(&c->dbug_state);
+
+  return ret;
+}
+
+int
+my_context_yield(struct my_context *c)
+{
+  uint64_t *save= &c->save[0];
+  __asm__ __volatile__
+    (
+     "movq (%[save]), %%rax\n\t"
+     "movq %%rsp, (%[save])\n\t"
+     "movq %%rax, %%rsp\n\t"
+     "movq 8(%[save]), %%rax\n\t"
+     "movq %%rbp, 8(%[save])\n\t"
+     "movq %%rax, %%rbp\n\t"
+     "movq 16(%[save]), %%rax\n\t"
+     "movq %%rbx, 16(%[save])\n\t"
+     "movq %%rax, %%rbx\n\t"
+     "movq 24(%[save]), %%rax\n\t"
+     "movq %%r12, 24(%[save])\n\t"
+     "movq %%rax, %%r12\n\t"
+     "movq 32(%[save]), %%rax\n\t"
+     "movq %%r13, 32(%[save])\n\t"
+     "movq %%rax, %%r13\n\t"
+     "movq 40(%[save]), %%rax\n\t"
+     "movq %%r14, 40(%[save])\n\t"
+     "movq %%rax, %%r14\n\t"
+     "movq 48(%[save]), %%rax\n\t"
+     "movq %%r15, 48(%[save])\n\t"
+     "movq %%rax, %%r15\n\t"
+     "movq 64(%[save]), %%rax\n\t"
+     "leaq 1f(%%rip), %%rcx\n\t"
+     "movq %%rcx, 64(%[save])\n\t"
+
+     "jmpq *%%rax\n"
+
+     "1:\n"
+     : [save] "+D" (save)
+     :
+     : "rax", "rcx", "rdx", "rsi", "r8", "r9", "r10", "r11", "memory", "cc"
+     );
+  return 0;
+}
+
+int
+my_context_init(struct my_context *c, size_t stack_size)
+{
+  bzero(c, sizeof(*c));
+
+  if (!(c->stack_bot= malloc(stack_size)))
+    return -1;                                  /* Out of memory */
+  /*
+    The x86_64 ABI specifies 16-byte stack alignment.
+    Also put two zero words at the top of the stack.
+  */
+  c->stack_top= (void *)
+    (( ((intptr)c->stack_bot + stack_size) & ~(intptr)0xf) - 16);
+  bzero(c->stack_top, 16);
+
+#ifdef HAVE_VALGRIND
+  c->valgrind_stack_id=
+    VALGRIND_STACK_REGISTER(c->stack_bot, c->stack_top);
+#endif
+  return 0;
+}
+
+void
+my_context_destroy(struct my_context *c)
+{
+  if (c->stack_bot)
+  {
+    free(c->stack_bot);
+#ifdef HAVE_VALGRIND
+    VALGRIND_STACK_DEREGISTER(c->valgrind_stack_id);
+#endif
+  }
+  DBUG_FREE_CODE_STATE(&c->dbug_state);
+}
+
+#endif  /* MY_CONTEXT_USE_X86_64_GCC_ASM */
+
+
+#ifdef MY_CONTEXT_USE_I386_GCC_ASM
+/*
+  GCC-i386 implementation of my_context.
+
+  This is slightly optimized in the common case where we never yield
+  (eg. fetch next row and it is already fully received in buffer). In this
+  case we do not need to restore registers at return (though we still need to
+  save them as we cannot know if we will yield or not in advance).
+*/
+
+#include <stdint.h>
+#include <stdlib.h>
+
+/*
+  Layout of saved registers etc.
+  Since this is accessed through gcc inline assembler, it is simpler to just
+  use numbers than to try to define nice constants or structs.
+
+   0    0   %esp
+   1    4   %ebp
+   2    8   %ebx
+   3   12   %esi
+   4   16   %edi
+   5   20   %eip for done
+   6   24   %eip for yield/continue
+*/
+
+int
+my_context_spawn(struct my_context *c, void (*f)(void *), void *d)
+{
+  int ret;
+
+  DBUG_SWAP_CODE_STATE(&c->dbug_state);
+
+  /*
+    There are 4 callee-save registers we need to save and restore when
+    suspending and continuing, plus stack pointer %esp and instruction pointer
+    %eip.
+
+    However, if we never suspend, the user-supplied function will in any case
+    restore the 4 callee-save registers, so we can avoid restoring them in
+    this case.
+  */
+  __asm__ __volatile__
+    (
+     "movl %%esp, (%[save])\n\t"
+     "movl %[stack], %%esp\n\t"
+     /* Push the parameter on the stack. */
+     "pushl %[d]\n\t"
+     "movl %%ebp, 4(%[save])\n\t"
+     "movl %%ebx, 8(%[save])\n\t"
+     "movl %%esi, 12(%[save])\n\t"
+     "movl %%edi, 16(%[save])\n\t"
+     /* Get label addresses in -fPIC-compatible way (no pc-relative on 32bit) */
+     "call 1f\n"
+     "1:\n\t"
+     "popl %%eax\n\t"
+     "addl $(2f-1b), %%eax\n\t"
+     "movl %%eax, 20(%[save])\n\t"
+     "addl $(3f-2f), %%eax\n\t"
+     "movl %%eax, 24(%[save])\n\t"
+     "call *%[f]\n\t"
+     "jmp *20(%[save])\n"
+     /*
+       Come here when operation is done.
+       We do not need to restore callee-save registers, as the called function
+       will do this for us if needed.
+     */
+     "2:\n\t"
+     "movl (%[save]), %%esp\n\t"
+     "xorl %[ret], %[ret]\n\t"
+     "jmp 4f\n"
+     /* Come here when operation was suspended. */
+     "3:\n\t"
+     "movl $1, %[ret]\n"
+     "4:\n"
+     : [ret] "=a" (ret)
+     : [stack] "a" (c->stack_top),
+       /* Need this in callee-save register to preserve across function call. */
+       [save] "D" (&c->save[0]),
+       [f] "m" (f),
+       [d] "m" (d)
+     : "ecx", "edx", "memory", "cc"
+  );
+
+  DBUG_SWAP_CODE_STATE(&c->dbug_state);
+
+  return ret;
+}
+
+int
+my_context_continue(struct my_context *c)
+{
+  int ret;
+
+  DBUG_SWAP_CODE_STATE(&c->dbug_state);
+
+  __asm__ __volatile__
+    (
+     "movl (%[save]), %%eax\n\t"
+     "movl %%esp, (%[save])\n\t"
+     "movl %%eax, %%esp\n\t"
+     "movl 4(%[save]), %%eax\n\t"
+     "movl %%ebp, 4(%[save])\n\t"
+     "movl %%eax, %%ebp\n\t"
+     "movl 8(%[save]), %%eax\n\t"
+     "movl %%ebx, 8(%[save])\n\t"
+     "movl %%eax, %%ebx\n\t"
+     "movl 12(%[save]), %%eax\n\t"
+     "movl %%esi, 12(%[save])\n\t"
+     "movl %%eax, %%esi\n\t"
+
+     "movl 24(%[save]), %%eax\n\t"
+     "call 1f\n"
+     "1:\n\t"
+     "popl %%ecx\n\t"
+     "addl $(2f-1b), %%ecx\n\t"
+     "movl %%ecx, 20(%[save])\n\t"
+     "addl $(3f-2f), %%ecx\n\t"
+     "movl %%ecx, 24(%[save])\n\t"
+
+     /* Must restore %edi last as it is also our %[save] register. */
+     "movl 16(%[save]), %%ecx\n\t"
+     "movl %%edi, 16(%[save])\n\t"
+     "movl %%ecx, %%edi\n\t"
+
+     "jmp *%%eax\n"
+     /*
+       Come here when operation is done.
+       Be sure to use the same callee-save register for %[save] here and in
+       my_context_spawn(), so we preserve the value correctly at this point.
+     */
+     "2:\n\t"
+     "movl (%[save]), %%esp\n\t"
+     "movl 4(%[save]), %%ebp\n\t"
+     "movl 8(%[save]), %%ebx\n\t"
+     "movl 12(%[save]), %%esi\n\t"
+     "movl 16(%[save]), %%edi\n\t"
+     "xorl %[ret], %[ret]\n\t"
+     "jmp 4f\n"
+     /* Come here when operation is suspended. */
+     "3:\n\t"
+     "movl $1, %[ret]\n"
+     "4:\n"
+     : [ret] "=a" (ret)
+     : /* Need this in callee-save register to preserve in function call. */
+       [save] "D" (&c->save[0])
+     : "ecx", "edx", "memory", "cc"
+        );
+
+  DBUG_SWAP_CODE_STATE(&c->dbug_state);
+
+  return ret;
+}
+
+int
+my_context_yield(struct my_context *c)
+{
+  uint64_t *save= &c->save[0];
+  __asm__ __volatile__
+    (
+     "movl (%[save]), %%eax\n\t"
+     "movl %%esp, (%[save])\n\t"
+     "movl %%eax, %%esp\n\t"
+     "movl 4(%[save]), %%eax\n\t"
+     "movl %%ebp, 4(%[save])\n\t"
+     "movl %%eax, %%ebp\n\t"
+     "movl 8(%[save]), %%eax\n\t"
+     "movl %%ebx, 8(%[save])\n\t"
+     "movl %%eax, %%ebx\n\t"
+     "movl 12(%[save]), %%eax\n\t"
+     "movl %%esi, 12(%[save])\n\t"
+     "movl %%eax, %%esi\n\t"
+     "movl 16(%[save]), %%eax\n\t"
+     "movl %%edi, 16(%[save])\n\t"
+     "movl %%eax, %%edi\n\t"
+
+     "movl 24(%[save]), %%eax\n\t"
+     "call 1f\n"
+     "1:\n\t"
+     "popl %%ecx\n\t"
+     "addl $(2f-1b), %%ecx\n\t"
+     "movl %%ecx, 24(%[save])\n\t"
+
+     "jmp *%%eax\n"
+
+     "2:\n"
+     : [save] "+d" (save)
+     :
+     : "eax", "ecx", "memory", "cc"
+     );
+  return 0;
+}
+
+int
+my_context_init(struct my_context *c, size_t stack_size)
+{
+  bzero(c, sizeof(*c));
+  if (!(c->stack_bot= malloc(stack_size)))
+    return -1;                                  /* Out of memory */
+  c->stack_top= (void *)
+    (( ((intptr)c->stack_bot + stack_size) & ~(intptr)0xf) - 16);
+  bzero(c->stack_top, 16);
+
+#ifdef HAVE_VALGRIND
+  c->valgrind_stack_id=
+    VALGRIND_STACK_REGISTER(c->stack_bot, c->stack_top);
+#endif
+  return 0;
+}
+
+void
+my_context_destroy(struct my_context *c)
+{
+  if (c->stack_bot)
+  {
+    free(c->stack_bot);
+#ifdef HAVE_VALGRIND
+    VALGRIND_STACK_DEREGISTER(c->valgrind_stack_id);
+#endif
+  }
+  DBUG_FREE_CODE_STATE(&c->dbug_state);
+}
+
+#endif  /* MY_CONTEXT_USE_I386_GCC_ASM */
+
+
+#ifdef MY_CONTEXT_USE_WIN32_FIBERS
+int
+my_context_yield(struct my_context *c)
+{
+  c->return_value= 1;
+  SwitchToFiber(c->app_fiber);
+  return 0;
+}
+
+
+static void WINAPI
+my_context_trampoline(void *p)
+{
+  struct my_context *c= (struct my_context *)p;
+  /*
+    Reuse the Fiber by looping infinitely, each time we are scheduled we
+    spawn the appropriate function and switch back when it is done.
+
+    This way we avoid the overhead of CreateFiber() for every asynchroneous
+    operation.
+  */
+  for(;;)
+  {
+    (*(c->user_func))(c->user_arg);
+    c->return_value= 0;
+    SwitchToFiber(c->app_fiber);
+  }
+}
+
+int
+my_context_init(struct my_context *c, size_t stack_size)
+{
+  bzero(c, sizeof(*c));
+  c->lib_fiber= CreateFiber(stack_size, my_context_trampoline, c);
+  if (c->lib_fiber)
+    return 0;
+  return -1;
+}
+
+void
+my_context_destroy(struct my_context *c)
+{
+  DBUG_FREE_CODE_STATE(&c->dbug_state);
+  if (c->lib_fiber)
+  {
+    DeleteFiber(c->lib_fiber);
+    c->lib_fiber= NULL;
+  }
+}
+
+int
+my_context_spawn(struct my_context *c, void (*f)(void *), void *d)
+{
+  void *current_fiber;
+  c->user_func= f;
+  c->user_arg= d;
+  /*
+    This seems to be a common trick to run ConvertThreadToFiber() only on the
+    first occurence in a thread, in a way that works on multiple Windows
+    versions.
+  */
+  current_fiber= GetCurrentFiber();
+  if (current_fiber == NULL || current_fiber == (void *)0x1e00)
+    current_fiber= ConvertThreadToFiber(c);
+  c->app_fiber= current_fiber;
+  DBUG_SWAP_CODE_STATE(&c->dbug_state);
+  SwitchToFiber(c->lib_fiber);
+  DBUG_SWAP_CODE_STATE(&c->dbug_state);
+  return c->return_value;
+}
+
+int
+my_context_continue(struct my_context *c)
+{
+  DBUG_SWAP_CODE_STATE(&c->dbug_state);
+  SwitchToFiber(c->lib_fiber);
+  DBUG_SWAP_CODE_STATE(&c->dbug_state);
+  return c->return_value;
+}
+
+#endif  /* MY_CONTEXT_USE_WIN32_FIBERS */
diff --git a/mysys/my_init.c b/mysys/my_init.c
index abb0c0d7824..bb72d0e0426 100644
--- a/mysys/my_init.c
+++ b/mysys/my_init.c
@@ -1,5 +1,6 @@
 /*
    Copyright (c) 2000, 2011, Oracle and/or its affiliates
+   Copyright (c) 2009, 2011, Monty Program Ab
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
diff --git a/mysys/stacktrace.c b/mysys/stacktrace.c
index 30c9fafcb82..db51195db25 100644
--- a/mysys/stacktrace.c
+++ b/mysys/stacktrace.c
@@ -163,7 +163,7 @@ void my_print_stacktrace(uchar* stack_bottom __attribute__((unused)),
     my_safe_printf_stderr("%s",
       "Error when traversing the stack, stack appears corrupt.\n");
   else
-    my_safe_printf_stderr("%s"
+    my_safe_printf_stderr("%s",
       "Please read "
       "http://dev.mysql.com/doc/refman/5.1/en/resolve-stack-dump.html\n"
       "and follow instructions on how to resolve the stack trace.\n"
@@ -499,10 +499,11 @@ static void add_to_symbol_path(char *path, size_t path_buffer_size,
 }
 
 /*
-  Get symbol path - semicolon-separated list of directories to search for debug
-  symbols. We expect PDB in the same directory as corresponding exe or dll,
-  so the path is build from directories of the loaded modules. If environment
-  variable _NT_SYMBOL_PATH is set, it's value appended to the symbol search path
+  Get symbol path - semicolon-separated list of directories to search
+  for debug symbols. We expect PDB in the same directory as
+  corresponding exe or dll, so the path is build from directories of
+  the loaded modules. If environment variable _NT_SYMBOL_PATH is set,
+  it's value appended to the symbol search path
 */
 static void get_symbol_path(char *path, size_t size)
 { 
@@ -640,9 +641,9 @@ void my_print_stacktrace(uchar* unused1, ulong unused2)
     if(!have_module)
     {
       /*
-        ModuleInfo structure has been "compatibly" extended in releases after XP,
-        and its size was increased. To make XP dbghelp.dll function
-        happy, pretend passing the old structure.
+        ModuleInfo structure has been "compatibly" extended in
+        releases after XP, and its size was increased. To make XP
+        dbghelp.dll function happy, pretend passing the old structure.
       */
       module.SizeOfStruct= MODULE64_SIZE_WINXP;
       have_module= SymGetModuleInfo64(hProcess, addr, &module);
diff --git a/mysys/thr_lock.c b/mysys/thr_lock.c
index c3a99d78d25..e99956f9c8f 100644
--- a/mysys/thr_lock.c
+++ b/mysys/thr_lock.c
@@ -1,5 +1,6 @@
 /*
    Copyright (c) 2000, 2011, Oracle and/or its affiliates
+   Copyright (c) 2012, Monty Program Ab
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -176,7 +177,8 @@ thr_lock_owner_equal(THR_LOCK_INFO *rhs, THR_LOCK_INFO *lhs)
 static uint found_errors=0;
 
 static int check_lock(struct st_lock_list *list, const char* lock_type,
-		      const char *where, my_bool same_owner, my_bool no_cond)
+		      const char *where, my_bool same_owner, my_bool no_cond,
+                      my_bool read_lock)
 {
   THR_LOCK_DATA *data,**prev;
   uint count=0;
@@ -189,6 +191,23 @@ static int check_lock(struct st_lock_list *list, const char* lock_type,
 
     for (data=list->data; data && count++ < MAX_LOCKS ; data=data->next)
     {
+      if (data->type == TL_UNLOCK)
+      {
+	fprintf(stderr,
+		"Warning: Found unlocked lock at %s: %s\n",
+                lock_type, where);
+        return 1;
+      }
+      if ((read_lock && data->type > TL_READ_NO_INSERT) ||
+          (!read_lock && data->type <= TL_READ_NO_INSERT))
+      {
+	fprintf(stderr,
+		"Warning: Found %s lock in %s queue at %s: %s\n",
+                read_lock ? "write" : "read",
+                read_lock ? "read" : "write",
+                lock_type, where);
+        return 1;
+      }
       if (data->type != last_lock_type)
 	last_lock_type=TL_IGNORE;
       if (data->prev != prev)
@@ -245,11 +264,14 @@ static void check_locks(THR_LOCK *lock, const char *where,
 
   if (found_errors < MAX_FOUND_ERRORS)
   {
-    if (check_lock(&lock->write,"write",where,1,1) |
-	check_lock(&lock->write_wait,"write_wait",where,0,0) |
-	check_lock(&lock->read,"read",where,0,1) |
-	check_lock(&lock->read_wait,"read_wait",where,0,0))
+    if (check_lock(&lock->write,"write",where,1,1,0) |
+	check_lock(&lock->write_wait,"write_wait",where,0,0,0) |
+	check_lock(&lock->read,"read",where,0,1,1) |
+	check_lock(&lock->read_wait,"read_wait",where,0,0,1))
+    {
+      DBUG_ASSERT(my_assert_on_error == 0);
       found_errors++;
+    }
 
     if (found_errors < MAX_FOUND_ERRORS)
     {
@@ -625,17 +647,16 @@ wait_for_lock(struct st_lock_list *wait, THR_LOCK_DATA *data,
 
 
 static enum enum_thr_lock_result
-thr_lock(THR_LOCK_DATA *data, THR_LOCK_INFO *owner,
-         enum thr_lock_type lock_type, ulong lock_wait_timeout)
+thr_lock(THR_LOCK_DATA *data, THR_LOCK_INFO *owner, ulong lock_wait_timeout)
 {
   THR_LOCK *lock=data->lock;
   enum enum_thr_lock_result result= THR_LOCK_SUCCESS;
   struct st_lock_list *wait_queue;
+  enum thr_lock_type lock_type= data->type;
   DBUG_ENTER("thr_lock");
 
   data->next=0;
   data->cond=0;					/* safety */
-  data->type=lock_type;
   data->owner= owner;                           /* Must be reset ! */
   data->priority&= ~THR_LOCK_LATE_PRIV;
   mysql_mutex_lock(&lock->mutex);
@@ -968,9 +989,7 @@ void thr_unlock(THR_LOCK_DATA *data, uint unlock_flags)
   if (lock_type == TL_READ_NO_INSERT)
     lock->read_no_write_count--;
   data->type=TL_UNLOCK;				/* Mark unlocked */
-  check_locks(lock,"after releasing lock", lock_type, 1);
   wake_up_waiters(lock);
-  check_locks(lock,"end of thr_unlock", lock_type, 1);
   mysql_mutex_unlock(&lock->mutex);
   DBUG_VOID_RETURN;
 }
@@ -990,6 +1009,7 @@ static void wake_up_waiters(THR_LOCK *lock)
   enum thr_lock_type lock_type;
   DBUG_ENTER("wake_up_waiters");
 
+  check_locks(lock, "before waking up waiters", TL_UNLOCK, 1);
   if (!lock->write.data)			/* If no active write locks */
   {
     data=lock->write_wait.data;
@@ -1144,8 +1164,7 @@ thr_multi_lock(THR_LOCK_DATA **data, uint count, THR_LOCK_INFO *owner,
   /* lock everything */
   for (pos=data,end=data+count; pos < end ; pos++)
   {
-    enum enum_thr_lock_result result= thr_lock(*pos, owner, (*pos)->type,
-                                               lock_wait_timeout);
+    enum enum_thr_lock_result result= thr_lock(*pos, owner, lock_wait_timeout);
     if (result != THR_LOCK_SUCCESS)
     {						/* Aborted */
       thr_multi_unlock(data,(uint) (pos-data), 0);
diff --git a/mysys/wqueue.c b/mysys/wqueue.c
index b6f52ba5c31..2fcced14f77 100644
--- a/mysys/wqueue.c
+++ b/mysys/wqueue.c
@@ -1,3 +1,19 @@
+/*
+   Copyright (c) 2007, 2008, Sun Microsystems, Inc,
+   Copyright (c) 2011, 2012, Monty Program Ab
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
 #include <wqueue.h>