diff options
author | Vladislav Vaintroub <vvaintroub@mysql.com> | 2009-11-25 01:50:10 +0100 |
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committer | Vladislav Vaintroub <vvaintroub@mysql.com> | 2009-11-25 01:50:10 +0100 |
commit | a3e391dd3c5550b39eab3bd8964061c5bbc6a6b2 (patch) | |
tree | 3e8610a140fd90a32965b4a7851c798a353fa14f /mysys | |
parent | afe4ee1e17edd8edbdc2d142da8ada747e759ea9 (diff) | |
parent | bd6467805a4d232718589f8ba0f2b84493843aba (diff) | |
download | mariadb-git-a3e391dd3c5550b39eab3bd8964061c5bbc6a6b2.tar.gz |
merge
Diffstat (limited to 'mysys')
-rwxr-xr-x | mysys/CMakeLists.txt | 4 | ||||
-rw-r--r-- | mysys/Makefile.am | 3 | ||||
-rw-r--r-- | mysys/lf_alloc-pin.c | 534 | ||||
-rw-r--r-- | mysys/lf_dynarray.c | 207 | ||||
-rw-r--r-- | mysys/lf_hash.c | 505 | ||||
-rw-r--r-- | mysys/my_atomic.c | 33 | ||||
-rw-r--r-- | mysys/my_getncpus.c | 34 | ||||
-rw-r--r-- | mysys/my_thr_init.c | 3 |
8 files changed, 1307 insertions, 16 deletions
diff --git a/mysys/CMakeLists.txt b/mysys/CMakeLists.txt index 07ca44244fc..5f271d0a4a3 100755 --- a/mysys/CMakeLists.txt +++ b/mysys/CMakeLists.txt @@ -33,7 +33,9 @@ SET(MYSYS_SOURCES array.c charset-def.c charset.c checksum.c default.c default_ my_static.c my_symlink.c my_symlink2.c my_sync.c my_thr_init.c my_write.c ptr_cmp.c queues.c stacktrace.c rijndael.c safemalloc.c sha1.c string.c thr_alarm.c thr_lock.c thr_mutex.c - thr_rwlock.c tree.c typelib.c my_vle.c base64.c my_memmem.c my_getpagesize.c) + thr_rwlock.c tree.c typelib.c my_vle.c base64.c my_memmem.c my_getpagesize.c + lf_alloc-pin.c lf_dynarray.c lf_hash.c + my_atomic.c my_getncpus.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/Makefile.am b/mysys/Makefile.am index 68fde34ee07..3b53fc1dd59 100644 --- a/mysys/Makefile.am +++ b/mysys/Makefile.am @@ -30,7 +30,8 @@ libmysys_a_SOURCES = my_init.c my_getwd.c mf_getdate.c my_mmap.c \ mf_tempdir.c my_lock.c mf_brkhant.c my_alarm.c \ my_malloc.c my_realloc.c my_once.c mulalloc.c \ my_alloc.c safemalloc.c my_new.cc \ - my_vle.c my_atomic.c \ + my_vle.c my_atomic.c lf_hash.c \ + lf_dynarray.c lf_alloc-pin.c \ my_fopen.c my_fstream.c my_getsystime.c \ my_error.c errors.c my_div.c my_messnc.c \ mf_format.c mf_same.c mf_dirname.c mf_fn_ext.c \ diff --git a/mysys/lf_alloc-pin.c b/mysys/lf_alloc-pin.c new file mode 100644 index 00000000000..fda9b97791d --- /dev/null +++ b/mysys/lf_alloc-pin.c @@ -0,0 +1,534 @@ +/* QQ: TODO multi-pinbox */ +/* Copyright (C) 2006-2008 MySQL AB, 2008-2009 Sun Microsystems, Inc. + + 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 */ + +/* + wait-free concurrent allocator based on pinning addresses + + It works as follows: every thread (strictly speaking - every CPU, but + it's too difficult to do) has a small array of pointers. They're called + "pins". Before using an object its address must be stored in this array + (pinned). When an object is no longer necessary its address must be + removed from this array (unpinned). When a thread wants to free() an + object it scans all pins of all threads to see if somebody has this + object pinned. If yes - the object is not freed (but stored in a + "purgatory"). To reduce the cost of a single free() pins are not scanned + on every free() but only added to (thread-local) purgatory. On every + LF_PURGATORY_SIZE free() purgatory is scanned and all unpinned objects + are freed. + + Pins are used to solve ABA problem. To use pins one must obey + a pinning protocol: + + 1. Let's assume that PTR is a shared pointer to an object. Shared means + that any thread may modify it anytime to point to a different object + and free the old object. Later the freed object may be potentially + allocated by another thread. If we're unlucky that other thread may + set PTR to point to this object again. This is ABA problem. + 2. Create a local pointer LOCAL_PTR. + 3. Pin the PTR in a loop: + do + { + LOCAL_PTR= PTR; + pin(PTR, PIN_NUMBER); + } while (LOCAL_PTR != PTR) + 4. It is guaranteed that after the loop has ended, LOCAL_PTR + points to an object (or NULL, if PTR may be NULL), that + will never be freed. It is not guaranteed though + that LOCAL_PTR == PTR (as PTR can change any time) + 5. When done working with the object, remove the pin: + unpin(PIN_NUMBER) + 6. When copying pins (as in the list traversing loop: + pin(CUR, 1); + while () + { + do // standard + { // pinning + NEXT=CUR->next; // loop + pin(NEXT, 0); // see #3 + } while (NEXT != CUR->next); // above + ... + ... + CUR=NEXT; + pin(CUR, 1); // copy pin[0] to pin[1] + } + which keeps CUR address constantly pinned), note than pins may be + copied only upwards (!!!), that is pin[N] to pin[M], M > N. + 7. Don't keep the object pinned longer than necessary - the number of + pins you have is limited (and small), keeping an object pinned + prevents its reuse and cause unnecessary mallocs. + + Explanations: + + 3. The loop is important. The following can occur: + thread1> LOCAL_PTR= PTR + thread2> free(PTR); PTR=0; + thread1> pin(PTR, PIN_NUMBER); + now thread1 cannot access LOCAL_PTR, even if it's pinned, + because it points to a freed memory. That is, it *must* + verify that it has indeed pinned PTR, the shared pointer. + + 6. When a thread wants to free some LOCAL_PTR, and it scans + all lists of pins to see whether it's pinned, it does it + upwards, from low pin numbers to high. Thus another thread + must copy an address from one pin to another in the same + direction - upwards, otherwise the scanning thread may + miss it. + + Implementation details: + + Pins are given away from a "pinbox". Pinbox is stack-based allocator. + It used dynarray for storing pins, new elements are allocated by dynarray + as necessary, old are pushed in the stack for reuse. ABA is solved by + versioning a pointer - because we use an array, a pointer to pins is 16 bit, + upper 16 bits are used for a version. + + It is assumed that pins belong to a THD and are not transferable + between THD's (LF_PINS::stack_ends_here being a primary reason + for this limitation). +*/ +#include <my_global.h> +#include <my_sys.h> +#include <lf.h> + +#define LF_PINBOX_MAX_PINS 65536 + +static void _lf_pinbox_real_free(LF_PINS *pins); + +/* + Initialize a pinbox. Normally called from lf_alloc_init. + See the latter for details. +*/ +void lf_pinbox_init(LF_PINBOX *pinbox, uint free_ptr_offset, + lf_pinbox_free_func *free_func, void *free_func_arg) +{ + DBUG_ASSERT(free_ptr_offset % sizeof(void *) == 0); + compile_time_assert(sizeof(LF_PINS) == 64); + lf_dynarray_init(&pinbox->pinarray, sizeof(LF_PINS)); + pinbox->pinstack_top_ver= 0; + pinbox->pins_in_array= 0; + pinbox->free_ptr_offset= free_ptr_offset; + pinbox->free_func= free_func; + pinbox->free_func_arg= free_func_arg; +} + +void lf_pinbox_destroy(LF_PINBOX *pinbox) +{ + lf_dynarray_destroy(&pinbox->pinarray); +} + +/* + Get pins from a pinbox. Usually called via lf_alloc_get_pins() or + lf_hash_get_pins(). + + SYNOPSYS + pinbox - + + DESCRIPTION + get a new LF_PINS structure from a stack of unused pins, + or allocate a new one out of dynarray. + + NOTE + It is assumed that pins belong to a thread and are not transferable + between threads. +*/ +LF_PINS *_lf_pinbox_get_pins(LF_PINBOX *pinbox) +{ + uint32 pins, next, top_ver; + LF_PINS *el; + /* + We have an array of max. 64k elements. + The highest index currently allocated is pinbox->pins_in_array. + Freed elements are in a lifo stack, pinstack_top_ver. + pinstack_top_ver is 32 bits; 16 low bits are the index in the + array, to the first element of the list. 16 high bits are a version + (every time the 16 low bits are updated, the 16 high bits are + incremented). Versioniong prevents the ABA problem. + */ + top_ver= pinbox->pinstack_top_ver; + do + { + if (!(pins= top_ver % LF_PINBOX_MAX_PINS)) + { + /* the stack of free elements is empty */ + pins= my_atomic_add32((int32 volatile*) &pinbox->pins_in_array, 1)+1; + if (unlikely(pins >= LF_PINBOX_MAX_PINS)) + return 0; + /* + note that the first allocated element has index 1 (pins==1). + index 0 is reserved to mean "NULL pointer" + */ + el= (LF_PINS *)_lf_dynarray_lvalue(&pinbox->pinarray, pins); + if (unlikely(!el)) + return 0; + break; + } + el= (LF_PINS *)_lf_dynarray_value(&pinbox->pinarray, pins); + next= el->link; + } while (!my_atomic_cas32((int32 volatile*) &pinbox->pinstack_top_ver, + (int32*) &top_ver, + top_ver-pins+next+LF_PINBOX_MAX_PINS)); + /* + set el->link to the index of el in the dynarray (el->link has two usages: + - if element is allocated, it's its own index + - if element is free, it's its next element in the free stack + */ + el->link= pins; + el->purgatory_count= 0; + el->pinbox= pinbox; + el->stack_ends_here= & my_thread_var->stack_ends_here; + return el; +} + +/* + Put pins back to a pinbox. Usually called via lf_alloc_put_pins() or + lf_hash_put_pins(). + + DESCRIPTION + empty the purgatory (XXX deadlock warning below!), + push LF_PINS structure to a stack +*/ +void _lf_pinbox_put_pins(LF_PINS *pins) +{ + LF_PINBOX *pinbox= pins->pinbox; + uint32 top_ver, nr; + nr= pins->link; +#ifdef MY_LF_EXTRA_DEBUG + { + int i; + for (i= 0; i < LF_PINBOX_PINS; i++) + DBUG_ASSERT(pins->pin[i] == 0); + } +#endif + /* + XXX this will deadlock if other threads will wait for + the caller to do something after _lf_pinbox_put_pins(), + and they would have pinned addresses that the caller wants to free. + Thus: only free pins when all work is done and nobody can wait for you!!! + */ + while (pins->purgatory_count) + { + _lf_pinbox_real_free(pins); + if (pins->purgatory_count) + { + my_atomic_rwlock_wrunlock(&pins->pinbox->pinarray.lock); + pthread_yield(); + my_atomic_rwlock_wrlock(&pins->pinbox->pinarray.lock); + } + } + top_ver= pinbox->pinstack_top_ver; + do + { + pins->link= top_ver % LF_PINBOX_MAX_PINS; + } while (!my_atomic_cas32((int32 volatile*) &pinbox->pinstack_top_ver, + (int32*) &top_ver, + top_ver-pins->link+nr+LF_PINBOX_MAX_PINS)); + return; +} + +static int ptr_cmp(void **a, void **b) +{ + return *a < *b ? -1 : *a == *b ? 0 : 1; +} + +#define add_to_purgatory(PINS, ADDR) \ + do \ + { \ + *(void **)((char *)(ADDR)+(PINS)->pinbox->free_ptr_offset)= \ + (PINS)->purgatory; \ + (PINS)->purgatory= (ADDR); \ + (PINS)->purgatory_count++; \ + } while (0) + +/* + Free an object allocated via pinbox allocator + + DESCRIPTION + add an object to purgatory. if necessary, call _lf_pinbox_real_free() + to actually free something. +*/ +void _lf_pinbox_free(LF_PINS *pins, void *addr) +{ + add_to_purgatory(pins, addr); + if (pins->purgatory_count % LF_PURGATORY_SIZE) + _lf_pinbox_real_free(pins); +} + +struct st_harvester { + void **granary; + int npins; +}; + +/* + callback for _lf_dynarray_iterate: + scan all pins of all threads and accumulate all pins +*/ +static int harvest_pins(LF_PINS *el, struct st_harvester *hv) +{ + int i; + LF_PINS *el_end= el+min(hv->npins, LF_DYNARRAY_LEVEL_LENGTH); + for (; el < el_end; el++) + { + for (i= 0; i < LF_PINBOX_PINS; i++) + { + void *p= el->pin[i]; + if (p) + *hv->granary++= p; + } + } + /* + hv->npins may become negative below, but it means that + we're on the last dynarray page and harvest_pins() won't be + called again. We don't bother to make hv->npins() correct + (that is 0) in this case. + */ + hv->npins-= LF_DYNARRAY_LEVEL_LENGTH; + return 0; +} + +/* + callback for _lf_dynarray_iterate: + scan all pins of all threads and see if addr is present there +*/ +static int match_pins(LF_PINS *el, void *addr) +{ + int i; + LF_PINS *el_end= el+LF_DYNARRAY_LEVEL_LENGTH; + for (; el < el_end; el++) + for (i= 0; i < LF_PINBOX_PINS; i++) + if (el->pin[i] == addr) + return 1; + return 0; +} + +#if STACK_DIRECTION < 0 +#define available_stack_size(CUR,END) (long) ((char*)(CUR) - (char*)(END)) +#else +#define available_stack_size(CUR,END) (long) ((char*)(END) - (char*)(CUR)) +#endif + +#define next_node(P, X) (*((uchar * volatile *)(((uchar *)(X)) + (P)->free_ptr_offset))) +#define anext_node(X) next_node(&allocator->pinbox, (X)) + +/* + Scan the purgatory and free everything that can be freed +*/ +static void _lf_pinbox_real_free(LF_PINS *pins) +{ + int npins, alloca_size; + void *list, **addr; + void *first, *last= NULL; + LF_PINBOX *pinbox= pins->pinbox; + + LINT_INIT(first); + npins= pinbox->pins_in_array+1; + +#ifdef HAVE_ALLOCA + alloca_size= sizeof(void *)*LF_PINBOX_PINS*npins; + /* create a sorted list of pinned addresses, to speed up searches */ + if (available_stack_size(&pinbox, *pins->stack_ends_here) > alloca_size) + { + struct st_harvester hv; + addr= (void **) alloca(alloca_size); + hv.granary= addr; + hv.npins= npins; + /* scan the dynarray and accumulate all pinned addresses */ + _lf_dynarray_iterate(&pinbox->pinarray, + (lf_dynarray_func)harvest_pins, &hv); + + npins= hv.granary-addr; + /* and sort them */ + if (npins) + qsort(addr, npins, sizeof(void *), (qsort_cmp)ptr_cmp); + } + else +#endif + addr= 0; + + list= pins->purgatory; + pins->purgatory= 0; + pins->purgatory_count= 0; + while (list) + { + void *cur= list; + list= *(void **)((char *)cur+pinbox->free_ptr_offset); + if (npins) + { + if (addr) /* use binary search */ + { + void **a, **b, **c; + for (a= addr, b= addr+npins-1, c= a+(b-a)/2; (b-a) > 1; c= a+(b-a)/2) + if (cur == *c) + a= b= c; + else if (cur > *c) + a= c; + else + b= c; + if (cur == *a || cur == *b) + goto found; + } + else /* no alloca - no cookie. linear search here */ + { + if (_lf_dynarray_iterate(&pinbox->pinarray, + (lf_dynarray_func)match_pins, cur)) + goto found; + } + } + /* not pinned - freeing */ + if (last) + last= next_node(pinbox, last)= (uchar *)cur; + else + first= last= (uchar *)cur; + continue; +found: + /* pinned - keeping */ + add_to_purgatory(pins, cur); + } + if (last) + pinbox->free_func(first, last, pinbox->free_func_arg); +} + +/* lock-free memory allocator for fixed-size objects */ + +LF_REQUIRE_PINS(1) + +/* + callback for _lf_pinbox_real_free to free a list of unpinned objects - + add it back to the allocator stack + + DESCRIPTION + 'first' and 'last' are the ends of the linked list of nodes: + first->el->el->....->el->last. Use first==last to free only one element. +*/ +static void alloc_free(uchar *first, + uchar volatile *last, + LF_ALLOCATOR *allocator) +{ + /* + we need a union here to access type-punned pointer reliably. + otherwise gcc -fstrict-aliasing will not see 'tmp' changed in the loop + */ + union { uchar * node; void *ptr; } tmp; + tmp.node= allocator->top; + do + { + anext_node(last)= tmp.node; + } while (!my_atomic_casptr((void **)(char *)&allocator->top, + (void **)&tmp.ptr, first) && LF_BACKOFF); +} + +/* + initialize lock-free allocator + + SYNOPSYS + allocator - + size a size of an object to allocate + free_ptr_offset an offset inside the object to a sizeof(void *) + memory that is guaranteed to be unused after + the object is put in the purgatory. Unused by ANY + thread, not only the purgatory owner. + This memory will be used to link waiting-to-be-freed + objects in a purgatory list. +*/ +void lf_alloc_init(LF_ALLOCATOR *allocator, uint size, uint free_ptr_offset) +{ + lf_pinbox_init(&allocator->pinbox, free_ptr_offset, + (lf_pinbox_free_func *)alloc_free, allocator); + allocator->top= 0; + allocator->mallocs= 0; + allocator->element_size= size; + allocator->constructor= 0; + allocator->destructor= 0; + DBUG_ASSERT(size >= sizeof(void*) + free_ptr_offset); +} + +/* + destroy the allocator, free everything that's in it + + NOTE + As every other init/destroy function here and elsewhere it + is not thread safe. No, this function is no different, ensure + that no thread needs the allocator before destroying it. + We are not responsible for any damage that may be caused by + accessing the allocator when it is being or has been destroyed. + Oh yes, and don't put your cat in a microwave. +*/ +void lf_alloc_destroy(LF_ALLOCATOR *allocator) +{ + uchar *node= allocator->top; + while (node) + { + uchar *tmp= anext_node(node); + if (allocator->destructor) + allocator->destructor(node); + my_free((void *)node, MYF(0)); + node= tmp; + } + lf_pinbox_destroy(&allocator->pinbox); + allocator->top= 0; +} + +/* + Allocate and return an new object. + + DESCRIPTION + Pop an unused object from the stack or malloc it is the stack is empty. + pin[0] is used, it's removed on return. +*/ +void *_lf_alloc_new(LF_PINS *pins) +{ + LF_ALLOCATOR *allocator= (LF_ALLOCATOR *)(pins->pinbox->free_func_arg); + uchar *node; + for (;;) + { + do + { + node= allocator->top; + _lf_pin(pins, 0, node); + } while (node != allocator->top && LF_BACKOFF); + if (!node) + { + node= (void *)my_malloc(allocator->element_size, MYF(MY_WME)); + if (allocator->constructor) + allocator->constructor(node); +#ifdef MY_LF_EXTRA_DEBUG + if (likely(node != 0)) + my_atomic_add32(&allocator->mallocs, 1); +#endif + break; + } + if (my_atomic_casptr((void **)(char *)&allocator->top, + (void *)&node, anext_node(node))) + break; + } + _lf_unpin(pins, 0); + return node; +} + +/* + count the number of objects in a pool. + + NOTE + This is NOT thread-safe !!! +*/ +uint lf_alloc_pool_count(LF_ALLOCATOR *allocator) +{ + uint i; + uchar *node; + for (node= allocator->top, i= 0; node; node= anext_node(node), i++) + /* no op */; + return i; +} + diff --git a/mysys/lf_dynarray.c b/mysys/lf_dynarray.c new file mode 100644 index 00000000000..b1cdce698a9 --- /dev/null +++ b/mysys/lf_dynarray.c @@ -0,0 +1,207 @@ +/* Copyright (C) 2006 MySQL 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 */ + +/* + Analog of DYNAMIC_ARRAY that never reallocs + (so no pointer into the array may ever become invalid). + + Memory is allocated in non-contiguous chunks. + This data structure is not space efficient for sparse arrays. + + Every element is aligned to sizeof(element) boundary + (to avoid false sharing if element is big enough). + + LF_DYNARRAY is a recursive structure. On the zero level + LF_DYNARRAY::level[0] it's an array of LF_DYNARRAY_LEVEL_LENGTH elements, + on the first level it's an array of LF_DYNARRAY_LEVEL_LENGTH pointers + to arrays of elements, on the second level it's an array of pointers + to arrays of pointers to arrays of elements. And so on. + + With four levels the number of elements is limited to 4311810304 + (but as in all functions index is uint, the real limit is 2^32-1) + + Actually, it's wait-free, not lock-free ;-) +*/ + +#include <my_global.h> +#include <m_string.h> +#include <my_sys.h> +#include <lf.h> + +void lf_dynarray_init(LF_DYNARRAY *array, uint element_size) +{ + bzero(array, sizeof(*array)); + array->size_of_element= element_size; + my_atomic_rwlock_init(&array->lock); +} + +static void recursive_free(void **alloc, int level) +{ + if (!alloc) + return; + + if (level) + { + int i; + for (i= 0; i < LF_DYNARRAY_LEVEL_LENGTH; i++) + recursive_free(alloc[i], level-1); + my_free((void *)alloc, MYF(0)); + } + else + my_free(alloc[-1], MYF(0)); +} + +void lf_dynarray_destroy(LF_DYNARRAY *array) +{ + int i; + for (i= 0; i < LF_DYNARRAY_LEVELS; i++) + recursive_free(array->level[i], i); + my_atomic_rwlock_destroy(&array->lock); +} + +static const ulong dynarray_idxes_in_prev_levels[LF_DYNARRAY_LEVELS]= +{ + 0, /* +1 here to to avoid -1's below */ + LF_DYNARRAY_LEVEL_LENGTH, + LF_DYNARRAY_LEVEL_LENGTH * LF_DYNARRAY_LEVEL_LENGTH + + LF_DYNARRAY_LEVEL_LENGTH, + LF_DYNARRAY_LEVEL_LENGTH * LF_DYNARRAY_LEVEL_LENGTH * + LF_DYNARRAY_LEVEL_LENGTH + LF_DYNARRAY_LEVEL_LENGTH * + LF_DYNARRAY_LEVEL_LENGTH + LF_DYNARRAY_LEVEL_LENGTH +}; + +static const ulong dynarray_idxes_in_prev_level[LF_DYNARRAY_LEVELS]= +{ + 0, /* +1 here to to avoid -1's below */ + LF_DYNARRAY_LEVEL_LENGTH, + LF_DYNARRAY_LEVEL_LENGTH * LF_DYNARRAY_LEVEL_LENGTH, + LF_DYNARRAY_LEVEL_LENGTH * LF_DYNARRAY_LEVEL_LENGTH * + LF_DYNARRAY_LEVEL_LENGTH, +}; + +/* + Returns a valid lvalue pointer to the element number 'idx'. + Allocates memory if necessary. +*/ +void *_lf_dynarray_lvalue(LF_DYNARRAY *array, uint idx) +{ + void * ptr, * volatile * ptr_ptr= 0; + int i; + + for (i= LF_DYNARRAY_LEVELS-1; idx < dynarray_idxes_in_prev_levels[i]; i--) + /* no-op */; + ptr_ptr= &array->level[i]; + idx-= dynarray_idxes_in_prev_levels[i]; + for (; i > 0; i--) + { + if (!(ptr= *ptr_ptr)) + { + void *alloc= my_malloc(LF_DYNARRAY_LEVEL_LENGTH * sizeof(void *), + MYF(MY_WME|MY_ZEROFILL)); + if (unlikely(!alloc)) + return(NULL); + if (my_atomic_casptr(ptr_ptr, &ptr, alloc)) + ptr= alloc; + else + my_free(alloc, MYF(0)); + } + ptr_ptr= ((void **)ptr) + idx / dynarray_idxes_in_prev_level[i]; + idx%= dynarray_idxes_in_prev_level[i]; + } + if (!(ptr= *ptr_ptr)) + { + uchar *alloc, *data; + alloc= my_malloc(LF_DYNARRAY_LEVEL_LENGTH * array->size_of_element + + max(array->size_of_element, sizeof(void *)), + MYF(MY_WME|MY_ZEROFILL)); + if (unlikely(!alloc)) + return(NULL); + /* reserve the space for free() address */ + data= alloc + sizeof(void *); + { /* alignment */ + intptr mod= ((intptr)data) % array->size_of_element; + if (mod) + data+= array->size_of_element - mod; + } + ((void **)data)[-1]= alloc; /* free() will need the original pointer */ + if (my_atomic_casptr(ptr_ptr, &ptr, data)) + ptr= data; + else + my_free(alloc, MYF(0)); + } + return ((uchar*)ptr) + array->size_of_element * idx; +} + +/* + Returns a pointer to the element number 'idx' + or NULL if an element does not exists +*/ +void *_lf_dynarray_value(LF_DYNARRAY *array, uint idx) +{ + void * ptr, * volatile * ptr_ptr= 0; + int i; + + for (i= LF_DYNARRAY_LEVELS-1; idx < dynarray_idxes_in_prev_levels[i]; i--) + /* no-op */; + ptr_ptr= &array->level[i]; + idx-= dynarray_idxes_in_prev_levels[i]; + for (; i > 0; i--) + { + if (!(ptr= *ptr_ptr)) + return(NULL); + ptr_ptr= ((void **)ptr) + idx / dynarray_idxes_in_prev_level[i]; + idx %= dynarray_idxes_in_prev_level[i]; + } + if (!(ptr= *ptr_ptr)) + return(NULL); + return ((uchar*)ptr) + array->size_of_element * idx; +} + +static int recursive_iterate(LF_DYNARRAY *array, void *ptr, int level, + lf_dynarray_func func, void *arg) +{ + int res, i; + if (!ptr) + return 0; + if (!level) + return func(ptr, arg); + for (i= 0; i < LF_DYNARRAY_LEVEL_LENGTH; i++) + if ((res= recursive_iterate(array, ((void **)ptr)[i], level-1, func, arg))) + return res; + return 0; +} + +/* + Calls func(array, arg) on every array of LF_DYNARRAY_LEVEL_LENGTH elements + in lf_dynarray. + + DESCRIPTION + lf_dynarray consists of a set of arrays, LF_DYNARRAY_LEVEL_LENGTH elements + each. _lf_dynarray_iterate() calls user-supplied function on every array + from the set. It is the fastest way to scan the array, faster than + for (i=0; i < N; i++) { func(_lf_dynarray_value(dynarray, i)); } + + NOTE + if func() returns non-zero, the scan is aborted +*/ +int _lf_dynarray_iterate(LF_DYNARRAY *array, lf_dynarray_func func, void *arg) +{ + int i, res; + for (i= 0; i < LF_DYNARRAY_LEVELS; i++) + if ((res= recursive_iterate(array, array->level[i], i, func, arg))) + return res; + return 0; +} + diff --git a/mysys/lf_hash.c b/mysys/lf_hash.c new file mode 100644 index 00000000000..f478196c7c8 --- /dev/null +++ b/mysys/lf_hash.c @@ -0,0 +1,505 @@ +/* Copyright (C) 2006-2008 MySQL AB, 2008-2009 Sun Microsystems, Inc. + + 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 */ + +/* + extensible hash + + TODO + try to get rid of dummy nodes ? + for non-unique hash, count only _distinct_ values + (but how to do it in lf_hash_delete ?) +*/ +#include <my_global.h> +#include <m_string.h> +#include <my_sys.h> +#include <my_bit.h> +#include <lf.h> + +LF_REQUIRE_PINS(3) + +/* An element of the list */ +typedef struct { + intptr volatile link; /* a pointer to the next element in a listand a flag */ + uint32 hashnr; /* reversed hash number, for sorting */ + const uchar *key; + size_t keylen; + /* + data is stored here, directly after the keylen. + thus the pointer to data is (void*)(slist_element_ptr+1) + */ +} LF_SLIST; + +const int LF_HASH_OVERHEAD= sizeof(LF_SLIST); + +/* + a structure to pass the context (pointers two the three successive elements + in a list) from lfind to linsert/ldelete +*/ +typedef struct { + intptr volatile *prev; + LF_SLIST *curr, *next; +} CURSOR; + +/* + the last bit in LF_SLIST::link is a "deleted" flag. + the helper macros below convert it to a pure pointer or a pure flag +*/ +#define PTR(V) (LF_SLIST *)((V) & (~(intptr)1)) +#define DELETED(V) ((V) & 1) + +/* + DESCRIPTION + Search for hashnr/key/keylen in the list starting from 'head' and + position the cursor. The list is ORDER BY hashnr, key + + RETURN + 0 - not found + 1 - found + + NOTE + cursor is positioned in either case + pins[0..2] are used, they are NOT removed on return +*/ +static int lfind(LF_SLIST * volatile *head, CHARSET_INFO *cs, uint32 hashnr, + const uchar *key, uint keylen, CURSOR *cursor, LF_PINS *pins) +{ + uint32 cur_hashnr; + const uchar *cur_key; + uint cur_keylen; + intptr link; + +retry: + cursor->prev= (intptr *)head; + do { /* PTR() isn't necessary below, head is a dummy node */ + cursor->curr= (LF_SLIST *)(*cursor->prev); + _lf_pin(pins, 1, cursor->curr); + } while (*cursor->prev != (intptr)cursor->curr && LF_BACKOFF); + for (;;) + { + if (unlikely(!cursor->curr)) + return 0; /* end of the list */ + do { + /* QQ: XXX or goto retry ? */ + link= cursor->curr->link; + cursor->next= PTR(link); + _lf_pin(pins, 0, cursor->next); + } while (link != cursor->curr->link && LF_BACKOFF); + cur_hashnr= cursor->curr->hashnr; + cur_key= cursor->curr->key; + cur_keylen= cursor->curr->keylen; + if (*cursor->prev != (intptr)cursor->curr) + { + (void)LF_BACKOFF; + goto retry; + } + if (!DELETED(link)) + { + if (cur_hashnr >= hashnr) + { + int r= 1; + if (cur_hashnr > hashnr || + (r= my_strnncoll(cs, (uchar*) cur_key, cur_keylen, (uchar*) key, + keylen)) >= 0) + return !r; + } + cursor->prev= &(cursor->curr->link); + _lf_pin(pins, 2, cursor->curr); + } + else + { + /* + we found a deleted node - be nice, help the other thread + and remove this deleted node + */ + if (my_atomic_casptr((void **)cursor->prev, + (void **)&cursor->curr, cursor->next)) + _lf_alloc_free(pins, cursor->curr); + else + { + (void)LF_BACKOFF; + goto retry; + } + } + cursor->curr= cursor->next; + _lf_pin(pins, 1, cursor->curr); + } +} + +/* + DESCRIPTION + insert a 'node' in the list that starts from 'head' in the correct + position (as found by lfind) + + RETURN + 0 - inserted + not 0 - a pointer to a duplicate (not pinned and thus unusable) + + NOTE + it uses pins[0..2], on return all pins are removed. + if there're nodes with the same key value, a new node is added before them. +*/ +static LF_SLIST *linsert(LF_SLIST * volatile *head, CHARSET_INFO *cs, + LF_SLIST *node, LF_PINS *pins, uint flags) +{ + CURSOR cursor; + int res; + + for (;;) + { + if (lfind(head, cs, node->hashnr, node->key, node->keylen, + &cursor, pins) && + (flags & LF_HASH_UNIQUE)) + { + res= 0; /* duplicate found */ + break; + } + else + { + node->link= (intptr)cursor.curr; + DBUG_ASSERT(node->link != (intptr)node); /* no circular references */ + DBUG_ASSERT(cursor.prev != &node->link); /* no circular references */ + if (my_atomic_casptr((void **)cursor.prev, (void **)&cursor.curr, node)) + { + res= 1; /* inserted ok */ + break; + } + } + } + _lf_unpin(pins, 0); + _lf_unpin(pins, 1); + _lf_unpin(pins, 2); + /* + Note that cursor.curr is not pinned here and the pointer is unreliable, + the object may dissapear anytime. But if it points to a dummy node, the + pointer is safe, because dummy nodes are never freed - initialize_bucket() + uses this fact. + */ + return res ? 0 : cursor.curr; +} + +/* + DESCRIPTION + deletes a node as identified by hashnr/keey/keylen from the list + that starts from 'head' + + RETURN + 0 - ok + 1 - not found + + NOTE + it uses pins[0..2], on return all pins are removed. +*/ +static int ldelete(LF_SLIST * volatile *head, CHARSET_INFO *cs, uint32 hashnr, + const uchar *key, uint keylen, LF_PINS *pins) +{ + CURSOR cursor; + int res; + + for (;;) + { + if (!lfind(head, cs, hashnr, key, keylen, &cursor, pins)) + { + res= 1; /* not found */ + break; + } + else + { + /* mark the node deleted */ + if (my_atomic_casptr((void **)&(cursor.curr->link), + (void **)&cursor.next, + (void *)(((intptr)cursor.next) | 1))) + { + /* and remove it from the list */ + if (my_atomic_casptr((void **)cursor.prev, + (void **)&cursor.curr, cursor.next)) + _lf_alloc_free(pins, cursor.curr); + else + { + /* + somebody already "helped" us and removed the node ? + Let's check if we need to help that someone too! + (to ensure the number of "set DELETED flag" actions + is equal to the number of "remove from the list" actions) + */ + lfind(head, cs, hashnr, key, keylen, &cursor, pins); + } + res= 0; + break; + } + } + } + _lf_unpin(pins, 0); + _lf_unpin(pins, 1); + _lf_unpin(pins, 2); + return res; +} + +/* + DESCRIPTION + searches for a node as identified by hashnr/keey/keylen in the list + that starts from 'head' + + RETURN + 0 - not found + node - found + + NOTE + it uses pins[0..2], on return the pin[2] keeps the node found + all other pins are removed. +*/ +static LF_SLIST *lsearch(LF_SLIST * volatile *head, CHARSET_INFO *cs, + uint32 hashnr, const uchar *key, uint keylen, + LF_PINS *pins) +{ + CURSOR cursor; + int res= lfind(head, cs, hashnr, key, keylen, &cursor, pins); + if (res) + _lf_pin(pins, 2, cursor.curr); + _lf_unpin(pins, 0); + _lf_unpin(pins, 1); + return res ? cursor.curr : 0; +} + +static inline const uchar* hash_key(const LF_HASH *hash, + const uchar *record, size_t *length) +{ + if (hash->get_key) + return (*hash->get_key)(record, length, 0); + *length= hash->key_length; + return record + hash->key_offset; +} + +/* + Compute the hash key value from the raw key. + + @note, that the hash value is limited to 2^31, because we need one + bit to distinguish between normal and dummy nodes. +*/ +static inline uint calc_hash(LF_HASH *hash, const uchar *key, uint keylen) +{ + ulong nr1= 1, nr2= 4; + hash->charset->coll->hash_sort(hash->charset, (uchar*) key, keylen, + &nr1, &nr2); + return nr1 & INT_MAX32; +} + +#define MAX_LOAD 1.0 /* average number of elements in a bucket */ + +static int initialize_bucket(LF_HASH *, LF_SLIST * volatile*, uint, LF_PINS *); + +/* + Initializes lf_hash, the arguments are compatible with hash_init + + @note element_size sets both the size of allocated memory block for + lf_alloc and a size of memcpy'ed block size in lf_hash_insert. Typically + they are the same, indeed. But LF_HASH::element_size can be decreased + after lf_hash_init, and then lf_alloc will allocate larger block that + lf_hash_insert will copy over. It is desireable if part of the element + is expensive to initialize - for example if there is a mutex or + DYNAMIC_ARRAY. In this case they should be initialize in the + LF_ALLOCATOR::constructor, and lf_hash_insert should not overwrite them. + See wt_init() for example. +*/ +void lf_hash_init(LF_HASH *hash, uint element_size, uint flags, + uint key_offset, uint key_length, my_hash_get_key get_key, + CHARSET_INFO *charset) +{ + lf_alloc_init(&hash->alloc, sizeof(LF_SLIST)+element_size, + offsetof(LF_SLIST, key)); + lf_dynarray_init(&hash->array, sizeof(LF_SLIST *)); + hash->size= 1; + hash->count= 0; + hash->element_size= element_size; + hash->flags= flags; + hash->charset= charset ? charset : &my_charset_bin; + hash->key_offset= key_offset; + hash->key_length= key_length; + hash->get_key= get_key; + DBUG_ASSERT(get_key ? !key_offset && !key_length : key_length); +} + +void lf_hash_destroy(LF_HASH *hash) +{ + LF_SLIST *el, **head= (LF_SLIST **)_lf_dynarray_value(&hash->array, 0); + + if (unlikely(!head)) + return; + el= *head; + + while (el) + { + intptr next= el->link; + if (el->hashnr & 1) + lf_alloc_direct_free(&hash->alloc, el); /* normal node */ + else + my_free((void *)el, MYF(0)); /* dummy node */ + el= (LF_SLIST *)next; + } + lf_alloc_destroy(&hash->alloc); + lf_dynarray_destroy(&hash->array); +} + +/* + DESCRIPTION + inserts a new element to a hash. it will have a _copy_ of + data, not a pointer to it. + + RETURN + 0 - inserted + 1 - didn't (unique key conflict) + -1 - out of memory + + NOTE + see linsert() for pin usage notes +*/ +int lf_hash_insert(LF_HASH *hash, LF_PINS *pins, const void *data) +{ + int csize, bucket, hashnr; + LF_SLIST *node, * volatile *el; + + lf_rwlock_by_pins(pins); + node= (LF_SLIST *)_lf_alloc_new(pins); + if (unlikely(!node)) + return -1; + memcpy(node+1, data, hash->element_size); + node->key= hash_key(hash, (uchar *)(node+1), &node->keylen); + hashnr= calc_hash(hash, node->key, node->keylen); + bucket= hashnr % hash->size; + el= _lf_dynarray_lvalue(&hash->array, bucket); + if (unlikely(!el)) + return -1; + if (*el == NULL && unlikely(initialize_bucket(hash, el, bucket, pins))) + return -1; + node->hashnr= my_reverse_bits(hashnr) | 1; /* normal node */ + if (linsert(el, hash->charset, node, pins, hash->flags)) + { + _lf_alloc_free(pins, node); + lf_rwunlock_by_pins(pins); + return 1; + } + csize= hash->size; + if ((my_atomic_add32(&hash->count, 1)+1.0) / csize > MAX_LOAD) + my_atomic_cas32(&hash->size, &csize, csize*2); + lf_rwunlock_by_pins(pins); + return 0; +} + +/* + DESCRIPTION + deletes an element with the given key from the hash (if a hash is + not unique and there're many elements with this key - the "first" + matching element is deleted) + RETURN + 0 - deleted + 1 - didn't (not found) + -1 - out of memory + NOTE + see ldelete() for pin usage notes +*/ +int lf_hash_delete(LF_HASH *hash, LF_PINS *pins, const void *key, uint keylen) +{ + LF_SLIST * volatile *el; + uint bucket, hashnr= calc_hash(hash, (uchar *)key, keylen); + + bucket= hashnr % hash->size; + lf_rwlock_by_pins(pins); + el= _lf_dynarray_lvalue(&hash->array, bucket); + if (unlikely(!el)) + return -1; + /* + note that we still need to initialize_bucket here, + we cannot return "node not found", because an old bucket of that + node may've been split and the node was assigned to a new bucket + that was never accessed before and thus is not initialized. + */ + if (*el == NULL && unlikely(initialize_bucket(hash, el, bucket, pins))) + return -1; + if (ldelete(el, hash->charset, my_reverse_bits(hashnr) | 1, + (uchar *)key, keylen, pins)) + { + lf_rwunlock_by_pins(pins); + return 1; + } + my_atomic_add32(&hash->count, -1); + lf_rwunlock_by_pins(pins); + return 0; +} + +/* + RETURN + a pointer to an element with the given key (if a hash is not unique and + there're many elements with this key - the "first" matching element) + NULL if nothing is found + MY_ERRPTR if OOM + + NOTE + see lsearch() for pin usage notes +*/ +void *lf_hash_search(LF_HASH *hash, LF_PINS *pins, const void *key, uint keylen) +{ + LF_SLIST * volatile *el, *found; + uint bucket, hashnr= calc_hash(hash, (uchar *)key, keylen); + + bucket= hashnr % hash->size; + lf_rwlock_by_pins(pins); + el= _lf_dynarray_lvalue(&hash->array, bucket); + if (unlikely(!el)) + return MY_ERRPTR; + if (*el == NULL && unlikely(initialize_bucket(hash, el, bucket, pins))) + return MY_ERRPTR; + found= lsearch(el, hash->charset, my_reverse_bits(hashnr) | 1, + (uchar *)key, keylen, pins); + lf_rwunlock_by_pins(pins); + return found ? found+1 : 0; +} + +static const uchar *dummy_key= (uchar*)""; + +/* + RETURN + 0 - ok + -1 - out of memory +*/ +static int initialize_bucket(LF_HASH *hash, LF_SLIST * volatile *node, + uint bucket, LF_PINS *pins) +{ + uint parent= my_clear_highest_bit(bucket); + LF_SLIST *dummy= (LF_SLIST *)my_malloc(sizeof(LF_SLIST), MYF(MY_WME)); + LF_SLIST **tmp= 0, *cur; + LF_SLIST * volatile *el= _lf_dynarray_lvalue(&hash->array, parent); + if (unlikely(!el || !dummy)) + return -1; + if (*el == NULL && bucket && + unlikely(initialize_bucket(hash, el, parent, pins))) + return -1; + dummy->hashnr= my_reverse_bits(bucket) | 0; /* dummy node */ + dummy->key= dummy_key; + dummy->keylen= 0; + if ((cur= linsert(el, hash->charset, dummy, pins, LF_HASH_UNIQUE))) + { + my_free((void *)dummy, MYF(0)); + dummy= cur; + } + my_atomic_casptr((void **)node, (void **)&tmp, dummy); + /* + note that if the CAS above failed (after linsert() succeeded), + it would mean that some other thread has executed linsert() for + the same dummy node, its linsert() failed, it picked up our + dummy node (in "dummy= cur") and executed the same CAS as above. + Which means that even if CAS above failed we don't need to retry, + and we should not free(dummy) - there's no memory leak here + */ + return 0; +} diff --git a/mysys/my_atomic.c b/mysys/my_atomic.c index aa04d55f624..6bc76f0de3c 100644 --- a/mysys/my_atomic.c +++ b/mysys/my_atomic.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2006 MySQL AB +/* Copyright (C) 2006 MySQL AB, 2008-2009 Sun Microsystems, Inc 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 @@ -14,7 +14,7 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <my_global.h> -#include <my_pthread.h> +#include <my_sys.h> #ifndef HAVE_INLINE /* the following will cause all inline functions to be instantiated */ @@ -43,3 +43,32 @@ int my_atomic_initialize() #endif } +#ifdef SAFE_MUTEX +#undef pthread_mutex_init +#undef pthread_mutex_destroy +#undef pthread_mutex_lock +#undef pthread_mutex_unlock + +void plain_pthread_mutex_init(safe_mutex_t *m) +{ + pthread_mutex_init(& m->mutex, NULL); +} + +void plain_pthread_mutex_destroy(safe_mutex_t *m) +{ + pthread_mutex_destroy(& m->mutex); +} + +void plain_pthread_mutex_lock(safe_mutex_t *m) +{ + pthread_mutex_lock(& m->mutex); +} + +void plain_pthread_mutex_unlock(safe_mutex_t *m) +{ + pthread_mutex_unlock(& m->mutex); +} + +#endif + + diff --git a/mysys/my_getncpus.c b/mysys/my_getncpus.c index 82e87dee2e4..5be961e3bc9 100644 --- a/mysys/my_getncpus.c +++ b/mysys/my_getncpus.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2006 MySQL AB +/* Copyright (C) 2006 MySQL AB, 2008-2009 Sun Microsystems, Inc 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 @@ -16,24 +16,34 @@ /* get the number of (online) CPUs */ #include "mysys_priv.h" +#ifdef HAVE_UNISTD_H #include <unistd.h> +#endif static int ncpus=0; -#ifdef _SC_NPROCESSORS_ONLN int my_getncpus() { if (!ncpus) + { +#ifdef _SC_NPROCESSORS_ONLN ncpus= sysconf(_SC_NPROCESSORS_ONLN); - return ncpus; -} - +#elif defined(__WIN__) + SYSTEM_INFO sysinfo; + + /* + * We are not calling GetNativeSystemInfo here because (1) we + * don't believe that they return different values for number + * of processors and (2) if WOW64 limits processors for Win32 + * then we don't want to try to override that. + */ + GetSystemInfo(&sysinfo); + + ncpus= sysinfo.dwNumberOfProcessors; #else -/* unknown */ -int my_getncpus() -{ - return 2; -} - +/* unknown so play safe: assume SMP and forbid uniprocessor build */ + ncpus= 2; #endif - + } + return ncpus; +} diff --git a/mysys/my_thr_init.c b/mysys/my_thr_init.c index b2972faf0f8..ba59c483012 100644 --- a/mysys/my_thr_init.c +++ b/mysys/my_thr_init.c @@ -284,6 +284,9 @@ my_bool my_thread_init(void) pthread_cond_init(&tmp->suspend, NULL); tmp->init= 1; + tmp->stack_ends_here= (char*)&tmp + + STACK_DIRECTION * (long)my_thread_stack_size; + pthread_mutex_lock(&THR_LOCK_threads); tmp->id= ++thread_id; ++THR_thread_count; |