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Diffstat (limited to '')
-rw-r--r-- | mysys/my_malloc.c | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/mysys/my_malloc.c b/mysys/my_malloc.c new file mode 100644 index 00000000..5a5ed6c8 --- /dev/null +++ b/mysys/my_malloc.c @@ -0,0 +1,260 @@ +/* + Copyright (c) 2000, 2013, Oracle and/or its affiliates + Copyright (c) 2009, 2014, SkySQL 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ + +#include "mysys_priv.h" +#include "mysys_err.h" +#include <m_string.h> + +struct my_memory_header +{ + PSI_thread *m_owner; + size_t m_size; + PSI_memory_key m_key; +}; +typedef struct my_memory_header my_memory_header; +#define HEADER_SIZE 24 + +#define USER_TO_HEADER(P) ((my_memory_header*)((char *)(P) - HEADER_SIZE)) +#define HEADER_TO_USER(P) ((char*)(P) + HEADER_SIZE) + +/** + Inform application that memory usage has changed + + @param size Size of memory segment allocated or freed + @param flag 1 if thread specific (allocated by MY_THREAD_SPECIFIC), + 0 if system specific. + + The type os size is long long, to be able to handle negative numbers to + decrement the memory usage + + @return 0 - ok + 1 - failure, abort the allocation +*/ + +static void dummy(long long size __attribute__((unused)), + my_bool is_thread_specific __attribute__((unused))) +{} + +MALLOC_SIZE_CB update_malloc_size= dummy; + +void set_malloc_size_cb(MALLOC_SIZE_CB func) +{ + update_malloc_size= func; +} + + +/** + Allocate a sized block of memory. + + @param key Key to register instrumented memory + @param size The size of the memory block in bytes. + @param flags Failure action modifiers (bitmasks). + + @return A pointer to the allocated memory block, or NULL on failure. +*/ +void *my_malloc(PSI_memory_key key, size_t size, myf my_flags) +{ + my_memory_header *mh; + void *point; + DBUG_ENTER("my_malloc"); + DBUG_PRINT("my",("size: %zu flags: %lu", size, my_flags)); + compile_time_assert(sizeof(my_memory_header) <= HEADER_SIZE); + + if (!(my_flags & (MY_WME | MY_FAE))) + my_flags|= my_global_flags; + + /* Safety */ + if (!size) + size=1; + if (size > SIZE_T_MAX - 1024L*1024L*16L) /* Wrong call */ + DBUG_RETURN(0); + + /* We have to align size as we store MY_THREAD_SPECIFIC flag in the LSB */ + size= ALIGN_SIZE(size); + + if (DBUG_IF("simulate_out_of_memory")) + mh= NULL; + else + mh= (my_memory_header*) sf_malloc(size + HEADER_SIZE, my_flags); + + if (mh == NULL) + { + my_errno=errno; + if (my_flags & MY_FAE) + error_handler_hook=fatal_error_handler_hook; + if (my_flags & (MY_FAE+MY_WME)) + my_error(EE_OUTOFMEMORY, MYF(ME_BELL+ME_ERROR_LOG+ME_FATAL),size); + if (my_flags & MY_FAE) + abort(); + point= NULL; + } + else + { + int flag= MY_TEST(my_flags & MY_THREAD_SPECIFIC); + mh->m_size= size | flag; + mh->m_key= PSI_CALL_memory_alloc(key, size, & mh->m_owner); + if (update_malloc_size) + { + mh->m_size|=2; + update_malloc_size(size + HEADER_SIZE, flag); + } + point= HEADER_TO_USER(mh); + if (my_flags & MY_ZEROFILL) + bzero(point, size); + else + TRASH_ALLOC(point, size); + } + DBUG_PRINT("exit",("ptr: %p", point)); + DBUG_RETURN(point); +} + + +/** + @brief wrapper around realloc() + + @param key key to register instrumented memory + @param old_point pointer to currently allocated area + @param size new size requested, must be >0 + @param my_flags flags + + @note if size==0 realloc() may return NULL; my_realloc() treats this as an + error which is not the intention of realloc() +*/ +void *my_realloc(PSI_memory_key key, void *old_point, size_t size, myf my_flags) +{ + my_memory_header *old_mh, *mh; + void *point; + size_t old_size; + my_bool old_flags; + DBUG_ENTER("my_realloc"); + DBUG_PRINT("my",("ptr: %p size: %zu flags: %lu", old_point, size, my_flags)); + + DBUG_ASSERT(size > 0); + if (!old_point && (my_flags & MY_ALLOW_ZERO_PTR)) + DBUG_RETURN(my_malloc(key, size, my_flags)); + + old_mh= USER_TO_HEADER(old_point); + old_size= old_mh->m_size & ~3; + old_flags= old_mh->m_size & 3; + + DBUG_ASSERT(old_mh->m_key == key || old_mh->m_key == PSI_NOT_INSTRUMENTED); + DBUG_ASSERT((old_flags & 1) == MY_TEST(my_flags & MY_THREAD_SPECIFIC)); + + size= ALIGN_SIZE(size); + mh= sf_realloc(old_mh, size + HEADER_SIZE, my_flags); + + if (mh == NULL) + { + if (size < old_size) + DBUG_RETURN(old_point); + my_errno=errno; + if (my_flags & MY_FREE_ON_ERROR) + { + /* my_free will take care of size accounting */ + my_free(old_point); + old_point= 0; + } + if (my_flags & (MY_FAE+MY_WME)) + my_error(EE_OUTOFMEMORY, MYF(ME_BELL + ME_FATAL), size); + point= NULL; + } + else + { + mh->m_size= size | old_flags; + mh->m_key= PSI_CALL_memory_realloc(key, old_size, size, & mh->m_owner); + if (update_malloc_size && (old_flags & 2)) + update_malloc_size((longlong)size - (longlong)old_size, old_flags & 1); + point= HEADER_TO_USER(mh); + } + + DBUG_PRINT("exit",("ptr: %p", point)); + DBUG_RETURN(point); +} + + +/** + Free memory allocated with my_malloc. + + @param ptr Pointer to the memory allocated by my_malloc. +*/ +void my_free(void *ptr) +{ + my_memory_header *mh; + size_t old_size; + my_bool old_flags; + DBUG_ENTER("my_free"); + DBUG_PRINT("my",("ptr: %p", ptr)); + + if (ptr == NULL) + DBUG_VOID_RETURN; + + mh= USER_TO_HEADER(ptr); + old_size= mh->m_size & ~3; + old_flags= mh->m_size & 3; + PSI_CALL_memory_free(mh->m_key, old_size, mh->m_owner); + + if (update_malloc_size && (old_flags & 2)) + update_malloc_size(- (longlong) old_size - HEADER_SIZE, old_flags & 1); + +#ifndef SAFEMALLOC + /* + Trash memory if not safemalloc. We don't have to do this if safemalloc + is used as safemalloc will also do trashing + */ + TRASH_FREE(ptr, old_size); +#endif + sf_free(mh); + DBUG_VOID_RETURN; +} + + +void *my_memdup(PSI_memory_key key, const void *from, size_t length, myf my_flags) +{ + void *ptr; + DBUG_ENTER("my_memdup"); + + if ((ptr= my_malloc(key, length,my_flags)) != 0) + memcpy(ptr, from, length); + DBUG_RETURN(ptr); +} + + +char *my_strdup(PSI_memory_key key, const char *from, myf my_flags) +{ + char *ptr; + size_t length= strlen(from)+1; + DBUG_ENTER("my_strdup"); + + if ((ptr= (char*) my_malloc(key, length, my_flags))) + memcpy(ptr, from, length); + DBUG_RETURN(ptr); +} + + +char *my_strndup(PSI_memory_key key, const char *from, size_t length, myf my_flags) +{ + char *ptr; + DBUG_ENTER("my_strndup"); + + if ((ptr= (char*) my_malloc(key, length+1, my_flags))) + { + memcpy(ptr, from, length); + ptr[length]= 0; + } + DBUG_RETURN(ptr); +} + |