/* Copyright (C) 2021 Free Software Foundation, Inc.
Contributed by Oracle.
This file is part of GNU Binutils.
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; either version 3, or (at your option)
any later version.
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, 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
#include "config.h"
#include <sys/mman.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "collector.h"
#include "libcol_util.h"
#include "gp-experiment.h"
#include "memmgr.h"
/* TprintfT(<level>,...) definitions. Adjust per module as needed */
#define DBG_LT0 0 // for high-level configuration, unexpected errors/warnings
#define DBG_LT1 1 // for configuration details, warnings
#define DBG_LT2 2
#define DBG_LT3 3
#define DBG_LT4 4
/*
* Memory allocation.
*
* Heap:
* chain[0] - linked list of chunks;
* chain[1] - linked list of free 16-byte objects;
* chain[2] - linked list of free 32-byte objects;
* ...
*
* Chunk:
*
* base lo hi
* V V V
* +------------------+---------+-------------------+--+--+-----+
* | Var size object | -> <-| Const size objects| | |Chunk|
* +------------------+---------+-------------------+--+--+-----+
*
* Limitations:
* - one var size object per chunk
* - can't allocate const size objects larger than 2^MAXCHAIN
*/
#define MAXCHAIN 32
#define ALIGNMENT 4 /* 2^ALIGNMENT == minimal size and alignment */
#define ALIGN(x) ((((x) - 1)/(1 << ALIGNMENT) + 1) * (1 << ALIGNMENT))
struct Heap
{
collector_mutex_t lock; /* master lock */
void *chain[MAXCHAIN]; /* chain[0] - chunks */
/* chain[i] - structs of size 2^i */
};
typedef struct Chunk
{
size_t size;
char *base;
char *lo;
char *hi;
struct Chunk *next;
} Chunk;
static void
not_implemented ()
{
__collector_log_write ("<event kind=\"%s\" id=\"%d\">error memmgr not_implemented()</event>\n",
SP_JCMD_CERROR, COL_ERROR_NOZMEM);
return;
}
/*
* void __collector_mmgr_init_mutex_locks( Heap *heap )
* Iinitialize mmgr mutex locks.
*/
void
__collector_mmgr_init_mutex_locks (Heap *heap)
{
if (heap == NULL)
return;
if (__collector_mutex_trylock (&heap->lock))
{
/*
* We are in a child process immediately after the fork().
* Parent process was in the middle of critical section when the fork() happened.
* This is a placeholder for the cleanup.
* See CR 6997020 for details.
*/
__collector_mutex_init (&heap->lock);
}
__collector_mutex_init (&heap->lock);
}
/*
* alloc_chunk( unsigned sz ) allocates a chunk of at least sz bytes.
* If sz == 0, allocates a chunk of the default size.
*/
static Chunk *
alloc_chunk (unsigned sz, int log)
{
static long pgsz = 0;
char *ptr;
Chunk *chnk;
size_t chunksz;
if (pgsz == 0)
{
pgsz = CALL_UTIL (sysconf)(_SC_PAGESIZE);
Tprintf (DBG_LT2, "memmgr: pgsz = %ld (0x%lx)\n", pgsz, pgsz);
}
/* Allocate 2^n >= sz bytes */
unsigned nsz = ALIGN (sizeof (Chunk)) + sz;
for (chunksz = pgsz; chunksz < nsz; chunksz *= 2);
if (log == 1)
Tprintf (DBG_LT2, "alloc_chunk mapping %u, rounded up from %u\n", (unsigned int) chunksz, sz);
/* mmap64 is only in 32-bits; this call goes to mmap in 64-bits */
ptr = (char*) CALL_UTIL (mmap64)(0, chunksz, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON, (int) -1, (off64_t) 0);
if (ptr == MAP_FAILED)
{
Tprintf (0, "alloc_chunk mapping failed COL_ERROR_NOZMEMMAP: %s\n", CALL_UTIL (strerror)(errno));
__collector_log_write ("<event kind=\"%s\" id=\"%d\" ec=\"%d\">%s</event>\n",
SP_JCMD_CERROR, COL_ERROR_NOZMEMMAP, errno, "0");
return NULL;
}
/* Put the chunk descriptor at the end of the chunk */
chnk = (Chunk*) (ptr + chunksz - ALIGN (sizeof (Chunk)));
chnk->size = chunksz;
chnk->base = ptr;
chnk->lo = chnk->base;
chnk->hi = (char*) chnk;
chnk->next = (Chunk*) NULL;
if (log == 1)
Tprintf (DBG_LT2, "memmgr: returning new chunk @%p, chunksx=%ld sz=%ld\n",
ptr, (long) chunksz, (long) sz);
return chnk;
}
Heap *
__collector_newHeap ()
{
Heap *heap;
Chunk *chnk;
Tprintf (DBG_LT2, "__collector_newHeap calling alloc_chunk(0)\n");
chnk = alloc_chunk (0, 1);
if (chnk == NULL)
return NULL;
/* A bit of hackery: allocate heap from its own chunk */
chnk->hi -= ALIGN (sizeof (Heap));
heap = (Heap*) chnk->hi;
heap->chain[0] = (void*) chnk;
__collector_mutex_init (&heap->lock);
return heap;
}
void
__collector_deleteHeap (Heap *heap)
{
if (heap == NULL)
return;
/* Note: heap itself is in the last chunk */
for (Chunk *chnk = heap->chain[0]; chnk;)
{
Chunk *next = chnk->next;
CALL_UTIL (munmap)((void*) chnk->base, chnk->size);
chnk = next;
}
}
void *
__collector_allocCSize (Heap *heap, unsigned sz, int log)
{
void *res;
Chunk *chnk;
if (heap == NULL)
return NULL;
/* block all signals and acquire lock */
sigset_t old_mask, new_mask;
CALL_UTIL (sigfillset)(&new_mask);
CALL_UTIL (sigprocmask)(SIG_SETMASK, &new_mask, &old_mask);
__collector_mutex_lock (&heap->lock);
/* Allocate nsz = 2^idx >= sz bytes */
unsigned idx = ALIGNMENT;
unsigned nsz = 1 << idx;
while (nsz < sz)
nsz = 1 << ++idx;
/* Look in the corresponding chain first */
if (idx < MAXCHAIN)
{
if (heap->chain[idx] != NULL)
{
res = heap->chain[idx];
heap->chain[idx] = *(void**) res;
__collector_mutex_unlock (&heap->lock);
CALL_UTIL (sigprocmask)(SIG_SETMASK, &old_mask, NULL);
if (log == 1)
Tprintf (DBG_LT2, "memmgr: allocCSize %p sz %d (0x%x) req = 0x%x, from chain idx = %d\n", res, nsz, nsz, sz, idx);
return res;
}
}
else
{
not_implemented ();
__collector_mutex_unlock (&heap->lock);
CALL_UTIL (sigprocmask)(SIG_SETMASK, &old_mask, NULL);
return NULL;
}
/* Chain is empty, allocate from chunks */
for (chnk = (Chunk*) heap->chain[0]; chnk; chnk = chnk->next)
if (chnk->lo + nsz < chnk->hi)
break;
if (chnk == NULL)
{
/* Get a new chunk */
if (log == 1)
Tprintf (DBG_LT2, "__collector_allocCSize (%u) calling alloc_chunk(%u)\n", sz, nsz);
chnk = alloc_chunk (nsz, 1);
if (chnk == NULL)
{
__collector_mutex_unlock (&heap->lock);
CALL_UTIL (sigprocmask)(SIG_SETMASK, &old_mask, NULL);
return NULL;
}
chnk->next = (Chunk*) heap->chain[0];
heap->chain[0] = chnk;
}
/* Allocate from the chunk */
chnk->hi -= nsz;
res = (void*) chnk->hi;
__collector_mutex_unlock (&heap->lock);
CALL_UTIL (sigprocmask)(SIG_SETMASK, &old_mask, NULL);
if (log == 1)
Tprintf (DBG_LT2, "memmgr: allocCSize %p sz %d (0x%x) req = 0x%x, new chunk\n", res, nsz, nsz, sz);
return res;
}
void
__collector_freeCSize (Heap *heap, void *ptr, unsigned sz)
{
if (heap == NULL || ptr == NULL)
return;
/* block all signals and acquire lock */
sigset_t old_mask, new_mask;
CALL_UTIL (sigfillset)(&new_mask);
CALL_UTIL (sigprocmask)(SIG_SETMASK, &new_mask, &old_mask);
__collector_mutex_lock (&heap->lock);
/* Free 2^idx >= sz bytes */
unsigned idx = ALIGNMENT;
unsigned nsz = 1 << idx;
while (nsz < sz)
nsz = 1 << ++idx;
if (idx < MAXCHAIN)
{
*(void**) ptr = heap->chain[idx];
heap->chain[idx] = ptr;
}
else
not_implemented ();
__collector_mutex_unlock (&heap->lock);
CALL_UTIL (sigprocmask)(SIG_SETMASK, &old_mask, NULL);
Tprintf (DBG_LT4, "memmgr: freeC %p sz %ld\n", ptr, (long) sz);
}
static void *
allocVSize_nolock (Heap *heap, unsigned sz)
{
void *res;
Chunk *chnk;
if (sz == 0)
return NULL;
/* Find a good chunk */
for (chnk = (Chunk*) heap->chain[0]; chnk; chnk = chnk->next)
if (chnk->lo == chnk->base && chnk->lo + sz < chnk->hi)
break;
if (chnk == NULL)
{
/* Get a new chunk */
Tprintf (DBG_LT2, "allocVsize_nolock calling alloc_chunk(%u)\n", sz);
chnk = alloc_chunk (sz, 0);
if (chnk == NULL)
return NULL;
chnk->next = (Chunk*) heap->chain[0];
heap->chain[0] = chnk;
}
chnk->lo = chnk->base + sz;
res = (void*) (chnk->base);
Tprintf (DBG_LT4, "memmgr: allocV %p for %ld\n", res, (long) sz);
return res;
}
void *
__collector_allocVSize (Heap *heap, unsigned sz)
{
void *res;
if (heap == NULL)
return NULL;
/* block all signals and acquire lock */
sigset_t old_mask, new_mask;
CALL_UTIL (sigfillset)(&new_mask);
CALL_UTIL (sigprocmask)(SIG_SETMASK, &new_mask, &old_mask);
__collector_mutex_lock (&heap->lock);
res = allocVSize_nolock (heap, sz);
__collector_mutex_unlock (&heap->lock);
CALL_UTIL (sigprocmask)(SIG_SETMASK, &old_mask, NULL);
return res;
}
/*
* reallocVSize( Heap *heap, void *ptr, unsigned newsz )
* Changes the size of memory pointed by ptr to newsz.
* If ptr == NULL, allocates new memory of size newsz.
* If newsz == 0, frees ptr and returns NULL.
*/
void *
__collector_reallocVSize (Heap *heap, void *ptr, unsigned newsz)
{
Chunk *chnk;
void *res;
if (heap == NULL)
return NULL;
if (ptr == NULL)
return __collector_allocVSize (heap, newsz);
/* block all signals and acquire lock */
sigset_t old_mask, new_mask;
CALL_UTIL (sigfillset)(&new_mask);
CALL_UTIL (sigprocmask)(SIG_SETMASK, &new_mask, &old_mask);
__collector_mutex_lock (&heap->lock);
/* Find its chunk */
for (chnk = (Chunk*) heap->chain[0]; chnk; chnk = chnk->next)
if (ptr == chnk->base)
break;
if (chnk == NULL)
{
/* memory corrpution */
not_implemented ();
__collector_mutex_unlock (&heap->lock);
CALL_UTIL (sigprocmask)(SIG_SETMASK, &old_mask, NULL);
return NULL;
}
if (chnk->base + newsz < chnk->hi)
{
/* easy case */
chnk->lo = chnk->base + newsz;
res = newsz ? chnk->base : NULL;
__collector_mutex_unlock (&heap->lock);
CALL_UTIL (sigprocmask)(SIG_SETMASK, &old_mask, NULL);
Tprintf (DBG_LT4, "memmgr: reallocV %p for %ld\n", ptr, (long) newsz);
return res;
}
res = allocVSize_nolock (heap, newsz);
/* Copy to new location */
if (res)
{
int size = chnk->lo - chnk->base;
if (newsz < size)
size = newsz;
char *s1 = (char*) res;
char *s2 = chnk->base;
while (size--)
*s1++ = *s2++;
}
/* Free old memory*/
chnk->lo = chnk->base;
__collector_mutex_unlock (&heap->lock);
CALL_UTIL (sigprocmask)(SIG_SETMASK, &old_mask, NULL);
return res;
}