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Date: Wed, 3 Jan 2018 14:17:12 +0100
From: Jens Gustedt <Jens.Gustedt@...ia.fr>
To: musl@...ts.openwall.com
Subject: [PATCH 5/7] use the new lock algorithm for malloc
Malloc used a specialized lock implementation in many places. Now that we
have a generic lock that has the desired properties, we should just use
this, instead of this multitude of very similar lock mechanisms.
---
src/malloc/malloc.c | 38 +++++++++++++-------------------------
1 file changed, 13 insertions(+), 25 deletions(-)
diff --git a/src/malloc/malloc.c b/src/malloc/malloc.c
index 9e05e1d6..6c667a5a 100644
--- a/src/malloc/malloc.c
+++ b/src/malloc/malloc.c
@@ -13,6 +13,8 @@
#define inline inline __attribute__((always_inline))
#endif
+#include "__lock.h"
+
void *__mmap(void *, size_t, int, int, int, off_t);
int __munmap(void *, size_t);
void *__mremap(void *, size_t, size_t, int, ...);
@@ -24,7 +26,7 @@ struct chunk {
};
struct bin {
- volatile int lock[2];
+ volatile int lock[1];
struct chunk *head;
struct chunk *tail;
};
@@ -32,7 +34,7 @@ struct bin {
static struct {
volatile uint64_t binmap;
struct bin bins[64];
- volatile int free_lock[2];
+ volatile int free_lock[1];
} mal;
@@ -58,30 +60,16 @@ static struct {
/* Synchronization tools */
-static inline void lock(volatile int *lk)
-{
- if (libc.threads_minus_1)
- while(a_swap(lk, 1)) __wait(lk, lk+1, 1, 1);
-}
-
-static inline void unlock(volatile int *lk)
-{
- if (lk[0]) {
- a_store(lk, 0);
- if (lk[1]) __wake(lk, 1, 1);
- }
-}
-
static inline void lock_bin(int i)
{
- lock(mal.bins[i].lock);
+ __lock_fast(mal.bins[i].lock);
if (!mal.bins[i].head)
mal.bins[i].head = mal.bins[i].tail = BIN_TO_CHUNK(i);
}
static inline void unlock_bin(int i)
{
- unlock(mal.bins[i].lock);
+ __unlock_fast(mal.bins[i].lock);
}
static int first_set(uint64_t x)
@@ -161,7 +149,7 @@ void *__expand_heap(size_t *);
static struct chunk *expand_heap(size_t n)
{
- static int heap_lock[2];
+ static volatile int heap_lock[1];
static void *end;
void *p;
struct chunk *w;
@@ -171,11 +159,11 @@ static struct chunk *expand_heap(size_t n)
* we need room for an extra zero-sized sentinel chunk. */
n += SIZE_ALIGN;
- lock(heap_lock);
+ __lock_fast(heap_lock);
p = __expand_heap(&n);
if (!p) {
- unlock(heap_lock);
+ __unlock_fast(heap_lock);
return 0;
}
@@ -200,7 +188,7 @@ static struct chunk *expand_heap(size_t n)
w = MEM_TO_CHUNK(p);
w->csize = n | C_INUSE;
- unlock(heap_lock);
+ __unlock_fast(heap_lock);
return w;
}
@@ -481,10 +469,10 @@ void free(void *p)
next->psize = final_size | C_INUSE;
i = bin_index(final_size);
lock_bin(i);
- lock(mal.free_lock);
+ __lock_fast(mal.free_lock);
if (self->psize & next->csize & C_INUSE)
break;
- unlock(mal.free_lock);
+ __unlock_fast(mal.free_lock);
unlock_bin(i);
}
@@ -510,7 +498,7 @@ void free(void *p)
self->csize = final_size;
next->psize = final_size;
- unlock(mal.free_lock);
+ __unlock_fast(mal.free_lock);
self->next = BIN_TO_CHUNK(i);
self->prev = mal.bins[i].tail;
--
2.15.1
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