diff options
Diffstat (limited to 'libc/stdlib/malloc/malloc.h')
| -rw-r--r-- | libc/stdlib/malloc/malloc.h | 38 |
1 files changed, 37 insertions, 1 deletions
diff --git a/libc/stdlib/malloc/malloc.h b/libc/stdlib/malloc/malloc.h index 0cab1dba2..f01484368 100644 --- a/libc/stdlib/malloc/malloc.h +++ b/libc/stdlib/malloc/malloc.h @@ -38,10 +38,46 @@ mmap/munmap, and guarantees contiguous allocation, but is also less flexible, and causes the heap to only be shrinkable from the end. */ #ifdef __UCLIBC_HAS_MMU__ -#define MALLOC_USE_SBRK +# define MALLOC_USE_SBRK #endif +#ifdef __UCLIBC_HAS_THREADS__ + +# include <pthread.h> + +# define MALLOC_USE_LOCKING + +typedef pthread_mutex_t malloc_mutex_t; +# define MALLOC_MUTEX_INIT PTHREAD_MUTEX_INITIALIZER + +/* The main malloc lock. This must be hold while accessing __malloc_heap, + and in order to gain __malloc_sbrk_lock. */ +extern malloc_mutex_t __malloc_lock; +# define __malloc_lock() pthread_mutex_lock (&__malloc_lock) +# define __malloc_unlock() pthread_mutex_unlock (&__malloc_lock) + +# ifdef MALLOC_USE_SBRK +/* This lock is used to serialize uses of the `sbrk' function (in both + malloc and free, sbrk may be used several times in succession, and + things will break if these multiple calls are interleaved with another + thread's use of sbrk!). */ +extern malloc_mutex_t __malloc_sbrk_lock; +# define __malloc_lock_sbrk() pthread_mutex_lock (&__malloc_sbrk_lock) +# define __malloc_unlock_sbrk() pthread_mutex_unlock (&__malloc_sbrk_lock) +# endif /* MALLOC_USE_SBRK */ + +#else /* !__UCLIBC_HAS_THREADS__ */ + +/* Without threads, mutex operations are a nop. */ +# define __malloc_lock() (void)0 +# define __malloc_unlock() (void)0 +# define __malloc_lock_sbrk() (void)0 +# define __malloc_unlock_sbrk() (void)0 + +#endif /* __UCLIBC_HAS_THREADS__ */ + + /* Change this to `#if 1' to cause malloc to emit debugging info to stderr. */ #if 0 #include <stdio.h> |