diff options
| -rw-r--r-- | libc/stdlib/atexit.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/libc/stdlib/atexit.c b/libc/stdlib/atexit.c index 95047e78f..d3632c276 100644 --- a/libc/stdlib/atexit.c +++ b/libc/stdlib/atexit.c @@ -29,12 +29,29 @@ * As a side effect of these changes, abort() no longer calls the exit * functions (it now matches the gnu libc definition). * + * August 2002 Erik Andersen + * Added locking so atexit and friends can be thread safe + * */ +#define _GNU_SOURCE +#include <features.h> #include <unistd.h> #include <stdlib.h> #include <errno.h> + +#ifdef __UCLIBC_HAS_THREADS__ +#include <pthread.h> +static pthread_mutex_t mylock = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP; +# define LOCK pthread_mutex_lock(&mylock) +# define UNLOCK pthread_mutex_unlock(&mylock); +#else +# define LOCK +# define UNLOCK +#endif + + #define __MAX_EXIT __UCLIBC_MAX_ATEXIT typedef void (*aefuncp) (void); /* atexit function pointer */ @@ -70,7 +87,9 @@ int atexit(aefuncp func) { struct exit_function *efp; + LOCK; if (__exit_count >= __MAX_EXIT) { + UNLOCK; __set_errno(ENOMEM); return -1; } @@ -80,6 +99,7 @@ int atexit(aefuncp func) efp->type = ef_atexit; efp->funcs.atexit = func; } + UNLOCK; return 0; } #endif @@ -95,7 +115,9 @@ int on_exit(oefuncp func, void *arg) { struct exit_function *efp; + LOCK; if (__exit_count >= __MAX_EXIT) { + UNLOCK; __set_errno(ENOMEM); return -1; } @@ -106,6 +128,7 @@ int on_exit(oefuncp func, void *arg) efp->funcs.on_exit.func = func; efp->funcs.on_exit.arg = arg; } + UNLOCK; return 0; } #endif @@ -116,6 +139,8 @@ int __exit_count = 0; /* Number of registered exit functions */ /* * Handle the work of executing the registered exit functions + * This is called while we are locked, so no additional locking + * is needed... */ void __exit_handler(int status) { @@ -150,9 +175,11 @@ void (*__exit_cleanup) (int) = 0; void exit(int rv) { /* Perform exit-specific cleanup (atexit and on_exit) */ + LOCK; if (__exit_cleanup) { __exit_cleanup(rv); } + UNLOCK; /* If we are using stdio, try to shut it down. At the very least, * this will attempt to commit all buffered writes. It may also |