diff options
author | Jari Vetoniemi <mailroxas@gmail.com> | 2018-02-27 14:12:33 +0200 |
---|---|---|
committer | Jari Vetoniemi <mailroxas@gmail.com> | 2018-02-27 14:12:33 +0200 |
commit | 6a30d17dc0cd210e31ab4f95d20327e5478d1948 (patch) | |
tree | e942fe4997b80ea5714de585daf4f3f3a1b0d570 | |
parent | d09793afbd992eaeb571aa77a6ecbe558d6e66bb (diff) |
pthread: More standard confirming implementation
Also allows to use valgrind without suppressions on good programs!
-rw-r--r-- | src/libpthread.c | 42 |
1 files changed, 29 insertions, 13 deletions
diff --git a/src/libpthread.c b/src/libpthread.c index 643b366..2508143 100644 --- a/src/libpthread.c +++ b/src/libpthread.c @@ -91,7 +91,12 @@ typedef long bionic_pthread_t; _Static_assert(sizeof(bionic_pthread_t) == sizeof(pthread_t), "bionic_pthread_t and pthread_t size mismatch"); #define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0])) + +// For checking, if our glibc version is mapped to memory. +// Used for sanity checking and static initialization below. #define IS_MAPPED(x) is_mapped(x->glibc, sizeof(x)) + +// For handling static initialization. #define INIT_IF_NOT_MAPPED(x, init) do { if (!IS_MAPPED(x)) init(x); } while(0) static bool @@ -145,8 +150,10 @@ int bionic_sem_init(bionic_sem_t *sem, int pshared, unsigned int value) { assert(sem); - if (!IS_MAPPED(sem)) - sem->glibc = mmap(NULL, sizeof(sem_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); + // From SEM_INIT(3) + // Initializing a semaphore that has already been initialized results in underined behavior. + *sem = (bionic_sem_t){0}; + sem->glibc = mmap(NULL, sizeof(sem_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); return sem_init(sem->glibc, pshared, value); } @@ -194,15 +201,18 @@ int bionic_pthread_attr_init(bionic_attr_t *attr) { assert(attr); - if (!IS_MAPPED(attr)) - attr->glibc = mmap(NULL, sizeof(pthread_attr_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); + // From PTHREAD_ATTR_INIT(3) + // Calling `pthread_attr_init` on a thread attributes object that has already been initialized results in ud. + *attr = (bionic_attr_t){0}; + attr->glibc = mmap(NULL, sizeof(pthread_attr_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); return pthread_attr_init(attr->glibc); } int bionic_pthread_getattr_np(bionic_pthread_t thread, bionic_attr_t *attr) { - assert(thread && attr && !IS_MAPPED(attr)); + assert(thread && attr); + *attr = (bionic_attr_t){0}; attr->glibc = mmap(NULL, sizeof(pthread_attr_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); return pthread_getattr_np((pthread_t*)thread, attr->glibc); } @@ -307,15 +317,17 @@ int bionic_pthread_mutexattr_init(bionic_mutexattr_t *attr) { assert(attr); - if (!IS_MAPPED(attr)) - attr->glibc = mmap(NULL, sizeof(pthread_mutexattr_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); + // From PTHREAD_MUTEXATTR_INIT(3) + // The results of initializing an already initialized mutex attributes object are undefined. + *attr = (bionic_mutexattr_t){0}; + attr->glibc = mmap(NULL, sizeof(pthread_mutexattr_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); return pthread_mutexattr_init(attr->glibc); } static void default_pthread_mutex_init(bionic_mutex_t *mutex) { - assert(mutex && !IS_MAPPED(mutex)); + assert(mutex); mutex->glibc = mmap(NULL, sizeof(pthread_mutex_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); for (size_t i = 0; i < ARRAY_SIZE(bionic_mutex_init_map); ++i) { @@ -345,8 +357,10 @@ int bionic_pthread_mutex_init(bionic_mutex_t *mutex, const bionic_mutexattr_t *attr) { assert(mutex && (!attr || IS_MAPPED(attr))); - if (!IS_MAPPED(mutex)) - mutex->glibc = mmap(NULL, sizeof(pthread_mutex_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); + // From PTHREAD_MUTEX_INIT(3) + // Attempting to initialize an already initialized mutex result in undefined behavior. + *mutex = (bionic_mutex_t){0}; + mutex->glibc = mmap(NULL, sizeof(pthread_mutex_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); return pthread_mutex_init(mutex->glibc, (attr ? attr->glibc : NULL)); } @@ -377,7 +391,7 @@ bionic_pthread_mutex_unlock(bionic_mutex_t *mutex) static void default_pthread_cond_init(bionic_cond_t *cond) { - assert(cond && !IS_MAPPED(cond)); + assert(cond); cond->glibc = mmap(NULL, sizeof(pthread_cond_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); memset(cond->glibc, 0, sizeof(pthread_cond_t)); } @@ -398,8 +412,10 @@ int bionic_pthread_cond_init(bionic_cond_t *cond, const bionic_condattr_t *attr) { assert(cond && (!attr || IS_MAPPED(attr))); - if (!IS_MAPPED(cond)) - cond->glibc = mmap(NULL, sizeof(pthread_cond_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); + // From PTHREAD_COND_INIT(3) + // Attempting to initialize an already initialized mutex result in undefined behavior. + *cond = (bionic_cond_t){0}; + cond->glibc = mmap(NULL, sizeof(pthread_cond_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); return pthread_cond_init(cond->glibc, (attr ? attr->glibc : NULL)); } |