From 3eb41435e3c266a6a8f3496ffa5d832f5951c50f Mon Sep 17 00:00:00 2001 From: Tavian Barnes Date: Mon, 22 Jun 2009 05:31:53 +0000 Subject: Make dmnsn_array*'s thread safe. --- libdimension/array.c | 111 ++++++++++++++++++++++++++++++++++------- libdimension/dimension/array.h | 24 ++++++--- libdimension/geometry.c | 3 +- 3 files changed, 111 insertions(+), 27 deletions(-) diff --git a/libdimension/array.c b/libdimension/array.c index 88eb88f..c106f2f 100644 --- a/libdimension/array.c +++ b/libdimension/array.c @@ -19,8 +19,14 @@ *************************************************************************/ #include "dimension.h" +#include #include /* For memcpy */ +/* The raw implementations, which don't do any thread synchronicity */ +static void dmnsn_array_get_impl(const dmnsn_array *array, size_t i, void *obj); +static void dmnsn_array_set_impl(dmnsn_array *array, size_t i, const void *obj); +static void dmnsn_array_resize_impl(dmnsn_array *array, size_t length); + dmnsn_array * dmnsn_new_array(size_t obj_size) { @@ -34,36 +40,69 @@ dmnsn_new_array(size_t obj_size) if (!array->ptr) { dmnsn_error(DMNSN_SEVERITY_HIGH, "Array allocation failed."); } + + array->rwlock = malloc(sizeof(pthread_rwlock_t)); + if (!array->rwlock || pthread_rwlock_init(array->rwlock, NULL) != 0) { + dmnsn_error(DMNSN_SEVERITY_HIGH, "Array rwlock allocation failed."); + } } return array; } +void dmnsn_delete_array(dmnsn_array *array) { + if (array) { + if (pthread_rwlock_destroy(array->rwlock) != 0) { + dmnsn_error(DMNSN_SEVERITY_LOW, "Leaking rwlock in array deallocation."); + } + + free(array->rwlock); + free(array->ptr); + free(array); + } +} + void dmnsn_array_push(dmnsn_array *array, const void *obj) { dmnsn_array_set(array, array->length, obj); } - void dmnsn_array_pop(dmnsn_array *array, void *obj) { - dmnsn_array_get(array, array->length - 1, obj); - dmnsn_array_resize(array, array->length - 1); + dmnsn_array_wrlock(array); + dmnsn_array_get_impl(array, array->length - 1, obj); + dmnsn_array_resize_impl(array, array->length - 1); + dmnsn_array_unlock(array); } -void * -dmnsn_array_at(dmnsn_array *array, size_t i) +void +dmnsn_array_get(const dmnsn_array *array, size_t i, void *obj) { - if (i >= array->length) { - dmnsn_error(DMNSN_SEVERITY_HIGH, "Array index out of bounds."); - } - return array->ptr + array->obj_size*i; + dmnsn_array_rdlock(array); + dmnsn_array_get_impl(array, i, obj); + dmnsn_array_unlock(array); } void -dmnsn_array_get(const dmnsn_array *array, size_t i, void *obj) +dmnsn_array_set(dmnsn_array *array, size_t i, const void *obj) +{ + dmnsn_array_wrlock(array); + dmnsn_array_set_impl(array, i, obj); + dmnsn_array_unlock(array); +} + +void +dmnsn_array_resize(dmnsn_array *array, size_t length) +{ + dmnsn_array_wrlock(array); + dmnsn_array_resize_impl(array, length); + dmnsn_array_unlock(array); +} + +static void +dmnsn_array_get_impl(const dmnsn_array *array, size_t i, void *obj) { if (i >= array->length) { dmnsn_error(DMNSN_SEVERITY_HIGH, "Array index out of bounds."); @@ -71,17 +110,17 @@ dmnsn_array_get(const dmnsn_array *array, size_t i, void *obj) memcpy(obj, array->ptr + array->obj_size*i, array->obj_size); } -void -dmnsn_array_set(dmnsn_array *array, size_t i, const void *obj) +static void +dmnsn_array_set_impl(dmnsn_array *array, size_t i, const void *obj) { if (i >= array->length) { - dmnsn_array_resize(array, i + 1); + dmnsn_array_resize_impl(array, i + 1); } memcpy(array->ptr + array->obj_size*i, obj, array->obj_size); } -void -dmnsn_array_resize(dmnsn_array *array, size_t length) +static void +dmnsn_array_resize_impl(dmnsn_array *array, size_t length) { if (length > array->capacity) { array->capacity = length*2; /* We are greedy */ @@ -94,9 +133,43 @@ dmnsn_array_resize(dmnsn_array *array, size_t length) array->length = length; } -void dmnsn_delete_array(dmnsn_array *array) { - if (array) { - free(array->ptr); - free(array); +void * +dmnsn_array_at(dmnsn_array *array, size_t i) +{ + if (i >= array->length) { + dmnsn_error(DMNSN_SEVERITY_HIGH, "Array index out of bounds."); + } + return array->ptr + array->obj_size*i; +} + +void +dmnsn_array_rdlock(const dmnsn_array *array) +{ + if (pthread_rwlock_rdlock(array->rwlock) != 0) { + /* Medium severity, because undefined behaviour is pretty likely if our + reads and writes aren't synced */ + dmnsn_error(DMNSN_SEVERITY_MEDIUM, + "Couldn't acquire read-lock for array."); + } +} + +void +dmnsn_array_wrlock(dmnsn_array *array) +{ + if (pthread_rwlock_wrlock(array->rwlock) != 0) { + /* Medium severity, because undefined behaviour is pretty likely if our + reads and writes aren't synced */ + dmnsn_error(DMNSN_SEVERITY_MEDIUM, + "Couldn't acquire write-lock for array."); + } +} + +void +dmnsn_array_unlock(const dmnsn_array *array) +{ + if (pthread_rwlock_unlock(array->rwlock) != 0) { + /* Medium severity, because if the array is locked, we're likely to hang + the next time we try to read or write it */ + dmnsn_error(DMNSN_SEVERITY_MEDIUM, "Couldn't unlock array."); } } diff --git a/libdimension/dimension/array.h b/libdimension/dimension/array.h index 0a64952..30a119d 100644 --- a/libdimension/dimension/array.h +++ b/libdimension/dimension/array.h @@ -22,28 +22,38 @@ #define DIMENSION_ARRAY_H /* - * Simple generalized arrays, for returning variable-length arrays from - * functions, and other fun stuff. + * Simple thread-safe generalized arrays, for returning variable-length arrays + * from functions, and other fun stuff. */ -#include /* For size_t */ +#include /* For pthread_rwlock_t */ +#include /* For size_t */ typedef struct { void *ptr; size_t obj_size, length, capacity; + + /* Synchronicity control (pointer so it's not const) */ + pthread_rwlock_t *rwlock; } dmnsn_array; dmnsn_array *dmnsn_new_array(size_t obj_size); +void dmnsn_delete_array(dmnsn_array *array); void dmnsn_array_push(dmnsn_array *array, const void *obj); void dmnsn_array_pop(dmnsn_array *array, void *obj); -void *dmnsn_array_at(dmnsn_array *array, size_t i); -void dmnsn_array_get(const dmnsn_array *array, size_t i, void *obj); -void dmnsn_array_set(dmnsn_array *array, size_t i, const void *obj); +void dmnsn_array_get(const dmnsn_array *array, size_t i, void *obj); +void dmnsn_array_set(dmnsn_array *array, size_t i, const void *obj); void dmnsn_array_resize(dmnsn_array *array, size_t length); -void dmnsn_delete_array(dmnsn_array *array); +/* Thread-unsafe! Don't give multiple threads the same raw pointer... */ +void *dmnsn_array_at(dmnsn_array *array, size_t i); + +/* Manual locking */ +void dmnsn_array_rdlock(const dmnsn_array *array); +void dmnsn_array_wrlock(dmnsn_array *array); +void dmnsn_array_unlock(const dmnsn_array *array); #endif /* DIMENSION_ARRAY_H */ diff --git a/libdimension/geometry.c b/libdimension/geometry.c index 4f46933..2446613 100644 --- a/libdimension/geometry.c +++ b/libdimension/geometry.c @@ -196,7 +196,8 @@ static double dmnsn_matrix_cofactor(dmnsn_matrix A, /* Invert a matrix, by partitioning */ dmnsn_matrix -dmnsn_matrix_inverse(dmnsn_matrix A) { +dmnsn_matrix_inverse(dmnsn_matrix A) +{ /* * Use partitioning to invert a matrix: * -- cgit v1.2.3