Edit File: apr_poll.h
/* Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef APR_POLL_H #define APR_POLL_H /** * @file apr_poll.h * @brief APR Poll interface */ #include "apr.h" #include "apr_pools.h" #include "apr_errno.h" #include "apr_inherit.h" #include "apr_file_io.h" #include "apr_network_io.h" #if APR_HAVE_NETINET_IN_H #include <netinet/in.h> #endif #ifdef __cplusplus extern "C" { #endif /* __cplusplus */ /** * @defgroup apr_poll Poll Routines * @ingroup APR * @{ */ /** * @defgroup pollopts Poll options * @ingroup apr_poll * @{ */ #define APR_POLLIN 0x001 /**< Can read without blocking */ #define APR_POLLPRI 0x002 /**< Priority data available */ #define APR_POLLOUT 0x004 /**< Can write without blocking */ #define APR_POLLERR 0x010 /**< Pending error */ #define APR_POLLHUP 0x020 /**< Hangup occurred */ #define APR_POLLNVAL 0x040 /**< Descriptor invalid */ /** @} */ /** * @defgroup pollflags Pollset Flags * @ingroup apr_poll * @{ */ #define APR_POLLSET_THREADSAFE 0x001 /**< Adding or removing a descriptor is * thread-safe */ #define APR_POLLSET_NOCOPY 0x002 /**< Descriptors passed to apr_pollset_add() * are not copied */ #define APR_POLLSET_WAKEABLE 0x004 /**< Poll operations are interruptable by * apr_pollset_wakeup() */ #define APR_POLLSET_NODEFAULT 0x010 /**< Do not try to use the default method if * the specified non-default method cannot be * used */ /** @} */ /** * Pollset Methods */ typedef enum { APR_POLLSET_DEFAULT, /**< Platform default poll method */ APR_POLLSET_SELECT, /**< Poll uses select method */ APR_POLLSET_KQUEUE, /**< Poll uses kqueue method */ APR_POLLSET_PORT, /**< Poll uses Solaris event port method */ APR_POLLSET_EPOLL, /**< Poll uses epoll method */ APR_POLLSET_POLL, /**< Poll uses poll method */ APR_POLLSET_AIO_MSGQ /**< Poll uses z/OS asio method */ } apr_pollset_method_e; /** Used in apr_pollfd_t to determine what the apr_descriptor is */ typedef enum { APR_NO_DESC, /**< nothing here */ APR_POLL_SOCKET, /**< descriptor refers to a socket */ APR_POLL_FILE, /**< descriptor refers to a file */ APR_POLL_LASTDESC /**< @deprecated descriptor is the last one in the list */ } apr_datatype_e ; /** Union of either an APR file or socket. */ typedef union { apr_file_t *f; /**< file */ apr_socket_t *s; /**< socket */ } apr_descriptor; /** @see apr_pollfd_t */ typedef struct apr_pollfd_t apr_pollfd_t; /** Poll descriptor set. */ struct apr_pollfd_t { apr_pool_t *p; /**< associated pool */ apr_datatype_e desc_type; /**< descriptor type */ apr_int16_t reqevents; /**< requested events */ apr_int16_t rtnevents; /**< returned events */ apr_descriptor desc; /**< @see apr_descriptor */ void *client_data; /**< allows app to associate context */ }; /* General-purpose poll API for arbitrarily large numbers of * file descriptors */ /** Opaque structure used for pollset API */ typedef struct apr_pollset_t apr_pollset_t; /** * Set up a pollset object * @param pollset The pointer in which to return the newly created object * @param size The maximum number of descriptors that this pollset can hold * @param p The pool from which to allocate the pollset * @param flags Optional flags to modify the operation of the pollset. * * @remark If flags contains APR_POLLSET_THREADSAFE, then a pollset is * created on which it is safe to make concurrent calls to * apr_pollset_add(), apr_pollset_remove() and apr_pollset_poll() * from separate threads. This feature is only supported on some * platforms; the apr_pollset_create() call will fail with * APR_ENOTIMPL on platforms where it is not supported. * @remark If flags contains APR_POLLSET_WAKEABLE, then a pollset is * created with an additional internal pipe object used for the * apr_pollset_wakeup() call. The actual size of pollset is * in that case @a size + 1. This feature is only supported on some * platforms; the apr_pollset_create() call will fail with * APR_ENOTIMPL on platforms where it is not supported. * @remark If flags contains APR_POLLSET_NOCOPY, then the apr_pollfd_t * structures passed to apr_pollset_add() are not copied and * must have a lifetime at least as long as the pollset. * @remark Some poll methods (including APR_POLLSET_KQUEUE, * APR_POLLSET_PORT, and APR_POLLSET_EPOLL) do not have a * fixed limit on the size of the pollset. For these methods, * the size parameter controls the maximum number of * descriptors that will be returned by a single call to * apr_pollset_poll(). */ APR_DECLARE(apr_status_t) apr_pollset_create(apr_pollset_t **pollset, apr_uint32_t size, apr_pool_t *p, apr_uint32_t flags); /** * Set up a pollset object * @param pollset The pointer in which to return the newly created object * @param size The maximum number of descriptors that this pollset can hold * @param p The pool from which to allocate the pollset * @param flags Optional flags to modify the operation of the pollset. * @param method Poll method to use. See #apr_pollset_method_e. If this * method cannot be used, the default method will be used unless the * APR_POLLSET_NODEFAULT flag has been specified. * * @remark If flags contains APR_POLLSET_THREADSAFE, then a pollset is * created on which it is safe to make concurrent calls to * apr_pollset_add(), apr_pollset_remove() and apr_pollset_poll() * from separate threads. This feature is only supported on some * platforms; the apr_pollset_create_ex() call will fail with * APR_ENOTIMPL on platforms where it is not supported. * @remark If flags contains APR_POLLSET_WAKEABLE, then a pollset is * created with additional internal pipe object used for the * apr_pollset_wakeup() call. The actual size of pollset is * in that case size + 1. This feature is only supported on some * platforms; the apr_pollset_create_ex() call will fail with * APR_ENOTIMPL on platforms where it is not supported. * @remark If flags contains APR_POLLSET_NOCOPY, then the apr_pollfd_t * structures passed to apr_pollset_add() are not copied and * must have a lifetime at least as long as the pollset. * @remark Some poll methods (including APR_POLLSET_KQUEUE, * APR_POLLSET_PORT, and APR_POLLSET_EPOLL) do not have a * fixed limit on the size of the pollset. For these methods, * the size parameter controls the maximum number of * descriptors that will be returned by a single call to * apr_pollset_poll(). */ APR_DECLARE(apr_status_t) apr_pollset_create_ex(apr_pollset_t **pollset, apr_uint32_t size, apr_pool_t *p, apr_uint32_t flags, apr_pollset_method_e method); /** * Destroy a pollset object * @param pollset The pollset to destroy */ APR_DECLARE(apr_status_t) apr_pollset_destroy(apr_pollset_t *pollset); /** * Add a socket or file descriptor to a pollset * @param pollset The pollset to which to add the descriptor * @param descriptor The descriptor to add * @remark If you set client_data in the descriptor, that value * will be returned in the client_data field whenever this * descriptor is signalled in apr_pollset_poll(). * @remark If the pollset has been created with APR_POLLSET_THREADSAFE * and thread T1 is blocked in a call to apr_pollset_poll() for * this same pollset that is being modified via apr_pollset_add() * in thread T2, the currently executing apr_pollset_poll() call in * T1 will either: (1) automatically include the newly added descriptor * in the set of descriptors it is watching or (2) return immediately * with APR_EINTR. Option (1) is recommended, but option (2) is * allowed for implementations where option (1) is impossible * or impractical. * @remark If the pollset has been created with APR_POLLSET_NOCOPY, the * apr_pollfd_t structure referenced by descriptor will not be copied * and must have a lifetime at least as long as the pollset. * @remark Do not add the same socket or file descriptor to the same pollset * multiple times, even if the requested events differ for the * different calls to apr_pollset_add(). If the events of interest * for a descriptor change, you must first remove the descriptor * from the pollset with apr_pollset_remove(), then add it again * specifying all requested events. */ APR_DECLARE(apr_status_t) apr_pollset_add(apr_pollset_t *pollset, const apr_pollfd_t *descriptor); /** * Remove a descriptor from a pollset * @param pollset The pollset from which to remove the descriptor * @param descriptor The descriptor to remove * @remark If the descriptor is not found, APR_NOTFOUND is returned. * @remark If the pollset has been created with APR_POLLSET_THREADSAFE * and thread T1 is blocked in a call to apr_pollset_poll() for * this same pollset that is being modified via apr_pollset_remove() * in thread T2, the currently executing apr_pollset_poll() call in * T1 will either: (1) automatically exclude the newly added descriptor * in the set of descriptors it is watching or (2) return immediately * with APR_EINTR. Option (1) is recommended, but option (2) is * allowed for implementations where option (1) is impossible * or impractical. * @remark apr_pollset_remove() cannot be used to remove a subset of requested * events for a descriptor. The reqevents field in the apr_pollfd_t * parameter must contain the same value when removing as when adding. */ APR_DECLARE(apr_status_t) apr_pollset_remove(apr_pollset_t *pollset, const apr_pollfd_t *descriptor); /** * Block for activity on the descriptor(s) in a pollset * @param pollset The pollset to use * @param timeout The amount of time in microseconds to wait. This is a * maximum, not a minimum. If a descriptor is signalled, the * function will return before this time. If timeout is * negative, the function will block until a descriptor is * signalled or until apr_pollset_wakeup() has been called. * @param num Number of signalled descriptors (output parameter) * @param descriptors Array of signalled descriptors (output parameter) * @remark APR_EINTR will be returned if the pollset has been created with * APR_POLLSET_WAKEABLE, apr_pollset_wakeup() has been called while * waiting for activity, and there were no signalled descriptors at the * time of the wakeup call. * @remark Multiple signalled conditions for the same descriptor may be reported * in one or more returned apr_pollfd_t structures, depending on the * implementation. */ APR_DECLARE(apr_status_t) apr_pollset_poll(apr_pollset_t *pollset, apr_interval_time_t timeout, apr_int32_t *num, const apr_pollfd_t **descriptors); /** * Interrupt the blocked apr_pollset_poll() call. * @param pollset The pollset to use * @remark If the pollset was not created with APR_POLLSET_WAKEABLE the * return value is APR_EINIT. */ APR_DECLARE(apr_status_t) apr_pollset_wakeup(apr_pollset_t *pollset); /** * Poll the descriptors in the poll structure * @param aprset The poll structure we will be using. * @param numsock The number of descriptors we are polling * @param nsds The number of descriptors signalled (output parameter) * @param timeout The amount of time in microseconds to wait. This is a * maximum, not a minimum. If a descriptor is signalled, the * function will return before this time. If timeout is * negative, the function will block until a descriptor is * signalled or until apr_pollset_wakeup() has been called. * @remark The number of descriptors signalled is returned in the third argument. * This is a blocking call, and it will not return until either a * descriptor has been signalled or the timeout has expired. * @remark The rtnevents field in the apr_pollfd_t array will only be filled- * in if the return value is APR_SUCCESS. */ APR_DECLARE(apr_status_t) apr_poll(apr_pollfd_t *aprset, apr_int32_t numsock, apr_int32_t *nsds, apr_interval_time_t timeout); /** * Return a printable representation of the pollset method. * @param pollset The pollset to use */ APR_DECLARE(const char *) apr_pollset_method_name(apr_pollset_t *pollset); /** * Return a printable representation of the default pollset method * (APR_POLLSET_DEFAULT). */ APR_DECLARE(const char *) apr_poll_method_defname(void); /** Opaque structure used for pollcb API */ typedef struct apr_pollcb_t apr_pollcb_t; /** * Set up a pollcb object * @param pollcb The pointer in which to return the newly created object * @param size The maximum number of descriptors that a single _poll can return. * @param p The pool from which to allocate the pollcb * @param flags Optional flags to modify the operation of the pollcb. * * @remark Pollcb is only supported on some platforms; the apr_pollcb_create() * call will fail with APR_ENOTIMPL on platforms where it is not supported. */ APR_DECLARE(apr_status_t) apr_pollcb_create(apr_pollcb_t **pollcb, apr_uint32_t size, apr_pool_t *p, apr_uint32_t flags); /** * Set up a pollcb object * @param pollcb The pointer in which to return the newly created object * @param size The maximum number of descriptors that a single _poll can return. * @param p The pool from which to allocate the pollcb * @param flags Optional flags to modify the operation of the pollcb. * @param method Poll method to use. See #apr_pollset_method_e. If this * method cannot be used, the default method will be used unless the * APR_POLLSET_NODEFAULT flag has been specified. * * @remark Pollcb is only supported on some platforms; the apr_pollcb_create_ex() * call will fail with APR_ENOTIMPL on platforms where it is not supported. */ APR_DECLARE(apr_status_t) apr_pollcb_create_ex(apr_pollcb_t **pollcb, apr_uint32_t size, apr_pool_t *p, apr_uint32_t flags, apr_pollset_method_e method); /** * Add a socket or file descriptor to a pollcb * @param pollcb The pollcb to which to add the descriptor * @param descriptor The descriptor to add * @remark If you set client_data in the descriptor, that value will be * returned in the client_data field whenever this descriptor is * signalled in apr_pollcb_poll(). * @remark Unlike the apr_pollset API, the descriptor is not copied, and users * must retain the memory used by descriptor, as the same pointer will * be returned to them from apr_pollcb_poll. * @remark Do not add the same socket or file descriptor to the same pollcb * multiple times, even if the requested events differ for the * different calls to apr_pollcb_add(). If the events of interest * for a descriptor change, you must first remove the descriptor * from the pollcb with apr_pollcb_remove(), then add it again * specifying all requested events. */ APR_DECLARE(apr_status_t) apr_pollcb_add(apr_pollcb_t *pollcb, apr_pollfd_t *descriptor); /** * Remove a descriptor from a pollcb * @param pollcb The pollcb from which to remove the descriptor * @param descriptor The descriptor to remove * @remark apr_pollcb_remove() cannot be used to remove a subset of requested * events for a descriptor. The reqevents field in the apr_pollfd_t * parameter must contain the same value when removing as when adding. */ APR_DECLARE(apr_status_t) apr_pollcb_remove(apr_pollcb_t *pollcb, apr_pollfd_t *descriptor); /** Function prototype for pollcb handlers * @param baton Opaque baton passed into apr_pollcb_poll() * @param descriptor Contains the notification for an active descriptor, * the rtnevents member contains what events were triggered * for this descriptor. */ typedef apr_status_t (*apr_pollcb_cb_t)(void *baton, apr_pollfd_t *descriptor); /** * Block for activity on the descriptor(s) in a pollcb * @param pollcb The pollcb to use * @param timeout The amount of time in microseconds to wait. This is a * maximum, not a minimum. If a descriptor is signalled, the * function will return before this time. If timeout is * negative, the function will block until a descriptor is * signalled. * @param func Callback function to call for each active descriptor. * @param baton Opaque baton passed to the callback function. * @remark Multiple signalled conditions for the same descriptor may be reported * in one or more calls to the callback function, depending on the * implementation. */ APR_DECLARE(apr_status_t) apr_pollcb_poll(apr_pollcb_t *pollcb, apr_interval_time_t timeout, apr_pollcb_cb_t func, void *baton); /** @} */ #ifdef __cplusplus } #endif #endif /* ! APR_POLL_H */
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