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/*
* Copyright 2011 Red Hat, Inc.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation files
* (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge,
* publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef VERTO_H_
#define VERTO_H_
#include <time.h> /* For time_t */
#include <unistd.h> /* For pid_t */
#ifdef WIN32
#include <windows.h>
typedef HANDLE verto_proc;
typedef DWORD verto_proc_status;
#else
typedef pid_t verto_proc;
typedef int verto_proc_status;
#endif
#define VERTO_SIG_IGN ((verto_callback *) 1)
typedef struct verto_ctx verto_ctx;
typedef struct verto_ev verto_ev;
typedef enum {
VERTO_EV_TYPE_NONE = 0,
VERTO_EV_TYPE_IO = 1,
VERTO_EV_TYPE_TIMEOUT = 1 << 1,
VERTO_EV_TYPE_IDLE = 1 << 2,
VERTO_EV_TYPE_SIGNAL = 1 << 3,
VERTO_EV_TYPE_CHILD = 1 << 4
} verto_ev_type;
typedef enum {
VERTO_EV_FLAG_NONE = 0,
VERTO_EV_FLAG_PERSIST = 1,
VERTO_EV_FLAG_PRIORITY_LOW = 1 << 1,
VERTO_EV_FLAG_PRIORITY_MEDIUM = 1 << 2,
VERTO_EV_FLAG_PRIORITY_HIGH = 1 << 3,
VERTO_EV_FLAG_IO_READ = 1 << 4,
VERTO_EV_FLAG_IO_WRITE = 1 << 5,
VERTO_EV_FLAG_REINITIABLE = 1 << 6,
_VERTO_EV_FLAG_MAX = VERTO_EV_FLAG_REINITIABLE
} verto_ev_flag;
typedef void (verto_callback)(verto_ctx *ctx, verto_ev *ev);
/**
* Creates a new event context using an optionally specified implementation
* and/or optionally specified required features.
*
* If you are an application that has already decided on using a particular
* event loop implementation, you should not call this function, but instead
* import the verto-NAME.h header and link against the verto-NAME.so, where
* NAME is the implementation you wish to use.
*
* If you are a library, you should generally avoid creating event contexts
* on your own but allow applications to pass in a verto_ctx you can use.
*
* There are two cases where you should use this function. The first is
* where you have a need to choose an implementation at run time, usually
* for testing purposes. The second and more common is when you simply
* wish to remain implementation agnostic. In this later case, you should
* always call like this: verto_new(NULL, ...). This lets verto choose the best
* implementation to use.
*
* If impl is not NULL, a new context is returned which is backed by the
* implementation specified. If the implementation specified is not
* available or if the required types (reqtypes) are not provided by the
* named implementation, NULL is returned. The parameter 'impl' can specify:
* * The full path to an implementation library
* * The name of the implementation library (i.e. - "glib" or "libev")
*
* If impl is NULL, verto will attempt to automatically determine the
* best implementation to use.
*
* First, verto will attempt to use an existing, previously loaded
* implementation. This is handled automatically by internal caching of either
* the first implementation loaded or the one specified by verto_set_default().
*
* Second, verto will attempt to discern if you are already linked to any
* of the supported implementations (to avoid wasting memory by loading
* extra unnecessary libraries). If you are linked to one supported
* implementation, that implementation will be chosen. If you are linked
* to more than one supported implementation one of the ones linked to
* will be chosen, but the order of the particular choice is undefined.
*
* Third, verto will attempt to load the compile-time default, if defined at
* build time and available at runtime.
*
* Last, verto will attempt to load any implementation installed. The specific
* order of this step is undefined.
*
* In all cases above, if the implementation does not support all the specified
* features (reqtypes), it will be skipped and processing will continue from
* where it left off. This means that if verto_new() returns non-NULL it is
* guaranteed to support the features you specified.
*
* @see verto_set_default()
* @param impl The implementation to use, or NULL.
* @param reqtypes A bitwise or'd list of required event type features.
* @return A new verto_ctx, or NULL on error. Call verto_free() when done.
*/
verto_ctx *
verto_new(const char *impl, verto_ev_type reqtypes);
/**
* Gets the default event context using an optionally specified implementation.
*
* This function is essentially a singleton version of verto_new(). However,
* since this function must return the same loop as the *_default() call of
* the underlying implementation (if such a function exists), it is NOT a
* global singleton, but a per-implementation singleton. For this reason, you
* must call verto_free() when you are done with this loop. Even after calling
* verto_free() on the default verto_ctx, you can safely call verto_default()
* again and receive a new reference to the same (internally default) loop.
*
* In all other respects, verto_default() acts exactly like verto_new().
*
* @see verto_new()
* @see verto_free()
* @param impl The implementation to use, or NULL.
* @param reqtypes A bitwise or'd list of required event type features.
* @return The default verto_ctx, or NULL on error. Call verto_free() when done.
*/
verto_ctx *
verto_default(const char *impl, verto_ev_type reqtypes);
/**
* Sets the default implementation to use by its name.
*
* This function returns 1 on success and 0 on failure. It can fail for the
* following reasons:
* 1. The default implementation was already set via verto_set_default().
* 2. The implementation specified could not be found.
* 3. The implementation specified didn't support the features specified.
* 4. The impl argument was NULL.
* 5. verto_new() was already called.
* 6. verto_default() was already called.
* 7. verto_new_NAME() was already called.
* 8. verto_default_NAME() was already called.
* 9. verto_convert_NAME() was already called.
*
* @see verto_new()
* @see verto_default()
* @param impl The implementation to use.
* @param reqtypes A bitwise or'd list of required event type features.
* @return The default verto_ctx, or NULL on error. Call verto_free() when done.
*/
int
verto_set_default(const char *impl, verto_ev_type reqtypes);
/**
* Frees a verto_ctx.
*
* When called on a default verto_ctx, the reference will be freed but the
* internal default loop will still be available via another call to
* verto_default().
*
* @see verto_new()
* @see verto_default()
* @param ctx The verto_ctx to free.
*/
void
verto_free(verto_ctx *ctx);
/**
* Run the verto_ctx forever, or at least until verto_break() is called.
*
* @see verto_break()
* @param ctx The verto_ctx to run.
*/
void
verto_run(verto_ctx *ctx);
/**
* Run the verto_ctx once. May block.
*
* @param ctx The verto_ctx to run once.
*/
void
verto_run_once(verto_ctx *ctx);
/**
* Exits the currently running verto_ctx.
*
* @see verto_run()
* @param ctx The verto_ctx to exit.
*/
void
verto_break(verto_ctx *ctx);
/**
* Re-initializes the verto_ctx.
*
* This function deletes all events, except those which have set the
* VERTO_EV_FLAG_REINITIABLE flag. If you fork(), you MUST call this in the
* child process after the fork!
*
* If this function fails it indicates that at least one
* VERTO_EV_FLAG_REINITIABLE event was not rearmed or that ctx was NULL.
*
* @see verto_new()
* @see verto_default()
* @param ctx The verto_ctx to re-initialize.
* @return Non-zero on success, 0 on error.
*/
int
verto_reinitialize(verto_ctx *ctx);
/**
* Adds a callback executed when a file descriptor is ready to be read/written.
*
* All verto_ev events are automatically freed when their parent verto_ctx is
* freed. You do not need to free them manually. If VERTO_EV_FLAG_PERSIST is
* provided, the event will repeat until verto_del() is called. If
* VERTO_EV_FLAG_PERSIST is not provided, the event will be freed automatically
* after its execution. In either case, you may call verto_del() at any time
* to prevent the event from executing.
*
* NOTE: On Windows, the underlying select() only works with sockets. As such,
* any attempt to add a non-socket io event on Windows will produce undefined
* results and may even crash.
*
* @see verto_del()
* @param ctx The verto_ctx which will fire the callback.
* @param flags The flags to set (at least one VERTO_EV_FLAG_IO* required).
* @param callback The callback to fire.
* @param fd The file descriptor to watch for reads.
* @return The verto_ev registered with the event context or NULL on error.
*/
verto_ev *
verto_add_io(verto_ctx *ctx, verto_ev_flag flags,
verto_callback *callback, int fd);
/**
* Adds a callback executed after a period of time.
*
* All verto_ev events are automatically freed when their parent verto_ctx is
* freed. You do not need to free them manually. If VERTO_EV_FLAG_PERSIST is
* provided, the event will repeat until verto_del() is called. If
* VERTO_EV_FLAG_PERSIST is not provided, the event will be freed automatically
* after its execution. In either case, you may call verto_del() at any time
* to prevent the event from executing.
*
* @see verto_del()
* @param ctx The verto_ctx which will fire the callback.
* @param flags The flags to set.
* @param callback The callback to fire.
* @param interval Time period to wait before firing (in milliseconds).
* @return The verto_ev registered with the event context.
*/
verto_ev *
verto_add_timeout(verto_ctx *ctx, verto_ev_flag flags,
verto_callback *callback, time_t interval);
/**
* Adds a callback executed when there is nothing else to do.
*
* All verto_ev events are automatically freed when their parent verto_ctx is
* freed. You do not need to free them manually. If VERTO_EV_FLAG_PERSIST is
* provided, the event will repeat until verto_del() is called. If
* VERTO_EV_FLAG_PERSIST is not provided, the event will be freed automatically
* after its execution. In either case, you may call verto_del() at any time
* to prevent the event from executing.
*
* @see verto_del()
* @param ctx The verto_ctx which will fire the callback.
* @param flags The flags to set.
* @param callback The callback to fire.
* @return The verto_ev registered with the event context.
*/
verto_ev *
verto_add_idle(verto_ctx *ctx, verto_ev_flag flags,
verto_callback *callback);
/**
* Adds a callback executed when a signal is received.
*
* All verto_ev events are automatically freed when their parent verto_ctx is
* freed. You do not need to free them manually. If VERTO_EV_FLAG_PERSIST is
* provided, the event will repeat until verto_del() is called. If
* VERTO_EV_FLAG_PERSIST is not provided, the event will be freed automatically
* after its execution. In either case, you may call verto_del() at any time
* to prevent the event from executing.
*
* NOTE: If you attempt to ignore a signal without the VERTO_EV_FLAG_PERSIST
* flag, this function fails.
*
* NOTE: SIGCHLD is expressly not supported. If you want this notification,
* please use verto_add_child().
*
* WARNNIG: Signal events can only be reliably received in the default verto_ctx
* in some implementations. Attempting to receive signal events in non-default
* loops may result in assert() failures.
*
* WARNING: While verto does its best to protect you from crashes, there is
* essentially no way to do signal events if you mix multiple implementations in
* a single process. Attempting to do so will result in undefined behavior,
* and potentially even a crash. You have been warned.
*
* @see verto_add_child()
* @see verto_repeat()
* @see verto_del()
* @param ctx The verto_ctx which will fire the callback.
* @param flags The flags to set.
* @param callback The callback to fire.
* @param signal The signal to watch for.
* @return The verto_ev registered with the event context.
*/
verto_ev *
verto_add_signal(verto_ctx *ctx, verto_ev_flag flags,
verto_callback *callback, int signal);
/**
* Adds a callback executed when a child process exits.
*
* This event will be freed automatically after its execution. Due to the
* nature of a process' life-cycle, child events cannot persist (processes only
* exit once). This function returns NULL if you attempt to use
* VERTO_EV_FLAG_PERSIST. You may, of course, call verto_del() at any time to
* prevent the callback from firing.
*
* @see verto_del()
* @param ctx The verto_ctx which will fire the callback.
* @param flags The flags to set.
* @param callback The callback to fire.
* @param child The pid (POSIX) or handle (Win32) of the child to watch for.
* @return The verto_ev registered with the event context.
*/
verto_ev *
verto_add_child(verto_ctx *ctx, verto_ev_flag flags,
verto_callback *callback, verto_proc proc);
/**
* Sets the private pointer of the verto_ev.
*
* The free callback will be called in two cases:
* 1. When the event is deleted (manually or automatically)
* 2. When verto_set_private() is called again, unless
* free is NULL.
*
* @see verto_get_private()
* @param ev The verto_ev
* @param priv The private value to store
* @param free The callback used to free the data or NULL
*/
void
verto_set_private(verto_ev *ev, void *priv, verto_callback *free);
/**
* Gets the private pointer of the verto_ev.
*
* @see verto_set_private()
* @param ev The verto_ev
* @return The verto_ev private pointer
*/
void *
verto_get_private(const verto_ev *ev);
/**
* Gets the type of the verto_ev.
*
* @see verto_add_io()
* @see verto_add_timeout()
* @see verto_add_idle()
* @see verto_add_signal()
* @see verto_add_child()
* @param ev The verto_ev
* @return The verto_ev type
*/
verto_ev_type
verto_get_type(const verto_ev *ev);
/**
* Gets the flags associated with the given verto_ev.
*
* @see verto_add_io()
* @see verto_add_timeout()
* @see verto_add_idle()
* @see verto_add_signal()
* @see verto_add_child()
* @param ev The verto_ev
* @return The verto_ev type
*/
verto_ev_flag
verto_get_flags(const verto_ev *ev);
/**
* Gets the file descriptor associated with a read/write verto_ev.
*
* @see verto_add_io()
* @param ev The verto_ev to retrieve the file descriptor from.
* @return The file descriptor, or -1 if not a read/write event.
*/
int
verto_get_fd(const verto_ev *ev);
/**
* Gets the interval associated with a timeout verto_ev.
*
* @see verto_add_timeout()
* @param ev The verto_ev to retrieve the interval from.
* @return The interval, or 0 if not a timeout event.
*/
time_t
verto_get_interval(const verto_ev *ev);
/**
* Gets the signal associated with a signal verto_ev.
*
* @see verto_add_signal()
* @param ev The verto_ev to retrieve the signal from.
* @return The signal, or -1 if not a signal event.
*/
int
verto_get_signal(const verto_ev *ev);
/**
* Gets the process associated with a child verto_ev.
*
* @see verto_add_child()
* @param ev The verto_ev to retrieve the process from.
* @return The pid/handle, or 0/NULL if not a child event (POSIX/Win32).
*/
verto_proc
verto_get_proc(const verto_ev *ev);
/**
* Gets the status of the process which caused this event to fire.
*
* @see verto_add_child()
* @param ev The verto_ev to retrieve the status from.
* @return The pid/handle status.
*/
verto_proc_status
verto_get_proc_status(const verto_ev *ev);
/**
* Removes an event from from the event context and frees it.
*
* The event and its contents cannot be used after this call.
*
* @see verto_add_io()
* @see verto_add_timeout()
* @see verto_add_idle()
* @see verto_add_signal()
* @see verto_add_child()
* @param ev The event to delete.
*/
void
verto_del(verto_ev *ev);
/**
* Returns the event types supported by this implementation.
*
* @param ctx The verto_ctx to query.
* @return The event types supported.
*/
verto_ev_type
verto_get_supported_types(verto_ctx *ctx);
#endif /* VERTO_H_ */