module Thread: sig .. endLightweight threads for Posix 1003.1c and Win32.
type t
The type of thread handles.
val create : ('a -> 'b) -> 'a -> tThread.create funct arg creates a new thread of control,
in which the function application funct arg
is executed concurrently with the other threads of the domain.
The application of Thread.create
returns the handle of the newly created thread.
The new thread terminates when the application funct arg
returns, either normally or by raising the Thread.Exit exception
or by raising any other uncaught exception.
In the last case, the uncaught exception is printed on standard error,
but not propagated back to the parent thread. Similarly, the
result of the application funct arg is discarded and not
directly accessible to the parent thread.
See also Domain.spawn if you want parallel execution instead.
val self : unit -> t
Return the handle for the thread currently executing.
val id : t -> int
Return the identifier of the given thread. A thread identifier is an integer that identifies uniquely the thread. It can be used to build data structures indexed by threads.
exception Exit
Exception raised by user code to initiate termination of the
current thread.
In a thread created by Thread.create funct arg, if the
Thread.Exit exception reaches the top of the application
funct arg, it has the effect of terminating the current thread
silently. In other contexts, there is no implicit handling of the
Thread.Exit exception.
val exit : unit -> unit
Raise the Thread.Exit exception.
In a thread created by Thread.create, this will cause the thread
to terminate prematurely, unless the thread function handles the
exception itself. Fun.protect finalizers and catch-all
exception handlers will be executed.
To make it clear that an exception is raised and will trigger
finalizers and catch-all exception handlers, it is recommended
to write raise Thread.Exit instead of Thread.exit ().
Thread.create.val delay : float -> unit
delay d suspends the execution of the calling thread for
d seconds. The other program threads continue to run during
this time.
val join : t -> unit
join th suspends the execution of the calling thread
until the thread th has terminated.
val yield : unit -> unit
Re-schedule the calling thread without suspending it. This function can be used to give scheduling hints, telling the scheduler that now is a good time to switch to other threads.
The functions below are leftovers from an earlier, VM-based threading
system. The Unix module provides equivalent functionality, in
a more general and more standard-conformant manner. It is recommended
to use Unix functions directly.
val wait_timed_read : Unix.file_descr -> float -> bool
val wait_timed_write : Unix.file_descr -> float -> bool
Suspend the execution of the calling thread until at least
one character or EOF is available for reading (wait_timed_read) or
one character can be written without blocking (wait_timed_write)
on the given Unix file descriptor. Wait for at most
the amount of time given as second argument (in seconds).
Return true if the file descriptor is ready for input/output
and false if the timeout expired.
The same functionality can be achieved with Unix.select.
val select : Unix.file_descr list -> Unix.file_descr list -> Unix.file_descr list -> float -> Unix.file_descr list * Unix.file_descr list * Unix.file_descr list
Same function as Unix.select.
Suspend the execution of the calling thread until input/output
becomes possible on the given Unix file descriptors.
The arguments and results have the same meaning as for
Unix.select.
val wait_pid : int -> int * Unix.process_status
Same function as Unix.waitpid.
wait_pid p suspends the execution of the calling thread
until the process specified by the process identifier p
terminates. Returns the pid of the child caught and
its termination status, as per Unix.wait.
Signal handling follows the POSIX thread model: signals generated
by a thread are delivered to that thread; signals generated externally
are delivered to one of the threads that does not block it.
Each thread possesses a set of blocked signals, which can be modified
using Thread.sigmask. This set is inherited at thread creation time.
Per-thread signal masks are supported only by the system thread library
under Unix, but not under Win32, nor by the VM thread library.
val sigmask : Unix.sigprocmask_command -> int list -> int list
sigmask cmd sigs changes the set of blocked signals for the
calling thread.
If cmd is SIG_SETMASK, blocked signals are set to those in
the list sigs.
If cmd is SIG_BLOCK, the signals in sigs are added to
the set of blocked signals.
If cmd is SIG_UNBLOCK, the signals in sigs are removed
from the set of blocked signals.
sigmask returns the set of previously blocked signals for the thread.
val wait_signal : int list -> int
wait_signal sigs suspends the execution of the calling thread
until the process receives one of the signals specified in the
list sigs. It then returns the number of the signal received.
Signal handlers attached to the signals in sigs will not
be invoked. The signals sigs are expected to be blocked before
calling wait_signal.
val default_uncaught_exception_handler : exn -> unit
Thread.default_uncaught_exception_handler will print the thread's id,
exception and backtrace (if available).
val set_uncaught_exception_handler : (exn -> unit) -> unit
Thread.set_uncaught_exception_handler fn registers fn as the handler
for uncaught exceptions.
If the newly set uncaught exception handler raise an exception,
Thread.default_uncaught_exception_handler will be called.