diff options
Diffstat (limited to 'README.NONPORTABLE')
| -rw-r--r-- | README.NONPORTABLE | 407 |
1 files changed, 258 insertions, 149 deletions
diff --git a/README.NONPORTABLE b/README.NONPORTABLE index 0985097..12336bd 100644 --- a/README.NONPORTABLE +++ b/README.NONPORTABLE @@ -1,149 +1,258 @@ -Non-portable functions included in pthreads-win32 -------------------------------------------------- - -void * -pthread_timechange_handler_np(void *) - - To improve tolerance against operator or time service - initiated system clock changes. - - This routine can be called by an application when it - receives a WM_TIMECHANGE message from the system. At - present it broadcasts all condition variables so that - waiting threads can wake up and re-evaluate their - conditions and restart their timed waits if required. - - It has the same return type and argument type as a - thread routine so that it may be called directly - through pthread_create() for asynchronicity. - - Parameters - - Although a parameter must be supplied, it is ignored. - The value NULL can be used. - - Return values - - It can return an error EAGAIN to indicate that not - all condition variables were broadcast for some reason. - Otherwise, 0 is returned. - - If run as a thread, the return value is returned - through pthread_join(), otherwise directly. - - The return value should be cast to an integer. - - -HANDLE -pthread_getw32threadhandle_np(pthread_t thread); - - Returns the win32 thread handle that the POSIX - thread "thread" is running as. - - Applications can use the win32 handle to set - win32 specific attributes of the thread. - - -int -pthread_mutexattr_setkind_np(pthread_mutexattr_t * attr, int kind) - -int -pthread_mutexattr_getkind_np(pthread_mutexattr_t * attr, int *kind) - - These two routines are included for Linux compatibility - and are direct equivalents to the standard routines - pthread_mutexattr_settype - pthread_mutexattr_gettype - - pthread_mutexattr_setkind_np accepts the following - mutex kinds: - PTHREAD_MUTEX_FAST_NP - PTHREAD_MUTEX_ERRORCHECK_NP - PTHREAD_MUTEX_RECURSIVE_NP - - These are really just equivalent to (respectively): - PTHREAD_MUTEX_NORMAL - PTHREAD_MUTEX_ERRORCHECK - PTHREAD_MUTEX_RECURSIVE - -int -pthread_delay_np (const struct timespec *interval); - - This routine causes a thread to delay execution for a specific period of time. - This period ends at the current time plus the specified interval. The routine - will not return before the end of the period is reached, but may return an - arbitrary amount of time after the period has gone by. This can be due to - system load, thread priorities, and system timer granularity. - - Specifying an interval of zero (0) seconds and zero (0) nanoseconds is - allowed and can be used to force the thread to give up the processor or to - deliver a pending cancelation request. - - This routine is a cancelation point. - - The timespec structure contains the following two fields: - - tv_sec is an integer number of seconds. - tv_nsec is an integer number of nanoseconds. - - Return Values - - If an error condition occurs, this routine returns an integer value - indicating the type of error. Possible return values are as follows: - - 0 Successful completion. - [EINVAL] The value specified by interval is invalid. - -int -pthread_num_processors_np - - This routine (found on HPUX systems) returns the number of processors - in the system. This implementation actually returns the number of - processors available to the process, which can be a lower number - than the system's number, depending on the process's affinity mask. - -BOOL -pthread_win32_process_attach_np (void); - -BOOL -pthread_win32_process_detach_np (void); - -BOOL -pthread_win32_thread_attach_np (void); - -BOOL -pthread_win32_thread_detach_np (void); - - These functions contain the code normally run via dllMain - when the library is used as a dll but which need to be - called explicitly by an application when the library - is statically linked. - - You will need to call pthread_win32_process_attach_np() before - you can call any pthread routines when statically linking. - You should call pthread_win32_process_detach_np() before - exiting your application to clean up. - - pthread_win32_thread_attach_np() is currently a no-op, but - pthread_win32_thread_detach_np() is needed to clean up - the implicit pthread handle that is allocated to a Win32 thread if - it calls certain pthreads routines. Call this routine when the - Win32 thread exits. - - These functions invariably return TRUE except for - pthread_win32_process_attach_np() which will return FALSE - if pthreads-win32 initialisation fails. - -int -pthreadCancelableWait (HANDLE waitHandle); - -int -pthreadCancelableTimedWait (HANDLE waitHandle, DWORD timeout); - - These two functions provide hooks into the pthread_cancel - mechanism that will allow you to wait on a Windows handle - and make it a cancellation point. Both functions block - until either the given w32 handle is signaled, or - pthread_cancel has been called. It is implemented using - WaitForMultipleObjects on 'waitHandle' and a manually - reset w32 event used to implement pthread_cancel. +This file documents non-portable functions and other issues.
+
+Non-portable functions included in pthreads-win32
+-------------------------------------------------
+
+void *
+pthread_timechange_handler_np(void *)
+
+ To improve tolerance against operator or time service
+ initiated system clock changes.
+
+ This routine can be called by an application when it
+ receives a WM_TIMECHANGE message from the system. At
+ present it broadcasts all condition variables so that
+ waiting threads can wake up and re-evaluate their
+ conditions and restart their timed waits if required.
+
+ It has the same return type and argument type as a
+ thread routine so that it may be called directly
+ through pthread_create() for asynchronicity.
+
+ Parameters
+
+ Although a parameter must be supplied, it is ignored.
+ The value NULL can be used.
+
+ Return values
+
+ It can return an error EAGAIN to indicate that not
+ all condition variables were broadcast for some reason.
+ Otherwise, 0 is returned.
+
+ If run as a thread, the return value is returned
+ through pthread_join(), otherwise directly.
+
+ The return value should be cast to an integer.
+
+
+HANDLE
+pthread_getw32threadhandle_np(pthread_t thread);
+
+ Returns the win32 thread handle that the POSIX
+ thread "thread" is running as.
+
+ Applications can use the win32 handle to set
+ win32 specific attributes of the thread.
+
+
+int
+pthread_mutexattr_setkind_np(pthread_mutexattr_t * attr, int kind)
+
+int
+pthread_mutexattr_getkind_np(pthread_mutexattr_t * attr, int *kind)
+
+ These two routines are included for Linux compatibility
+ and are direct equivalents to the standard routines
+ pthread_mutexattr_settype
+ pthread_mutexattr_gettype
+
+ pthread_mutexattr_setkind_np accepts the following
+ mutex kinds:
+ PTHREAD_MUTEX_FAST_NP
+ PTHREAD_MUTEX_ERRORCHECK_NP
+ PTHREAD_MUTEX_RECURSIVE_NP
+
+ These are really just equivalent to (respectively):
+ PTHREAD_MUTEX_NORMAL
+ PTHREAD_MUTEX_ERRORCHECK
+ PTHREAD_MUTEX_RECURSIVE
+
+int
+pthread_delay_np (const struct timespec *interval);
+
+ This routine causes a thread to delay execution for a specific period of time.
+ This period ends at the current time plus the specified interval. The routine
+ will not return before the end of the period is reached, but may return an
+ arbitrary amount of time after the period has gone by. This can be due to
+ system load, thread priorities, and system timer granularity.
+
+ Specifying an interval of zero (0) seconds and zero (0) nanoseconds is
+ allowed and can be used to force the thread to give up the processor or to
+ deliver a pending cancelation request.
+
+ This routine is a cancelation point.
+
+ The timespec structure contains the following two fields:
+
+ tv_sec is an integer number of seconds.
+ tv_nsec is an integer number of nanoseconds.
+
+ Return Values
+
+ If an error condition occurs, this routine returns an integer value
+ indicating the type of error. Possible return values are as follows:
+
+ 0 Successful completion.
+ [EINVAL] The value specified by interval is invalid.
+
+int
+pthread_num_processors_np
+
+ This routine (found on HPUX systems) returns the number of processors
+ in the system. This implementation actually returns the number of
+ processors available to the process, which can be a lower number
+ than the system's number, depending on the process's affinity mask.
+
+BOOL
+pthread_win32_process_attach_np (void);
+
+BOOL
+pthread_win32_process_detach_np (void);
+
+BOOL
+pthread_win32_thread_attach_np (void);
+
+BOOL
+pthread_win32_thread_detach_np (void);
+
+ These functions contain the code normally run via dllMain
+ when the library is used as a dll but which need to be
+ called explicitly by an application when the library
+ is statically linked.
+
+ You will need to call pthread_win32_process_attach_np() before
+ you can call any pthread routines when statically linking.
+ You should call pthread_win32_process_detach_np() before
+ exiting your application to clean up.
+
+ pthread_win32_thread_attach_np() is currently a no-op, but
+ pthread_win32_thread_detach_np() is needed to clean up
+ the implicit pthread handle that is allocated to a Win32 thread if
+ it calls certain pthreads routines. Call this routine when the
+ Win32 thread exits.
+
+ These functions invariably return TRUE except for
+ pthread_win32_process_attach_np() which will return FALSE
+ if pthreads-win32 initialisation fails.
+
+int
+pthreadCancelableWait (HANDLE waitHandle);
+
+int
+pthreadCancelableTimedWait (HANDLE waitHandle, DWORD timeout);
+
+ These two functions provide hooks into the pthread_cancel
+ mechanism that will allow you to wait on a Windows handle
+ and make it a cancellation point. Both functions block
+ until either the given w32 handle is signaled, or
+ pthread_cancel has been called. It is implemented using
+ WaitForMultipleObjects on 'waitHandle' and a manually
+ reset w32 event used to implement pthread_cancel.
+
+
+Non-portable issues
+-------------------
+
+Thread priority
+
+ POSIX defines a single contiguous range of numbers that determine a
+ thread's priority. Win32 defines priority classes and priority
+ levels relative to these classes. Classes are simply priority base
+ levels that the defined priority levels are relative to such that,
+ changing a process's priority class will change the priority of all
+ of it's threads, while the threads retain the same relativity to each
+ other.
+
+ A Win32 system defines a single contiguous monotonic range of values
+ that define system priority levels, just like POSIX. However, Win32
+ restricts individual threads to a subset of this range on a
+ per-process basis.
+
+ The following table shows the base priority levels for combinations
+ of priority class and priority value in Win32.
+
+ Process Priority Class Thread Priority Level
+ -----------------------------------------------------------------
+ 1 IDLE_PRIORITY_CLASS THREAD_PRIORITY_IDLE
+ 1 BELOW_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_IDLE
+ 1 NORMAL_PRIORITY_CLASS THREAD_PRIORITY_IDLE
+ 1 ABOVE_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_IDLE
+ 1 HIGH_PRIORITY_CLASS THREAD_PRIORITY_IDLE
+ 2 IDLE_PRIORITY_CLASS THREAD_PRIORITY_LOWEST
+ 3 IDLE_PRIORITY_CLASS THREAD_PRIORITY_BELOW_NORMAL
+ 4 IDLE_PRIORITY_CLASS THREAD_PRIORITY_NORMAL
+ 4 BELOW_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_LOWEST
+ 5 IDLE_PRIORITY_CLASS THREAD_PRIORITY_ABOVE_NORMAL
+ 5 BELOW_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_BELOW_NORMAL
+ 5 Background NORMAL_PRIORITY_CLASS THREAD_PRIORITY_LOWEST
+ 6 IDLE_PRIORITY_CLASS THREAD_PRIORITY_HIGHEST
+ 6 BELOW_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_NORMAL
+ 6 Background NORMAL_PRIORITY_CLASS THREAD_PRIORITY_BELOW_NORMAL
+ 7 BELOW_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_ABOVE_NORMAL
+ 7 Background NORMAL_PRIORITY_CLASS THREAD_PRIORITY_NORMAL
+ 7 Foreground NORMAL_PRIORITY_CLASS THREAD_PRIORITY_LOWEST
+ 8 BELOW_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_HIGHEST
+ 8 NORMAL_PRIORITY_CLASS THREAD_PRIORITY_ABOVE_NORMAL
+ 8 Foreground NORMAL_PRIORITY_CLASS THREAD_PRIORITY_BELOW_NORMAL
+ 8 ABOVE_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_LOWEST
+ 9 NORMAL_PRIORITY_CLASS THREAD_PRIORITY_HIGHEST
+ 9 Foreground NORMAL_PRIORITY_CLASS THREAD_PRIORITY_NORMAL
+ 9 ABOVE_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_BELOW_NORMAL
+ 10 Foreground NORMAL_PRIORITY_CLASS THREAD_PRIORITY_ABOVE_NORMAL
+ 10 ABOVE_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_NORMAL
+ 11 Foreground NORMAL_PRIORITY_CLASS THREAD_PRIORITY_HIGHEST
+ 11 ABOVE_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_ABOVE_NORMAL
+ 11 HIGH_PRIORITY_CLASS THREAD_PRIORITY_LOWEST
+ 12 ABOVE_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_HIGHEST
+ 12 HIGH_PRIORITY_CLASS THREAD_PRIORITY_BELOW_NORMAL
+ 13 HIGH_PRIORITY_CLASS THREAD_PRIORITY_NORMAL
+ 14 HIGH_PRIORITY_CLASS THREAD_PRIORITY_ABOVE_NORMAL
+ 15 HIGH_PRIORITY_CLASS THREAD_PRIORITY_HIGHEST
+ 15 HIGH_PRIORITY_CLASS THREAD_PRIORITY_TIME_CRITICAL
+ 15 IDLE_PRIORITY_CLASS THREAD_PRIORITY_TIME_CRITICAL
+ 15 BELOW_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_TIME_CRITICAL
+ 15 NORMAL_PRIORITY_CLASS THREAD_PRIORITY_TIME_CRITICAL
+ 15 ABOVE_NORMAL_PRIORITY_CLASS THREAD_PRIORITY_TIME_CRITICAL
+ 16 REALTIME_PRIORITY_CLASS THREAD_PRIORITY_IDLE
+ 17 REALTIME_PRIORITY_CLASS -7
+ 18 REALTIME_PRIORITY_CLASS -6
+ 19 REALTIME_PRIORITY_CLASS -5
+ 20 REALTIME_PRIORITY_CLASS -4
+ 21 REALTIME_PRIORITY_CLASS -3
+ 22 REALTIME_PRIORITY_CLASS THREAD_PRIORITY_LOWEST
+ 23 REALTIME_PRIORITY_CLASS THREAD_PRIORITY_BELOW_NORMAL
+ 24 REALTIME_PRIORITY_CLASS THREAD_PRIORITY_NORMAL
+ 25 REALTIME_PRIORITY_CLASS THREAD_PRIORITY_ABOVE_NORMAL
+ 26 REALTIME_PRIORITY_CLASS THREAD_PRIORITY_HIGHEST
+ 27 REALTIME_PRIORITY_CLASS 3
+ 28 REALTIME_PRIORITY_CLASS 4
+ 29 REALTIME_PRIORITY_CLASS 5
+ 30 REALTIME_PRIORITY_CLASS 6
+ 31 REALTIME_PRIORITY_CLASS THREAD_PRIORITY_TIME_CRITICAL
+
+ Windows NT: Values -7, -6, -5, -4, -3, 3, 4, 5, and 6 are not supported.
+
+
+ As you can see, the real priority levels available to any individual
+ Win32 thread are non-contiguous.
+
+ An application using pthreads-win32 should not make assumptions about
+ the numbers used to represent thread priority levels, except that they
+ are monotonic between the values returned by sched_get_priority_min()
+ and sched_get_priority_max(). E.g. Windows 95, 98, NT, 2000, XP make
+ available a non-contiguous range of numbers between -15 and 15, while
+ at least one version of WinCE (3.0) defines the minimum priority
+ (THREAD_PRIORITY_LOWEST) as 5, and the maximum priority
+ (THREAD_PRIORITY_HIGHEST) as 1.
+
+ Internally, pthreads-win32 maps any priority levels between
+ THREAD_PRIORITY_IDLE and THREAD_PRIORITY_LOWEST to THREAD_PRIORITY_LOWEST,
+ or between THREAD_PRIORITY_TIME_CRITICAL and THREAD_PRIORITY_HIGHEST to
+ THREAD_PRIORITY_HIGHEST. Currently, this also applies to
+ REALTIME_PRIORITY_CLASSi even if levels -7, -6, -5, -4, -3, 3, 4, 5, and 6
+ are supported.
+
+ If it wishes, a Win32 application using pthreads-win32 can use the Win32
+ defined priority macros THREAD_PRIORITY_IDLE through
+ THREAD_PRIORITY_TIME_CRITICAL.
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