--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nspr/pr/include/prmwait.h	Mon Jul 28 10:47:06 2014 +0200
@@ -0,0 +1,380 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#if defined(_PRMWAIT_H)
+#else
+#define _PRMWAIT_H
+
+#include "prio.h"
+#include "prtypes.h"
+#include "prclist.h"
+
+PR_BEGIN_EXTERN_C
+
+/********************************************************************************/
+/********************************************************************************/
+/********************************************************************************/
+/******************************       WARNING        ****************************/
+/********************************************************************************/
+/**************************** This is work in progress. *************************/
+/************************** Do not make any assumptions *************************/
+/************************** about the stability of this *************************/
+/************************** API or the underlying imple- ************************/
+/************************** mentation.                   ************************/
+/********************************************************************************/
+/********************************************************************************/
+
+/*
+** STRUCTURE:   PRWaitGroup
+** DESCRIPTION:
+**      The client may define several wait groups in order to semantically
+**      tie a collection of file descriptors for a single purpose. This allows
+**      easier dispatching of threads that returned with active file descriptors
+**      from the wait function.
+*/
+typedef struct PRWaitGroup PRWaitGroup;
+
+/*
+** ENUMERATION: PRMWStatus
+** DESCRIPTION:
+**      This enumeration is used to indicate the completion status of
+**      a receive wait object. Generally stated, a positive value indicates
+**      that the operation is not yet complete. A zero value indicates
+**      success (similar to PR_SUCCESS) and any negative value is an
+**      indication of failure. The reason for the failure can be retrieved
+**      by calling PR_GetError().
+**
+**  PR_MW_PENDING       The operation is still pending. None of the other
+**                      fields of the object are currently valid.
+**  PR_MW_SUCCESS       The operation is complete and it was successful.
+**  PR_MW_FAILURE       The operation failed. The reason for the failure
+**                      can be retrieved by calling PR_GetError().
+**  PR_MW_TIMEOUT       The amount of time allowed for by the object's
+**                      'timeout' field has expired w/o the operation
+**                      otherwise coming to closure.
+**  PR_MW_INTERRUPT     The operation was cancelled, either by the client
+**                      calling PR_CancelWaitFileDesc() or destroying the
+**                      entire wait group (PR_DestroyWaitGroup()).
+*/
+typedef enum PRMWStatus
+{
+    PR_MW_PENDING = 1,
+    PR_MW_SUCCESS = 0,
+    PR_MW_FAILURE = -1,
+    PR_MW_TIMEOUT = -2,
+    PR_MW_INTERRUPT = -3
+} PRMWStatus;
+
+/*
+** STRUCTURE:   PRMemoryDescriptor
+** DESCRIPTION:
+**      THis is a descriptor for an interval of memory. It contains a
+**      pointer to the first byte of that memory and the length (in
+**      bytes) of the interval.
+*/
+typedef struct PRMemoryDescriptor
+{
+    void *start;                /* pointer to first byte of memory */
+    PRSize length;              /* length (in bytes) of memory interval */
+} PRMemoryDescriptor;
+
+/*
+** STRUCTURE:   PRMWaitClientData
+** DESCRIPTION:
+**      An opague stucture for which a client MAY give provide a concrete
+**      definition and associate with a receive descriptor. The NSPR runtime
+**      does not manage this field. It is completely up to the client.
+*/
+typedef struct PRMWaitClientData PRMWaitClientData;
+
+/*
+** STRUCTURE:   PRRecvWait
+** DESCRIPTION:
+**      A receive wait object contains the file descriptor that is subject
+**      to the wait and the amount of time (beginning epoch established
+**      when the object is presented to the runtime) the the channel should
+**      block before abandoning the process.
+**
+**      The success of the wait operation will be noted in the object's
+**      'outcome' field. The fields are not valid when the NSPR runtime
+**      is in possession of the object.
+**
+**      The memory descriptor describes an interval of writable memory
+**      in the caller's address space where data from an initial read
+**      can be placed. The description may indicate a null interval.
+*/
+typedef struct PRRecvWait 
+{
+    PRCList internal;           /* internal runtime linkages */
+
+    PRFileDesc *fd;             /* file descriptor associated w/ object */
+    PRMWStatus outcome;         /* outcome of the current/last operation */
+    PRIntervalTime timeout;     /* time allowed for entire operation */
+
+    PRInt32 bytesRecv;          /* number of bytes transferred into buffer */
+    PRMemoryDescriptor buffer;  /* where to store first segment of input data */
+    PRMWaitClientData *client;  /* pointer to arbitrary client defined data */
+} PRRecvWait;
+
+/*
+** STRUCTURE:   PRMWaitEnumerator
+** DESCRIPTION:
+**      An enumeration object is used to store the state of an existing
+**      enumeration over a wait group. The opaque object must be allocated
+**      by the client and the reference presented on each call to the
+**      pseudo-stateless enumerator. The enumeration objects are sharable
+**      only in serial fashion.
+*/
+typedef struct PRMWaitEnumerator PRMWaitEnumerator;
+
+
+/*
+** FUNCTION:    PR_AddWaitFileDesc
+** DESCRIPTION:
+**      This function will effectively add a file descriptor to the
+**      list of those waiting for network receive. The new descriptor
+**      will be semantically tied to the wait group specified.
+**
+**      The ownership for the storage pointed to by 'desc' is temporarily
+**      passed over the the NSPR runtime. It will be handed back by the
+**      function PR_WaitRecvReady().
+**
+**  INPUTS
+**      group       A reference to a PRWaitGroup or NULL. Wait groups are
+**                  created by calling PR_CreateWaitGroup() and are used
+**                  to semantically group various file descriptors by the
+**                  client's application.
+**      desc        A reference to a valid PRRecvWait. The object of the
+**                  reference must be preserved and not be modified
+**                  until its ownership is returned to the client.
+**  RETURN
+**      PRStatus    An indication of success. If equal to PR_FAILUE details
+**                  of the failure are avaiable via PR_GetError().
+**
+**  ERRORS
+**      PR_INVALID_ARGUMENT_ERROR
+**                  Invalid 'group' identifier or duplicate 'desc' object.
+**      PR_OUT_OF_MEMORY_ERROR
+**                  Insuffient memory for internal data structures.
+**      PR_INVALID_STATE_ERROR
+**                  The group is being destroyed.
+*/
+NSPR_API(PRStatus) PR_AddWaitFileDesc(PRWaitGroup *group, PRRecvWait *desc);
+
+/*
+** FUNCTION:    PR_WaitRecvReady
+** DESCRIPTION:
+**      PR_WaitRecvReady will block the calling thread until one of the
+**      file descriptors that have been added via PR_AddWaitFileDesc is
+**      available for input I/O.
+**  INPUT
+**      group       A pointer to a valid PRWaitGroup or NULL (the null
+**                  group. The function will block the caller until a
+**                  channel from the wait group becomes ready for receive
+**                  or there is some sort of error.
+**  RETURN
+**      PRReciveWait
+**                  When the caller is resumed it is either returned a
+**                  valid pointer to a previously added receive wait or
+**                  a NULL. If the latter, the function has terminated
+**                  for a reason that can be determined by calling
+**                  PR_GetError().
+**                  If a valid pointer is returned, the reference is to the
+**                  file descriptor contained in the receive wait object.
+**                  The outcome of the wait operation may still fail, and
+**                  if it has, that fact will be noted in the object's
+**                  outcome field. Details can be retrieved from PR_GetError().
+**
+**  ERRORS
+**      PR_INVALID_ARGUMENT_ERROR
+**                  The 'group' is not known by the runtime.
+**      PR_PENDING_INTERRUPT_ERROR
+                    The thread was interrupted.
+**      PR_INVALID_STATE_ERROR
+**                  The group is being destroyed.
+*/
+NSPR_API(PRRecvWait*) PR_WaitRecvReady(PRWaitGroup *group);
+
+/*
+** FUNCTION:    PR_CancelWaitFileDesc
+** DESCRIPTION:
+**      PR_CancelWaitFileDesc is provided as a means for cancelling operations
+**      on objects previously submitted by use of PR_AddWaitFileDesc(). If
+**      the runtime knows of the object, it will be marked as having failed
+**      because it was interrupted (similar to PR_Interrupt()). The first
+**      available thread waiting on the group will be made to return the
+**      PRRecvWait object with the outcome noted.
+**
+**  INPUTS
+**      group       The wait group under which the wait receive object was
+**                  added.
+**      desc        A pointer to the wait receive object that is to be
+**                  cancelled.
+**  RETURN
+**      PRStatus    If the wait receive object was located and associated
+**                  with the specified wait group, the status returned will
+**                  be PR_SUCCESS. There is still a race condition that would
+**                  permit the offected object to complete normally, but it
+**                  is assured that it will complete in the near future.
+**                  If the receive object or wait group are invalid, the
+**                  function will return with a status of PR_FAILURE.
+**
+**  ERRORS
+**      PR_INVALID_ARGUMENT_ERROR
+**                  The 'group' argument is not recognized as a valid group.
+**      PR_COLLECTION_EMPTY_ERROR
+**                  There are no more receive wait objects in the group's
+**                  collection.
+**      PR_INVALID_STATE_ERROR
+**                  The group is being destroyed.
+*/
+NSPR_API(PRStatus) PR_CancelWaitFileDesc(PRWaitGroup *group, PRRecvWait *desc);
+
+/*
+** FUNCTION:    PR_CancelWaitGroup
+** DESCRIPTION:
+**      PR_CancelWaitGroup is provided as a means for cancelling operations
+**      on objects previously submitted by use of PR_AddWaitFileDesc(). Each
+**      successive call will return a pointer to a PRRecvWait object that
+**      was previously registered via PR_AddWaitFileDesc(). If no wait
+**      objects are associated with the wait group, a NULL will be returned.
+**      This function should be called in a loop until a NULL is returned
+**      to reclaim all the wait objects prior to calling PR_DestroyWaitGroup().
+**
+**  INPUTS
+**      group       The wait group under which the wait receive object was
+**                  added.
+**  RETURN
+**      PRRecvWait* If the wait group is valid and at least one receive wait
+**                  object is present in the group, that object will be
+**                  marked as PR_MW_INTERRUPT'd and removed from the group's
+**                  queues. Otherwise a NULL will be returned and the reason
+**                  for the NULL may be retrieved by calling PR_GetError().
+**
+**  ERRORS
+**      PR_INVALID_ARGUMENT_ERROR
+**      PR_GROUP_EMPTY_ERROR
+*/
+NSPR_API(PRRecvWait*) PR_CancelWaitGroup(PRWaitGroup *group);
+
+/*
+** FUNCTION:    PR_CreateWaitGroup
+** DESCRIPTION:
+**      A wait group is an opaque object that a client may create in order
+**      to semantically group various wait requests. Each wait group is
+**      unique, including the default wait group (NULL). A wait request
+**      that was added under a wait group will only be serviced by a caller
+**      that specified the same wait group.
+**
+**  INPUT
+**      size        The size of the hash table to be used to contain the
+**                  receive wait objects. This is just the initial size.
+**                  It will grow as it needs to, but to avoid that hassle
+**                  one can suggest a suitable size initially. It should
+**                  be ~30% larger than the maximum number of receive wait
+**                  objects expected.
+**  RETURN
+**      PRWaitGroup If successful, the function will return a pointer to an
+**                  object that was allocated by and owned by the runtime.
+**                  The reference remains valid until it is explicitly destroyed
+**                  by calling PR_DestroyWaitGroup().
+**
+**  ERRORS
+**      PR_OUT_OF_MEMORY_ERROR
+*/
+NSPR_API(PRWaitGroup*) PR_CreateWaitGroup(PRInt32 size);
+
+/*
+** FUNCTION:    PR_DestroyWaitGroup
+** DESCRIPTION:
+**      Undo the effects of PR_CreateWaitGroup(). Any receive wait operations
+**      on the group will be treated as if the each had been the target of a
+**      PR_CancelWaitFileDesc().
+**
+**  INPUT
+**      group       Reference to a wait group previously allocated using
+**                  PR_CreateWaitGroup().
+**  RETURN
+**      PRStatus    Will be PR_SUCCESS if the wait group was valid and there
+**                  are no receive wait objects in that group. Otherwise
+**                  will indicate PR_FAILURE.
+**
+**  ERRORS
+**      PR_INVALID_ARGUMENT_ERROR
+**                  The 'group' argument does not reference a known object.
+**      PR_INVALID_STATE_ERROR
+**                  The group still contains receive wait objects.
+*/
+NSPR_API(PRStatus) PR_DestroyWaitGroup(PRWaitGroup *group);
+
+/*
+** FUNCTION:    PR_CreateMWaitEnumerator
+** DESCRIPTION:
+**      The PR_CreateMWaitEnumerator() function returns a reference to an
+**      opaque PRMWaitEnumerator object. The enumerator object is required
+**      as an argument for each successive call in the stateless enumeration
+**      of the indicated wait group.
+**
+**      group       The wait group that the enumeration is intended to
+**                  process. It may be be the default wait group (NULL).
+** RETURN
+**      PRMWaitEnumerator* group
+**                  A reference to an object that will be used to store
+**                  intermediate state of enumerations.
+** ERRORS
+**      Errors are indicated by the function returning a NULL.
+**      PR_INVALID_ARGUMENT_ERROR
+**                  The 'group' argument does not reference a known object.
+**      PR_OUT_OF_MEMORY_ERROR
+*/
+NSPR_API(PRMWaitEnumerator*) PR_CreateMWaitEnumerator(PRWaitGroup *group);
+
+/*
+** FUNCTION:    PR_DestroyMWaitEnumerator
+** DESCRIPTION:
+**      Destroys the object created by PR_CreateMWaitEnumerator(). The reference
+**      used as an argument becomes invalid.
+**
+** INPUT
+**      PRMWaitEnumerator* enumerator
+**          The PRMWaitEnumerator object to destroy.
+** RETURN
+**      PRStatus
+**          PR_SUCCESS if successful, PR_FAILURE otherwise.
+** ERRORS
+**      PR_INVALID_ARGUMENT_ERROR
+**                  The enumerator is invalid.
+*/
+NSPR_API(PRStatus) PR_DestroyMWaitEnumerator(PRMWaitEnumerator* enumerator);
+
+/*
+** FUNCTION:    PR_EnumerateWaitGroup
+** DESCRIPTION:
+**      PR_EnumerateWaitGroup is a thread safe enumerator over a wait group.
+**      Each call to the enumerator must present a valid PRMWaitEnumerator
+**      rererence and a pointer to the "previous" element returned from the
+**      enumeration process or a NULL.
+**
+**      An enumeration is started by passing a NULL as the "previous" value.
+**      Subsequent calls to the enumerator must pass in the result of the
+**      previous call. The enumeration end is signaled by the runtime returning
+**      a NULL as the result.
+**
+**      Modifications to the content of the wait group are allowed during
+**      an enumeration. The effect is that the enumeration may have to be
+**      "reset" and that may result in duplicates being returned from the
+**      enumeration.
+**
+**      An enumeration may be abandoned at any time. The runtime is not
+**      keeping any state, so there are no issues in that regard.
+*/
+NSPR_API(PRRecvWait*) PR_EnumerateWaitGroup(
+    PRMWaitEnumerator *enumerator, const PRRecvWait *previous);
+   
+PR_END_EXTERN_C
+
+#endif /* defined(_PRMWAIT_H) */
+
+/* prmwait.h */