Point-To-Point Synchronization

The following section discusses Intel® SHMEM interfaces that provide a mechanism for synchronization between two PEs based on the value of a symmetric data object. The point-to-point synchronization routines can be used to portably ensure that memory access operations observe remote updates in the order enforced by the initiator PE.

The point-to-point synchronization routines support values (the ivar and cmp_value arguments) having a type in the Standard AMO Types Table.

The point-to-point synchronization interface provides named constants whose values are integer constant expressions that specify the comparison operators used by the ishmem synchronization routines. The constant names and associated operations are presented in Table Point-to-point Comparison Constants.

Point-to-point Comparison Constants

Constant Name	Comparison
ISHMEM_CMP_EQ	Equal
ISHMEM_CMP_NE	Not equal
ISHMEM_CMP_GT	Greater than
ISHMEM_CMP_GE	Greater than or equal to
ISHMEM_CMP_LT	Less than
ISHMEM_CMP_LE	Less than or equal to

ISHMEM_WAIT_UNTIL

Wait for a variable on the local PE to change.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

void ishmem_TYPENAME_wait_until(TYPE *ivar, int cmp, TYPE cmp_value)

Parameters:

• ivar – Symmetric address of a remotely accessible data object. The type of ivar should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivar with cmp_value.

• cmp_value – The value to be compared with ivar. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

Returns:

None.

Callable from the host and the device.

Description: The ishmem_wait_until operation blocks until the value contained in the symmetric data object, ivar, at the calling PE satisfies the wait condition. The ivar object at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE.

These routines can be used to implement point-to-point synchronization between PEs or between threads within the same PE. A call to ishmem_wait_until blocks until the value of ivar at the calling PE satisfies the wait condition specified by the comparison operator, cmp, and comparison value, cmp_value.

Implementations must ensure that ishmem_wait_until does not return before the update of the memory indicated by ivar is fully complete.

ISHMEMX_WAIT_UNTIL_WORK_GROUP

Wait for a variable on the local PE to change.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

template<typename Group>
void ishmemx_TYPENAME_wait_until_work_group(TYPE *ivar, int cmp, TYPE cmp_value, const Group &group)

Parameters:

• ivar – Symmetric address of a remotely accessible data object. The type of ivar should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivar with cmp_value.

• cmp_value – The value to be compared with ivar. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• group – The SYCL group or sub_group with which to collectively perform the wait operation.

Returns:

None.

Callable from the device.

Description: The ishmemx_wait_until_work_group operation blocks until the value contained in the symmetric data object, ivar, at the calling PE satisfies the wait condition. The ivar object at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE.

These routines can be used to implement point-to-point synchronization between PEs or between threads within the same PE. A call to ishmemx_wait_until_work_group blocks until the value of ivar at the calling PE satisfies the wait condition specified by the comparison operator, cmp, and comparison value, cmp_value.

Implementations must ensure that ishmemx_wait_until_work_group does not return before the update of the memory indicated by ivar is fully complete.

ISHMEM_WAIT_UNTIL_ALL

Wait for an array of variables on the local PE until all variables meet the specified wait condition.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

void ishmem_TYPENAME_wait_until_all(TYPE *ivars, size_t nelems, const int *status, int cmp, TYPE cmp_value)

Parameters:

• ivars – Symmetric address of an array of remotely accessible data objects. The type of ivars should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• nelems – The number of elements in the ivars array.

• status – Local address of an optional mask array of length nelems that indicates which elements in ivars are excluded from the wait set.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivars with cmp_value.

• cmp_value – The value to be compared with the objects pointed to by ivars. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

Returns:

None.

Callable from the host and the device.

Description: The ishmem_wait_until_all routine waits until all entries in the wait set specified by ivars and status have satisfied the wait condition at the calling PE. The ivars objects at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE. If nelems is 0, the wait set is empty and this routine returns immediately. This routine compares each element of the ivars array in the wait set with the value cmp_value according to the comparison operator cmp at the calling PE. This routine is semantically similar to ishmem_wait_until, but adds support for point-to-point synchronization involving an array of symmetric data objects.

The optional status is a mask array of length nelems where each element corresponds to the respective element in ivars and indicates whether the element is excluded from the wait set. Elements of status set to 0 will be included in the wait set, and elements set to a nonzero value will be ignored. If all elements in status are nonzero or nelems is 0, the wait set is empty and this routine returns immediately. If status is a null pointer, it is ignored and all elements in ivars are included in the wait set. The ivars and status arrays must not overlap in memory.

Implementations must ensure that ishmem_wait_until_all does not return before the update of the memory indicated by ivars is fully complete.

ISHMEMX_WAIT_UNTIL_ALL_WORK_GROUP

Wait for an array of variables on the local PE until all variables meet the specified wait condition.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

template<typename Group>
void ishmemx_TYPENAME_wait_until_all_work_group(TYPE *ivars, size_t nelems, const int *status, int cmp, TYPE cmp_value, const Group &group)

Parameters:

• ivars – Symmetric address of an array of remotely accessible data objects. The type of ivars should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• nelems – The number of elements in the ivars array.

• status – Local address of an optional mask array of length nelems that indicates which elements in ivars are excluded from the wait set.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivars with cmp_value.

• cmp_value – The value to be compared with the objects pointed to by ivars. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• group – The SYCL group or sub_group with which to collectively perform the wait operation.

Returns:

None.

Callable from the device.

Description: The ishmemx_wait_until_all_work_group routine waits until all entries in the wait set specified by ivars and status have satisfied the wait condition at the calling PE. The ivars objects at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE. If nelems is 0, the wait set is empty and this routine returns immediately. This routine compares each element of the ivars array in the wait set with the value cmp_value according to the comparison operator cmp at the calling PE. This routine is semantically similar to ishmemx_wait_until_work_group, but adds support for point-to-point synchronization involving an array of symmetric data objects.

The optional status is a mask array of length nelems where each element corresponds to the respective element in ivars and indicates whether the element is excluded from the wait set. Elements of status set to 0 will be included in the wait set, and elements set to a nonzero value will be ignored. If all elements in status are nonzero or nelems is 0, the wait set is empty and this routine returns immediately. If status is a null pointer, it is ignored and all elements in ivars are included in the wait set. The ivars and status arrays must not overlap in memory.

Implementations must ensure that ishmemx_wait_until_all_work_group does not return before the update of the memory indicated by ivars is fully complete.

ISHMEM_WAIT_UNTIL_ANY

Wait for an array of variables on the local PE until any one variable meets the specified wait condition.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

size_t ishmem_TYPENAME_wait_until_any(TYPE *ivars, size_t nelems, const int *status, int cmp, TYPE cmp_value)

Parameters:

• ivars – Symmetric address of an array of remotely accessible data objects. The type of ivars should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• nelems – The number of elements in the ivars array.

• status – Local address of an optional mask array of length nelems that indicates which elements in ivars are excluded from the wait set.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivars with cmp_value.

• cmp_value – The value to be compared with the objects pointed to by ivars. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

Returns:

ishmem_wait_until_any returns the index of an element in the ivars array that satisfies the wait condition. If the wait set is empty, this routine returns SIZE_MAX.

Callable from the host and the device.

Description: The ishmem_wait_until_any routine waits until any one entry in the wait set specified by ivars and status satisfies the wait condition at the calling PE. The ivars objects at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE. This routine compares each element of the ivars array in the wait set with the value cmp_value according to the comparison operator cmp at the calling PE. The order in which these elements are tested is unspecified. If an entry i in ivars within the wait set satisfies the wait condition, a series of calls to ishmem_wait_until_any must eventually return i.

The optional status is a mask array of length nelems where each element corresponds to the respective element in ivars and indicates whether the element is excluded from the wait set. Elements of status set to 0 will be included in the wait set, and elements set to a nonzero value will be ignored. If all elements in status are nonzero or nelems is 0, the wait set is empty and this routine returns SIZE_MAX. If status is a null pointer, it is ignored and all elements in ivars are included in the wait set. The ivars and status arrays must not overlap in memory.

Implementations must ensure that ishmem_wait_until_any does not return before the update of the memory indicated by ivars is fully complete.

ISHMEMX_WAIT_UNTIL_ANY_WORK_GROUP

Wait for an array of variables on the local PE until any one variable meets the specified wait condition.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

template<typename Group>
size_t ishmemx_TYPENAME_wait_until_any_work_group(TYPE *ivars, size_t nelems, const int *status, int cmp, TYPE cmp_value, const Group &group)

Parameters:

• ivars – Symmetric address of an array of remotely accessible data objects. The type of ivars should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• nelems – The number of elements in the ivars array.

• status – Local address of an optional mask array of length nelems that indicates which elements in ivars are excluded from the wait set.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivars with cmp_value.

• cmp_value – The value to be compared with the objects pointed to by ivars. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• group – The SYCL group or sub_group with which to collectively perform the wait operation.

Returns:

ishmemx_wait_until_any_work_group returns the index of an element in the ivars array that satisfies the wait condition. If the wait set is empty, this routine returns SIZE_MAX.

Callable from the device.

Description: The ishmemx_wait_until_any_work_group routine waits until any one entry in the wait set specified by ivars and status satisfies the wait condition at the calling PE. The ivars objects at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE. This routine compares each element of the ivars array in the wait set with the value cmp_value according to the comparison operator cmp at the calling PE. The order in which these elements are tested is unspecified. If an entry i in ivars within the wait set satisfies the wait condition, a series of calls to ishmemx_wait_until_any_work_group must eventually return i.

The optional status is a mask array of length nelems where each element corresponds to the respective element in ivars and indicates whether the element is excluded from the wait set. Elements of status set to 0 will be included in the wait set, and elements set to a nonzero value will be ignored. If all elements in status are nonzero or nelems is 0, the wait set is empty and this routine returns SIZE_MAX. If status is a null pointer, it is ignored and all elements in ivars are included in the wait set. The ivars and status arrays must not overlap in memory.

Implementations must ensure that ishmemx_wait_until_any_work_group does not return before the update of the memory indicated by ivars is fully complete.

ISHMEM_WAIT_UNTIL_SOME

Wait on an array of variables on the local PE until at least one variable meets the specified wait condition.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

size_t ishmem_TYPENAME_wait_until_some(TYPE *ivars, size_t nelems, size_t *indices, const int *status, int cmp, TYPE cmp_value)

Parameters:

• ivars – Symmetric address of an array of remotely accessible data objects. The type of ivars should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• nelems – The number of elements in the ivars array.

• indices – Local address of an array of indices of length at least nelems into ivars that satisfied the wait condition.

• status – Local address of an optional mask array of length nelems that indicates which elements in ivars are excluded from the wait set.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivars with cmp_value.

• cmp_value – The value to be compared with the objects pointed to by ivars. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

Returns:

ishmem_wait_until_some returns the number of indices returned in the indices array. If the wait set is empty, this routine returns 0.

Callable from the host and the device.

Description: The ishmem_wait_until_some routine waits until at least one entry in the wait set specified by ivars and status satisfies the wait condition at the calling PE. The ivars objects at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE. This routine compares each element of the ivars array in the wait set with the value cmp_value according to the comparison operator cmp at the calling PE. This routine tests all elements of ivars in the wait set at least once, and the order in which the elements are tested is unspecified.

Upon return, the indices array contains the indices of at least one element in the wait set that satisfied the wait condition during the call to ishmem_wait_until_some. The return value of ishmem_wait_until_some is equal to the total number of these satisfied elements. For a given return value N, the first N elements of the indices array contain those unique indices that satisfied the wait condition. These first N elements of indices may be unordered with respect to the corresponding indices of ivars. The array pointed to by indices must be at least nelems long. If an entry i in ivars within the wait set satisfies the wait condition, a series of calls to ishmem_wait_until_some must eventually include i in the indices array.

The optional status is a mask array of length nelems where each element corresponds to the respective element in ivars and indicates whether the element is excluded from the wait set. Elements of status set to 0 will be included in the wait set, and elements set to a nonzero value will be ignored. If all elements in status are nonzero or nelems is 0, the wait set is empty and this routine returns 0. If status is a null pointer, it is ignored and all elements in ivars are included in the wait set. The ivars, indices, and status arrays must not overlap in memory.

Implementations must ensure that ishmem_wait_until_some does not return before the update of the memory indicated by ivars is fully complete.

ISHMEMX_WAIT_UNTIL_SOME_WORK_GROUP

Wait on an array of variables on the local PE until at least one variable meets the specified wait condition.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

template<typename Group>
size_t ishmemx_TYPENAME_wait_until_some_work_group(TYPE *ivars, size_t nelems, size_t *indices, const int *status, int cmp, TYPE cmp_value, const Group &group)

Parameters:

• ivars – Symmetric address of an array of remotely accessible data objects. The type of ivars should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• nelems – The number of elements in the ivars array.

• indices – Local address of an array of indices of length at least nelems into ivars that satisfied the wait condition.

• status – Local address of an optional mask array of length nelems that indicates which elements in ivars are excluded from the wait set.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivars with cmp_value.

• cmp_value – The value to be compared with the objects pointed to by ivars. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• group – The SYCL group or sub_group with which to collectively perform the wait operation.

Returns:

ishmemx_wait_until_some_work_group returns the number of indices returned in the indices array. If the wait set is empty, this routine returns 0.

Callable from the device.

Description: The ishmemx_wait_until_some_work_group routine waits until at least one entry in the wait set specified by ivars and status satisfies the wait condition at the calling PE. The ivars objects at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE. This routine compares each element of the ivars array in the wait set with the value cmp_value according to the comparison operator cmp at the calling PE. This routine tests all elements of ivars in the wait set at least once, and the order in which the elements are tested is unspecified.

Upon return, the indices array contains the indices of at least one element in the wait set that satisfied the wait condition during the call to ishmemx_wait_until_some_work_group. The return value of ishmemx_wait_until_some_work_group is equal to the total number of these satisfied elements. For a given return value N, the first N elements of the indices array contain those unique indices that satisfied the wait condition. These first N elements of indices may be unordered with respect to the corresponding indices of ivars. The array pointed to by indices must be at least nelems long. If an entry i in ivars within the wait set satisfies the wait condition, a series of calls to ishmemx_wait_until_some_work_group must eventually include i in the indices array.

The optional status is a mask array of length nelems where each element corresponds to the respective element in ivars and indicates whether the element is excluded from the wait set. Elements of status set to 0 will be included in the wait set, and elements set to a nonzero value will be ignored. If all elements in status are nonzero or nelems is 0, the wait set is empty and this routine returns 0. If status is a null pointer, it is ignored and all elements in ivars are included in the wait set. The ivars, indices, and status arrays must not overlap in memory.

Implementations must ensure that ishmemx_wait_until_some_work_group does not return before the update of the memory indicated by ivars is fully complete.

ISHMEM_TEST

Indicate whether a variable on the local PE meets the specified condition.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

int ishmem_TYPENAME_test(TYPE *ivar, int cmp, TYPE cmp_value)

Parameters:

• ivar – Symmetric address of a remotely accessible data object. The type of ivar should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivar with cmp_value.

• cmp_value – The value to be compared with ivar. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

Returns:

ishmem_test returns 1 if the comparison of the symmetric object pointed to by ivar with the value cmp_value according to the comparison operator cmp evaluates to true; otherwise, it returns 0.

Callable from the host and device.

Description: ishmem_test tests the numeric comparison of the symmetric object pointed to by ivar with the value cmp_value according to the comparison operator cmp. The ivar object at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE.

Implementations must ensure that ishmem_test does not return 1 before the update of the memory indicated by ivar is fully complete.

ISHMEMX_TEST_WORK_GROUP

Indicate whether a variable on the local PE meets the specified condition.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

template<typename Group>
int ishmemx_TYPENAME_test_work_group(TYPE *ivar, int cmp, TYPE cmp_value, const Group &group)

Parameters:

• ivar – Symmetric address of a remotely accessible data object. The type of ivar should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivar with cmp_value.

• cmp_value – The value to be compared with ivar. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• group – The SYCL group or sub_group with which to collectively perform the test operation.

Returns:

ishmemx_test_work_group returns 1 if the comparison of the symmetric object pointed to by ivar with the value cmp_value according to the comparison operator cmp evaluates to true; otherwise, it returns 0.

Callable from the device.

Description: ishmemx_test_work_group tests the numeric comparison of the symmetric object pointed to by ivar with the value cmp_value according to the comparison operator cmp. The ivar object at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE.

Implementations must ensure that ishmemx_test_work_group does not return 1 before the update of the memory indicated by ivar is fully complete.

ISHMEM_TEST_ALL

Indicate whether all variables within an array of variables on the local PE meet a specified test condition.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

int ishmem_TYPENAME_test_all(TYPE *ivars, size_t nelems, const int *status, int cmp, TYPE cmp_value)

Parameters:

• ivars – Symmetric address of an array of remotely accessible data objects. The type of ivars should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• nelems – The number of elements in the ivars array.

• status – Local address of an optional mask array of length nelems that indicates which elements in ivars are excluded from the wait set.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivar with cmp_value.

• cmp_value – The value to be compared with ivar. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

Returns:

ishmem_test_all returns 1 if all variables in ivars satisfy the test condition or if nelems is 0, otherwise this routine returns 0.

Callable from the host and device.

Description: The ishmem_test_all routine indicates whether all entries in the test set specified by ivars and status have satisfied the test condition at the calling PE. The ivars objects at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE. This routine does not block and returns zero if not all entries in ivars satisfied the test condition. This routine compares each element of the ivars array in the test set with the value cmp_value according to the comparison operator cmp at the calling PE.

If nelems is 0, the test set is empty and this routine returns 1.

The optional status is a mask array of length nelems where each element corresponds to the respective element in ivars and indicates whether the element is excluded from the test set. Elements of status set to 0 will be included in the test set, and elements set to a nonzero value will be ignored. If all elements in status are nonzero or nelems is 0, the test set is empty and this routine returns 0. If status is a null pointer, it is ignored and all elements in ivars are included in the test set. The ivars and status arrays must not overlap in memory.

Implementations must ensure that ishmem_test_all does not return 1 before the update of the memory indicated by ivars is fully complete.

ISHMEMX_TEST_ALL_WORK_GROUP

Indicate whether all variables within an array of variables on the local PE meet a specified test condition.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

template<typename Group>
int ishmemx_TYPENAME_test_all_work_group(TYPE *ivars, size_t nelems, const int *status, int cmp, TYPE cmp_value, const Group &group)

Parameters:

• ivars – Symmetric address of an array of remotely accessible data objects. The type of ivars should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• nelems – The number of elements in the ivars array.

• status – Local address of an optional mask array of length nelems that indicates which elements in ivars are excluded from the wait set.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivar with cmp_value.

• cmp_value – The value to be compared with ivar. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• group – The SYCL group or sub_group with which to collectively perform the test operation.

Returns:

ishmemx_test_all_work_group returns 1 if all variables in ivars satisfy the test condition or if nelems is 0, otherwise this routine returns 0.

Callable from the device.

Description: The ishmemx_test_all_work_group routine indicates whether all entries in the test set specified by ivars and status have satisfied the test condition at the calling PE. The ivars objects at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE. This routine does not block and returns zero if not all entries in ivars satisfied the test condition. This routine compares each element of the ivars array in the test set with the value cmp_value according to the comparison operator cmp at the calling PE.

If nelems is 0, the test set is empty and this routine returns 1.

The optional status is a mask array of length nelems where each element corresponds to the respective element in ivars and indicates whether the element is excluded from the test set. Elements of status set to 0 will be included in the test set, and elements set to a nonzero value will be ignored. If all elements in status are nonzero or nelems is 0, the test set is empty and this routine returns 0. If status is a null pointer, it is ignored and all elements in ivars are included in the test set. The ivars and status arrays must not overlap in memory.

Implementations must ensure that ishmemx_test_all_work_group does not return 1 before the update of the memory indicated by ivars is fully complete.

ISHMEM_TEST_ANY

Indicate whether any one variable within an array of variables on the local PE meets a specified test condition.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

size_t ishmem_TYPENAME_test_any(TYPE *ivars, size_t nelems, const int *status, int cmp, TYPE cmp_value)

Parameters:

• ivars – Symmetric address of an array of remotely accessible data objects. The type of ivars should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• nelems – The number of elements in the ivars array.

• status – Local address of an optional mask array of length nelems that indicates which elements in ivars are excluded from the wait set.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivar with cmp_value.

• cmp_value – The value to be compared with ivar. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

Returns:

ishmem_test_any returns the index of an element in the ivars array that satisfies the test condition. If the test set is empty or no conditions in the test set are satisfied, this routine returns SIZE_MAX.

Callable from the host and device.

Description: The ishmem_test_any routine indicates whether any entry in the test set specified by ivars and status has satisfied the test condition at the calling PE. The ivars objects at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE. This routine does not block and returns SIZE_MAX if no entries in ivars satisfied the test condition. This routine compares each element of the ivars array in the test set with the value cmp_value according to the comparison operator cmp at the calling PE. The order in which these elements are tested is unspecified. If an entry i in ivars within the test set satisfies the test condition, a series of calls to ishmem_test_any must eventually return i.

The optional status is a mask array of length nelems where each element corresponds to the respective element in ivars and indicates whether the element is excluded from the test set. Elements of status set to 0 will be included in the test set, and elements set to a nonzero value will be ignored. If all elements in status are nonzero or nelems is 0, the test set is empty and this routine returns SIZE_MAX. If status is a null pointer, it is ignored and all elements in ivars are included in the test set. The ivars and status arrays must not overlap in memory.

Implementations must ensure that ishmem_test_any does not return an index before the update of the memory indicated by the corresponding ivars element is fully complete.

ISHMEMX_TEST_ANY_WORK_GROUP

Indicate whether any one variable within an array of variables on the local PE meets a specified test condition.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

template<typename Group>
size_t ishmemx_TYPENAME_test_any_work_group(TYPE *ivars, size_t nelems, const int *status, int cmp, TYPE cmp_value, const Group &group)

Parameters:

• ivars – Symmetric address of an array of remotely accessible data objects. The type of ivars should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• nelems – The number of elements in the ivars array.

• status – Local address of an optional mask array of length nelems that indicates which elements in ivars are excluded from the wait set.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivar with cmp_value.

• cmp_value – The value to be compared with ivar. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• group – The SYCL group or sub_group with which to collectively perform the test operation.

Returns:

ishmemx_test_any_work_group returns the index of an element in the ivars array that satisfies the test condition. If the test set is empty or no conditions in the test set are satisfied, this routine returns SIZE_MAX.

Callable from the device.

Description: The ishmemx_test_any_work_group routine indicates whether any entry in the test set specified by ivars and status has satisfied the test condition at the calling PE. The ivars objects at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE. This routine does not block and returns SIZE_MAX if no entries in ivars satisfied the test condition. This routine compares each element of the ivars array in the test set with the value cmp_value according to the comparison operator cmp at the calling PE. The order in which these elements are tested is unspecified. If an entry i in ivars within the test set satisfies the test condition, a series of calls to ishmemx_test_any_work_group must eventually return i.

The optional status is a mask array of length nelems where each element corresponds to the respective element in ivars and indicates whether the element is excluded from the test set. Elements of status set to 0 will be included in the test set, and elements set to a nonzero value will be ignored. If all elements in status are nonzero or nelems is 0, the test set is empty and this routine returns SIZE_MAX. If status is a null pointer, it is ignored and all elements in ivars are included in the test set. The ivars and status arrays must not overlap in memory.

Implementations must ensure that ishmemx_test_any_work_group does not return an index before the update of the memory indicated by the corresponding ivars element is fully complete.

ISHMEM_TEST_SOME

Indicate whether at least one variable within an array of variables on the local PE meets a specified test condition.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

size_t ishmem_TYPENAME_test_some(TYPE *ivars, size_t nelems, size_t *indices, const int *status, int cmp, TYPE cmp_value)

Parameters:

• ivars – Symmetric address of an array of remotely accessible data objects. The type of ivars should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• nelems – The number of elements in the ivars array.

• indices – Local address of an array of indices of length at least nelems into ivars that satisfied the wait condition.

• status – Local address of an optional mask array of length nelems that indicates which elements in ivars are excluded from the wait set.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivars with cmp_value.

• cmp_value – The value to be compared with the objects pointed to by ivars. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

Returns:

ishmem_test_some returns the number of indices returned in the indices array. If the test set is empty, this routine returns 0.

Callable from the host and device.

Description: The ishmem_test_some routine indicates whether at least one entry in the test set specified by ivars and status satisfies the test condition at the calling PE. The ivars objects at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE. This routine does not block and returns zero if no entries in ivars satisfied the test condition. This routine compares each element of the ivars array in the test set with the value cmp_value according to the comparison operator cmp at the calling PE. This routine tests all elements of ivars in the test set at least once, and the order in which the elements are tested is unspecified.

Upon return, the indices array contains the indices of the elements in the test set that satisfied the test condition during the call to ishmem_test_some. The return value of ishmem_test_some is equal to the total number of these satisfied elements. If the return value is N, then the first N elements of the indices array contain those unique indices that satisfied the test condition. These first N elements of indices may be unordered with respect to the corresponding indices of ivars. The array pointed to by indices must be at least nelems long. If an entry i in ivars within the test set satisfies the test condition, a series of calls to ishmem_test_some must eventually include i in the indices array.

The optional status is a mask array of length nelems where each element corresponds to the respective element in ivars and indicates whether the element is excluded from the test set. Elements of status set to 0 will be included in the test set, and elements set to a nonzero value will be ignored. If all elements in status are nonzero or nelems is 0, the test set is empty and this routine returns 0. If status is a null pointer, it is ignored and all elements in ivars are included in the test set. The ivars, indices, and status arrays must not overlap in memory.

Implementations must ensure that ishmem_test_some does not return indices before the updates of the memory indicated by the corresponding ivars elements are fully complete.

ISHMEMX_TEST_SOME_WORK_GROUP

Indicate whether at least one variable within an array of variables on the local PE meets a specified test condition.

Below, TYPE is one of the standard AMO types and has a corresponding TYPENAME specified by Table Standard AMO Types.

template<typename Group>
size_t ishmemx_TYPENAME_test_some_work_group(TYPE *ivars, size_t nelems, size_t *indices, const int *status, int cmp, TYPE cmp_value, const Group &group)

Parameters:

• ivars – Symmetric address of an array of remotely accessible data objects. The type of ivars should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• nelems – The number of elements in the ivars array.

• indices – Local address of an array of indices of length at least nelems into ivars that satisfied the wait condition.

• status – Local address of an optional mask array of length nelems that indicates which elements in ivars are excluded from the wait set.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares ivars with cmp_value.

• cmp_value – The value to be compared with the objects pointed to by ivars. The type of cmp_value should match the TYPE and TYPENAME according to the table of Standard AMO Types.

• group – The SYCL group or sub_group with which to collectively perform the test operation.

Returns:

ishmemx_test_some_work_group returns the number of indices returned in the indices array. If the test set is empty, this routine returns 0.

Callable from the device.

Description: The ishmemx_test_some_work_group routine indicates whether at least one entry in the test set specified by ivars and status satisfies the test condition at the calling PE. The ivars objects at the calling PE may be updated by an AMO performed by a thread located within the calling PE or within another PE. This routine does not block and returns zero if no entries in ivars satisfied the test condition. This routine compares each element of the ivars array in the test set with the value cmp_value according to the comparison operator cmp at the calling PE. This routine tests all elements of ivars in the test set at least once, and the order in which the elements are tested is unspecified.

Upon return, the indices array contains the indices of the elements in the test set that satisfied the test condition during the call to ishmemx_test_some_work_group. The return value of ishmemx_test_some_work_group is equal to the total number of these satisfied elements. If the return value is N, then the first N elements of the indices array contain those unique indices that satisfied the test condition. These first N elements of indices may be unordered with respect to the corresponding indices of ivars. The array pointed to by indices must be at least nelems long. If an entry i in ivars within the test set satisfies the test condition, a series of calls to ishmemx_test_some_work_group must eventually include i in the indices array.

The optional status is a mask array of length nelems where each element corresponds to the respective element in ivars and indicates whether the element is excluded from the test set. Elements of status set to 0 will be included in the test set, and elements set to a nonzero value will be ignored. If all elements in status are nonzero or nelems is 0, the test set is empty and this routine returns 0. If status is a null pointer, it is ignored and all elements in ivars are included in the test set. The ivars, indices, and status arrays must not overlap in memory.

Implementations must ensure that ishmemx_test_some_work_group does not return indices before the updates of the memory indicated by the corresponding ivars elements are fully complete.

ISHMEM_SIGNAL_WAIT_UNTIL

Wait for a variable on the local PE to change from a signaling operation.

uint64_t ishmem_signal_wait_until(uint64_t *sig_addr, int cmp, uint64_t cmp_value)

Parameters:

• sig_addr – Local, symmetric address of the source signal variable.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares sig_addr with cmp_value.

• cmp_value – The value against which the object pointed to by sig_addr will be compared.

Returns:

ishmem_signal_wait_until returns the contents of the signal data object, sig_addr, at the calling PE that satisfies the wait condition.

Callable from the host and device.

Description: ishmem_signal_wait_until operation blocks until the value contained in the signal data object, sig_addr, at the calling PE satisfies the wait condition.

The sig_addr object at the calling PE is expected only to be updated using the APIs defined in Signaling Operations that perform a write to a signal variable. This routine can be used to implement point-to-point synchronization between PEs or between threads within the same PE. A call to this routine blocks until the value of sig_addr at the calling PE satisfies the wait condition specified by the comparison operator, cmp, and comparison value, cmp_value. Implementations must ensure that ishmem_signal_wait_until do not return before the update of the memory indicated by sig_addr is fully complete.

ISHMEMX_SIGNAL_WAIT_UNTIL_WORK_GROUP

Wait for a variable on the local PE to change from a signaling operation.

uint64_t ishmemx_signal_wait_until_work_group(uint64_t *sig_addr, int cmp, uint64_t cmp_value, const Group &group)

Parameters:

• sig_addr – Local, symmetric address of the source signal variable.

• cmp – A comparison operator from Table Point-to-point Comparison Constants that compares sig_addr with cmp_value.

• cmp_value – The value against which the object pointed to by sig_addr will be compared.

• group – The SYCL group or sub_group with which to collectively perform the wait operation.

Returns:

ishmemx_signal_wait_until_work_group returns the contents of the signal data object, sig_addr, at the calling PE that satisfies the wait condition.

Callable from the device.

Description: ishmemx_signal_wait_until_work_group operation blocks until the value contained in the signal data object, sig_addr, at the calling PE satisfies the wait condition.

The sig_addr object at the calling PE is expected only to be updated using the APIs defined in Signaling Operations that perform a write to a signal variable. This routine can be used to implement point-to-point synchronization between PEs or between threads within the same PE. A call to this routine blocks until the value of sig_addr at the calling PE satisfies the wait condition specified by the comparison operator, cmp, and comparison value, cmp_value. Implementations must ensure that ishmemx_signal_wait_until_work_group do not return before the update of the memory indicated by sig_addr is fully complete.