View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000659 | 1003.1(2008)/Issue 7 | Base Definitions and Headers | public | 2013-02-10 04:46 | 2019-06-10 08:55 |
| Reporter | dalias | Assigned To | ajosey | ||
| Priority | normal | Severity | Editorial | Type | Enhancement Request |
| Status | Closed | Resolution | Accepted As Marked | ||
| Name | Rich Felker | ||||
| Organization | musl libc | ||||
| User Reference | |||||
| Section | sys/types.h | ||||
| Page Number | unknown | ||||
| Line Number | unknown | ||||
| Interp Status | Approved | ||||
| Final Accepted Text | 0000659:0001463 | ||||
| Summary | 0000659: Remove the requirement that timer_t be an arithmetic type | ||||
| Description | The text in the standard describing the contents of sys/types.h includes "All of the types shall be defined as arithmetic types of an appropriate length, with the following exceptions:". timer_t is not listed in the exceptions. As far as I can tell, there is no reason for timer_t to have arithmetic type; for all practical purposes, timer_t is an opaque handle. I suspect it was just omitted from the list of exceptions by mistake. Making timer_t an arithmetic type would not be a major burden for new implementations, but at least one major implementation, the GNU C library, has timer_t defined as void *, and changing the definition seems undesirable from a standpoint of maintaining a stable C++ ABI. | ||||
| Desired Action | Add timer_t to the list of exceptions below the quoted text, so that implementations where timer_t has non-arithmetic type will no longer be non-conforming. Possibly also add text requiring timer_t to have scalar type, if it is desirable to allow applications to print timer_t values by casting to uintmax_t or similar. | ||||
| Tags | tc2-2008 | ||||
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I agree that omission of timer_t from the list of types that need not be arithmetic types is likely the result of an oversight. However, it should be noted that if we remove all restrictions on the types allowed for timer_t then we should also remove all of the "may fail" EINVAL errors for invalid timer_t values. There should instead be a statement that the behaviour is undefined and some rationale, similar to what we did for invalid pthread_attr_t values. |
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Interpretation response ------------------------ The standard states that timer_t is an arithmetic type, and conforming implementations must conform to this. However, concerns have been raised about this which are being referred to the sponsor. Rationale: ------------- It appears that this requirement may be an accident of the way timer_t was added to POSIX.1 via the .1b amendment. Notes to the Editor (not part of this interpretation): ------------------------------------------------------- At page 399 line 13408 add timer_t to the list of exceptions to the arithmetic types requirement. At page 400 line 13438 add timer_t to the list of types that have no comparison or assignment operators. Cross-volume changes to XSH... At page 2113 line 66876 section timer_delete() add a new paragraph to the end of the DESCRIPTION: The behavior is undefined if the value specified by the timerid argument does not correspond to a timer ID returned by timer_create() but not yet deleted by timer_delete(). At page 2113 line 66881-66882 section timer_delete() replace the entire ERRORS section with: No errors are defined. At page 2113 line 66888 section timer_delete() change the RATIONALE section from: None. to: If an implementation detects that the value specified by the timerid argument to timer_delete() does not correspond to a timer ID returned by timer_create() but not yet deleted by timer_delete(), it is recommended that the function should fail and report an [EINVAL] error. At page 2115 line 66956 section timer_getoverrun() add a new paragraph to the end of the DESCRIPTION: The behavior is undefined if the value specified by the timerid argument to timer_getoverrun(), timer_gettime(), or timer_settime() does not correspond to a timer ID returned by timer_create() but not yet deleted by timer_delete(). At page 2115 line 66968-66970 section timer_getoverrun() delete: These functions may fail if: [EINVAL] The timerid argument does not correspond to an ID returned by timer_create() but not yet deleted by timer_delete(). At page 2116 line 66997 section timer_getoverrun() add a new paragraph to the end of the RATIONALE section: If an implementation detects that the value specified by the timerid argument to timer_getoverrun(), timer_gettime(), or timer_settime() does not correspond to a timer ID returned by timer_create() but not yet deleted by timer_delete(), it is recommended that the function should fail and report an [EINVAL] error. |
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Interpretation Proposed 29 Mar 2013 |
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Interpretation approved 3 May 2013 |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2013-02-10 04:46 | dalias | New Issue | |
| 2013-02-10 04:46 | dalias | Status | New => Under Review |
| 2013-02-10 04:46 | dalias | Assigned To | => ajosey |
| 2013-02-10 04:46 | dalias | Name | => Rich Felker |
| 2013-02-10 04:46 | dalias | Organization | => musl libc |
| 2013-02-10 04:46 | dalias | Section | => sys/types.h |
| 2013-02-10 04:46 | dalias | Page Number | => unknown |
| 2013-02-10 04:46 | dalias | Line Number | => unknown |
| 2013-02-11 10:44 | geoffclare | Note Added: 0001461 | |
| 2013-02-15 09:59 | geoffclare | Note Added: 0001463 | |
| 2013-02-21 16:12 | geoffclare | Interp Status | => Pending |
| 2013-02-21 16:12 | geoffclare | Final Accepted Text | => 0000659:0001463 |
| 2013-02-21 16:12 | geoffclare | Status | Under Review => Interpretation Required |
| 2013-02-21 16:12 | geoffclare | Resolution | Open => Accepted As Marked |
| 2013-02-21 16:13 | geoffclare | Tag Attached: tc2-2008 | |
| 2013-03-29 08:04 | ajosey | Interp Status | Pending => Proposed |
| 2013-03-29 08:04 | ajosey | Note Added: 0001513 | |
| 2013-05-03 12:20 | ajosey | Interp Status | Proposed => Approved |
| 2013-05-03 12:20 | ajosey | Note Added: 0001583 | |
| 2019-06-10 08:55 | agadmin | Status | Interpretation Required => Closed |
