42714 - Remove NSPR's dependency on winmm.dll

Status: RESOLVED FIXED

(NSPR :: NSPR, defect, P3)

Description

[Wan-Teh Chang]

NSPR uses only one function in winmm.dll: timeGetTime().
If we can replace timeGetTime() by an equivalent function,
we will be able to remove the dependency on winmm.dll.

A good candidate is GetTickCount().  It is documented
(http://msdn.microsoft.com/library/psdk/sysmgmt/time_8wz8.htm)
that a multimedia timer (timeGetTime()) or a high-resolution
timer (QueryPerformanceCounter()) has a higher resolution than
GetTickCount().  Because we always try QueryPerformanceCounter()
first, if all the hardware that we need to support has a
high-resolution performance counter, we should never need to
call GetTickCount().  Then, the lower resolution of GetTickCount()
will have negligible effect.

Comment 1

[Wan-Teh Chang]

Attachment: Proposed patch. Replace timeGetTime() with GetTickCount().

Comment 2

[Wan-Teh Chang]

I did a test on our Win95 OSR2 and Win98 SE systems,
both with Pentium CPUs, and found that QueryPerformanceFrequency()
and QueryPerformanceCounter() are supported.  So the
high-resolution performance counter should be supported
on practically all the Windows systems that are in use
today.

I checked in the patch (id=10201) on the main trunk.
/cvsroot/mozilla/nsprpub/pr/src/Makefile, revision 3.34
/cvsroot/mozilla/nsprpub/pr/src/Makefile.in, revision 1.13
/cvsroot/mozilla/nsprpub/pr/src/md/windows/ntinrval.c, revision 3.8

Note that Mozilla is pulling the NSPRPUB_CLIENT_BRANCH of
NSPR so it is not picking up this change right now.

Comment 3

[Wan-Teh Chang]

I checked in the fix on both NSPRPUB_CLIENT_BRANCH
and NSPRPUB_RELEASE_4_0_BRANCH.  See bug #52725.

Set Target Milestone to 4.0.2.