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| author | Florian Weimer <fweimer@redhat.com> | 2020-05-20 15:40:35 +0200 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2020-07-06 11:15:58 +0200 |
| commit | 706ad1e7af37be1d25fc2359bda006d31fe0d11b (patch) | |
| tree | d06e6a96c1d319a1d27fa6b6e87cfadf8bd6ef08 /NEWS | |
| parent | 8f4632deb3545b2949cec5454afc3cb21a0024ea (diff) | |
| download | glibc-706ad1e7af37be1d25fc2359bda006d31fe0d11b.tar.gz glibc-706ad1e7af37be1d25fc2359bda006d31fe0d11b.tar.xz glibc-706ad1e7af37be1d25fc2359bda006d31fe0d11b.zip | |
Add the __libc_single_threaded variable
The variable is placed in libc.so, and it can be true only in an outer libc, not libcs loaded via dlmopen or static dlopen. Since thread creation from inner namespaces does not work, pthread_create can update __libc_single_threaded directly. Using __libc_early_init and its initial flag, implementation of this variable is very straightforward. A future version may reset the flag during fork (but not in an inner namespace), or after joining all threads except one. Reviewed-by: DJ Delorie <dj@redhat.com>
Diffstat (limited to 'NEWS')
| -rw-r--r-- | NEWS | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/NEWS b/NEWS index a12b9378e7..839934d649 100644 --- a/NEWS +++ b/NEWS @@ -41,6 +41,12 @@ Major new features: The GNU C Library manual has details on integration of Restartable Sequences. +* The GNU C Library now provides the header file <sys/single_threaded.h> + which declares the variable __libc_single_threaded. Applications are + encouraged to use this variable for single-thread optimizations, + instead of weak references to symbols historically defined in + libpthread. + Deprecated and removed features, and other changes affecting compatibility: * The deprecated <sys/sysctl.h> header and the sysctl function have been |