git/thread-utils.h

#ifndef THREAD_COMPAT_H
#define THREAD_COMPAT_H

#ifndef NO_PTHREADS
#include <pthread.h>

extern int online_cpus(void);
extern int init_recursive_mutex(pthread_mutex_t*);

#else

#define online_cpus() 1

#endif
#endif /* THREAD_COMPAT_H */
pack-objects: Add runtime detection of online CPU's Packing objects can be done in parallell nowadays, but it's only done if the config option pack.threads is set to a value above 1. Because of that, the code-path used is often not the most optimal one. This patch adds a routine to detect the number of online CPU's at runtime (online_cpus()). When pack.threads (or --threads=) is given a value of 0, the number of threads is set to the number of online CPU's. This feature is also documented. As per Nicolas Pitre's recommendations, the default is still to run pack-objects single-threaded unless explicitly activated, either by configuration or by command line parameter. The routine online_cpus() is a rework of "numcpus.c", written by one Philip Willoughby <pgw99@doc.ic.ac.uk>. numcpus.c is in the public domain and can presently be downloaded from http://csgsoft.doc.ic.ac.uk/numcpus/ Signed-off-by: Andreas Ericsson <ae@op5.se> Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil> Signed-off-by: Junio C Hamano <gitster@pobox.com> 2008-02-23 10:11:56 +08:00			`#ifndef THREAD_COMPAT_H`
			`#define THREAD_COMPAT_H`

thread-utils.h: simplify the inclusion All files that include this header file use the same four line incantation: #ifndef NO_PTHREADS #include <pthread.h> #include "thread-utils.h" #endif Move the responsibility for that gymnastics to the header file from the files that include it. This approach makes it easier to later declare new services that are related to threading in thread-utils.h and have them available to all the threading code. Signed-off-by: Junio C Hamano <gitster@pobox.com> 2010-12-11 02:32:12 +08:00			`#ifndef NO_PTHREADS`
			`#include <pthread.h>`

pack-objects: Add runtime detection of online CPU's Packing objects can be done in parallell nowadays, but it's only done if the config option pack.threads is set to a value above 1. Because of that, the code-path used is often not the most optimal one. This patch adds a routine to detect the number of online CPU's at runtime (online_cpus()). When pack.threads (or --threads=) is given a value of 0, the number of threads is set to the number of online CPU's. This feature is also documented. As per Nicolas Pitre's recommendations, the default is still to run pack-objects single-threaded unless explicitly activated, either by configuration or by command line parameter. The routine online_cpus() is a rework of "numcpus.c", written by one Philip Willoughby <pgw99@doc.ic.ac.uk>. numcpus.c is in the public domain and can presently be downloaded from http://csgsoft.doc.ic.ac.uk/numcpus/ Signed-off-by: Andreas Ericsson <ae@op5.se> Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil> Signed-off-by: Junio C Hamano <gitster@pobox.com> 2008-02-23 10:11:56 +08:00			`extern int online_cpus(void);`
Thread-safe xmalloc and xrealloc needs a recursive mutex The mutex used to protect object access (read_mutex) may need to be acquired recursively. Introduce init_recursive_mutex() helper function in thread-utils.c that constructs a mutex with the PHREAD_MUTEX_RECURSIVE attribute. pthread_mutex_init() emulation on Win32 is already recursive as it is implemented on top of the CRITICAL_SECTION type, which is recursive. http://msdn.microsoft.com/en-us/library/ms682530%28VS.85%29.aspx Add do-nothing compatibility wrappers for pthread_mutexattr* functions. Initial-version-by: Fredrik Kuivinen <frekui@gmail.com> Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com> 2010-04-08 15:15:39 +08:00			`extern int init_recursive_mutex(pthread_mutex_t*);`
pack-objects: Add runtime detection of online CPU's Packing objects can be done in parallell nowadays, but it's only done if the config option pack.threads is set to a value above 1. Because of that, the code-path used is often not the most optimal one. This patch adds a routine to detect the number of online CPU's at runtime (online_cpus()). When pack.threads (or --threads=) is given a value of 0, the number of threads is set to the number of online CPU's. This feature is also documented. As per Nicolas Pitre's recommendations, the default is still to run pack-objects single-threaded unless explicitly activated, either by configuration or by command line parameter. The routine online_cpus() is a rework of "numcpus.c", written by one Philip Willoughby <pgw99@doc.ic.ac.uk>. numcpus.c is in the public domain and can presently be downloaded from http://csgsoft.doc.ic.ac.uk/numcpus/ Signed-off-by: Andreas Ericsson <ae@op5.se> Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil> Signed-off-by: Junio C Hamano <gitster@pobox.com> 2008-02-23 10:11:56 +08:00
pack-objects: set number of threads before checking and warning Under NO_PTHREADS build, we warn when delta_search_threads is not set to 1, because that is the only sensible value on a single threaded build. However, the auto detection that kicks in when that variable is set to 0 (e.g. there is no configuration variable or command line option, or an explicit --threads=0 is given from the command line to override the pack.threads configuration to force auto-detection) was not done before the condition to issue this warning was tested. Move the auto-detection code and place it at an appropriate spot. Signed-off-by: Junio C Hamano <gitster@pobox.com> 2014-10-14 03:46:14 +08:00			`#else`

			`#define online_cpus() 1`

thread-utils.h: simplify the inclusion All files that include this header file use the same four line incantation: #ifndef NO_PTHREADS #include <pthread.h> #include "thread-utils.h" #endif Move the responsibility for that gymnastics to the header file from the files that include it. This approach makes it easier to later declare new services that are related to threading in thread-utils.h and have them available to all the threading code. Signed-off-by: Junio C Hamano <gitster@pobox.com> 2010-12-11 02:32:12 +08:00			`#endif`
pack-objects: Add runtime detection of online CPU's Packing objects can be done in parallell nowadays, but it's only done if the config option pack.threads is set to a value above 1. Because of that, the code-path used is often not the most optimal one. This patch adds a routine to detect the number of online CPU's at runtime (online_cpus()). When pack.threads (or --threads=) is given a value of 0, the number of threads is set to the number of online CPU's. This feature is also documented. As per Nicolas Pitre's recommendations, the default is still to run pack-objects single-threaded unless explicitly activated, either by configuration or by command line parameter. The routine online_cpus() is a rework of "numcpus.c", written by one Philip Willoughby <pgw99@doc.ic.ac.uk>. numcpus.c is in the public domain and can presently be downloaded from http://csgsoft.doc.ic.ac.uk/numcpus/ Signed-off-by: Andreas Ericsson <ae@op5.se> Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil> Signed-off-by: Junio C Hamano <gitster@pobox.com> 2008-02-23 10:11:56 +08:00			`#endif /* THREAD_COMPAT_H */`