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Diffstat (limited to 'manual/process.texi')
| -rw-r--r-- | manual/process.texi | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/manual/process.texi b/manual/process.texi index d382df5df1..43230154f6 100644 --- a/manual/process.texi +++ b/manual/process.texi @@ -62,6 +62,14 @@ possible to create the shell process, and otherwise is the status of the shell process. @xref{Process Completion}, for details on how this status code can be interpreted. +This function is a cancelation point in multi-threaded programs. This +is a problem if the thread allocates some resources (like memory, file +descriptors, semaphores or whatever) at the time @code{system} is +called. If the thread gets canceled these resources stay allocated +until the program ends. To avoid this calls to @code{system} should be +protected using cancelation handlers. +@c ref pthread_cleanup_push / pthread_cleanup_pop + @pindex stdlib.h The @code{system} function is declared in the header file @file{stdlib.h}. @@ -477,6 +485,14 @@ processes as well as processes that have terminated. The status information from the child process is stored in the object that @var{status-ptr} points to, unless @var{status-ptr} is a null pointer. +This function is a cancelation point in multi-threaded programs. This +is a problem if the thread allocates some resources (like memory, file +descriptors, semaphores or whatever) at the time @code{waitpid} is +called. If the thread gets canceled these resources stay allocated +until the program ends. To avoid this calls to @code{waitpid} should be +protected using cancelation handlers. +@c ref pthread_cleanup_push / pthread_cleanup_pop + The return value is normally the process ID of the child process whose status is reported. If the @code{WNOHANG} option was specified and no child process is waiting to be noticed, the value is zero. A value of @@ -547,6 +563,14 @@ is exactly equivalent to: @smallexample waitpid (-1, &status, 0) @end smallexample + +This function is a cancelation point in multi-threaded programs. This +is a problem if the thread allocates some resources (like memory, file +descriptors, semaphores or whatever) at the time @code{wait} is +called. If the thread gets canceled these resources stay allocated +until the program ends. To avoid this calls to @code{wait} should be +protected using cancelation handlers. +@c ref pthread_cleanup_push / pthread_cleanup_pop @end deftypefun @comment sys/wait.h |