diff options
Diffstat (limited to 'manual')
| -rw-r--r-- | manual/search.texi | 18 | ||||
| -rw-r--r-- | manual/signal.texi | 6 |
2 files changed, 15 insertions, 9 deletions
diff --git a/manual/search.texi b/manual/search.texi index eb6786d188..fdc4a7ee1c 100644 --- a/manual/search.texi +++ b/manual/search.texi @@ -330,20 +330,20 @@ this element might stay undefined since it is not used. To search in a hashing table created using @code{hcreate} the @code{hsearch} function must be used. This function can perform simple search for an element (if @var{action} has the @code{FIND}) or it can -alternatively insert the key element into the hashing table, possibly -replacing a previous value (if @var{action} is @code{ENTER}). +alternatively insert the key element into the hashing table. Entries +are never replaced. The key is denoted by a pointer to an object of type @code{ENTRY}. For locating the corresponding position in the hashing table only the @code{key} element of the structure is used. -The return value depends on the @var{action} parameter value. If it is -@code{FIND} the value is a pointer to the matching element in the -hashing table or @code{NULL} if no matching element exists. If -@var{action} is @code{ENTER} the return value is only @code{NULL} if the -programs runs out of memory while adding the new element to the table. -Otherwise the return value is a pointer to the element in the hashing -table which contains newly added element based on the data in @var{key}. +If an entry with matching key is found the @var{action} parameter is +irrelevant. The found entry is returned. If no matching entry is found +and the @var{action} parameter has the value @code{FIND} the function +returns a @code{NULL} pointer. If no entry is found and the +@var{action} parameter has the value @code{ENTER} a new entry is added +to the hashing table which is initialized with the parameter @var{item}. +A pointer to the newly added entry is returned. @end deftypefun As mentioned before the hashing table used by the functions described so diff --git a/manual/signal.texi b/manual/signal.texi index 59094023ad..903062f3c6 100644 --- a/manual/signal.texi +++ b/manual/signal.texi @@ -2561,6 +2561,12 @@ by modifying the signal mask. The prototype for the @code{sigprocmask} function is in @file{signal.h}. @pindex signal.h +Note that you must not use @code{sigprocmask} in multi-threaded processes, +because each thread has its own signal mask and there is no single process +signal mask. According to POSIX, the behavior of @code{sigprocmask} in a +multi-threaded process is ``unspeficied''. Instead, use +@code{pthread_sigmask} (@pxref{Threads and Signal Handling}). + @comment signal.h @comment POSIX.1 @deftypefun int sigprocmask (int @var{how}, const sigset_t *restrict @var{set}, sigset_t *restrict @var{oldset}) |