do_test malloc5-1.3 {
  # Call [sqlite3_release_memory] when there is exactly one unused page 
  # in the cache belonging to db2.
  #
  set ::pgalloc [sqlite3_release_memory]
  expr $::pgalloc > 0
} {1}


















do_test malloc5-1.4 {
  # Commit the transaction and open a new one. Read 1 page into the cache.
  # Because the page is not dirty, it is eligible for collection even
  # before the transaction is concluded.
  #
  execsql {
    COMMIT;
    BEGIN;
    SELECT * FROM abc;
  }
  sqlite3_release_memory
} $::pgalloc

do_test malloc5-1.5 {
  # Conclude the transaction opened in the previous [do_test] block. This
  # causes another page (page 1) to become eligible for recycling.
  #
  execsql { COMMIT }
  sqlite3_release_memory
} $::pgalloc

do_test malloc5-1.6 {
  # Manipulate the cache so that it contains two unused pages. One requires 
  # a journal-sync to free, the other does not.
  db2 close
  execsql {
    BEGIN;
    SELECT * FROM abc;
    CREATE TABLE def(d, e, f);
  }
  sqlite3_release_memory 500
} $::pgalloc

do_test malloc5-1.7 {
  # Database should not be locked this time. 
  sqlite3 db2 test.db
  catchsql { SELECT * FROM abc } db2
} {0 {}}
do_test malloc5-1.8 {

do_test malloc5-1.3 {
  # Call [sqlite3_release_memory] when there is exactly one unused page 
  # in the cache belonging to db2.
  #
  set ::pgalloc [sqlite3_release_memory]
  expr $::pgalloc > 0
} {1}

# The sizes of memory allocations from system malloc() might vary,
# depending on the memory allocator algorithms used.  The following
# routine is designed to support answers that fall within a range
# of values while also supplying easy-to-understand "expected" values
# when errors occur.
#
proc value_in_range {target x args} {
  set v [lindex $args 0]
  if {$v!=""} {
    if {$v<$target*$x} {return $v}
    if {$v>$target/$x} {return $v}
  }
  return "number between [expr {int($target*$x)}] and [expr {int($target/$x)}]"
}
set mrange 0.98   ;#  plus or minus 2%


do_test malloc5-1.4 {
  # Commit the transaction and open a new one. Read 1 page into the cache.
  # Because the page is not dirty, it is eligible for collection even
  # before the transaction is concluded.
  #
  execsql {
    COMMIT;
    BEGIN;
    SELECT * FROM abc;
  }
  value_in_range $::pgalloc $::mrange [sqlite3_release_memory]
} [value_in_range $::pgalloc $::mrange]

do_test malloc5-1.5 {
  # Conclude the transaction opened in the previous [do_test] block. This
  # causes another page (page 1) to become eligible for recycling.
  #
  execsql { COMMIT }
  value_in_range $::pgalloc $::mrange [sqlite3_release_memory]
} [value_in_range $::pgalloc $::mrange]

do_test malloc5-1.6 {
  # Manipulate the cache so that it contains two unused pages. One requires 
  # a journal-sync to free, the other does not.
  db2 close
  execsql {
    BEGIN;
    SELECT * FROM abc;
    CREATE TABLE def(d, e, f);
  }
  value_in_range $::pgalloc $::mrange [sqlite3_release_memory 500]
} [value_in_range $::pgalloc $::mrange]

do_test malloc5-1.7 {
  # Database should not be locked this time. 
  sqlite3 db2 test.db
  catchsql { SELECT * FROM abc } db2
} {0 {}}
do_test malloc5-1.8 {